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Message-Id: <201005290334.o4T3YHS0029970@farm-0002.internal.tilera.com>
Date: Fri, 28 May 2010 23:13:59 -0400
From: Chris Metcalf <cmetcalf@...era.com>
To: linux-kernel@...r.kernel.org
Cc: linux-arch@...r.kernel.org, torvalds@...ux-foundation.org
Subject: [PATCH 6/8] arch/tile: the mm/ directory.
Signed-off-by: Chris Metcalf <cmetcalf@...era.com>
---
arch/tile/mm/Makefile | 9 +
arch/tile/mm/elf.c | 164 +++++++
arch/tile/mm/extable.c | 30 ++
arch/tile/mm/fault.c | 905 ++++++++++++++++++++++++++++++++++++
arch/tile/mm/highmem.c | 328 ++++++++++++++
arch/tile/mm/homecache.c | 445 ++++++++++++++++++
arch/tile/mm/hugetlbpage.c | 343 ++++++++++++++
arch/tile/mm/init.c | 1082 ++++++++++++++++++++++++++++++++++++++++++++
arch/tile/mm/migrate.h | 50 ++
arch/tile/mm/migrate_32.S | 211 +++++++++
arch/tile/mm/mmap.c | 75 +++
arch/tile/mm/pgtable.c | 566 +++++++++++++++++++++++
12 files changed, 4208 insertions(+), 0 deletions(-)
create mode 100644 arch/tile/mm/Makefile
create mode 100644 arch/tile/mm/elf.c
create mode 100644 arch/tile/mm/extable.c
create mode 100644 arch/tile/mm/fault.c
create mode 100644 arch/tile/mm/highmem.c
create mode 100644 arch/tile/mm/homecache.c
create mode 100644 arch/tile/mm/hugetlbpage.c
create mode 100644 arch/tile/mm/init.c
create mode 100644 arch/tile/mm/migrate.h
create mode 100644 arch/tile/mm/migrate_32.S
create mode 100644 arch/tile/mm/mmap.c
create mode 100644 arch/tile/mm/pgtable.c
diff --git a/arch/tile/mm/Makefile b/arch/tile/mm/Makefile
new file mode 100644
index 0000000..e252aed
--- /dev/null
+++ b/arch/tile/mm/Makefile
@@ -0,0 +1,9 @@
+#
+# Makefile for the linux tile-specific parts of the memory manager.
+#
+
+obj-y := init.o pgtable.o fault.o extable.o elf.o \
+ mmap.o homecache.o migrate_$(BITS).o
+
+obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
+obj-$(CONFIG_HIGHMEM) += highmem.o
diff --git a/arch/tile/mm/elf.c b/arch/tile/mm/elf.c
new file mode 100644
index 0000000..818c9be
--- /dev/null
+++ b/arch/tile/mm/elf.c
@@ -0,0 +1,164 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/binfmts.h>
+#include <linux/compat.h>
+#include <linux/mman.h>
+#include <linux/elf.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+
+/* Notify a running simulator, if any, that an exec just occurred. */
+static void sim_notify_exec(const char *binary_name)
+{
+ unsigned char c;
+ do {
+ c = *binary_name++;
+ __insn_mtspr(SPR_SIM_CONTROL,
+ (SIM_CONTROL_OS_EXEC
+ | (c << _SIM_CONTROL_OPERATOR_BITS)));
+
+ } while (c);
+}
+
+static int notify_exec(void)
+{
+ int retval = 0; /* failure */
+ struct vm_area_struct *vma = current->mm->mmap;
+ while (vma) {
+ if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file)
+ break;
+ vma = vma->vm_next;
+ }
+ if (vma) {
+ char *buf = (char *) __get_free_page(GFP_KERNEL);
+ if (buf) {
+ char *path = d_path(&vma->vm_file->f_path,
+ buf, PAGE_SIZE);
+ if (!IS_ERR(path)) {
+ sim_notify_exec(path);
+ retval = 1;
+ }
+ free_page((unsigned long)buf);
+ }
+ }
+ return retval;
+}
+
+/* Notify a running simulator, if any, that we loaded an interpreter. */
+static void sim_notify_interp(unsigned long load_addr)
+{
+ size_t i;
+ for (i = 0; i < sizeof(load_addr); i++) {
+ unsigned char c = load_addr >> (i * 8);
+ __insn_mtspr(SPR_SIM_CONTROL,
+ (SIM_CONTROL_OS_INTERP
+ | (c << _SIM_CONTROL_OPERATOR_BITS)));
+ }
+}
+
+
+/* Kernel address of page used to map read-only kernel data into userspace. */
+static void *vdso_page;
+
+/* One-entry array used for install_special_mapping. */
+static struct page *vdso_pages[1];
+
+int __init vdso_setup(void)
+{
+ extern char __rt_sigreturn[], __rt_sigreturn_end[];
+ vdso_page = (void *)get_zeroed_page(GFP_ATOMIC);
+ memcpy(vdso_page, __rt_sigreturn, __rt_sigreturn_end - __rt_sigreturn);
+ vdso_pages[0] = virt_to_page(vdso_page);
+ return 0;
+}
+device_initcall(vdso_setup);
+
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+ if (vma->vm_private_data == vdso_pages)
+ return "[vdso]";
+#ifndef __tilegx__
+ if (vma->vm_start == MEM_USER_INTRPT)
+ return "[intrpt]";
+#endif
+ return NULL;
+}
+
+int arch_setup_additional_pages(struct linux_binprm *bprm,
+ int executable_stack)
+{
+ struct mm_struct *mm = current->mm;
+ unsigned long vdso_base;
+ int retval = 0;
+
+ /*
+ * Notify the simulator that an exec just occurred.
+ * If we can't find the filename of the mapping, just use
+ * whatever was passed as the linux_binprm filename.
+ */
+ if (!notify_exec())
+ sim_notify_exec(bprm->filename);
+
+ down_write(&mm->mmap_sem);
+
+ /*
+ * MAYWRITE to allow gdb to COW and set breakpoints
+ *
+ * Make sure the vDSO gets into every core dump. Dumping its
+ * contents makes post-mortem fully interpretable later
+ * without matching up the same kernel and hardware config to
+ * see what PC values meant.
+ */
+ vdso_base = VDSO_BASE;
+ retval = install_special_mapping(mm, vdso_base, PAGE_SIZE,
+ VM_READ|VM_EXEC|
+ VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
+ VM_ALWAYSDUMP,
+ vdso_pages);
+
+#ifndef __tilegx__
+ /*
+ * Set up a user-interrupt mapping here; the user can't
+ * create one themselves since it is above TASK_SIZE.
+ * We make it unwritable by default, so the model for adding
+ * interrupt vectors always involves an mprotect.
+ */
+ if (!retval) {
+ unsigned long addr = MEM_USER_INTRPT;
+ addr = mmap_region(NULL, addr, INTRPT_SIZE,
+ MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE,
+ VM_READ|VM_EXEC|
+ VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, 0);
+ if (addr > (unsigned long) -PAGE_SIZE)
+ retval = (int) addr;
+ }
+#endif
+
+ up_write(&mm->mmap_sem);
+
+ return retval;
+}
+
+
+void elf_plat_init(struct pt_regs *regs, unsigned long load_addr)
+{
+ /* Zero all registers. */
+ memset(regs, 0, sizeof(*regs));
+
+ /* Report the interpreter's load address. */
+ sim_notify_interp(load_addr);
+}
diff --git a/arch/tile/mm/extable.c b/arch/tile/mm/extable.c
new file mode 100644
index 0000000..4fb0acb
--- /dev/null
+++ b/arch/tile/mm/extable.c
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+
+int fixup_exception(struct pt_regs *regs)
+{
+ const struct exception_table_entry *fixup;
+
+ fixup = search_exception_tables(regs->pc);
+ if (fixup) {
+ regs->pc = fixup->fixup;
+ return 1;
+ }
+
+ return 0;
+}
diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c
new file mode 100644
index 0000000..9b6b92f
--- /dev/null
+++ b/arch/tile/mm/fault.c
@@ -0,0 +1,905 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ *
+ * From i386 code copyright (C) 1995 Linus Torvalds
+ */
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/tty.h>
+#include <linux/vt_kern.h> /* For unblank_screen() */
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <linux/kprobes.h>
+#include <linux/hugetlb.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+
+#include <asm/system.h>
+#include <asm/pgalloc.h>
+#include <asm/sections.h>
+
+#include <arch/interrupts.h>
+
+/*
+ * Unlock any spinlocks which will prevent us from getting the
+ * message out
+ */
+void bust_spinlocks(int yes)
+{
+ int loglevel_save = console_loglevel;
+
+ if (yes) {
+ oops_in_progress = 1;
+ return;
+ }
+ oops_in_progress = 0;
+ /*
+ * OK, the message is on the console. Now we call printk()
+ * without oops_in_progress set so that printk will give klogd
+ * a poke. Hold onto your hats...
+ */
+ console_loglevel = 15; /* NMI oopser may have shut the console up */
+ printk(" ");
+ console_loglevel = loglevel_save;
+}
+
+static noinline void force_sig_info_fault(int si_signo, int si_code,
+ unsigned long address, int fault_num, struct task_struct *tsk)
+{
+ siginfo_t info;
+
+ if (unlikely(tsk->pid < 2)) {
+ panic("Signal %d (code %d) at %#lx sent to %s!",
+ si_signo, si_code & 0xffff, address,
+ tsk->pid ? "init" : "the idle task");
+ }
+
+ info.si_signo = si_signo;
+ info.si_errno = 0;
+ info.si_code = si_code;
+ info.si_addr = (void __user *)address;
+ info.si_trapno = fault_num;
+ force_sig_info(si_signo, &info, tsk);
+}
+
+#ifndef __tilegx__
+/*
+ * Synthesize the fault a PL0 process would get by doing a word-load of
+ * an unaligned address or a high kernel address. Called indirectly
+ * from sys_cmpxchg() in kernel/intvec.S.
+ */
+int _sys_cmpxchg_badaddr(unsigned long address, struct pt_regs *regs)
+{
+ if (address >= PAGE_OFFSET)
+ force_sig_info_fault(SIGSEGV, SEGV_MAPERR, address,
+ INT_DTLB_MISS, current);
+ else
+ force_sig_info_fault(SIGBUS, BUS_ADRALN, address,
+ INT_UNALIGN_DATA, current);
+
+ /*
+ * Adjust pc to point at the actual instruction, which is unusual
+ * for syscalls normally, but is appropriate when we are claiming
+ * that a syscall swint1 caused a page fault or bus error.
+ */
+ regs->pc -= 8;
+
+ /*
+ * Mark this as a caller-save interrupt, like a normal page fault,
+ * so that when we go through the signal handler path we will
+ * properly restore r0, r1, and r2 for the signal handler arguments.
+ */
+ regs->flags |= PT_FLAGS_CALLER_SAVES;
+
+ return 0;
+}
+#endif
+
+static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
+{
+ unsigned index = pgd_index(address);
+ pgd_t *pgd_k;
+ pud_t *pud, *pud_k;
+ pmd_t *pmd, *pmd_k;
+
+ pgd += index;
+ pgd_k = init_mm.pgd + index;
+
+ if (!pgd_present(*pgd_k))
+ return NULL;
+
+ pud = pud_offset(pgd, address);
+ pud_k = pud_offset(pgd_k, address);
+ if (!pud_present(*pud_k))
+ return NULL;
+
+ pmd = pmd_offset(pud, address);
+ pmd_k = pmd_offset(pud_k, address);
+ if (!pmd_present(*pmd_k))
+ return NULL;
+ if (!pmd_present(*pmd)) {
+ set_pmd(pmd, *pmd_k);
+ arch_flush_lazy_mmu_mode();
+ } else
+ BUG_ON(pmd_ptfn(*pmd) != pmd_ptfn(*pmd_k));
+ return pmd_k;
+}
+
+/*
+ * Handle a fault on the vmalloc or module mapping area
+ */
+static inline int vmalloc_fault(pgd_t *pgd, unsigned long address)
+{
+ pmd_t *pmd_k;
+ pte_t *pte_k;
+
+ /* Make sure we are in vmalloc area */
+ if (!(address >= VMALLOC_START && address < VMALLOC_END))
+ return -1;
+
+ /*
+ * Synchronize this task's top level page-table
+ * with the 'reference' page table.
+ */
+ pmd_k = vmalloc_sync_one(pgd, address);
+ if (!pmd_k)
+ return -1;
+ if (pmd_huge(*pmd_k))
+ return 0; /* support TILE huge_vmap() API */
+ pte_k = pte_offset_kernel(pmd_k, address);
+ if (!pte_present(*pte_k))
+ return -1;
+ return 0;
+}
+
+/* Wait until this PTE has completed migration. */
+static void wait_for_migration(pte_t *pte)
+{
+ if (pte_migrating(*pte)) {
+ /*
+ * Wait until the migrater fixes up this pte.
+ * We scale the loop count by the clock rate so we'll wait for
+ * a few seconds here.
+ */
+ int retries = 0;
+ int bound = get_clock_rate();
+ while (pte_migrating(*pte)) {
+ barrier();
+ if (++retries > bound)
+ panic("Hit migrating PTE (%#llx) and"
+ " page PFN %#lx still migrating",
+ pte->val, pte_pfn(*pte));
+ }
+ }
+}
+
+/*
+ * It's not generally safe to use "current" to get the page table pointer,
+ * since we might be running an oprofile interrupt in the middle of a
+ * task switch.
+ */
+static pgd_t *get_current_pgd(void)
+{
+ HV_Context ctx = hv_inquire_context();
+ unsigned long pgd_pfn = ctx.page_table >> PAGE_SHIFT;
+ struct page *pgd_page = pfn_to_page(pgd_pfn);
+ BUG_ON(PageHighMem(pgd_page)); /* oops, HIGHPTE? */
+ return (pgd_t *) __va(ctx.page_table);
+}
+
+/*
+ * We can receive a page fault from a migrating PTE at any time.
+ * Handle it by just waiting until the fault resolves.
+ *
+ * It's also possible to get a migrating kernel PTE that resolves
+ * itself during the downcall from hypervisor to Linux. We just check
+ * here to see if the PTE seems valid, and if so we retry it.
+ *
+ * NOTE! We MUST NOT take any locks for this case. We may be in an
+ * interrupt or a critical region, and must do as little as possible.
+ * Similarly, we can't use atomic ops here, since we may be handling a
+ * fault caused by an atomic op access.
+ */
+static int handle_migrating_pte(pgd_t *pgd, int fault_num,
+ unsigned long address,
+ int is_kernel_mode, int write)
+{
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+ pte_t pteval;
+
+ if (pgd_addr_invalid(address))
+ return 0;
+
+ pgd += pgd_index(address);
+ pud = pud_offset(pgd, address);
+ if (!pud || !pud_present(*pud))
+ return 0;
+ pmd = pmd_offset(pud, address);
+ if (!pmd || !pmd_present(*pmd))
+ return 0;
+ pte = pmd_huge_page(*pmd) ? ((pte_t *)pmd) :
+ pte_offset_kernel(pmd, address);
+ pteval = *pte;
+ if (pte_migrating(pteval)) {
+ wait_for_migration(pte);
+ return 1;
+ }
+
+ if (!is_kernel_mode || !pte_present(pteval))
+ return 0;
+ if (fault_num == INT_ITLB_MISS) {
+ if (pte_exec(pteval))
+ return 1;
+ } else if (write) {
+ if (pte_write(pteval))
+ return 1;
+ } else {
+ if (pte_read(pteval))
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * This routine is responsible for faulting in user pages.
+ * It passes the work off to one of the appropriate routines.
+ * It returns true if the fault was successfully handled.
+ */
+static int handle_page_fault(struct pt_regs *regs,
+ int fault_num,
+ int is_page_fault,
+ unsigned long address,
+ int write)
+{
+ struct task_struct *tsk;
+ struct mm_struct *mm;
+ struct vm_area_struct *vma;
+ unsigned long stack_offset;
+ int fault;
+ int si_code;
+ int is_kernel_mode;
+ pgd_t *pgd;
+
+ /* on TILE, protection faults are always writes */
+ if (!is_page_fault)
+ write = 1;
+
+ is_kernel_mode = (EX1_PL(regs->ex1) != USER_PL);
+
+ tsk = validate_current();
+
+ /*
+ * Check to see if we might be overwriting the stack, and bail
+ * out if so. The page fault code is a relatively likely
+ * place to get trapped in an infinite regress, and once we
+ * overwrite the whole stack, it becomes very hard to recover.
+ */
+ stack_offset = stack_pointer & (THREAD_SIZE-1);
+ if (stack_offset < THREAD_SIZE / 8) {
+ printk(KERN_ALERT "Potential stack overrun: sp %#lx\n",
+ stack_pointer);
+ show_regs(regs);
+ printk(KERN_ALERT "Killing current process %d/%s\n",
+ tsk->pid, tsk->comm);
+ do_group_exit(SIGKILL);
+ }
+
+ /*
+ * Early on, we need to check for migrating PTE entries;
+ * see homecache.c. If we find a migrating PTE, we wait until
+ * the backing page claims to be done migrating, then we procede.
+ * For kernel PTEs, we rewrite the PTE and return and retry.
+ * Otherwise, we treat the fault like a normal "no PTE" fault,
+ * rather than trying to patch up the existing PTE.
+ */
+ pgd = get_current_pgd();
+ if (handle_migrating_pte(pgd, fault_num, address,
+ is_kernel_mode, write))
+ return 1;
+
+ si_code = SEGV_MAPERR;
+
+ /*
+ * We fault-in kernel-space virtual memory on-demand. The
+ * 'reference' page table is init_mm.pgd.
