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linux/arch/powerpc/include/asm/pgalloc.h
Benjamin Herrenschmidt af984b8165 powerpc/mm: Fix encoding of page table cache numbers
The mask used to encode the page table cache number in the
batch when freeing page tables was too small for the new
possible values of MMU page sizes. This increases it along
with a comment explaining the constraints.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-08-20 10:25:12 +10:00

76 lines
1.9 KiB
C

#ifndef _ASM_POWERPC_PGALLOC_H
#define _ASM_POWERPC_PGALLOC_H
#ifdef __KERNEL__
#include <linux/mm.h>
#ifdef CONFIG_PPC_BOOK3E
extern void tlb_flush_pgtable(struct mmu_gather *tlb, unsigned long address);
#else /* CONFIG_PPC_BOOK3E */
static inline void tlb_flush_pgtable(struct mmu_gather *tlb,
unsigned long address)
{
}
#endif /* !CONFIG_PPC_BOOK3E */
static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{
free_page((unsigned long)pte);
}
static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage)
{
pgtable_page_dtor(ptepage);
__free_page(ptepage);
}
typedef struct pgtable_free {
unsigned long val;
} pgtable_free_t;
/* This needs to be big enough to allow for MMU_PAGE_COUNT + 2 to be stored
* and small enough to fit in the low bits of any naturally aligned page
* table cache entry. Arbitrarily set to 0x1f, that should give us some
* room to grow
*/
#define PGF_CACHENUM_MASK 0x1f
static inline pgtable_free_t pgtable_free_cache(void *p, int cachenum,
unsigned long mask)
{
BUG_ON(cachenum > PGF_CACHENUM_MASK);
return (pgtable_free_t){.val = ((unsigned long) p & ~mask) | cachenum};
}
#ifdef CONFIG_PPC64
#include <asm/pgalloc-64.h>
#else
#include <asm/pgalloc-32.h>
#endif
#ifdef CONFIG_SMP
extern void pgtable_free_tlb(struct mmu_gather *tlb, pgtable_free_t pgf);
extern void pte_free_finish(void);
#else /* CONFIG_SMP */
static inline void pgtable_free_tlb(struct mmu_gather *tlb, pgtable_free_t pgf)
{
pgtable_free(pgf);
}
static inline void pte_free_finish(void) { }
#endif /* !CONFIG_SMP */
static inline void __pte_free_tlb(struct mmu_gather *tlb, struct page *ptepage,
unsigned long address)
{
pgtable_free_t pgf = pgtable_free_cache(page_address(ptepage),
PTE_NONCACHE_NUM,
PTE_TABLE_SIZE-1);
tlb_flush_pgtable(tlb, address);
pgtable_page_dtor(ptepage);
pgtable_free_tlb(tlb, pgf);
}
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_PGALLOC_H */