Commit 85958b46 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Ingo Molnar
Browse files

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: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 68db065c

arch/x86/mm/pgtable.c

+13 −46
Original line number Diff line number Diff line
@@ -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,

include/asm-x86/pgtable.h

+16 −0
Original line number Diff line number Diff line
@@ -438,6 +438,22 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, 
	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__ */

include/asm-x86/pgtable_32.h

+0 −15
Original line number Diff line number Diff line
@@ -105,21 +105,6 @@ extern int pmd_bad(pmd_t pmd); 
# 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 it, this is a no-op.

include/asm-x86/pgtable_64.h

+1 −1
Original line number Diff line number Diff line
@@ -24,7 +24,7 @@ extern void paging_init(void); 


#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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