+ *
+ * NOTE! We MUST NOT take any locks for this case. We may
+ * be in an interrupt or a critical region, and should
+ * only copy the information from the master page table,
+ * nothing more.
+ *
+ * This verifies that the fault happens in kernel space
+ * and that the fault was not a protection fault.
+ */
+ if (unlikely(address >= TASK_SIZE &&
+ !is_arch_mappable_range(address, 0))) {
+ if (is_kernel_mode && is_page_fault &&
+ vmalloc_fault(pgd, address) >= 0)
+ return 1;
+ /*
+ * Don't take the mm semaphore here. If we fixup a prefetch
+ * fault we could otherwise deadlock.
+ */
+ mm = NULL; /* happy compiler */
+ vma = NULL;
+ goto bad_area_nosemaphore;
+ }
+
+ /*
+ * If we're trying to touch user-space addresses, we must
+ * be either at PL0, or else with interrupts enabled in the
+ * kernel, so either way we can re-enable interrupts here.
+ */
+ local_irq_enable();
+
+ mm = tsk->mm;
+
+ /*
+ * If we're in an interrupt, have no user context or are running in an
+ * atomic region then we must not take the fault.
+ */
+ if (in_atomic() || !mm) {
+ vma = NULL; /* happy compiler */
+ goto bad_area_nosemaphore;
+ }
+
+ /*
+ * When running in the kernel we expect faults to occur only to
+ * addresses in user space. All other faults represent errors in the
+ * kernel and should generate an OOPS. Unfortunately, in the case of an
+ * erroneous fault occurring in a code path which already holds mmap_sem
+ * we will deadlock attempting to validate the fault against the
+ * address space. Luckily the kernel only validly references user
+ * space from well defined areas of code, which are listed in the
+ * exceptions table.
+ *
+ * As the vast majority of faults will be valid we will only perform
+ * the source reference check when there is a possibility of a deadlock.
+ * Attempt to lock the address space, if we cannot we then validate the
+ * source. If this is invalid we can skip the address space check,
+ * thus avoiding the deadlock.
+ */
+ if (!down_read_trylock(&mm->mmap_sem)) {
+ if (is_kernel_mode &&
+ !search_exception_tables(regs->pc)) {
+ vma = NULL; /* happy compiler */
+ goto bad_area_nosemaphore;
+ }
+ down_read(&mm->mmap_sem);
+ }
+
+ vma = find_vma(mm, address);
+ if (!vma)
+ goto bad_area;
+ if (vma->vm_start <= address)
+ goto good_area;
+ if (!(vma->vm_flags & VM_GROWSDOWN))
+ goto bad_area;
+ if (regs->sp < PAGE_OFFSET) {
+ /*
+ * accessing the stack below sp is always a bug.
+ */
+ if (address < regs->sp)
+ goto bad_area;
+ }
+ if (expand_stack(vma, address))
+ goto bad_area;
+
+/*
+ * Ok, we have a good vm_area for this memory access, so
+ * we can handle it..
+ */
+good_area:
+ si_code = SEGV_ACCERR;
+ if (fault_num == INT_ITLB_MISS) {
+ if (!(vma->vm_flags & VM_EXEC))
+ goto bad_area;
+ } else if (write) {
+#ifdef TEST_VERIFY_AREA
+ if (!is_page_fault && regs->cs == KERNEL_CS)
+ printk("WP fault at "REGFMT"\n", regs->eip);
+#endif
+ if (!(vma->vm_flags & VM_WRITE))
+ goto bad_area;
+ } else {
+ if (!is_page_fault || !(vma->vm_flags & VM_READ))
+ goto bad_area;
+ }
+
+ survive:
+ /*
+ * If for any reason at all we couldn't handle the fault,
+ * make sure we exit gracefully rather than endlessly redo
+ * the fault.
+ */
+ fault = handle_mm_fault(mm, vma, address, write);
+ if (unlikely(fault & VM_FAULT_ERROR)) {
+ if (fault & VM_FAULT_OOM)
+ goto out_of_memory;
+ else if (fault & VM_FAULT_SIGBUS)
+ goto do_sigbus;
+ BUG();
+ }
+ if (fault & VM_FAULT_MAJOR)
+ tsk->maj_flt++;
+ else
+ tsk->min_flt++;
+
+ /*
+ * If this was an asynchronous fault,
+ * restart the appropriate engine.
+ */
+ switch (fault_num) {
+#if CHIP_HAS_TILE_DMA()
+ case INT_DMATLB_MISS:
+ case INT_DMATLB_MISS_DWNCL:
+ case INT_DMATLB_ACCESS:
+ case INT_DMATLB_ACCESS_DWNCL:
+ __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK);
+ break;
+#endif
+#if CHIP_HAS_SN_PROC()
+ case INT_SNITLB_MISS:
+ case INT_SNITLB_MISS_DWNCL:
+ __insn_mtspr(SPR_SNCTL,
+ __insn_mfspr(SPR_SNCTL) &
+ ~SPR_SNCTL__FRZPROC_MASK);
+ break;
+#endif
+ }
+
+ up_read(&mm->mmap_sem);
+ return 1;
+
+/*
+ * Something tried to access memory that isn't in our memory map..
+ * Fix it, but check if it's kernel or user first..
+ */
+bad_area:
+ up_read(&mm->mmap_sem);
+
+bad_area_nosemaphore:
+ /* User mode accesses just cause a SIGSEGV */
+ if (!is_kernel_mode) {
+ /*
+ * It's possible to have interrupts off here.
+ */
+ local_irq_enable();
+
+ force_sig_info_fault(SIGSEGV, si_code, address,
+ fault_num, tsk);
+ return 0;
+ }
+
+no_context:
+ /* Are we prepared to handle this kernel fault? */
+ if (fixup_exception(regs))
+ return 0;
+
+/*
+ * Oops. The kernel tried to access some bad page. We'll have to
+ * terminate things with extreme prejudice.
+ */
+
+ bust_spinlocks(1);
+
+ /* FIXME: no lookup_address() yet */
+#ifdef SUPPORT_LOOKUP_ADDRESS
+ if (fault_num == INT_ITLB_MISS) {
+ pte_t *pte = lookup_address(address);
+
+ if (pte && pte_present(*pte) && !pte_exec_kernel(*pte))
+ printk(KERN_CRIT "kernel tried to execute"
+ " non-executable page - exploit attempt?"
+ " (uid: %d)\n", current->uid);
+ }
+#endif
+ if (address < PAGE_SIZE)
+ printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference\n");
+ else
+ printk(KERN_ALERT "Unable to handle kernel paging request\n");
+ printk(" at virtual address "REGFMT", pc "REGFMT"\n",
+ address, regs->pc);
+
+ show_regs(regs);
+
+ if (unlikely(tsk->pid < 2)) {
+ panic("Kernel page fault running %s!",
+ tsk->pid ? "init" : "the idle task");
+ }
+
+ /*
+ * More FIXME: we should probably copy the i386 here and
+ * implement a generic die() routine. Not today.
+ */
+#ifdef SUPPORT_DIE
+ die("Oops", regs);
+#endif
+ bust_spinlocks(1);
+
+ do_group_exit(SIGKILL);
+
+/*
+ * We ran out of memory, or some other thing happened to us that made
+ * us unable to handle the page fault gracefully.
+ */
+out_of_memory:
+ up_read(&mm->mmap_sem);
+ if (is_global_init(tsk)) {
+ yield();
+ down_read(&mm->mmap_sem);
+ goto survive;
+ }
+ printk("VM: killing process %s\n", tsk->comm);
+ if (!is_kernel_mode)
+ do_group_exit(SIGKILL);
+ goto no_context;
+
+do_sigbus:
+ up_read(&mm->mmap_sem);
+
+ /* Kernel mode? Handle exceptions or die */
+ if (is_kernel_mode)
+ goto no_context;
+
+ force_sig_info_fault(SIGBUS, BUS_ADRERR, address, fault_num, tsk);
+ return 0;
+}
+
+#ifndef __tilegx__
+
+extern char sys_cmpxchg[], __sys_cmpxchg_end[];
+extern char __sys_cmpxchg_grab_lock[];
+extern char __start_atomic_asm_code[], __end_atomic_asm_code[];
+
+/*
+ * We return this structure in registers to avoid having to write
+ * additional save/restore code in the intvec.S caller.
+ */
+struct intvec_state {
+ void *handler;
+ unsigned long vecnum;
+ unsigned long fault_num;
+ unsigned long info;
+ unsigned long retval;
+};
+
+/* We must release ICS before panicking or we won't get anywhere. */
+#define ics_panic(fmt, ...) do { \
+ __insn_mtspr(SPR_INTERRUPT_CRITICAL_SECTION, 0); \
+ panic(fmt, __VA_ARGS__); \
+} while (0)
+
+void do_page_fault(struct pt_regs *regs, int fault_num,
+ unsigned long address, unsigned long write);
+
+/*
+ * When we take an ITLB or DTLB fault or access violation in the
+ * supervisor while the critical section bit is set, the hypervisor is
+ * reluctant to write new values into the EX_CONTEXT_1_x registers,
+ * since that might indicate we have not yet squirreled the SPR
+ * contents away and can thus safely take a recursive interrupt.
+ * Accordingly, the hypervisor passes us the PC via SYSTEM_SAVE_1_2.
+ */
+struct intvec_state do_page_fault_ics(struct pt_regs *regs, int fault_num,
+ unsigned long address,
+ unsigned long info)
+{
+ unsigned long pc = info & ~1;
+ int write = info & 1;
+ pgd_t *pgd = get_current_pgd();
+
+ /* Retval is 1 at first since we will handle the fault fully. */
+ struct intvec_state state = {
+ do_page_fault, fault_num, address, write, 1
+ };
+
+ /* Validate that we are plausibly in the right routine. */
+ if ((pc & 0x7) != 0 || pc < PAGE_OFFSET ||
+ (fault_num != INT_DTLB_MISS &&
+ fault_num != INT_DTLB_ACCESS)) {
+ unsigned long old_pc = regs->pc;
+ regs->pc = pc;
+ ics_panic("Bad ICS page fault args:"
+ " old PC %#lx, fault %d/%d at %#lx\n",
+ old_pc, fault_num, write, address);
+ }
+
+ /* We might be faulting on a vmalloc page, so check that first. */
+ if (fault_num != INT_DTLB_ACCESS && vmalloc_fault(pgd, address) >= 0)
+ return state;
+
+ /*
+ * If we faulted with ICS set in sys_cmpxchg, we are providing
+ * a user syscall service that should generate a signal on
+ * fault. We didn't set up a kernel stack on initial entry to
+ * sys_cmpxchg, but instead had one set up by the fault, which
+ * (because sys_cmpxchg never releases ICS) came to us via the
+ * SYSTEM_SAVE_1_2 mechanism, and thus EX_CONTEXT_1_[01] are
+ * still referencing the original user code. We release the
+ * atomic lock and rewrite pt_regs so that it appears that we
+ * came from user-space directly, and after we finish the
+ * fault we'll go back to user space and re-issue the swint.
+ * This way the backtrace information is correct if we need to
+ * emit a stack dump at any point while handling this.
+ *
+ * Must match register use in sys_cmpxchg().
+ */
+ if (pc >= (unsigned long) sys_cmpxchg &&
+ pc < (unsigned long) __sys_cmpxchg_end) {
+#ifdef CONFIG_SMP
+ /* Don't unlock before we could have locked. */
+ if (pc >= (unsigned long)__sys_cmpxchg_grab_lock) {
+ int *lock_ptr = (int *)(regs->regs[ATOMIC_LOCK_REG]);
+ __atomic_fault_unlock(lock_ptr);
+ }
+#endif
+ regs->sp = regs->regs[27];
+ }
+
+ /*
+ * We can also fault in the atomic assembly, in which
+ * case we use the exception table to do the first-level fixup.
+ * We may re-fixup again in the real fault handler if it
+ * turns out the faulting address is just bad, and not,
+ * for example, migrating.
+ */
+ else if (pc >= (unsigned long) __start_atomic_asm_code &&
+ pc < (unsigned long) __end_atomic_asm_code) {
+ const struct exception_table_entry *fixup;
+#ifdef CONFIG_SMP
+ /* Unlock the atomic lock. */
+ int *lock_ptr = (int *)(regs->regs[ATOMIC_LOCK_REG]);
+ __atomic_fault_unlock(lock_ptr);
+#endif
+ fixup = search_exception_tables(pc);
+ if (!fixup)
+ ics_panic("ICS atomic fault not in table:"
+ " PC %#lx, fault %d", pc, fault_num);
+ regs->pc = fixup->fixup;
+ regs->ex1 = PL_ICS_EX1(KERNEL_PL, 0);
+ }
+
+ /*
+ * NOTE: the one other type of access that might bring us here
+ * are the memory ops in __tns_atomic_acquire/__tns_atomic_release,
+ * but we don't have to check specially for them since we can
+ * always safely return to the address of the fault and retry,
+ * since no separate atomic locks are involved.
+ */
+
+ /*
+ * Now that we have released the atomic lock (if necessary),
+ * it's safe to spin if the PTE that caused the fault was migrating.
+ */
+ if (fault_num == INT_DTLB_ACCESS)
+ write = 1;
+ if (handle_migrating_pte(pgd, fault_num, address, 1, write))
+ return state;
+
+ /* Return zero so that we continue on with normal fault handling. */
+ state.retval = 0;
+ return state;
+}
+
+#endif /* !__tilegx__ */
+
+/*
+ * This routine handles page faults. It determines the address, and the
+ * problem, and then passes it handle_page_fault() for normal DTLB and
+ * ITLB issues, and for DMA or SN processor faults when we are in user
+ * space. For the latter, if we're in kernel mode, we just save the
+ * interrupt away appropriately and return immediately. We can't do
+ * page faults for user code while in kernel mode.
+ */
+void do_page_fault(struct pt_regs *regs, int fault_num,
+ unsigned long address, unsigned long write)
+{
+ int is_page_fault;
+
+ /* This case should have been handled by do_page_fault_ics(). */
+ BUG_ON(write & ~1);
+
+#if CHIP_HAS_TILE_DMA()
+ /*
+ * If it's a DMA fault, suspend the transfer while we're
+ * handling the miss; we'll restart after it's handled. If we
+ * don't suspend, it's possible that this process could swap
+ * out and back in, and restart the engine since the DMA is
+ * still 'running'.
+ */
+ if (fault_num == INT_DMATLB_MISS ||
+ fault_num == INT_DMATLB_ACCESS ||
+ fault_num == INT_DMATLB_MISS_DWNCL ||
+ fault_num == INT_DMATLB_ACCESS_DWNCL) {
+ __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__SUSPEND_MASK);
+ while (__insn_mfspr(SPR_DMA_USER_STATUS) &
+ SPR_DMA_STATUS__BUSY_MASK)
+ ;
+ }
+#endif
+
+ /* Validate fault num and decide if this is a first-time page fault. */
+ switch (fault_num) {
+ case INT_ITLB_MISS:
+ case INT_DTLB_MISS:
+#if CHIP_HAS_TILE_DMA()
+ case INT_DMATLB_MISS:
+ case INT_DMATLB_MISS_DWNCL:
+#endif
+#if CHIP_HAS_SN_PROC()
+ case INT_SNITLB_MISS:
+ case INT_SNITLB_MISS_DWNCL:
+#endif
+ is_page_fault = 1;
+ break;
+
+ case INT_DTLB_ACCESS:
+#if CHIP_HAS_TILE_DMA()
+ case INT_DMATLB_ACCESS:
+ case INT_DMATLB_ACCESS_DWNCL:
+#endif
+ is_page_fault = 0;
+ break;
+
+ default:
+ panic("Bad fault number %d in do_page_fault", fault_num);
+ }
+
+ if (EX1_PL(regs->ex1) != USER_PL) {
+ struct async_tlb *async;
+ switch (fault_num) {
+#if CHIP_HAS_TILE_DMA()
+ case INT_DMATLB_MISS:
+ case INT_DMATLB_ACCESS:
+ case INT_DMATLB_MISS_DWNCL:
+ case INT_DMATLB_ACCESS_DWNCL:
+ async = ¤t->thread.dma_async_tlb;
+ break;
+#endif
+#if CHIP_HAS_SN_PROC()
+ case INT_SNITLB_MISS:
+ case INT_SNITLB_MISS_DWNCL:
+ async = ¤t->thread.sn_async_tlb;
+ break;
+#endif
+ default:
+ async = NULL;
+ }
+ if (async) {
+
+ /*
+ * No vmalloc check required, so we can allow
+ * interrupts immediately at this point.
+ */
+ local_irq_enable();
+
+ set_thread_flag(TIF_ASYNC_TLB);
+ if (async->fault_num != 0) {
+ panic("Second async fault %d;"
+ " old fault was %d (%#lx/%ld)",
+ fault_num, async->fault_num,
+ address, write);
+ }
+ BUG_ON(fault_num == 0);
+ async->fault_num = fault_num;
+ async->is_fault = is_page_fault;
+ async->is_write = write;
+ async->address = address;
+ return;
+ }
+ }
+
+ handle_page_fault(regs, fault_num, is_page_fault, address, write);
+}
+
+
+#if CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC()
+/*
+ * Check an async_tlb structure to see if a deferred fault is waiting,
+ * and if so pass it to the page-fault code.
+ */
+static void handle_async_page_fault(struct pt_regs *regs,
+ struct async_tlb *async)
+{
+ if (async->fault_num) {
+ /*
+ * Clear async->fault_num before calling the page-fault
+ * handler so that if we re-interrupt before returning
+ * from the function we have somewhere to put the
+ * information from the new interrupt.
