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Date: Fri, 16 Feb 2018 02:54:33 -0800
From: "tip-bot for Kirill A. Shutemov" <tipbot@...or.com>
To: linux-tip-commits@...r.kernel.org
Cc: bp@...e.de, hpa@...or.com, tglx@...utronix.de, jpoimboe@...hat.com,
peterz@...radead.org, kirill.shutemov@...ux.intel.com,
linux-kernel@...r.kernel.org, dave.hansen@...ux.intel.com,
dwmw2@...radead.org, arjan@...ux.intel.com,
dan.j.williams@...el.com, torvalds@...ux-foundation.org,
mingo@...nel.org, luto@...nel.org
Subject: [tip:x86/mm] x86/mm: Support boot-time switching of paging modes in
the early boot code
Commit-ID: 6f9dd329717f696f578347c0781a0247db957596
Gitweb: https://git.kernel.org/tip/6f9dd329717f696f578347c0781a0247db957596
Author: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
AuthorDate: Wed, 14 Feb 2018 21:25:39 +0300
Committer: Ingo Molnar <mingo@...nel.org>
CommitDate: Fri, 16 Feb 2018 10:48:48 +0100
x86/mm: Support boot-time switching of paging modes in the early boot code
Early boot code should be able to initialize page tables for both 4- and
5-level paging modes.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Arjan van de Ven <arjan@...ux.intel.com>
Cc: Borislav Petkov <bp@...e.de>
Cc: Dan Williams <dan.j.williams@...el.com>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: David Woodhouse <dwmw2@...radead.org>
Cc: Josh Poimboeuf <jpoimboe@...hat.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: linux-mm@...ck.org
Link: http://lkml.kernel.org/r/20180214182542.69302-7-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
arch/x86/kernel/head64.c | 33 ++++++++++++++++++++++-----------
arch/x86/kernel/head_64.S | 10 ++++------
2 files changed, 26 insertions(+), 17 deletions(-)
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 795e762..8161e71 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -75,13 +75,13 @@ static unsigned int __head *fixup_int(void *ptr, unsigned long physaddr)
return fixup_pointer(ptr, physaddr);
}
-static void __head check_la57_support(unsigned long physaddr)
+static bool __head check_la57_support(unsigned long physaddr)
{
if (native_cpuid_eax(0) < 7)
- return;
+ return false;
if (!(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31))))
- return;
+ return false;
*fixup_int(&pgtable_l5_enabled, physaddr) = 1;
*fixup_int(&pgdir_shift, physaddr) = 48;
@@ -89,24 +89,30 @@ static void __head check_la57_support(unsigned long physaddr)
*fixup_long(&page_offset_base, physaddr) = __PAGE_OFFSET_BASE_L5;
*fixup_long(&vmalloc_base, physaddr) = __VMALLOC_BASE_L5;
*fixup_long(&vmemmap_base, physaddr) = __VMEMMAP_BASE_L5;
+
+ return true;
}
#else
-static void __head check_la57_support(unsigned long physaddr) {}
+static bool __head check_la57_support(unsigned long physaddr)
+{
+ return false;
+}
#endif
unsigned long __head __startup_64(unsigned long physaddr,
struct boot_params *bp)
{
- unsigned long load_delta;
+ unsigned long load_delta, *p;
unsigned long pgtable_flags;
pgdval_t *pgd;
p4dval_t *p4d;
pudval_t *pud;
pmdval_t *pmd, pmd_entry;
+ bool la57;
int i;
unsigned int *next_pgt_ptr;
- check_la57_support(physaddr);
+ la57 = check_la57_support(physaddr);
/* Is the address too large? */
if (physaddr >> MAX_PHYSMEM_BITS)
@@ -131,9 +137,14 @@ unsigned long __head __startup_64(unsigned long physaddr,
/* Fixup the physical addresses in the page table */
pgd = fixup_pointer(&early_top_pgt, physaddr);
- pgd[pgd_index(__START_KERNEL_map)] += load_delta;
-
- if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+ p = pgd + pgd_index(__START_KERNEL_map);
+ if (la57)
+ *p = (unsigned long)level4_kernel_pgt;
+ else
+ *p = (unsigned long)level3_kernel_pgt;
+ *p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
+
+ if (la57) {
p4d = fixup_pointer(&level4_kernel_pgt, physaddr);
p4d[511] += load_delta;
}
@@ -158,7 +169,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
pgtable_flags = _KERNPG_TABLE_NOENC + sme_get_me_mask();
- if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+ if (la57) {
p4d = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr);
i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
@@ -255,7 +266,7 @@ again:
* critical -- __PAGE_OFFSET would point us back into the dynamic
* range and we might end up looping forever...
*/
- if (!IS_ENABLED(CONFIG_X86_5LEVEL))
+ if (!pgtable_l5_enabled)
p4d_p = pgd_p;
else if (pgd)
p4d_p = (p4dval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index d3f8b43..145d7b9 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -124,7 +124,10 @@ ENTRY(secondary_startup_64)
/* Enable PAE mode, PGE and LA57 */
movl $(X86_CR4_PAE | X86_CR4_PGE), %ecx
#ifdef CONFIG_X86_5LEVEL
+ testl $1, pgtable_l5_enabled(%rip)
+ jz 1f
orl $X86_CR4_LA57, %ecx
+1:
#endif
movq %rcx, %cr4
@@ -372,12 +375,7 @@ GLOBAL(name)
__INITDATA
NEXT_PGD_PAGE(early_top_pgt)
- .fill 511,8,0
-#ifdef CONFIG_X86_5LEVEL
- .quad level4_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
-#else
- .quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
-#endif
+ .fill 512,8,0
.fill PTI_USER_PGD_FILL,8,0
NEXT_PAGE(early_dynamic_pgts)
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