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powerpc: New hugepage directory format

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Change the hugepage directory format so that we can have leaf ptes directly
at page directory avoiding the allocation of hugepage directory.

With the new table format we have 3 cases for pgds and pmds:
(1) invalid (all zeroes)
(2) pointer to next table, as normal; bottom 6 bits == 0
(4) hugepd pointer, bottom two bits == 00, next 4 bits indicate size of table

Instead of storing shift value in hugepd pointer we use mmu_psize_def index
so that we can fit all the supported hugepage size in 4 bits

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Aneesh Kumar K.V
2013-04-28 09:37:29 +00:00
committed by Benjamin Herrenschmidt
parent 0e5f35d0e4
commit cf9427b85e
6 changed files with 75 additions and 22 deletions
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26
arch/powerpc/mm/hugetlbpage.c
View File

@@ -48,23 +48,6 @@ static u64 gpage_freearray[MAX_NUMBER_GPAGES];
static unsigned nr_gpages;
#endif
static inline int shift_to_mmu_psize(unsigned int shift)
{
int psize;
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize)
if (mmu_psize_defs[psize].shift == shift)
return psize;
return -1;
}
static inline unsigned int mmu_psize_to_shift(unsigned int mmu_psize)
{
if (mmu_psize_defs[mmu_psize].shift)
return mmu_psize_defs[mmu_psize].shift;
BUG();
}
#define hugepd_none(hpd) ((hpd).pd == 0)
pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift)
@@ -145,6 +128,7 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
if (unlikely(!hugepd_none(*hpdp)))
break;
else
/* We use the old format for PPC_FSL_BOOK3E */
hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift;
}
/* If we bailed from the for loop early, an error occurred, clean up */
@@ -156,8 +140,14 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
#else
if (!hugepd_none(*hpdp))
kmem_cache_free(cachep, new);
else
else {
#ifdef CONFIG_PPC_BOOK3S_64
hpdp->pd = (unsigned long)new |
(shift_to_mmu_psize(pshift) << 2);
#else
hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift;
#endif
}
#endif
spin_unlock(&mm->page_table_lock);
return 0;

3
arch/powerpc/mm/init_64.c
View File

@@ -129,8 +129,7 @@ void pgtable_cache_add(unsigned shift, void (*ctor)(void *))
align = max_t(unsigned long, align, minalign);
name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
new = kmem_cache_create(name, table_size, align, 0, ctor);
PGT_CACHE(shift) = new;
pgtable_cache[shift - 1] = new;
pr_debug("Allocated pgtable cache for order %d\n", shift);
}