+ */
+ int fault_num = async->fault_num;
+ async->fault_num = 0;
+ handle_page_fault(regs, fault_num, async->is_fault,
+ async->address, async->is_write);
+ }
+}
+#endif /* CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC() */
+
+
+/*
+ * This routine effectively re-issues asynchronous page faults
+ * when we are returning to user space.
+ */
+void do_async_page_fault(struct pt_regs *regs)
+{
+ /*
+ * Clear thread flag early. If we re-interrupt while processing
+ * code here, we will reset it and recall this routine before
+ * returning to user space.
+ */
+ clear_thread_flag(TIF_ASYNC_TLB);
+
+#if CHIP_HAS_TILE_DMA()
+ handle_async_page_fault(regs, ¤t->thread.dma_async_tlb);
+#endif
+#if CHIP_HAS_SN_PROC()
+ handle_async_page_fault(regs, ¤t->thread.sn_async_tlb);
+#endif
+}
+
+void vmalloc_sync_all(void)
+{
+#ifdef __tilegx__
+ /* Currently all L1 kernel pmd's are static and shared. */
+ BUG_ON(pgd_index(VMALLOC_END) != pgd_index(VMALLOC_START));
+#else
+ /*
+ * Note that races in the updates of insync and start aren't
+ * problematic: insync can only get set bits added, and updates to
+ * start are only improving performance (without affecting correctness
+ * if undone).
+ */
+ static DECLARE_BITMAP(insync, PTRS_PER_PGD);
+ static unsigned long start = PAGE_OFFSET;
+ unsigned long address;
+
+ BUILD_BUG_ON(PAGE_OFFSET & ~PGDIR_MASK);
+ for (address = start; address >= PAGE_OFFSET; address += PGDIR_SIZE) {
+ if (!test_bit(pgd_index(address), insync)) {
+ unsigned long flags;
+ struct list_head *pos;
+
+ spin_lock_irqsave(&pgd_lock, flags);
+ list_for_each(pos, &pgd_list)
+ if (!vmalloc_sync_one(list_to_pgd(pos),
+ address)) {
+ /* Must be at first entry in list. */
+ BUG_ON(pos != pgd_list.next);
+ break;
+ }
+ spin_unlock_irqrestore(&pgd_lock, flags);
+ if (pos != pgd_list.next)
+ set_bit(pgd_index(address), insync);
+ }
+ if (address == start && test_bit(pgd_index(address), insync))
+ start = address + PGDIR_SIZE;
+ }
+#endif
+}
diff --git a/arch/tile/mm/highmem.c b/arch/tile/mm/highmem.c
new file mode 100644
index 0000000..1fcecc5
--- /dev/null
+++ b/arch/tile/mm/highmem.c
@@ -0,0 +1,328 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <linux/pagemap.h>
+#include <asm/homecache.h>
+
+#define kmap_get_pte(vaddr) \
+ pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\
+ (vaddr)), (vaddr))
+
+
+void *kmap(struct page *page)
+{
+ void *kva;
+ unsigned long flags;
+ pte_t *ptep;
+
+ might_sleep();
+ if (!PageHighMem(page))
+ return page_address(page);
+ kva = kmap_high(page);
+
+ /*
+ * Rewrite the PTE under the lock. This ensures that the page
+ * is not currently migrating.
+ */
+ ptep = kmap_get_pte((unsigned long)kva);
+ flags = homecache_kpte_lock();
+ set_pte_at(&init_mm, kva, ptep, mk_pte(page, page_to_kpgprot(page)));
+ homecache_kpte_unlock(flags);
+
+ return kva;
+}
+EXPORT_SYMBOL(kmap);
+
+void kunmap(struct page *page)
+{
+ if (in_interrupt())
+ BUG();
+ if (!PageHighMem(page))
+ return;
+ kunmap_high(page);
+}
+EXPORT_SYMBOL(kunmap);
+
+static void debug_kmap_atomic_prot(enum km_type type)
+{
+#ifdef CONFIG_DEBUG_HIGHMEM
+ static unsigned warn_count = 10;
+
+ if (unlikely(warn_count == 0))
+ return;
+
+ if (unlikely(in_interrupt())) {
+ if (in_irq()) {
+ if (type != KM_IRQ0 && type != KM_IRQ1 &&
+ type != KM_BIO_SRC_IRQ &&
+ /* type != KM_BIO_DST_IRQ && */
+ type != KM_BOUNCE_READ) {
+ WARN_ON(1);
+ warn_count--;
+ }
+ } else if (!irqs_disabled()) { /* softirq */
+ if (type != KM_IRQ0 && type != KM_IRQ1 &&
+ type != KM_SOFTIRQ0 && type != KM_SOFTIRQ1 &&
+ type != KM_SKB_SUNRPC_DATA &&
+ type != KM_SKB_DATA_SOFTIRQ &&
+ type != KM_BOUNCE_READ) {
+ WARN_ON(1);
+ warn_count--;
+ }
+ }
+ }
+
+ if (type == KM_IRQ0 || type == KM_IRQ1 || type == KM_BOUNCE_READ ||
+ type == KM_BIO_SRC_IRQ /* || type == KM_BIO_DST_IRQ */) {
+ if (!irqs_disabled()) {
+ WARN_ON(1);
+ warn_count--;
+ }
+ } else if (type == KM_SOFTIRQ0 || type == KM_SOFTIRQ1) {
+ if (irq_count() == 0 && !irqs_disabled()) {
+ WARN_ON(1);
+ warn_count--;
+ }
+ }
+#endif
+}
+
+/*
+ * Describe a single atomic mapping of a page on a given cpu at a
+ * given address, and allow it to be linked into a list.
+ */
+struct atomic_mapped_page {
+ struct list_head list;
+ struct page *page;
+ int cpu;
+ unsigned long va;
+};
+
+static spinlock_t amp_lock = __SPIN_LOCK_UNLOCKED(&_lock);
+static struct list_head amp_list = LIST_HEAD_INIT(amp_list);
+
+/*
+ * Combining this structure with a per-cpu declaration lets us give
+ * each cpu an atomic_mapped_page structure per type.
+ */
+struct kmap_amps {
+ struct atomic_mapped_page per_type[KM_TYPE_NR];
+};
+DEFINE_PER_CPU(struct kmap_amps, amps);
+
+/*
+ * Add a page and va, on this cpu, to the list of kmap_atomic pages,
+ * and write the new pte to memory. Writing the new PTE under the
+ * lock guarantees that it is either on the list before migration starts
+ * (if we won the race), or set_pte() sets the migrating bit in the PTE
+ * (if we lost the race). And doing it under the lock guarantees
+ * that when kmap_atomic_fix_one_pte() comes along, it finds a valid
+ * PTE in memory, iff the mapping is still on the amp_list.
+ *
+ * Finally, doing it under the lock lets us safely examine the page
+ * to see if it is immutable or not, for the generic kmap_atomic() case.
+ * If we examine it earlier we are exposed to a race where it looks
+ * writable earlier, but becomes immutable before we write the PTE.
+ */
+static void kmap_atomic_register(struct page *page, enum km_type type,
+ unsigned long va, pte_t *ptep, pte_t pteval)
+{
+ unsigned long flags;
+ struct atomic_mapped_page *amp;
+
+ flags = homecache_kpte_lock();
+ spin_lock(&_lock);
+
+ /* With interrupts disabled, now fill in the per-cpu info. */
+ amp = &__get_cpu_var(amps).per_type[type];
+ amp->page = page;
+ amp->cpu = smp_processor_id();
+ amp->va = va;
+
+ /* For generic kmap_atomic(), choose the PTE writability now. */
+ if (!pte_read(pteval))
+ pteval = mk_pte(page, page_to_kpgprot(page));
+
+ list_add(&->list, &_list);
+ set_pte(ptep, pteval);
+ arch_flush_lazy_mmu_mode();
+
+ spin_unlock(&_lock);
+ homecache_kpte_unlock(flags);
+}
+
+/*
+ * Remove a page and va, on this cpu, from the list of kmap_atomic pages.
+ * Linear-time search, but we count on the lists being short.
+ * We don't need to adjust the PTE under the lock (as opposed to the
+ * kmap_atomic_register() case), since we're just unconditionally
+ * zeroing the PTE after it's off the list.
+ */
+static void kmap_atomic_unregister(struct page *page, unsigned long va)
+{
+ unsigned long flags;
+ struct atomic_mapped_page *amp;
+ int cpu = smp_processor_id();
+ spin_lock_irqsave(&_lock, flags);
+ list_for_each_entry(amp, &_list, list) {
+ if (amp->page == page && amp->cpu == cpu && amp->va == va)
+ break;
+ }
+ BUG_ON(&->list == &_list);
+ list_del(&->list);
+ spin_unlock_irqrestore(&_lock, flags);
+}
+
+/* Helper routine for kmap_atomic_fix_kpte(), below. */
+static void kmap_atomic_fix_one_kpte(struct atomic_mapped_page *amp,
+ int finished)
+{
+ pte_t *ptep = kmap_get_pte(amp->va);
+ if (!finished) {
+ set_pte(ptep, pte_mkmigrate(*ptep));
+ flush_remote(0, 0, NULL, amp->va, PAGE_SIZE, PAGE_SIZE,
+ cpumask_of(amp->cpu), NULL, 0);
+ } else {
+ /*
+ * Rewrite a default kernel PTE for this page.
+ * We rely on the fact that set_pte() writes the
+ * present+migrating bits last.
+ */
+ pte_t pte = mk_pte(amp->page, page_to_kpgprot(amp->page));
+ set_pte(ptep, pte);
+ }
+}
+
+/*
+ * This routine is a helper function for homecache_fix_kpte(); see
+ * its comments for more information on the "finished" argument here.
+ *
+ * Note that we hold the lock while doing the remote flushes, which
+ * will stall any unrelated cpus trying to do kmap_atomic operations.
+ * We could just update the PTEs under the lock, and save away copies
+ * of the structs (or just the va+cpu), then flush them after we
+ * release the lock, but it seems easier just to do it all under the lock.
+ */
+void kmap_atomic_fix_kpte(struct page *page, int finished)
+{
+ struct atomic_mapped_page *amp;
+ unsigned long flags;
+ spin_lock_irqsave(&_lock, flags);
+ list_for_each_entry(amp, &_list, list) {
+ if (amp->page == page)
+ kmap_atomic_fix_one_kpte(amp, finished);
+ }
+ spin_unlock_irqrestore(&_lock, flags);
+}
+
+/*
+ * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap
+ * because the kmap code must perform a global TLB invalidation when
+ * the kmap pool wraps.
+ *
+ * Note that they may be slower than on x86 (etc.) because unlike on
+ * those platforms, we do have to take a global lock to map and unmap
+ * pages on Tile (see above).
+ *
+ * When holding an atomic kmap is is not legal to sleep, so atomic
+ * kmaps are appropriate for short, tight code paths only.
+ */
+void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
+{
+ enum fixed_addresses idx;
+ unsigned long vaddr;
+ pte_t *pte;
+
+ /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+ pagefault_disable();
+
+ /* Avoid icache flushes by disallowing atomic executable mappings. */
+ BUG_ON(pte_exec(prot));
+
+ if (!PageHighMem(page))
+ return page_address(page);
+
+ debug_kmap_atomic_prot(type);
+
+ idx = type + KM_TYPE_NR*smp_processor_id();
+ vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+ pte = kmap_get_pte(vaddr);
+ BUG_ON(!pte_none(*pte));
+
+ /* Register that this page is mapped atomically on this cpu. */
+ kmap_atomic_register(page, type, vaddr, pte, mk_pte(page, prot));
+
+ return (void *)vaddr;
+}
+EXPORT_SYMBOL(kmap_atomic_prot);
+
+void *kmap_atomic(struct page *page, enum km_type type)
+{
+ /* PAGE_NONE is a magic value that tells us to check immutability. */
+ return kmap_atomic_prot(page, type, PAGE_NONE);
+}
+EXPORT_SYMBOL(kmap_atomic);
+
+void kunmap_atomic(void *kvaddr, enum km_type type)
+{
+ unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
+ enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
+
+ /*
+ * Force other mappings to Oops if they try to access this pte without
+ * first remapping it. Keeping stale mappings around is a bad idea.
+ */
+ if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx)) {
+ pte_t *pte = kmap_get_pte(vaddr);
+ pte_t pteval = *pte;
+ BUG_ON(!pte_present(pteval) && !pte_migrating(pteval));
+ kmap_atomic_unregister(pte_page(pteval), vaddr);
+ kpte_clear_flush(pte, vaddr);
+ } else {
+ /* Must be a lowmem page */
+ BUG_ON(vaddr < PAGE_OFFSET);
+ BUG_ON(vaddr >= (unsigned long)high_memory);
+ }
+
+ arch_flush_lazy_mmu_mode();
+ pagefault_enable();
+}
+EXPORT_SYMBOL(kunmap_atomic);
+
+/*
+ * This API is supposed to allow us to map memory without a "struct page".
+ * Currently we don't support this, though this may change in the future.
+ */
+void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
+{
+ return kmap_atomic(pfn_to_page(pfn), type);
+}
+void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot)
+{
+ return kmap_atomic_prot(pfn_to_page(pfn), type, prot);
+}
+
+struct page *kmap_atomic_to_page(void *ptr)
+{
+ pte_t *pte;
+ unsigned long vaddr = (unsigned long)ptr;
+
+ if (vaddr < FIXADDR_START)
+ return virt_to_page(ptr);
+
+ pte = kmap_get_pte(vaddr);
+ return pte_page(*pte);
+}
diff --git a/arch/tile/mm/homecache.c b/arch/tile/mm/homecache.c
new file mode 100644
index 0000000..52feb77
--- /dev/null
+++ b/arch/tile/mm/homecache.c
@@ -0,0 +1,445 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ *
+ * This code maintains the "home" for each page in the system.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/bootmem.h>
+#include <linux/rmap.h>
+#include <linux/pagemap.h>
+#include <linux/mutex.h>
+#include <linux/interrupt.h>
+#include <linux/sysctl.h>
+#include <linux/pagevec.h>
+#include <linux/ptrace.h>
+#include <linux/timex.h>
+#include <linux/cache.h>
+#include <linux/smp.h>
+
+#include <asm/page.h>
+#include <asm/sections.h>
+#include <asm/tlbflush.h>
+#include <asm/pgalloc.h>
+#include <asm/homecache.h>
+
+#include "migrate.h"
+
+
+#if CHIP_HAS_COHERENT_LOCAL_CACHE()
+
+/*
+ * The noallocl2 option suppresses all use of the L2 cache to cache
+ * locally from a remote home. There's no point in using it if we
+ * don't have coherent local caching, though.
+ */
+int __write_once noallocl2;
+static int __init set_noallocl2(char *str)
+{
+ noallocl2 = 1;
+ return 0;
+}
+early_param("noallocl2", set_noallocl2);
+
+#else
+
+#define noallocl2 0
+
+#endif
+
+
+
+/* Provide no-op versions of these routines to keep flush_remote() cleaner. */
+#define mark_caches_evicted_start() 0
+#define mark_caches_evicted_finish(mask, timestamp) do {} while (0)
+
+
+
+
+/*
+ * Update the irq_stat for cpus that we are going to interrupt
+ * with TLB or cache flushes. Also handle removing dataplane cpus
+ * from the TLB flush set, and setting dataplane_tlb_state instead.
+ */
+static void hv_flush_update(const struct cpumask *cache_cpumask,
+ struct cpumask *tlb_cpumask,
+ unsigned long tlb_va, unsigned long tlb_length,
+ HV_Remote_ASID *asids, int asidcount)
+{
+ struct cpumask mask;
+ int i, cpu;
+
+ cpumask_clear(&mask);
+ if (cache_cpumask)
+ cpumask_or(&mask, &mask, cache_cpumask);
+ if (tlb_cpumask && tlb_length) {
+ cpumask_or(&mask, &mask, tlb_cpumask);
+ }
+
+ for (i = 0; i < asidcount; ++i)
+ cpumask_set_cpu(asids[i].y * smp_width + asids[i].x, &mask);
+
+ /*
+ * Don't bother to update atomically; losing a count
+ * here is not that critical.
+ */
+ for_each_cpu(cpu, &mask)
+ ++per_cpu(irq_stat, cpu).irq_hv_flush_count;
+}
+
+/*
+ * This wrapper function around hv_flush_remote() does several things:
+ *
+ * - Provides a return value error-checking panic path, since
+ * there's never any good reason for hv_flush_remote() to fail.
+ * - Accepts a 32-bit PFN rather than a 64-bit PA, which generally
+ * is the type that Linux wants to pass around anyway.
+ * - Centralizes the mark_caches_evicted() handling.
+ * - Canonicalizes that lengths of zero make cpumasks NULL.
+ * - Handles deferring TLB flushes for dataplane tiles.
+ * - Tracks remote interrupts in the per-cpu irq_cpustat_t.
+ *
+ * Note that we have to wait until the cache flush completes before
+ * updating the per-cpu last_cache_flush word, since otherwise another
+ * concurrent flush can race, conclude the flush has already
+ * completed, and start to use the page while it's still dirty
+ * remotely (running concurrently with the actual evict, presumably).
+ */
+void flush_remote(unsigned long cache_pfn, unsigned long cache_control,
+ const struct cpumask *cache_cpumask_orig,
+ HV_VirtAddr tlb_va, unsigned long tlb_length,
+ unsigned long tlb_pgsize,
+ const struct cpumask *tlb_cpumask_orig,
+ HV_Remote_ASID *asids, int asidcount)
+{
+ int rc;
+ int timestamp = 0; /* happy compiler */
+ struct cpumask cache_cpumask_copy, tlb_cpumask_copy;
+ struct cpumask *cache_cpumask, *tlb_cpumask;
+ HV_PhysAddr cache_pa;
+ char cache_buf[NR_CPUS*5], tlb_buf[NR_CPUS*5];
+
+ mb(); /* provided just to simplify "magic hypervisor" mode */
+
+ /*
+ * Canonicalize and copy the cpumasks.
