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Date: Mon, 17 Mar 2008 16:37:14 -0700
From: Jeremy Fitzhardinge <jeremy@...p.org>
To: Ingo Molnar <mingo@...e.hu>
Cc: LKML <linux-kernel@...r.kernel.org>,
Ian Campbell <ijc@...lion.org.uk>, Andi Kleen <ak@...e.de>
Subject: [PATCH 23 of 31] x86: unify pgd ctor/dtor
All pagetables need fundamentally the same setup and destruction, so
just use the same code for everything.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@...rix.com>
Cc: Andi Kleen <ak@...e.de>
---
arch/x86/mm/pgtable.c | 59 +++++++++---------------------------------
include/asm-x86/pgtable.h | 16 +++++++++++
include/asm-x86/pgtable_32.h | 15 ----------
include/asm-x86/pgtable_64.h | 2 -
4 files changed, 30 insertions(+), 62 deletions(-)
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -59,50 +59,6 @@
list_del(&page->lru);
}
-#ifdef CONFIG_X86_64
-pgd_t *pgd_alloc(struct mm_struct *mm)
-{
- unsigned boundary;
- pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
- unsigned long flags;
- if (!pgd)
- return NULL;
- spin_lock_irqsave(&pgd_lock, flags);
- pgd_list_add(pgd);
- spin_unlock_irqrestore(&pgd_lock, flags);
- /*
- * Copy kernel pointers in from init.
- * Could keep a freelist or slab cache of those because the kernel
- * part never changes.
- */
- boundary = pgd_index(__PAGE_OFFSET);
- memset(pgd, 0, boundary * sizeof(pgd_t));
- memcpy(pgd + boundary,
- init_level4_pgt + boundary,
- (PTRS_PER_PGD - boundary) * sizeof(pgd_t));
- return pgd;
-}
-
-void pgd_free(struct mm_struct *mm, pgd_t *pgd)
-{
- unsigned long flags;
- BUG_ON((unsigned long)pgd & (PAGE_SIZE-1));
- spin_lock_irqsave(&pgd_lock, flags);
- pgd_list_del(pgd);
- spin_unlock_irqrestore(&pgd_lock, flags);
- free_page((unsigned long)pgd);
-}
-#else
-/*
- * List of all pgd's needed for non-PAE so it can invalidate entries
- * in both cached and uncached pgd's; not needed for PAE since the
- * kernel pmd is shared. If PAE were not to share the pmd a similar
- * tactic would be needed. 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.
- * -- wli
- */
#define UNSHARED_PTRS_PER_PGD \
(SHARED_KERNEL_PMD ? KERNEL_PGD_BOUNDARY : PTRS_PER_PGD)
@@ -120,7 +76,8 @@
ptes in non-PAE, or shared PMD in PAE), then just copy the
references from swapper_pg_dir. */
if (PAGETABLE_LEVELS == 2 ||
- (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD)) {
+ (PAGETABLE_LEVELS == 3 && SHARED_KERNEL_PMD) ||
+ PAGETABLE_LEVELS == 4) {
clone_pgd_range(pgd + KERNEL_PGD_BOUNDARY,
swapper_pg_dir + KERNEL_PGD_BOUNDARY,
KERNEL_PGD_PTRS);
@@ -148,6 +105,17 @@
pgd_list_del(pgd);
spin_unlock_irqrestore(&pgd_lock, flags);
}
+
+/*
+ * List of all pgd's needed for non-PAE so it can invalidate entries
+ * in both cached and uncached pgd's; not needed for PAE since the
+ * kernel pmd is shared. If PAE were not to share the pmd a similar
+ * tactic would be needed. 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.
+ * -- wli
+ */
#ifdef CONFIG_X86_PAE
/*
@@ -246,7 +214,6 @@
pgd_dtor(pgd);
free_page((unsigned long)pgd);
}
-#endif
int ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep,
diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h
--- a/include/asm-x86/pgtable.h
+++ b/include/asm-x86/pgtable.h
@@ -344,6 +344,22 @@
pte_update(mm, addr, ptep);
}
+/*
+ * clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
+ *
+ * dst - pointer to pgd range anwhere on a pgd page
+ * src - ""
+ * count - the number of pgds to copy.
+ *
+ * dst and src can be on the same page, but the range must not overlap,
+ * and must not cross a page boundary.
+ */
+static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count)
+{
+ memcpy(dst, src, count * sizeof(pgd_t));
+}
+
+
#include <asm-generic/pgtable.h>
#endif /* __ASSEMBLY__ */
diff --git a/include/asm-x86/pgtable_32.h b/include/asm-x86/pgtable_32.h
--- a/include/asm-x86/pgtable_32.h
+++ b/include/asm-x86/pgtable_32.h
@@ -104,21 +104,6 @@
#else
# include <asm/pgtable-2level.h>
#endif
-
-/*
- * clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
- *
- * dst - pointer to pgd range anwhere on a pgd page
- * src - ""
- * count - the number of pgds to copy.
- *
- * dst and src can be on the same page, but the range must not overlap,
- * and must not cross a page boundary.
- */
-static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count)
-{
- memcpy(dst, src, count * sizeof(pgd_t));
-}
/*
* Macro to mark a page protection value as "uncacheable". On processors which do not support
diff --git a/include/asm-x86/pgtable_64.h b/include/asm-x86/pgtable_64.h
--- a/include/asm-x86/pgtable_64.h
+++ b/include/asm-x86/pgtable_64.h
@@ -24,7 +24,7 @@
#endif /* !__ASSEMBLY__ */
-#define SHARED_KERNEL_PMD 1
+#define SHARED_KERNEL_PMD 0
/*
* PGDIR_SHIFT determines what a top-level page table entry can map
--
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