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powerpc32: Use kmem_cache memory for PGDIR

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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: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>
This commit is contained in:
LEROY Christophe 2015-01-20 10:57:34 +01:00 committed by Scott Wood
parent 5ddb75cee5
commit ce67f5d0a0
2 changed files with 18 additions and 2 deletions
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4
arch/powerpc/include/asm/pgtable-ppc32.h
View file

@ -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);

16
arch/powerpc/mm/pgtable_32.c
View file

@ -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