+ */
+ if (cache_cpumask_orig && cache_control) {
+ cpumask_copy(&cache_cpumask_copy, cache_cpumask_orig);
+ cache_cpumask = &cache_cpumask_copy;
+ } else {
+ cpumask_clear(&cache_cpumask_copy);
+ cache_cpumask = NULL;
+ }
+ if (cache_cpumask == NULL)
+ cache_control = 0;
+ if (tlb_cpumask_orig && tlb_length) {
+ cpumask_copy(&tlb_cpumask_copy, tlb_cpumask_orig);
+ tlb_cpumask = &tlb_cpumask_copy;
+ } else {
+ cpumask_clear(&tlb_cpumask_copy);
+ tlb_cpumask = NULL;
+ }
+
+ hv_flush_update(cache_cpumask, tlb_cpumask, tlb_va, tlb_length,
+ asids, asidcount);
+ cache_pa = (HV_PhysAddr)cache_pfn << PAGE_SHIFT;
+ if (cache_control & HV_FLUSH_EVICT_L2)
+ timestamp = mark_caches_evicted_start();
+ rc = hv_flush_remote(cache_pa, cache_control,
+ cpumask_bits(cache_cpumask),
+ tlb_va, tlb_length, tlb_pgsize,
+ cpumask_bits(tlb_cpumask),
+ asids, asidcount);
+ if (cache_control & HV_FLUSH_EVICT_L2)
+ mark_caches_evicted_finish(cache_cpumask, timestamp);
+ if (rc == 0)
+ return;
+ cpumask_scnprintf(cache_buf, sizeof(cache_buf), &cache_cpumask_copy);
+ cpumask_scnprintf(tlb_buf, sizeof(tlb_buf), &tlb_cpumask_copy);
+
+ printk("hv_flush_remote(%#llx, %#lx, %p [%s],"
+ " %#lx, %#lx, %#lx, %p [%s], %p, %d) = %d\n",
+ cache_pa, cache_control, cache_cpumask, cache_buf,
+ (unsigned long)tlb_va, tlb_length, tlb_pgsize,
+ tlb_cpumask, tlb_buf,
+ asids, asidcount, rc);
+ if (asidcount > 0) {
+ int i;
+ printk(" asids:");
+ for (i = 0; i < asidcount; ++i)
+ printk(" %d,%d,%d",
+ asids[i].x, asids[i].y, asids[i].asid);
+ printk("\n");
+ }
+ panic("Unsafe to continue.");
+}
+
+void homecache_evict(const struct cpumask *mask)
+{
+ flush_remote(0, HV_FLUSH_EVICT_L2, mask, 0, 0, 0, NULL, NULL, 0);
+}
+
+/* Return a mask of the cpus whose caches currently own these pages. */
+static void homecache_mask(struct page *page, int pages,
+ struct cpumask *home_mask)
+{
+ int i;
+ cpumask_clear(home_mask);
+ for (i = 0; i < pages; ++i) {
+ int home = page_home(&page[i]);
+ if (home == PAGE_HOME_IMMUTABLE ||
+ home == PAGE_HOME_INCOHERENT) {
+ cpumask_copy(home_mask, cpu_possible_mask);
+ return;
+ }
+#if CHIP_HAS_CBOX_HOME_MAP()
+ if (home == PAGE_HOME_HASH) {
+ cpumask_or(home_mask, home_mask, &hash_for_home_map);
+ continue;
+ }
+#endif
+ if (home == PAGE_HOME_UNCACHED)
+ continue;
+ BUG_ON(home < 0 || home >= NR_CPUS);
+ cpumask_set_cpu(home, home_mask);
+ }
+}
+
+/*
+ * Return the passed length, or zero if it's long enough that we
+ * believe we should evict the whole L2 cache.
+ */
+static unsigned long cache_flush_length(unsigned long length)
+{
+ return (length >= CHIP_L2_CACHE_SIZE()) ? HV_FLUSH_EVICT_L2 : length;
+}
+
+/* On the simulator, confirm lines have been evicted everywhere. */
+static void validate_lines_evicted(unsigned long pfn, size_t length)
+{
+ sim_syscall(SIM_SYSCALL_VALIDATE_LINES_EVICTED,
+ (HV_PhysAddr)pfn << PAGE_SHIFT, length);
+}
+
+/* Flush a page out of whatever cache(s) it is in. */
+void homecache_flush_cache(struct page *page, int order)
+{
+ int pages = 1 << order;
+ int length = cache_flush_length(pages * PAGE_SIZE);
+ unsigned long pfn = page_to_pfn(page);
+ struct cpumask home_mask;
+
+ homecache_mask(page, pages, &home_mask);
+ flush_remote(pfn, length, &home_mask, 0, 0, 0, NULL, NULL, 0);
+ validate_lines_evicted(pfn, pages * PAGE_SIZE);
+}
+
+
+/* Report the home corresponding to a given PTE. */
+static int pte_to_home(pte_t pte)
+{
+ if (hv_pte_get_nc(pte))
+ return PAGE_HOME_IMMUTABLE;
+ switch (hv_pte_get_mode(pte)) {
+ case HV_PTE_MODE_CACHE_TILE_L3:
+ return get_remote_cache_cpu(pte);
+ case HV_PTE_MODE_CACHE_NO_L3:
+ return PAGE_HOME_INCOHERENT;
+ case HV_PTE_MODE_UNCACHED:
+ return PAGE_HOME_UNCACHED;
+#if CHIP_HAS_CBOX_HOME_MAP()
+ case HV_PTE_MODE_CACHE_HASH_L3:
+ return PAGE_HOME_HASH;
+#endif
+ }
+ panic("Bad PTE %#llx\n", pte.val);
+}
+
+/* Update the home of a PTE if necessary (can also be used for a pgprot_t). */
+pte_t pte_set_home(pte_t pte, int home)
+{
+ /* Check for non-linear file mapping "PTEs" and pass them through. */
+ if (pte_file(pte))
+ return pte;
+
+#if CHIP_HAS_MMIO()
+ /* Check for MMIO mappings and pass them through. */
+ if (hv_pte_get_mode(pte) == HV_PTE_MODE_MMIO)
+ return pte;
+#endif
+
+
+ /*
+ * Only immutable pages get NC mappings. If we have a
+ * non-coherent PTE, but the underlying page is not
+ * immutable, it's likely the result of a forced
+ * caching setting running up against ptrace setting
+ * the page to be writable underneath. In this case,
+ * just keep the PTE coherent.
+ */
+ if (hv_pte_get_nc(pte) && home != PAGE_HOME_IMMUTABLE) {
+ pte = hv_pte_clear_nc(pte);
+ printk("non-immutable page incoherently referenced: %#llx\n",
+ pte.val);
+ }
+
+ switch (home) {
+
+ case PAGE_HOME_UNCACHED:
+ pte = hv_pte_set_mode(pte, HV_PTE_MODE_UNCACHED);
+ break;
+
+ case PAGE_HOME_INCOHERENT:
+ pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_NO_L3);
+ break;
+
+ case PAGE_HOME_IMMUTABLE:
+ /*
+ * We could home this page anywhere, since it's immutable,
+ * but by default just home it to follow "hash_default".
+ */
+ BUG_ON(hv_pte_get_writable(pte));
+ if (pte_get_forcecache(pte)) {
+ /* Upgrade "force any cpu" to "No L3" for immutable. */
+ if (hv_pte_get_mode(pte) == HV_PTE_MODE_CACHE_TILE_L3
+ && pte_get_anyhome(pte)) {
+ pte = hv_pte_set_mode(pte,
+ HV_PTE_MODE_CACHE_NO_L3);
+ }
+ } else
+#if CHIP_HAS_CBOX_HOME_MAP()
+ if (hash_default)
+ pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_HASH_L3);
+ else
+#endif
+ pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_NO_L3);
+ pte = hv_pte_set_nc(pte);
+ break;
+
+#if CHIP_HAS_CBOX_HOME_MAP()
+ case PAGE_HOME_HASH:
+ pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_HASH_L3);
+ break;
+#endif
+
+ default:
+ BUG_ON(home < 0 || home >= NR_CPUS ||
+ !cpu_is_valid_lotar(home));
+ pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_TILE_L3);
+ pte = set_remote_cache_cpu(pte, home);
+ break;
+ }
+
+#if CHIP_HAS_NC_AND_NOALLOC_BITS()
+ if (noallocl2)
+ pte = hv_pte_set_no_alloc_l2(pte);
+
+ /* Simplify "no local and no l3" to "uncached" */
+ if (hv_pte_get_no_alloc_l2(pte) && hv_pte_get_no_alloc_l1(pte) &&
+ hv_pte_get_mode(pte) == HV_PTE_MODE_CACHE_NO_L3) {
+ pte = hv_pte_set_mode(pte, HV_PTE_MODE_UNCACHED);
+ }
+#endif
+
+ /* Checking this case here gives a better panic than from the hv. */
+ BUG_ON(hv_pte_get_mode(pte) == 0);
+
+ return pte;
+}
+
+/*
+ * The routines in this section are the "static" versions of the normal
+ * dynamic homecaching routines; they just set the home cache
+ * of a kernel page once, and require a full-chip cache/TLB flush,
+ * so they're not suitable for anything but infrequent use.
+ */
+
+#if CHIP_HAS_CBOX_HOME_MAP()
+static inline int initial_page_home(void) { return PAGE_HOME_HASH; }
+#else
+static inline int initial_page_home(void) { return 0; }
+#endif
+
+int page_home(struct page *page)
+{
+ if (PageHighMem(page)) {
+ return initial_page_home();
+ } else {
+ unsigned long kva = (unsigned long)page_address(page);
+ return pte_to_home(*virt_to_pte(NULL, kva));
+ }
+}
+
+void homecache_change_page_home(struct page *page, int order, int home)
+{
+ int i, pages = (1 << order);
+ unsigned long kva;
+
+ BUG_ON(PageHighMem(page));
+ BUG_ON(page_count(page) > 1);
+ BUG_ON(page_mapcount(page) != 0);
+ kva = (unsigned long) page_address(page);
+ flush_remote(0, HV_FLUSH_EVICT_L2, &cpu_cacheable_map,
+ kva, pages * PAGE_SIZE, PAGE_SIZE, cpu_online_mask,
+ NULL, 0);
+
+ for (i = 0; i < pages; ++i, kva += PAGE_SIZE) {
+ pte_t *ptep = virt_to_pte(NULL, kva);
+ pte_t pteval = *ptep;
+ BUG_ON(!pte_present(pteval) || pte_huge(pteval));
+ *ptep = pte_set_home(pteval, home);
+ }
+}
+
+struct page *homecache_alloc_pages(gfp_t gfp_mask,
+ unsigned int order, int home)
+{
+ struct page *page;
+ BUG_ON(gfp_mask & __GFP_HIGHMEM); /* must be lowmem */
+ page = alloc_pages(gfp_mask, order);
+ if (page)
+ homecache_change_page_home(page, order, home);
+ return page;
+}
+
+struct page *homecache_alloc_pages_node(int nid, gfp_t gfp_mask,
+ unsigned int order, int home)
+{
+ struct page *page;
+ BUG_ON(gfp_mask & __GFP_HIGHMEM); /* must be lowmem */
+ page = alloc_pages_node(nid, gfp_mask, order);
+ if (page)
+ homecache_change_page_home(page, order, home);
+ return page;
+}
+
+void homecache_free_pages(unsigned long addr, unsigned int order)
+{
+ struct page *page;
+
+ if (addr == 0)
+ return;
+
+ VM_BUG_ON(!virt_addr_valid((void *)addr));
+ page = virt_to_page((void *)addr);
+ if (put_page_testzero(page)) {
+ int pages = (1 << order);
+ homecache_change_page_home(page, order, initial_page_home());
+ while (pages--)
+ __free_page(page++);
+ }
+}
diff --git a/arch/tile/mm/hugetlbpage.c b/arch/tile/mm/hugetlbpage.c
new file mode 100644
index 0000000..c38570f
--- /dev/null
+++ b/arch/tile/mm/hugetlbpage.c
@@ -0,0 +1,343 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ *
+ * TILE Huge TLB Page Support for Kernel.
+ * Taken from i386 hugetlb implementation:
+ * Copyright (C) 2002, Rohit Seth <rohit.seth@...el.com>
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/pagemap.h>
+#include <linux/smp_lock.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/sysctl.h>
+#include <linux/mman.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+
+pte_t *huge_pte_alloc(struct mm_struct *mm,
+ unsigned long addr, unsigned long sz)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pte_t *pte = NULL;
+
+ /* We do not yet support multiple huge page sizes. */
+ BUG_ON(sz != PMD_SIZE);
+
+ pgd = pgd_offset(mm, addr);
+ pud = pud_alloc(mm, pgd, addr);
+ if (pud)
+ pte = (pte_t *) pmd_alloc(mm, pud, addr);
+ BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte));
+
+ return pte;
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd = NULL;
+
+ pgd = pgd_offset(mm, addr);
+ if (pgd_present(*pgd)) {
+ pud = pud_offset(pgd, addr);
+ if (pud_present(*pud))
+ pmd = pmd_offset(pud, addr);
+ }
+ return (pte_t *) pmd;
+}
+
+#ifdef HUGETLB_TEST
+struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
+ int write)
+{
+ unsigned long start = address;
+ int length = 1;
+ int nr;
+ struct page *page;
+ struct vm_area_struct *vma;
+
+ vma = find_vma(mm, addr);
+ if (!vma || !is_vm_hugetlb_page(vma))
+ return ERR_PTR(-EINVAL);
+
+ pte = huge_pte_offset(mm, address);
+
+ /* hugetlb should be locked, and hence, prefaulted */
+ WARN_ON(!pte || pte_none(*pte));
+
+ page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)];
+
+ WARN_ON(!PageHead(page));
+
+ return page;
+}
+
+int pmd_huge(pmd_t pmd)
+{
+ return 0;
+}
+
+int pud_huge(pud_t pud)
+{
+ return 0;
+}
+
+struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
+ pmd_t *pmd, int write)
+{
+ return NULL;
+}
+
+#else
+
+struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
+ int write)
+{
+ return ERR_PTR(-EINVAL);
+}
+
+int pmd_huge(pmd_t pmd)
+{
+ return !!(pmd_val(pmd) & _PAGE_HUGE_PAGE);
+}
+
+int pud_huge(pud_t pud)
+{
+ return !!(pud_val(pud) & _PAGE_HUGE_PAGE);
+}
+
+struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
+ pmd_t *pmd, int write)
+{
+ struct page *page;
+
+ page = pte_page(*(pte_t *)pmd);
+ if (page)
+ page += ((address & ~PMD_MASK) >> PAGE_SHIFT);
+ return page;
+}
+
+struct page *follow_huge_pud(struct mm_struct *mm, unsigned long address,
+ pud_t *pud, int write)
+{
+ struct page *page;
+
+ page = pte_page(*(pte_t *)pud);
+ if (page)
+ page += ((address & ~PUD_MASK) >> PAGE_SHIFT);
+ return page;
+}
+
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
+{
+ return 0;
+}
+
+#endif
+
+#ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
+static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
+ unsigned long addr, unsigned long len,
+ unsigned long pgoff, unsigned long flags)
+{
+ struct hstate *h = hstate_file(file);
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ unsigned long start_addr;
+
+ if (len > mm->cached_hole_size) {
+ start_addr = mm->free_area_cache;
+ } else {
+ start_addr = TASK_UNMAPPED_BASE;
+ mm->cached_hole_size = 0;
+ }
+
+full_search:
+ addr = ALIGN(start_addr, huge_page_size(h));
+
+ for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
+ /* At this point: (!vma || addr < vma->vm_end). */
+ if (TASK_SIZE - len < addr) {
+ /*
+ * Start a new search - just in case we missed
+ * some holes.
+ */
+ if (start_addr != TASK_UNMAPPED_BASE) {
+ start_addr = TASK_UNMAPPED_BASE;
+ mm->cached_hole_size = 0;
+ goto full_search;
+ }
+ return -ENOMEM;
+ }
+ if (!vma || addr + len <= vma->vm_start) {
+ mm->free_area_cache = addr + len;
+ return addr;
+ }
+ if (addr + mm->cached_hole_size < vma->vm_start)
+ mm->cached_hole_size = vma->vm_start - addr;
+ addr = ALIGN(vma->vm_end, huge_page_size(h));
+ }
+}
+
+static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
+ unsigned long addr0, unsigned long len,
+ unsigned long pgoff, unsigned long flags)
+{
+ struct hstate *h = hstate_file(file);
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma, *prev_vma;
+ unsigned long base = mm->mmap_base, addr = addr0;
+ unsigned long largest_hole = mm->cached_hole_size;
+ int first_time = 1;
+
+ /* don't allow allocations above current base */
+ if (mm->free_area_cache > base)
+ mm->free_area_cache = base;
+
+ if (len <= largest_hole) {
+ largest_hole = 0;
+ mm->free_area_cache = base;
+ }
+try_again:
+ /* make sure it can fit in the remaining address space */
+ if (mm->free_area_cache < len)
+ goto fail;
+
+ /* either no address requested or cant fit in requested address hole */
+ addr = (mm->free_area_cache - len) & huge_page_mask(h);
+ do {
+ /*
+ * Lookup failure means no vma is above this address,
+ * i.e. return with success:
+ */
+ vma = find_vma_prev(mm, addr, &prev_vma);
+ if (!vma) {
+ return addr;
+ break;
+ }
+
+ /*
+ * new region fits between prev_vma->vm_end and
+ * vma->vm_start, use it:
+ */
+ if (addr + len <= vma->vm_start &&
+ (!prev_vma || (addr >= prev_vma->vm_end))) {
+ /* remember the address as a hint for next time */
+ mm->cached_hole_size = largest_hole;
+ mm->free_area_cache = addr;
+ return addr;
+ } else {
+ /* pull free_area_cache down to the first hole */
+ if (mm->free_area_cache == vma->vm_end) {
+ mm->free_area_cache = vma->vm_start;
+ mm->cached_hole_size = largest_hole;
+ }
+ }
+
+ /* remember the largest hole we saw so far */
+ if (addr + largest_hole < vma->vm_start)
+ largest_hole = vma->vm_start - addr;
+
+ /* try just below the current vma->vm_start */
+ addr = (vma->vm_start - len) & huge_page_mask(h);
+
+ } while (len <= vma->vm_start);
+
+fail:
+ /*
+ * if hint left us with no space for the requested
+ * mapping then try again:
+ */
+ if (first_time) {
+ mm->free_area_cache = base;
+ largest_hole = 0;
+ first_time = 0;
+ goto try_again;
+ }
+ /*
+ * A failed mmap() very likely causes application failure,
+ * so fall back to the bottom-up function here. This scenario
+ * can happen with large stack limits and large mmap()
+ * allocations.
