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x86: unify pgd ctor/dtor

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All pagetables need fundamentally the same setup and destruction, so
just use the same code for everything.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Jeremy Fitzhardinge
2008-03-17 16:37:14 -07:00
committed by Ingo Molnar
parent 68db065c84
commit 85958b465c
4 changed files with 30 additions and 62 deletions
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59
arch/x86/mm/pgtable.c
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@ -59,50 +59,6 @@ static inline void pgd_list_del(pgd_t *pgd)
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 @@ static void pgd_ctor(void *p)
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);
@ -149,6 +106,17 @@ static void pgd_dtor(void *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
/*
* Mop up any pmd pages which may still be attached to the pgd.
@ -264,7 +232,6 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd)
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,