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Commit ce67f5d0 authored by LEROY Christophe's avatar LEROY Christophe Committed by Scott Wood
Browse files

powerpc32: Use kmem_cache memory for PGDIR 



When pages are not 4K, PGDIR table is allocated with kmalloc(). In order to
optimise TLB handlers, aligned memory is needed. kmalloc() doesn't provide
aligned memory blocks, so lets use a kmem_cache pool instead.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
parent 5ddb75ce

arch/powerpc/include/asm/pgtable-ppc32.h

+4 −0
Original line number Diff line number Diff line
@@ -347,10 +347,14 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry) 
#define pte_to_pgoff(pte)	(pte_val(pte) >> 3)

#define pgoff_to_pte(off)	((pte_t) { ((off) << 3) | _PAGE_FILE })



#ifndef CONFIG_PPC_4K_PAGES

void pgtable_cache_init(void);

#else

/*

 * No page table caches to initialise

 */

#define pgtable_cache_init()	do { } while (0)

#endif



extern int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep,

		      pmd_t **pmdp);

arch/powerpc/mm/pgtable_32.c

+14 −2
Original line number Diff line number Diff line
@@ -72,13 +72,25 @@ extern unsigned long p_mapped_by_tlbcam(phys_addr_t pa); 


#define PGDIR_ORDER	(32 + PGD_T_LOG2 - PGDIR_SHIFT)



#ifndef CONFIG_PPC_4K_PAGES

static struct kmem_cache *pgtable_cache;



void pgtable_cache_init(void)

{

	pgtable_cache = kmem_cache_create("PGDIR cache", 1 << PGDIR_ORDER,

					  1 << PGDIR_ORDER, 0, NULL);

	if (pgtable_cache == NULL)

		panic("Couldn't allocate pgtable caches");

}

#endif



pgd_t *pgd_alloc(struct mm_struct *mm)

{

	pgd_t *ret;



	/* pgdir take page or two with 4K pages and a page fraction otherwise */

#ifndef CONFIG_PPC_4K_PAGES

	ret = kzalloc(1 << PGDIR_ORDER, GFP_KERNEL);

	ret = kmem_cache_alloc(pgtable_cache, GFP_KERNEL | __GFP_ZERO);

#else

	ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,

			PGDIR_ORDER - PAGE_SHIFT);
@@ -89,7 +101,7 @@ pgd_t *pgd_alloc(struct mm_struct *mm) 
void pgd_free(struct mm_struct *mm, pgd_t *pgd)

{

#ifndef CONFIG_PPC_4K_PAGES

	kfree((void *)pgd);

	kmem_cache_free(pgtable_cache, (void *)pgd);

#else

	free_pages((unsigned long)pgd, PGDIR_ORDER - PAGE_SHIFT);

#endif