+ */
+ mm->free_area_cache = TASK_UNMAPPED_BASE;
+ mm->cached_hole_size = ~0UL;
+ addr = hugetlb_get_unmapped_area_bottomup(file, addr0,
+ len, pgoff, flags);
+
+ /*
+ * Restore the topdown base:
+ */
+ mm->free_area_cache = base;
+ mm->cached_hole_size = ~0UL;
+
+ return addr;
+}
+
+unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long pgoff, unsigned long flags)
+{
+ struct hstate *h = hstate_file(file);
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+
+ if (len & ~huge_page_mask(h))
+ return -EINVAL;
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
+ if (flags & MAP_FIXED) {
+ if (prepare_hugepage_range(file, addr, len))
+ return -EINVAL;
+ return addr;
+ }
+
+ if (addr) {
+ addr = ALIGN(addr, huge_page_size(h));
+ vma = find_vma(mm, addr);
+ if (TASK_SIZE - len >= addr &&
+ (!vma || addr + len <= vma->vm_start))
+ return addr;
+ }
+ if (current->mm->get_unmapped_area == arch_get_unmapped_area)
+ return hugetlb_get_unmapped_area_bottomup(file, addr, len,
+ pgoff, flags);
+ else
+ return hugetlb_get_unmapped_area_topdown(file, addr, len,
+ pgoff, flags);
+}
+
+static __init int setup_hugepagesz(char *opt)
+{
+ unsigned long ps = memparse(opt, &opt);
+ if (ps == PMD_SIZE) {
+ hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
+ } else if (ps == PUD_SIZE) {
+ hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
+ } else {
+ printk(KERN_ERR "hugepagesz: Unsupported page size %lu M\n",
+ ps >> 20);
+ return 0;
+ }
+ return 1;
+}
+__setup("hugepagesz=", setup_hugepagesz);
+
+#endif /*HAVE_ARCH_HUGETLB_UNMAPPED_AREA*/
diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c
new file mode 100644
index 0000000..31b5c09
--- /dev/null
+++ b/arch/tile/mm/init.c
@@ -0,0 +1,1082 @@
+/*
+ * Copyright (C) 1995 Linus Torvalds
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/module.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/poison.h>
+#include <linux/bootmem.h>
+#include <linux/slab.h>
+#include <linux/proc_fs.h>
+#include <linux/efi.h>
+#include <linux/memory_hotplug.h>
+#include <linux/uaccess.h>
+#include <asm/mmu_context.h>
+#include <asm/processor.h>
+#include <asm/system.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/dma.h>
+#include <asm/fixmap.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/homecache.h>
+#include <hv/hypervisor.h>
+#include <arch/chip.h>
+
+#include "migrate.h"
+
+/*
+ * We could set FORCE_MAX_ZONEORDER to "(HPAGE_SHIFT - PAGE_SHIFT + 1)"
+ * in the Tile Kconfig, but this generates configure warnings.
+ * Do it here and force people to get it right to compile this file.
+ * The problem is that with 4KB small pages and 16MB huge pages,
+ * the default value doesn't allow us to group enough small pages
+ * together to make up a huge page.
+ */
+#if CONFIG_FORCE_MAX_ZONEORDER < HPAGE_SHIFT - PAGE_SHIFT + 1
+# error "Change FORCE_MAX_ZONEORDER in arch/tile/Kconfig to match page size"
+#endif
+
+#define clear_pgd(pmdptr) (*(pmdptr) = hv_pte(0))
+
+unsigned long VMALLOC_RESERVE = CONFIG_VMALLOC_RESERVE;
+
+DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+
+/* Create an L2 page table */
+static pte_t * __init alloc_pte(void)
+{
+ return __alloc_bootmem(L2_KERNEL_PGTABLE_SIZE, HV_PAGE_TABLE_ALIGN, 0);
+}
+
+/*
+ * L2 page tables per controller. We allocate these all at once from
+ * the bootmem allocator and store them here. This saves on kernel L2
+ * page table memory, compared to allocating a full 64K page per L2
+ * page table, and also means that in cases where we use huge pages,
+ * we are guaranteed to later be able to shatter those huge pages and
+ * switch to using these page tables instead, without requiring
+ * further allocation. Each l2_ptes[] entry points to the first page
+ * table for the first hugepage-size piece of memory on the
+ * controller; other page tables are just indexed directly, i.e. the
+ * L2 page tables are contiguous in memory for each controller.
+ */
+static pte_t *l2_ptes[MAX_NUMNODES];
+static int num_l2_ptes[MAX_NUMNODES];
+
+static void init_prealloc_ptes(int node, int pages)
+{
+ BUG_ON(pages & (HV_L2_ENTRIES-1));
+ if (pages) {
+ num_l2_ptes[node] = pages;
+ l2_ptes[node] = __alloc_bootmem(pages * sizeof(pte_t),
+ HV_PAGE_TABLE_ALIGN, 0);
+ }
+}
+
+pte_t *get_prealloc_pte(unsigned long pfn)
+{
+ int node = pfn_to_nid(pfn);
+ pfn &= ~(-1UL << (NR_PA_HIGHBIT_SHIFT - PAGE_SHIFT));
+ BUG_ON(node >= MAX_NUMNODES);
+ BUG_ON(pfn >= num_l2_ptes[node]);
+ return &l2_ptes[node][pfn];
+}
+
+/*
+ * What caching do we expect pages from the heap to have when
+ * they are allocated during bootup? (Once we've installed the
+ * "real" swapper_pg_dir.)
+ */
+static int initial_heap_home(void)
+{
+#if CHIP_HAS_CBOX_HOME_MAP()
+ if (hash_default)
+ return PAGE_HOME_HASH;
+#endif
+ return smp_processor_id();
+}
+
+/*
+ * Place a pointer to an L2 page table in a middle page
+ * directory entry.
+ */
+static void __init assign_pte(pmd_t *pmd, pte_t *page_table)
+{
+ phys_addr_t pa = __pa(page_table);
+ unsigned long l2_ptfn = pa >> HV_LOG2_PAGE_TABLE_ALIGN;
+ pte_t pteval = hv_pte_set_ptfn(__pgprot(_PAGE_TABLE), l2_ptfn);
+ BUG_ON((pa & (HV_PAGE_TABLE_ALIGN-1)) != 0);
+ pteval = pte_set_home(pteval, initial_heap_home());
+ *(pte_t *)pmd = pteval;
+ if (page_table != (pte_t *)pmd_page_vaddr(*pmd))
+ BUG();
+}
+
+#ifdef __tilegx__
+
+#if HV_L1_SIZE != HV_L2_SIZE
+# error Rework assumption that L1 and L2 page tables are same size.
+#endif
+
+/* Since pmd_t arrays and pte_t arrays are the same size, just use casts. */
+static inline pmd_t *alloc_pmd(void)
+{
+ return (pmd_t *)alloc_pte();
+}
+
+static inline void assign_pmd(pud_t *pud, pmd_t *pmd)
+{
+ assign_pte((pmd_t *)pud, (pte_t *)pmd);
+}
+
+#endif /* __tilegx__ */
+
+/* Replace the given pmd with a full PTE table. */
+void __init shatter_pmd(pmd_t *pmd)
+{
+ pte_t *pte = get_prealloc_pte(pte_pfn(*(pte_t *)pmd));
+ assign_pte(pmd, pte);
+}
+
+#ifdef CONFIG_HIGHMEM
+/*
+ * This function initializes a certain range of kernel virtual memory
+ * with new bootmem page tables, everywhere page tables are missing in
+ * the given range.
+ */
+
+/*
+ * NOTE: The pagetables are allocated contiguous on the physical space
+ * so we can cache the place of the first one and move around without
+ * checking the pgd every time.
+ */
+static void __init page_table_range_init(unsigned long start,
+ unsigned long end, pgd_t *pgd_base)
+{
+ pgd_t *pgd;
+ int pgd_idx;
+ unsigned long vaddr;
+
+ vaddr = start;
+ pgd_idx = pgd_index(vaddr);
+ pgd = pgd_base + pgd_idx;
+
+ for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
+ pmd_t *pmd = pmd_offset(pud_offset(pgd, vaddr), vaddr);
+ if (pmd_none(*pmd))
+ assign_pte(pmd, alloc_pte());
+ vaddr += PMD_SIZE;
+ }
+}
+#endif /* CONFIG_HIGHMEM */
+
+
+#if CHIP_HAS_CBOX_HOME_MAP()
+
+static int __initdata ktext_hash = 1; /* .text pages */
+static int __initdata kdata_hash = 1; /* .data and .bss pages */
+int __write_once hash_default = 1; /* kernel allocator pages */
+EXPORT_SYMBOL(hash_default);
+int __write_once kstack_hash = 1; /* if no homecaching, use h4h */
+#endif /* CHIP_HAS_CBOX_HOME_MAP */
+
+/*
+ * CPUs to use to for striping the pages of kernel data. If hash-for-home
+ * is available, this is only relevant if kcache_hash sets up the
+ * .data and .bss to be page-homed, and we don't want the default mode
+ * of using the full set of kernel cpus for the striping.
+ */
+static __initdata struct cpumask kdata_mask;
+static __initdata int kdata_arg_seen;
+
+int __write_once kdata_huge; /* if no homecaching, small pages */
+
+
+/* Combine a generic pgprot_t with cache home to get a cache-aware pgprot. */
+static pgprot_t __init construct_pgprot(pgprot_t prot, int home)
+{
+ prot = pte_set_home(prot, home);
+#if CHIP_HAS_CBOX_HOME_MAP()
+ if (home == PAGE_HOME_IMMUTABLE) {
+ if (ktext_hash)
+ prot = hv_pte_set_mode(prot, HV_PTE_MODE_CACHE_HASH_L3);
+ else
+ prot = hv_pte_set_mode(prot, HV_PTE_MODE_CACHE_NO_L3);
+ }
+#endif
+ return prot;
+}
+
+/*
+ * For a given kernel data VA, how should it be cached?
+ * We return the complete pgprot_t with caching bits set.
+ */
+static pgprot_t __init init_pgprot(ulong address)
+{
+ int cpu;
+ unsigned long page;
+ enum { CODE_DELTA = MEM_SV_INTRPT - PAGE_OFFSET };
+
+#if CHIP_HAS_CBOX_HOME_MAP()
+ /* For kdata=huge, everything is just hash-for-home. */
+ if (kdata_huge)
+ return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
+#endif
+
+ /* We map the aliased pages of permanent text inaccessible. */
+ if (address < (ulong) _sinittext - CODE_DELTA)
+ return PAGE_NONE;
+
+ /*
+ * We map read-only data non-coherent for performance. We could
+ * use neighborhood caching on TILE64, but it's not clear it's a win.
+ */
+ if ((address >= (ulong) __start_rodata &&
+ address < (ulong) __end_rodata) ||
+ address == (ulong) empty_zero_page) {
+ return construct_pgprot(PAGE_KERNEL_RO, PAGE_HOME_IMMUTABLE);
+ }
+
+ /* As a performance optimization, keep the boot init stack here. */
+ if (address >= (ulong)&init_thread_union &&
+ address < (ulong)&init_thread_union + THREAD_SIZE)
+ return construct_pgprot(PAGE_KERNEL, smp_processor_id());
+
+#ifndef __tilegx__
+#if !ATOMIC_LOCKS_FOUND_VIA_TABLE()
+ /* Force the atomic_locks[] array page to be hash-for-home. */
+ if (address == (ulong) atomic_locks)
+ return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
+#endif
+#endif
+
+ /*
+ * Everything else that isn't data or bss is heap, so mark it
+ * with the initial heap home (hash-for-home, or this cpu). This
+ * includes any addresses after the loaded image; any address before
+ * _einittext (since we already captured the case of text before
+ * _sinittext); and any init-data pages.
+ *
+ * All the LOWMEM pages that we mark this way will get their
+ * struct page homecache properly marked later, in set_page_homes().
+ * The HIGHMEM pages we leave with a default zero for their
+ * homes, but with a zero free_time we don't have to actually
+ * do a flush action the first time we use them, either.
+ */
+ if (address >= (ulong) _end || address < (ulong) _sdata ||
+ (address >= (ulong) _sinitdata &&
+ address < (ulong) _einitdata))
+ return construct_pgprot(PAGE_KERNEL, initial_heap_home());
+
+#if CHIP_HAS_CBOX_HOME_MAP()
+ /* Use hash-for-home if requested for data/bss. */
+ if (kdata_hash)
+ return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
+#endif
+
+ /*
+ * Otherwise we just hand out consecutive cpus. To avoid
+ * requiring this function to hold state, we just walk forward from
+ * _sdata by PAGE_SIZE, skipping the readonly and init data, to reach
+ * the requested address, while walking cpu home around kdata_mask.
+ * This is typically no more than a dozen or so iterations.
+ */
+ BUG_ON(_einitdata != __bss_start);
+ for (page = (ulong)_sdata, cpu = NR_CPUS; ; ) {
+ cpu = cpumask_next(cpu, &kdata_mask);
+ if (cpu == NR_CPUS)
+ cpu = cpumask_first(&kdata_mask);
+ if (page >= address)
+ break;
+ page += PAGE_SIZE;
+ if (page == (ulong)__start_rodata)
+ page = (ulong)__end_rodata;
+ if (page == (ulong)&init_thread_union)
+ page += THREAD_SIZE;
+ if (page == (ulong)_sinitdata)
+ page = (ulong)_einitdata;
+ if (page == (ulong)empty_zero_page)
+ page += PAGE_SIZE;
+#ifndef __tilegx__
+#if !ATOMIC_LOCKS_FOUND_VIA_TABLE()
+ if (page == (ulong)atomic_locks)
+ page += PAGE_SIZE;
+#endif
+#endif
+
+ }
+ return construct_pgprot(PAGE_KERNEL, cpu);
+}
+
+/*
+ * This function sets up how we cache the kernel text. If we have
+ * hash-for-home support, normally that is used instead (see the
+ * kcache_hash boot flag for more information). But if we end up
+ * using a page-based caching technique, this option sets up the
+ * details of that. In addition, the "ktext=nocache" option may
+ * always be used to disable local caching of text pages, if desired.
+ */
+
+static int __initdata ktext_arg_seen;
+static int __initdata ktext_small;
+static int __initdata ktext_local;
+static int __initdata ktext_all;
+static int __initdata ktext_nondataplane;
+static int __initdata ktext_nocache;
+static struct cpumask __initdata ktext_mask;
+
+static int __init setup_ktext(char *str)
+{
+ if (str == NULL)
+ return -EINVAL;
+
+ /* If you have a leading "nocache", turn off ktext caching */
+ if (strncmp(str, "nocache", 7) == 0) {
+ ktext_nocache = 1;
+ printk("ktext: disabling local caching of kernel text\n");
+ str += 7;
+ if (*str == ',')
+ ++str;
+ if (*str == '\0')
+ return 0;
+ }
+
+ ktext_arg_seen = 1;
+
+ /* Default setting on Tile64: use a huge page */
+ if (strcmp(str, "huge") == 0)
+ printk("ktext: using one huge locally cached page\n");
+
+ /* Pay TLB cost but get no cache benefit: cache small pages locally */
+ else if (strcmp(str, "local") == 0) {
+ ktext_small = 1;
+ ktext_local = 1;
+ printk("ktext: using small pages with local caching\n");
+ }
+
+ /* Neighborhood cache ktext pages on all cpus. */
+ else if (strcmp(str, "all") == 0) {
+ ktext_small = 1;
+ ktext_all = 1;
+ printk("ktext: using maximal caching neighborhood\n");
+ }
+
+
+ /* Neighborhood ktext pages on specified mask */
+ else if (cpulist_parse(str, &ktext_mask) == 0) {
+ char buf[NR_CPUS * 5];
+ cpulist_scnprintf(buf, sizeof(buf), &ktext_mask);
+ if (cpumask_weight(&ktext_mask) > 1) {
+ ktext_small = 1;
+ printk("ktext: using caching neighborhood %s "
+ "with small pages\n", buf);
+ } else {
+ printk("ktext: caching on cpu %s with one huge page\n",
+ buf);
+ }
+ }
+
+ else if (*str)
+ return -EINVAL;
+
+ return 0;
+}
+
+early_param("ktext", setup_ktext);
+
+
+static inline pgprot_t ktext_set_nocache(pgprot_t prot)
+{
+ if (!ktext_nocache)
+ prot = hv_pte_set_nc(prot);
+#if CHIP_HAS_NC_AND_NOALLOC_BITS()
+ else
+ prot = hv_pte_set_no_alloc_l2(prot);
+#endif
+ return prot;
+}
+
+#ifndef __tilegx__
+static pmd_t *__init get_pmd(pgd_t pgtables[], unsigned long va)
+{
+ return pmd_offset(pud_offset(&pgtables[pgd_index(va)], va), va);
+}
+#else
+static pmd_t *__init get_pmd(pgd_t pgtables[], unsigned long va)
+{
+ pud_t *pud = pud_offset(&pgtables[pgd_index(va)], va);
+ if (pud_none(*pud))
+ assign_pmd(pud, alloc_pmd());
+ return pmd_offset(pud, va);
+}
+#endif
+
+/* Temporary page table we use for staging. */
+static pgd_t pgtables[PTRS_PER_PGD]
+ __attribute__((section(".init.page")));
+
+/*
+ * This maps the physical memory to kernel virtual address space, a total
+ * of max_low_pfn pages, by creating page tables starting from address
+ * PAGE_OFFSET.
+ *
+ * This routine transitions us from using a set of compiled-in large
+ * pages to using some more precise caching, including removing access
+ * to code pages mapped at PAGE_OFFSET (executed only at MEM_SV_START)
+ * marking read-only data as locally cacheable, striping the remaining
+ * .data and .bss across all the available tiles, and removing access
+ * to pages above the top of RAM (thus ensuring a page fault from a bad
+ * virtual address rather than a hypervisor shoot down for accessing
+ * memory outside the assigned limits).
+ */
+static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
+{
+ unsigned long address, pfn;
+ pmd_t *pmd;
+ pte_t *pte;
+ int pte_ofs;
+ const struct cpumask *my_cpu_mask = cpumask_of(smp_processor_id());
+ struct cpumask kstripe_mask;
+ int rc, i;
+
+#if CHIP_HAS_CBOX_HOME_MAP()
+ if (ktext_arg_seen && ktext_hash) {
+ printk("warning: \"ktext\" boot argument ignored"
+ " if \"kcache_hash\" sets up text hash-for-home\n");
+ ktext_small = 0;
+ }
+
+ if (kdata_arg_seen && kdata_hash) {
+ printk("warning: \"kdata\" boot argument ignored"
+ " if \"kcache_hash\" sets up data hash-for-home\n");
+ }
+
+ if (kdata_huge && !hash_default) {
+ printk("warning: disabling \"kdata=huge\"; requires"
+ " kcache_hash=all or =allbutstack\n");
+ kdata_huge = 0;
+ }
+#endif
+
+ /*
+ * Set up a mask for cpus to use for kernel striping.
+ * This is normally all cpus, but minus dataplane cpus if any.
+ * If the dataplane covers the whole chip, we stripe over
+ * the whole chip too.
+ */
+ cpumask_copy(&kstripe_mask, cpu_possible_mask);
+ if (!kdata_arg_seen)
+ kdata_mask = kstripe_mask;
+
+ /* Allocate and fill in L2 page tables */
+ for (i = 0; i < MAX_NUMNODES; ++i) {
+#ifdef CONFIG_HIGHMEM
+ unsigned long end_pfn = node_lowmem_end_pfn[i];
+#else
+ unsigned long end_pfn = node_end_pfn[i];
+#endif
+ unsigned long end_huge_pfn = 0;
+
+ /* Pre-shatter the last huge page to allow per-cpu pages. */
+ if (kdata_huge)
+ end_huge_pfn = end_pfn - (HPAGE_SIZE >> PAGE_SHIFT);
+
+ pfn = node_start_pfn[i];
+
+ /* Allocate enough memory to hold L2 page tables for node. */
+ init_prealloc_ptes(i, end_pfn - pfn);
+
+ address = (unsigned long) pfn_to_kaddr(pfn);
+ while (pfn < end_pfn) {
+ BUG_ON(address & (HPAGE_SIZE-1));
+ pmd = get_pmd(pgtables, address);
+ pte = get_prealloc_pte(pfn);
+ if (pfn < end_huge_pfn) {
+ pgprot_t prot = init_pgprot(address);
+ *(pte_t *)pmd = pte_mkhuge(pfn_pte(pfn, prot));
+ for (pte_ofs = 0; pte_ofs < PTRS_PER_PTE;
+ pfn++, pte_ofs++, address += PAGE_SIZE)
+ pte[pte_ofs] = pfn_pte(pfn, prot);
+ } else {
+ if (kdata_huge)
+ printk(KERN_DEBUG "pre-shattered huge"
+ " page at %#lx\n", address);
+ for (pte_ofs = 0; pte_ofs < PTRS_PER_PTE;
+ pfn++, pte_ofs++, address += PAGE_SIZE) {
+ pgprot_t prot = init_pgprot(address);
+ pte[pte_ofs] = pfn_pte(pfn, prot);
+ }
+ assign_pte(pmd, pte);
+ }
+ }
+ }
+
+ /*
+ * Set or check ktext_map now that we have cpu_possible_mask
+ * and kstripe_mask to work with.
+ */
+ if (ktext_all)
+ cpumask_copy(&ktext_mask, cpu_possible_mask);
+ else if (ktext_nondataplane)
+ ktext_mask = kstripe_mask;
+ else if (!cpumask_empty(&ktext_mask)) {
+ /* Sanity-check any mask that was requested */
+ struct cpumask bad;
+ cpumask_andnot(&bad, &ktext_mask, cpu_possible_mask);
+ cpumask_and(&ktext_mask, &ktext_mask, cpu_possible_mask);
+ if (!cpumask_empty(&bad)) {
+ char buf[NR_CPUS * 5];
+ cpulist_scnprintf(buf, sizeof(buf), &bad);
+ printk("ktext: not using unavailable cpus %s\n", buf);
+ }
+ if (cpumask_empty(&ktext_mask)) {
+ printk("ktext: no valid cpus; caching on %d.\n",
+ smp_processor_id());
+ cpumask_copy(&ktext_mask,
+ cpumask_of(smp_processor_id()));
+ }
+ }
+
+ address = MEM_SV_INTRPT;
+ pmd = get_pmd(pgtables, address);
+ if (ktext_small) {
+ /* Allocate an L2 PTE for the kernel text */
+ int cpu = 0;
+ pgprot_t prot = construct_pgprot(PAGE_KERNEL_EXEC,
+ PAGE_HOME_IMMUTABLE);
+
+ if (ktext_local) {
+ if (ktext_nocache)
+ prot = hv_pte_set_mode(prot,
+ HV_PTE_MODE_UNCACHED);
+ else
+ prot = hv_pte_set_mode(prot,
+ HV_PTE_MODE_CACHE_NO_L3);
+ } else {
+ prot = hv_pte_set_mode(prot,
+ HV_PTE_MODE_CACHE_TILE_L3);
+ cpu = cpumask_first(&ktext_mask);
+
+ prot = ktext_set_nocache(prot);
+ }
+
+ BUG_ON(address != (unsigned long)_stext);
+ pfn = 0; /* code starts at PA 0 */
+ pte = alloc_pte();
+ for (pte_ofs = 0; address < (unsigned long)_einittext;
+ pfn++, pte_ofs++, address += PAGE_SIZE) {
+ if (!ktext_local) {
+ prot = set_remote_cache_cpu(prot, cpu);
+ cpu = cpumask_next(cpu, &ktext_mask);
+ if (cpu == NR_CPUS)
+ cpu = cpumask_first(&ktext_mask);
+ }
+ pte[pte_ofs] = pfn_pte(pfn, prot);
+ }
+ assign_pte(pmd, pte);
+ } else {
+ pte_t pteval = pfn_pte(0, PAGE_KERNEL_EXEC);
+ pteval = pte_mkhuge(pteval);
+#if CHIP_HAS_CBOX_HOME_MAP()
+ if (ktext_hash) {
+ pteval = hv_pte_set_mode(pteval,
+ HV_PTE_MODE_CACHE_HASH_L3);
+ pteval = ktext_set_nocache(pteval);
+ } else
+#endif /* CHIP_HAS_CBOX_HOME_MAP() */
+ if (cpumask_weight(&ktext_mask) == 1) {
+ pteval = set_remote_cache_cpu(pteval,
+ cpumask_first(&ktext_mask));
+ pteval = hv_pte_set_mode(pteval,
+ HV_PTE_MODE_CACHE_TILE_L3);
+ pteval = ktext_set_nocache(pteval);
+ } else if (ktext_nocache)
+ pteval = hv_pte_set_mode(pteval,
+ HV_PTE_MODE_UNCACHED);
+ else
+ pteval = hv_pte_set_mode(pteval,
+ HV_PTE_MODE_CACHE_NO_L3);
+ *(pte_t *)pmd = pteval;
+ }
+
+ /* Set swapper_pgprot here so it is flushed to memory right away. */
+ swapper_pgprot = init_pgprot((unsigned long)swapper_pg_dir);
+
+ /*
+ * Since we may be changing the caching of the stack and page
+ * table itself, we invoke an assembly helper to do the
+ * following steps:
+ *
+ * - flush the cache so we start with an empty slate
+ * - install pgtables[] as the real page table
+ * - flush the TLB so the new page table takes effect
+ */
+ rc = flush_and_install_context(__pa(pgtables),
+ init_pgprot((unsigned long)pgtables),
+ __get_cpu_var(current_asid),
+ cpumask_bits(my_cpu_mask));
+ BUG_ON(rc != 0);
+
+ /* Copy the page table back to the normal swapper_pg_dir. */
+ memcpy(pgd_base, pgtables, sizeof(pgtables));
+ __install_page_table(pgd_base, __get_cpu_var(current_asid),
+ swapper_pgprot);
+}
+
+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain address
+ * is valid. The argument is a physical page number.
+ *
+ * On Tile, the only valid things for which we can just hand out unchecked
+ * PTEs are the kernel code and data. Anything else might change its
+ * homing with time, and we wouldn't know to adjust the /dev/mem PTEs.
+ * Note that init_thread_union is released to heap soon after boot,
+ * so we include it in the init data.
+ *
+ * For TILE-Gx, we might want to consider allowing access to PA
+ * regions corresponding to PCI space, etc.
+ */
+int devmem_is_allowed(unsigned long pagenr)
+{
+ return pagenr < kaddr_to_pfn(_end) &&
+ !(pagenr >= kaddr_to_pfn(&init_thread_union) ||
+ pagenr < kaddr_to_pfn(_einitdata)) &&
+ !(pagenr >= kaddr_to_pfn(_sinittext) ||
+ pagenr <= kaddr_to_pfn(_einittext-1));
+}
+
+#ifdef CONFIG_HIGHMEM
+static void __init permanent_kmaps_init(pgd_t *pgd_base)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+ unsigned long vaddr;
+
+ vaddr = PKMAP_BASE;
+ page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
+
+ pgd = swapper_pg_dir + pgd_index(vaddr);
+ pud = pud_offset(pgd, vaddr);
+ pmd = pmd_offset(pud, vaddr);
+ pte = pte_offset_kernel(pmd, vaddr);
+ pkmap_page_table = pte;
+}
+#endif /* CONFIG_HIGHMEM */
+
+
+static void __init init_free_pfn_range(unsigned long start, unsigned long end)
+{
+ unsigned long pfn;
+ struct page *page = pfn_to_page(start);
+
+ for (pfn = start; pfn < end; ) {
+ /* Optimize by freeing pages in large batches */
+ int order = __ffs(pfn);
+ int count, i;
+ struct page *p;
+
+ if (order >= MAX_ORDER)
+ order = MAX_ORDER-1;
+ count = 1 << order;
+ while (pfn + count > end) {
+ count >>= 1;
+ --order;
+ }
+ for (p = page, i = 0; i < count; ++i, ++p) {
+ __ClearPageReserved(p);
+ /*
+ * Hacky direct set to avoid unnecessary
+ * lock take/release for EVERY page here.
+ */
+ p->_count.counter = 0;
+ p->_mapcount.counter = -1;
+ }
+ init_page_count(page);
+ __free_pages(page, order);
+ totalram_pages += count;
+
+ page += count;
+ pfn += count;
+ }
+}
+
+static void __init set_non_bootmem_pages_init(void)
+{
+ struct zone *z;
+ for_each_zone(z) {
+ unsigned long start, end;
+ int nid = z->zone_pgdat->node_id;
+
+ start = z->zone_start_pfn;
+ if (start == 0)
+ continue; /* bootmem */
+ end = start + z->spanned_pages;
+ if (zone_idx(z) == ZONE_DMA) {
+ BUG_ON(start != node_start_pfn[nid]);
+ start = node_free_pfn[nid];
+ }
+#ifdef CONFIG_HIGHMEM
+ if (zone_idx(z) == ZONE_HIGHMEM)
+ totalhigh_pages += z->spanned_pages;
+#endif
+ if (kdata_huge) {
+ unsigned long percpu_pfn = node_percpu_pfn[nid];
+ if (start < percpu_pfn && end > percpu_pfn)
+ end = percpu_pfn;
+ }
+#ifdef CONFIG_PCI
+ if (start <= pci_reserve_start_pfn &&
+ end > pci_reserve_start_pfn) {
+ if (end > pci_reserve_end_pfn)
+ init_free_pfn_range(pci_reserve_end_pfn, end);
+ end = pci_reserve_start_pfn;
+ }
+#endif
+ init_free_pfn_range(start, end);
+ }
+}
+
+/*
+ * paging_init() sets up the page tables - note that all of lowmem is
+ * already mapped by head.S.
+ */
+void __init paging_init(void)
+{
+#ifdef CONFIG_HIGHMEM
+ unsigned long vaddr, end;
+#endif
+#ifdef __tilegx__
+ pud_t *pud;
+#endif
+ pgd_t *pgd_base = swapper_pg_dir;
+
+ kernel_physical_mapping_init(pgd_base);
+
+#ifdef CONFIG_HIGHMEM
+ /*
+ * Fixed mappings, only the page table structure has to be
+ * created - mappings will be set by set_fixmap():
+ */
+ vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
+ end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
+ page_table_range_init(vaddr, end, pgd_base);
+ permanent_kmaps_init(pgd_base);
+#endif
+
+#ifdef __tilegx__
+ /*
+ * Since GX allocates just one pmd_t array worth of vmalloc space,
+ * we go ahead and allocate it statically here, then share it
+ * globally. As a result we don't have to worry about any task
+ * changing init_mm once we get up and running, and there's no
+ * need for e.g. vmalloc_sync_all().
+ */
+ BUILD_BUG_ON(pgd_index(VMALLOC_START) != pgd_index(VMALLOC_END));
+ pud = pud_offset(pgd_base + pgd_index(VMALLOC_START), VMALLOC_START);
+ assign_pmd(pud, alloc_pmd());
+#endif
+}
+
+
+/*
+ * Walk the kernel page tables and derive the page_home() from
+ * the PTEs, so that set_pte() can properly validate the caching
+ * of all PTEs it sees.
+ */
+void __init set_page_homes(void)
+{
+}
+
+static void __init set_max_mapnr_init(void)
+{
+#ifdef CONFIG_FLATMEM
+ max_mapnr = max_low_pfn;
+#endif
+}
+
+void __init mem_init(void)
+{
+ int codesize, datasize, initsize;
+ int i;
+#ifndef __tilegx__
+ void *last;
+#endif
+
+#ifdef CONFIG_FLATMEM
+ if (!mem_map)
+ BUG();
+#endif
+
+#ifdef CONFIG_HIGHMEM
+ /* check that fixmap and pkmap do not overlap */
+ if (PKMAP_ADDR(LAST_PKMAP-1) >= FIXADDR_START) {
+ printk(KERN_ERR "fixmap and kmap areas overlap"
+ " - this will crash\n");
+ printk(KERN_ERR "pkstart: %lxh pkend: %lxh fixstart %lxh\n",
+ PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP-1),
+ FIXADDR_START);
+ BUG();
+ }
+#endif
+
+ set_max_mapnr_init();
+
+ /* this will put all bootmem onto the freelists */
+ totalram_pages += free_all_bootmem();
+
+ /* count all remaining LOWMEM and give all HIGHMEM to page allocator */
+ set_non_bootmem_pages_init();
+
+ codesize = (unsigned long)&_etext - (unsigned long)&_text;
+ datasize = (unsigned long)&_end - (unsigned long)&_sdata;
+ initsize = (unsigned long)&_einittext - (unsigned long)&_sinittext;
+ initsize += (unsigned long)&_einitdata - (unsigned long)&_sinitdata;
+
+ printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, %dk data, %dk init, %ldk highmem)\n",
+ (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
+ num_physpages << (PAGE_SHIFT-10),
+ codesize >> 10,
+ datasize >> 10,
+ initsize >> 10,
+ (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10))
+ );
+
+ /*
+ * In debug mode, dump some interesting memory mappings.
+ */
+#ifdef CONFIG_HIGHMEM
+ printk(KERN_DEBUG " KMAP %#lx - %#lx\n",
+ FIXADDR_START, FIXADDR_TOP + PAGE_SIZE - 1);
+ printk(KERN_DEBUG " PKMAP %#lx - %#lx\n",
+ PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP) - 1);
+#endif
+#ifdef CONFIG_HUGEVMAP
+ printk(KERN_DEBUG " HUGEMAP %#lx - %#lx\n",
+ HUGE_VMAP_BASE, HUGE_VMAP_END - 1);
+#endif
+ printk(KERN_DEBUG " VMALLOC %#lx - %#lx\n",
+ _VMALLOC_START, _VMALLOC_END - 1);
+#ifdef __tilegx__
+ for (i = MAX_NUMNODES-1; i >= 0; --i) {
+ struct pglist_data *node = &node_data[i];
+ if (node->node_present_pages) {
+ unsigned long start = (unsigned long)
+ pfn_to_kaddr(node->node_start_pfn);
+ unsigned long end = start +
+ (node->node_present_pages << PAGE_SHIFT);
+ printk(KERN_DEBUG " MEM%d %#lx - %#lx\n",
+ i, start, end - 1);
+ }
+ }
+#else
+ last = high_memory;
+ for (i = MAX_NUMNODES-1; i >= 0; --i) {
+ if ((unsigned long)vbase_map[i] != -1UL) {
+ printk(KERN_DEBUG " LOWMEM%d %#lx - %#lx\n",
+ i, (unsigned long) (vbase_map[i]),
+ (unsigned long) (last-1));
+ last = vbase_map[i];
+ }
+ }
+#endif
+
+#ifndef __tilegx__
+ /*
+ * Convert from using one lock for all atomic operations to
+ * one per cpu.
+ */
+ __init_atomic_per_cpu();
+#endif
+}
+
+/*
+ * this is for the non-NUMA, single node SMP system case.
+ * Specifically, in the case of x86, we will always add
+ * memory to the highmem for now.
+ */
+#ifndef CONFIG_NEED_MULTIPLE_NODES
+int arch_add_memory(u64 start, u64 size)
+{
+ struct pglist_data *pgdata = &contig_page_data;
+ struct zone *zone = pgdata->node_zones + MAX_NR_ZONES-1;
+ unsigned long start_pfn = start >> PAGE_SHIFT;
+ unsigned long nr_pages = size >> PAGE_SHIFT;
+
+ return __add_pages(zone, start_pfn, nr_pages);
+}
+
+int remove_memory(u64 start, u64 size)
+{
+ return -EINVAL;
+}
+#endif
+
+struct kmem_cache *pgd_cache;
+
+void __init pgtable_cache_init(void)
+{
+ pgd_cache = kmem_cache_create("pgd",
+ PTRS_PER_PGD*sizeof(pgd_t),
+ PTRS_PER_PGD*sizeof(pgd_t),
+ 0,
+ NULL);
+ if (!pgd_cache)
+ panic("pgtable_cache_init(): Cannot create pgd cache");
+}
+
+#if !CHIP_HAS_COHERENT_LOCAL_CACHE()
+/*
+ * The __w1data area holds data that is only written during initialization,
+ * and is read-only and thus freely cacheable thereafter. Fix the page
+ * table entries that cover that region accordingly.
+ */
+static void mark_w1data_ro(void)
+{
+ /* Loop over page table entries */
+ unsigned long addr = (unsigned long)__w1data_begin;
+ BUG_ON((addr & (PAGE_SIZE-1)) != 0);
+ for (; addr <= (unsigned long)__w1data_end - 1; addr += PAGE_SIZE) {
+ unsigned long pfn = kaddr_to_pfn((void *)addr);
+ struct page *page = pfn_to_page(pfn);
+ pte_t *ptep = virt_to_pte(NULL, addr);
+ BUG_ON(pte_huge(*ptep)); /* not relevant for kdata_huge */
+ set_pte_at(&init_mm, addr, ptep, pfn_pte(pfn, PAGE_KERNEL_RO));
+ }
+}
+#endif
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+static long __write_once initfree;
+#else
+static long __write_once initfree = 1;
+#endif
+
+/* Select whether to free (1) or mark unusable (0) the __init pages. */
+static int __init set_initfree(char *str)
+{
+ strict_strtol(str, 0, &initfree);
+ printk("initfree: %s free init pages\n", initfree ? "will" : "won't");
+ return 1;
+}
+__setup("initfree=", set_initfree);
+
+static void free_init_pages(char *what, unsigned long begin, unsigned long end)
+{
+ unsigned long addr = (unsigned long) begin;
+
+ if (kdata_huge && !initfree) {
+ printk("Warning: ignoring initfree=0:"
+ " incompatible with kdata=huge\n");
+ initfree = 1;
+ }
+ end = (end + PAGE_SIZE - 1) & PAGE_MASK;
+ local_flush_tlb_pages(NULL, begin, PAGE_SIZE, end - begin);
+ for (addr = begin; addr < end; addr += PAGE_SIZE) {
+ /*
+ * Note we just reset the home here directly in the
+ * page table. We know this is safe because our caller
+ * just flushed the caches on all the other cpus,
+ * and they won't be touching any of these pages.
+ */
+ int pfn = kaddr_to_pfn((void *)addr);
+ struct page *page = pfn_to_page(pfn);
+ pte_t *ptep = virt_to_pte(NULL, addr);
+ if (!initfree) {
+ /*
+ * If debugging page accesses then do not free
+ * this memory but mark them not present - any
+ * buggy init-section access will create a
+ * kernel page fault:
+ */
+ pte_clear(&init_mm, addr, ptep);
+ continue;
+ }
+ __ClearPageReserved(page);
+ init_page_count(page);
+ if (pte_huge(*ptep))
+ BUG_ON(!kdata_huge);
+ else
+ set_pte_at(&init_mm, addr, ptep,
+ pfn_pte(pfn, PAGE_KERNEL));
+ memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
+ free_page(addr);
+ totalram_pages++;
+ }
+ printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
+}
+
+void free_initmem(void)
+{
+ const unsigned long text_delta = MEM_SV_INTRPT - PAGE_OFFSET;
+
+ /*
+ * Evict the dirty initdata on the boot cpu, evict the w1data
+ * wherever it's homed, and evict all the init code everywhere.
+ * We are guaranteed that no one will touch the init pages any
+ * more, and although other cpus may be touching the w1data,
+ * we only actually change the caching on tile64, which won't
+ * be keeping local copies in the other tiles' caches anyway.
+ */
+ homecache_evict(&cpu_cacheable_map);
+
+ /* Free the data pages that we won't use again after init. */
+ free_init_pages("unused kernel data",
+ (unsigned long)_sinitdata,
+ (unsigned long)_einitdata);
+
+ /*
+ * Free the pages mapped from 0xc0000000 that correspond to code
+ * pages from 0xfd000000 that we won't use again after init.
+ */
+ free_init_pages("unused kernel text",
+ (unsigned long)_sinittext - text_delta,
+ (unsigned long)_einittext - text_delta);
+
+#if !CHIP_HAS_COHERENT_LOCAL_CACHE()
+ /*
+ * Upgrade the .w1data section to globally cached.
+ * We don't do this on tilepro, since the cache architecture
+ * pretty much makes it irrelevant, and in any case we end
+ * up having racing issues with other tiles that may touch
+ * the data after we flush the cache but before we update
+ * the PTEs and flush the TLBs, causing sharer shootdowns
+ * later. Even though this is to clean data, it seems like
+ * an unnecessary complication.
+ */
+ mark_w1data_ro();
+#endif
+
+ /* Do a global TLB flush so everyone sees the changes. */
+ flush_tlb_all();
+}
diff --git a/arch/tile/mm/migrate.h b/arch/tile/mm/migrate.h
new file mode 100644
index 0000000..cd45a08
--- /dev/null
+++ b/arch/tile/mm/migrate.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ *
+ * Structure definitions for migration, exposed here for use by
+ * arch/tile/kernel/asm-offsets.c.
+ */
+
+#ifndef MM_MIGRATE_H
+#define MM_MIGRATE_H
+
+#include <linux/cpumask.h>
+#include <hv/hypervisor.h>
+
+/*
+ * This function is used as a helper when setting up the initial
+ * page table (swapper_pg_dir).
+ */
+extern int flush_and_install_context(HV_PhysAddr page_table, HV_PTE access,
+ HV_ASID asid,
+ const unsigned long *cpumask);
+
+/*
+ * This function supports migration as a "helper" as follows:
+ *
+ * - Set the stack PTE itself to "migrating".
+ * - Do a global TLB flush for (va,length) and the specified ASIDs.
+ * - Do a cache-evict on all necessary cpus.
+ * - Write the new stack PTE.
+ *
+ * Note that any non-NULL pointers must not point to the page that
+ * is handled by the stack_pte itself.
+ */
+extern int homecache_migrate_stack_and_flush(pte_t stack_pte, unsigned long va,
+ size_t length, pte_t *stack_ptep,
+ const struct cpumask *cache_cpumask,
+ const struct cpumask *tlb_cpumask,
+ HV_Remote_ASID *asids,
+ int asidcount);
+
+#endif /* MM_MIGRATE_H */
diff --git a/arch/tile/mm/migrate_32.S b/arch/tile/mm/migrate_32.S
new file mode 100644
index 0000000..f738765
--- /dev/null
+++ b/arch/tile/mm/migrate_32.S
@@ -0,0 +1,211 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ *
+ * This routine is a helper for migrating the home of a set of pages to
+ * a new cpu. See the documentation in homecache.c for more information.
+ */
+
+#include <linux/linkage.h>
+#include <linux/threads.h>
+#include <asm/page.h>
+#include <asm/types.h>
+#include <asm/asm-offsets.h>
+#include <hv/hypervisor.h>
+
+ .text
+
+/*
+ * First, some definitions that apply to all the code in the file.
+ */
+
+/* Locals (caller-save) */
+#define r_tmp r10
+#define r_save_sp r11
+
+/* What we save where in the stack frame; must include all callee-saves. */
+#define FRAME_SP 4
+#define FRAME_R30 8
+#define FRAME_R31 12
+#define FRAME_R32 16
+#define FRAME_R33 20
+#define FRAME_R34 24
+#define FRAME_R35 28
+#define FRAME_SIZE 32
+
+
+
+
+/*
+ * On entry:
+ *
+ * r0 low word of the new context PA to install (moved to r_context_lo)
+ * r1 high word of the new context PA to install (moved to r_context_hi)
+ * r2 low word of PTE to use for context access (moved to r_access_lo)
+ * r3 high word of PTE to use for context access (moved to r_access_lo)
+ * r4 ASID to use for new context (moved to r_asid)
+ * r5 pointer to cpumask with just this cpu set in it (r_my_cpumask)
+ */
+
+/* Arguments (caller-save) */
+#define r_context_lo_in r0
+#define r_context_hi_in r1
+#define r_access_lo_in r2
+#define r_access_hi_in r3
+#define r_asid_in r4
+#define r_my_cpumask r5
+
+/* Locals (callee-save); must not be more than FRAME_xxx above. */
+#define r_save_ics r30
+#define r_context_lo r31
+#define r_context_hi r32
+#define r_access_lo r33
+#define r_access_hi r34
+#define r_asid r35
+
+STD_ENTRY(flush_and_install_context)
+ /*
+ * Create a stack frame; we can't touch it once we flush the
+ * cache until we install the new page table and flush the TLB.
+ */
+ {
+ move r_save_sp, sp
+ sw sp, lr
+ addi sp, sp, -FRAME_SIZE
+ }
+ addi r_tmp, sp, FRAME_SP
+ {
+ sw r_tmp, r_save_sp
+ addi r_tmp, sp, FRAME_R30
+ }
+ {
+ sw r_tmp, r30
+ addi r_tmp, sp, FRAME_R31
+ }
+ {
+ sw r_tmp, r31
+ addi r_tmp, sp, FRAME_R32
+ }
+ {
+ sw r_tmp, r32
+ addi r_tmp, sp, FRAME_R33
+ }
+ {
+ sw r_tmp, r33
+ addi r_tmp, sp, FRAME_R34
+ }
+ {
+ sw r_tmp, r34
+ addi r_tmp, sp, FRAME_R35
+ }
+ sw r_tmp, r35
+
+ /* Move some arguments to callee-save registers. */
+ {
+ move r_context_lo, r_context_lo_in
+ move r_context_hi, r_context_hi_in
+ }
+ {
+ move r_access_lo, r_access_lo_in
+ move r_access_hi, r_access_hi_in
+ }
+ move r_asid, r_asid_in
+
+ /* Disable interrupts, since we can't use our stack. */
+ {
+ mfspr r_save_ics, INTERRUPT_CRITICAL_SECTION
+ movei r_tmp, 1
+ }
+ mtspr INTERRUPT_CRITICAL_SECTION, r_tmp
+
+ /* First, flush our L2 cache. */
+ {
+ move r0, zero /* cache_pa */
+ move r1, zero
+ }
+ {
+ auli r2, zero, ha16(HV_FLUSH_EVICT_L2) /* cache_control */
+ move r3, r_my_cpumask /* cache_cpumask */
+ }
+ {
+ move r4, zero /* tlb_va */
+ move r5, zero /* tlb_length */
+ }
+ {
+ move r6, zero /* tlb_pgsize */
+ move r7, zero /* tlb_cpumask */
+ }
+ {
+ move r8, zero /* asids */
+ move r9, zero /* asidcount */
+ }
+ jal hv_flush_remote
+ bnz r0, .Ldone
+
+ /* Now install the new page table. */
+ {
+ move r0, r_context_lo
+ move r1, r_context_hi
+ }
+ {
+ move r2, r_access_lo
+ move r3, r_access_hi
+ }
+ {
+ move r4, r_asid
+ movei r5, HV_CTX_DIRECTIO
+ }
+ jal hv_install_context
+ bnz r0, .Ldone
+
+ /* Finally, flush the TLB. */
+ {
+ movei r0, 0 /* preserve_global */
+ jal hv_flush_all
+ }
+
+.Ldone:
+ /* Reset interrupts back how they were before. */
+ mtspr INTERRUPT_CRITICAL_SECTION, r_save_ics
+
+ /* Restore the callee-saved registers and return. */
+ addli lr, sp, FRAME_SIZE
+ {
+ lw lr, lr
+ addli r_tmp, sp, FRAME_R30
+ }
+ {
+ lw r30, r_tmp
+ addli r_tmp, sp, FRAME_R31
+ }
+ {
+ lw r31, r_tmp
+ addli r_tmp, sp, FRAME_R32
+ }
+ {
+ lw r32, r_tmp
+ addli r_tmp, sp, FRAME_R33
+ }
+ {
+ lw r33, r_tmp
+ addli r_tmp, sp, FRAME_R34
+ }
+ {
+ lw r34, r_tmp
+ addli r_tmp, sp, FRAME_R35
+ }
+ {
+ lw r35, r_tmp
+ addi sp, sp, FRAME_SIZE
+ }
+ jrp lr
+ STD_ENDPROC(flush_and_install_context)
diff --git a/arch/tile/mm/mmap.c b/arch/tile/mm/mmap.c
new file mode 100644
index 0000000..f96f4ce
--- /dev/null
+++ b/arch/tile/mm/mmap.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ *
+ * Taken from the i386 architecture and simplified.
+ */
+
+#include <linux/mm.h>
+#include <linux/random.h>
+#include <linux/limits.h>
+#include <linux/sched.h>
+#include <linux/mman.h>
+#include <linux/compat.h>
+
+/*
+ * Top of mmap area (just below the process stack).
+ *
+ * Leave an at least ~128 MB hole.
+ */
+#define MIN_GAP (128*1024*1024)
+#define MAX_GAP (TASK_SIZE/6*5)
+
+static inline unsigned long mmap_base(struct mm_struct *mm)
+{
+ unsigned long gap = rlimit(RLIMIT_STACK);
+ unsigned long random_factor = 0;
+
+ if (current->flags & PF_RANDOMIZE)
+ random_factor = get_random_int() % (1024*1024);
+
+ if (gap < MIN_GAP)
+ gap = MIN_GAP;
+ else if (gap > MAX_GAP)
+ gap = MAX_GAP;
+
+ return PAGE_ALIGN(TASK_SIZE - gap - random_factor);
+}
+
+/*
+ * This function, called very early during the creation of a new
+ * process VM image, sets up which VM layout function to use:
+ */
+void arch_pick_mmap_layout(struct mm_struct *mm)
+{
+#if !defined(__tilegx__)
+ int is_32bit = 1;
+#elif defined(CONFIG_COMPAT)
+ int is_32bit = is_compat_task();
+#else
+ int is_32bit = 0;
+#endif
+
+ /*
+ * Use standard layout if the expected stack growth is unlimited
+ * or we are running native 64 bits.
+ */
+ if (!is_32bit || rlimit(RLIMIT_STACK) == RLIM_INFINITY) {
+ mm->mmap_base = TASK_UNMAPPED_BASE;
+ mm->get_unmapped_area = arch_get_unmapped_area;
+ mm->unmap_area = arch_unmap_area;
+ } else {
+ mm->mmap_base = mmap_base(mm);
+ mm->get_unmapped_area = arch_get_unmapped_area_topdown;
+ mm->unmap_area = arch_unmap_area_topdown;
+ }
+}
diff --git a/arch/tile/mm/pgtable.c b/arch/tile/mm/pgtable.c
new file mode 100644
index 0000000..289e729
--- /dev/null
+++ b/arch/tile/mm/pgtable.c
@@ -0,0 +1,566 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/spinlock.h>
+#include <linux/cpumask.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/vmalloc.h>
+#include <linux/smp.h>
+
+#include <asm/system.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/fixmap.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/homecache.h>
+
+#define K(x) ((x) << (PAGE_SHIFT-10))
+
+/*
+ * The normal show_free_areas() is too verbose on Tile, with dozens
+ * of processors and often four NUMA zones each with high and lowmem.
+ */
+void show_mem(void)
+{
+ struct zone *zone;
+
+ printk("Active:%lu inactive:%lu dirty:%lu writeback:%lu unstable:%lu"
+ " free:%lu\n slab:%lu mapped:%lu pagetables:%lu bounce:%lu"
+ " pagecache:%lu swap:%lu\n",
+ (global_page_state(NR_ACTIVE_ANON) +
+ global_page_state(NR_ACTIVE_FILE)),
+ (global_page_state(NR_INACTIVE_ANON) +
+ global_page_state(NR_INACTIVE_FILE)),
+ global_page_state(NR_FILE_DIRTY),
+ global_page_state(NR_WRITEBACK),
+ global_page_state(NR_UNSTABLE_NFS),
+ global_page_state(NR_FREE_PAGES),
+ (global_page_state(NR_SLAB_RECLAIMABLE) +
+ global_page_state(NR_SLAB_UNRECLAIMABLE)),
+ global_page_state(NR_FILE_MAPPED),
+ global_page_state(NR_PAGETABLE),
+ global_page_state(NR_BOUNCE),
+ global_page_state(NR_FILE_PAGES),
+ nr_swap_pages);
+
+ for_each_zone(zone) {
+ unsigned long flags, order, total = 0, largest_order = -1;
+
+ if (!populated_zone(zone))
+ continue;
+
+ printk("Node %d %7s: ", zone_to_nid(zone), zone->name);
+ spin_lock_irqsave(&zone->lock, flags);
+ for (order = 0; order < MAX_ORDER; order++) {
+ int nr = zone->free_area[order].nr_free;
+ total += nr << order;
+ if (nr)
+ largest_order = order;
+ }
+ spin_unlock_irqrestore(&zone->lock, flags);
+ printk("%lukB (largest %luKb)\n",
+ K(total), largest_order ? K(1UL) << largest_order : 0);
+ }
+}
+
+/*
+ * Associate a virtual page frame with a given physical page frame
+ * and protection flags for that frame.
+ */
+static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ pgd = swapper_pg_dir + pgd_index(vaddr);
+ if (pgd_none(*pgd)) {
+ BUG();
+ return;
+ }
+ pud = pud_offset(pgd, vaddr);
+ if (pud_none(*pud)) {
+ BUG();
+ return;
+ }
+ pmd = pmd_offset(pud, vaddr);
+ if (pmd_none(*pmd)) {
+ BUG();
+ return;
+ }
+ pte = pte_offset_kernel(pmd, vaddr);
+ /* <pfn,flags> stored as-is, to permit clearing entries */
+ set_pte(pte, pfn_pte(pfn, flags));
+
+ /*
+ * It's enough to flush this one mapping.
+ * This appears conservative since it is only called
+ * from __set_fixmap.
+ */
+ local_flush_tlb_page(NULL, vaddr, PAGE_SIZE);
+}
+
+/*
+ * Associate a huge virtual page frame with a given physical page frame
+ * and protection flags for that frame. pfn is for the base of the page,
+ * vaddr is what the page gets mapped to - both must be properly aligned.
+ * The pmd must already be instantiated.
+ */
+void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */
+ printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
+ return; /* BUG(); */
+ }
+ if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */
+ printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
+ return; /* BUG(); */
+ }
+ pgd = swapper_pg_dir + pgd_index(vaddr);
+ if (pgd_none(*pgd)) {
+ printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
+ return; /* BUG(); */
+ }
+ pud = pud_offset(pgd, vaddr);
+ pmd = pmd_offset(pud, vaddr);
+ set_pmd(pmd, ptfn_pmd(HV_PFN_TO_PTFN(pfn), flags));
+ /*
+ * It's enough to flush this one mapping.
+ * We flush both small and huge TSBs to be sure.
+ */
+ local_flush_tlb_page(NULL, vaddr, HPAGE_SIZE);
+ local_flush_tlb_pages(NULL, vaddr, PAGE_SIZE, HPAGE_SIZE);
+}
+
+void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
+{
+ unsigned long address = __fix_to_virt(idx);
+
+ if (idx >= __end_of_fixed_addresses) {
+ BUG();
+ return;
+ }
+ set_pte_pfn(address, phys >> PAGE_SHIFT, flags);
+}
+
+#if defined(CONFIG_HIGHPTE)
+pte_t *_pte_offset_map(pmd_t *dir, unsigned long address, enum km_type type)
+{
+ pte_t *pte = kmap_atomic(pmd_page(*dir), type) +
+ (pmd_ptfn(*dir) << HV_LOG2_PAGE_TABLE_ALIGN) & ~PAGE_MASK;
+ return &pte[pte_index(address)];
+}
+#endif
+
+/*
+ * List of all pgd's needed so it can invalidate entries in both cached
+ * and uncached pgd's. This is essentially codepath-based locking
+ * against pageattr.c; it is the unique case in which a valid change
+ * of kernel pagetables can't be lazily synchronized by vmalloc faults.
+ * vmalloc faults work because attached pagetables are never freed.
+ * The locking scheme was chosen on the basis of manfred's
+ * recommendations and having no core impact whatsoever.
+ * -- wli
+ */
+DEFINE_SPINLOCK(pgd_lock);
+LIST_HEAD(pgd_list);
+
+static inline void pgd_list_add(pgd_t *pgd)
+{
+ list_add(pgd_to_list(pgd), &pgd_list);
+}
+
+static inline void pgd_list_del(pgd_t *pgd)
+{
+ list_del(pgd_to_list(pgd));
+}
+
+#define KERNEL_PGD_INDEX_START pgd_index(PAGE_OFFSET)
+#define KERNEL_PGD_PTRS (PTRS_PER_PGD - KERNEL_PGD_INDEX_START)
+
+static void pgd_ctor(pgd_t *pgd)
+{
+ unsigned long flags;
+
+ memset(pgd, 0, KERNEL_PGD_INDEX_START*sizeof(pgd_t));
+ spin_lock_irqsave(&pgd_lock, flags);
+
+#ifndef __tilegx__
+ /*
+ * Check that the user interrupt vector has no L2.
+ * It never should for the swapper, and new page tables
+ * should always start with an empty user interrupt vector.
+ */
+ BUG_ON(((u64 *)swapper_pg_dir)[pgd_index(MEM_USER_INTRPT)] != 0);
+#endif
+
+ clone_pgd_range(pgd + KERNEL_PGD_INDEX_START,
+ swapper_pg_dir + KERNEL_PGD_INDEX_START,
+ KERNEL_PGD_PTRS);
+
+ pgd_list_add(pgd);
+ spin_unlock_irqrestore(&pgd_lock, flags);
+}
+
+static void pgd_dtor(pgd_t *pgd)
+{
+ unsigned long flags; /* can be called from interrupt context */
+
+ spin_lock_irqsave(&pgd_lock, flags);
+ pgd_list_del(pgd);
+ spin_unlock_irqrestore(&pgd_lock, flags);
+}
+
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+ pgd_t *pgd = kmem_cache_alloc(pgd_cache, GFP_KERNEL);
+ if (pgd)
+ pgd_ctor(pgd);
+ return pgd;
+}
+
+void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+ pgd_dtor(pgd);
+ kmem_cache_free(pgd_cache, pgd);
+}
+
+
+#define L2_USER_PGTABLE_PAGES (1 << L2_USER_PGTABLE_ORDER)
+
+struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+ int flags = GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO|__GFP_COMP;
+ struct page *p;
+
+#ifdef CONFIG_HIGHPTE
+ flags |= __GFP_HIGHMEM;
+#endif
+
+ p = alloc_pages(flags, L2_USER_PGTABLE_ORDER);
+ if (p == NULL)
+ return NULL;
+
+ pgtable_page_ctor(p);
+ return p;
+}
+
+/*
+ * Free page immediately (used in __pte_alloc if we raced with another
+ * process). We have to correct whatever pte_alloc_one() did before
+ * returning the pages to the allocator.
+ */
+void pte_free(struct mm_struct *mm, struct page *p)
+{
+ pgtable_page_dtor(p);
+ __free_pages(p, L2_USER_PGTABLE_ORDER);
+}
+
+void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte,
+ unsigned long address)
+{
+ int i;
+
+ pgtable_page_dtor(pte);
+ tlb->need_flush = 1;
+ if (tlb_fast_mode(tlb)) {
+ struct page *pte_pages[L2_USER_PGTABLE_PAGES];
+ for (i = 0; i < L2_USER_PGTABLE_PAGES; ++i)
+ pte_pages[i] = pte + i;
+ free_pages_and_swap_cache(pte_pages, L2_USER_PGTABLE_PAGES);
+ return;
+ }
+ for (i = 0; i < L2_USER_PGTABLE_PAGES; ++i) {
+ tlb->pages[tlb->nr++] = pte + i;
+ if (tlb->nr >= FREE_PTE_NR)
+ tlb_flush_mmu(tlb, 0, 0);
+ }
+}
+
+#ifndef __tilegx__
+
+/*
+ * FIXME: needs to be atomic vs hypervisor writes. For now we make the
+ * window of vulnerability a bit smaller by doing an unlocked 8-bit update.
+ */
+int ptep_test_and_clear_young(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep)
+{
+#if HV_PTE_INDEX_ACCESSED < 8 || HV_PTE_INDEX_ACCESSED >= 16
+# error Code assumes HV_PTE "accessed" bit in second byte
+#endif
+ u8 *tmp = (u8 *)ptep;
+ u8 second_byte = tmp[1];
+ if (!(second_byte & (1 << (HV_PTE_INDEX_ACCESSED - 8))))
+ return 0;
+ tmp[1] = second_byte & ~(1 << (HV_PTE_INDEX_ACCESSED - 8));
+ return 1;
+}
+
+/*
+ * This implementation is atomic vs hypervisor writes, since the hypervisor
+ * always writes the low word (where "accessed" and "dirty" are) and this
+ * routine only writes the high word.
+ */
+void ptep_set_wrprotect(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+#if HV_PTE_INDEX_WRITABLE < 32
+# error Code assumes HV_PTE "writable" bit in high word
+#endif
+ u32 *tmp = (u32 *)ptep;
+ tmp[1] = tmp[1] & ~(1 << (HV_PTE_INDEX_WRITABLE - 32));
+}
+
+#endif
+
+pte_t *virt_to_pte(struct mm_struct* mm, unsigned long addr)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ if (pgd_addr_invalid(addr))
+ return NULL;
+
+ pgd = mm ? pgd_offset(mm, addr) : swapper_pg_dir + pgd_index(addr);
+ pud = pud_offset(pgd, addr);
+ if (!pud_present(*pud))
+ return NULL;
+ pmd = pmd_offset(pud, addr);
+ if (pmd_huge_page(*pmd))
+ return (pte_t *)pmd;
+ if (!pmd_present(*pmd))
+ return NULL;
+ return pte_offset_kernel(pmd, addr);
+}
+
+pgprot_t set_remote_cache_cpu(pgprot_t prot, int cpu)
+{
+ unsigned int width = smp_width;
+ int x = cpu % width;
+ int y = cpu / width;
+ BUG_ON(y >= smp_height);
+ BUG_ON(hv_pte_get_mode(prot) != HV_PTE_MODE_CACHE_TILE_L3);
+ BUG_ON(cpu < 0 || cpu >= NR_CPUS);
+ BUG_ON(!cpu_is_valid_lotar(cpu));
+ return hv_pte_set_lotar(prot, HV_XY_TO_LOTAR(x, y));
+}
+
+int get_remote_cache_cpu(pgprot_t prot)
+{
+ HV_LOTAR lotar = hv_pte_get_lotar(prot);
+ int x = HV_LOTAR_X(lotar);
+ int y = HV_LOTAR_Y(lotar);
+ BUG_ON(hv_pte_get_mode(prot) != HV_PTE_MODE_CACHE_TILE_L3);
+ return x + y * smp_width;
+}
+
+void set_pte_order(pte_t *ptep, pte_t pte, int order)
+{
+ unsigned long pfn = pte_pfn(pte);
+ struct page *page = pfn_to_page(pfn);
+
+ /* Update the home of a PTE if necessary */
+ pte = pte_set_home(pte, page_home(page));
+
+#ifdef __tilegx__
+ *ptep = pte;
+#else
+ /*
+ * When setting a PTE, write the high bits first, then write
+ * the low bits. This sets the "present" bit only after the
+ * other bits are in place. If a particular PTE update
+ * involves transitioning from one valid PTE to another, it
+ * may be necessary to call set_pte_order() more than once,
+ * transitioning via a suitable intermediate state.
+ * Note that this sequence also means that if we are transitioning
+ * from any migrating PTE to a non-migrating one, we will not
+ * see a half-updated PTE with the migrating bit off.
+ */
+#if HV_PTE_INDEX_PRESENT >= 32 || HV_PTE_INDEX_MIGRATING >= 32
+# error Must write the present and migrating bits last
+#endif
+ ((u32 *)ptep)[1] = (u32)(pte_val(pte) >> 32);
+ barrier();
+ ((u32 *)ptep)[0] = (u32)(pte_val(pte));
+#endif
+}
+
+/* Can this mm load a PTE with cached_priority set? */
+static inline int mm_is_priority_cached(struct mm_struct *mm)
+{
+ return mm->context.priority_cached;
+}
+
+/*
+ * Add a priority mapping to an mm_context and
+ * notify the hypervisor if this is the first one.
+ */
+void start_mm_caching(struct mm_struct *mm)
+{
+ if (!mm_is_priority_cached(mm)) {
+ mm->context.priority_cached = -1U;
+ hv_set_caching(-1U);
+ }
+}
+
+/*
+ * Validate and return the priority_cached flag. We know if it's zero
+ * that we don't need to scan, since we immediately set it non-zero
+ * when we first consider a MAP_CACHE_PRIORITY mapping.
+ *
+ * We only _try_ to acquire the mmap_sem semaphore; if we can't acquire it,
+ * since we're in an interrupt context (servicing switch_mm) we don't
+ * worry about it and don't unset the "priority_cached" field.
+ * Presumably we'll come back later and have more luck and clear
+ * the value then; for now we'll just keep the cache marked for priority.
+ */
+static unsigned int update_priority_cached(struct mm_struct *mm)
+{
+ if (mm->context.priority_cached && down_write_trylock(&mm->mmap_sem)) {
+ struct vm_area_struct *vm;
+ for (vm = mm->mmap; vm; vm = vm->vm_next) {
+ if (hv_pte_get_cached_priority(vm->vm_page_prot))
+ break;
+ }
+ if (vm == NULL)
+ mm->context.priority_cached = 0;
+ up_write(&mm->mmap_sem);
+ }
+ return mm->context.priority_cached;
+}
+
+/* Set caching correctly for an mm that we are switching to. */
+void check_mm_caching(struct mm_struct *prev, struct mm_struct *next)
+{
+ if (!mm_is_priority_cached(next)) {
+ /*
+ * If the new mm doesn't use priority caching, just see if we
+ * need the hv_set_caching(), or can assume it's already zero.
+ */
+ if (mm_is_priority_cached(prev))
+ hv_set_caching(0);
+ } else {
+ hv_set_caching(update_priority_cached(next));
+ }
+}
+
+#if CHIP_HAS_MMIO()
+
+/* Map an arbitrary MMIO address, homed according to pgprot, into VA space. */
+void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
+ pgprot_t home)
+{
+ void *addr;
+ struct vm_struct *area;
+ unsigned long offset, last_addr;
+ pgprot_t pgprot;
+
+ /* Don't allow wraparound or zero size */
+ last_addr = phys_addr + size - 1;
+ if (!size || last_addr < phys_addr)
+ return NULL;
+
+ /* Create a read/write, MMIO VA mapping homed at the requested shim. */
+ pgprot = PAGE_KERNEL;
+ pgprot = hv_pte_set_mode(pgprot, HV_PTE_MODE_MMIO);
+ pgprot = hv_pte_set_lotar(pgprot, hv_pte_get_lotar(home));
+
+ /*
+ * Mappings have to be page-aligned
+ */
+ offset = phys_addr & ~PAGE_MASK;
+ phys_addr &= PAGE_MASK;
+ size = PAGE_ALIGN(last_addr+1) - phys_addr;
+
+ /*
+ * Ok, go for it..
+ */
+ area = get_vm_area(size, VM_IOREMAP /* | other flags? */);
+ if (!area)
+ return NULL;
+ area->phys_addr = phys_addr;
+ addr = area->addr;
+ if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
+ phys_addr, pgprot)) {
+ remove_vm_area((void *)(PAGE_MASK & (unsigned long) addr));
+ return NULL;
+ }
+ return (__force void __iomem *) (offset + (char *)addr);
+}
+EXPORT_SYMBOL(ioremap_prot);
+
+/* Map a PCI MMIO bus address into VA space. */
+void __iomem *ioremap(resource_size_t phys_addr, unsigned long size)
+{
+ panic("ioremap for PCI MMIO is not supported");
+}
+EXPORT_SYMBOL(ioremap);
+
+/* Unmap an MMIO VA mapping. */
+void iounmap(volatile void __iomem *addr_in)
+{
+ volatile void __iomem *addr = (volatile void __iomem *)
+ (PAGE_MASK & (unsigned long __force)addr_in);
+#if 1
+ vunmap((void * __force)addr);
+#else
+ /* x86 uses this complicated flow instead of vunmap(). Is
+ * there any particular reason we should do the same? */
+ struct vm_struct *p, *o;
+
+ /* Use the vm area unlocked, assuming the caller
+ ensures there isn't another iounmap for the same address
+ in parallel. Reuse of the virtual address is prevented by
+ leaving it in the global lists until we're done with it.
+ cpa takes care of the direct mappings. */
+ read_lock(&vmlist_lock);
+ for (p = vmlist; p; p = p->next) {
+ if (p->addr == addr)
+ break;
+ }
+ read_unlock(&vmlist_lock);
+
+ if (!p) {
+ printk("iounmap: bad address %p\n", addr);
+ dump_stack();
+ return;
+ }
+
+ /* Finally remove it */
+ o = remove_vm_area((void *)addr);
+ BUG_ON(p != o || o == NULL);
+ kfree(p);
+#endif
+}
+EXPORT_SYMBOL(iounmap);
+
+#endif /* CHIP_HAS_MMIO() */
--
1.6.5.2
--
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