[PATCH v4 2/3] powerpc: get hugetlbpage handling more generic
From: Christophe Leroy
Date: Wed Dec 07 2016 - 02:47:43 EST
Today there are two implementations of hugetlbpages which are managed
by exclusive #ifdefs:
* FSL_BOOKE: several directory entries points to the same single hugepage
* BOOK3S: one upper level directory entry points to a table of hugepages
In preparation of implementation of hugepage support on the 8xx, we
need a mix of the two above solutions, because the 8xx needs both cases
depending on the size of pages:
* In 4k page size mode, each PGD entry covers a 4M bytes area. It means
that 2 PGD entries will be necessary to cover an 8M hugepage while a
single PGD entry will cover 8x 512k hugepages.
* In 16 page size mode, each PGD entry covers a 64M bytes area. It means
that 8x 8M hugepages will be covered by one PGD entry and 64x 512k
hugepages will be covers by one PGD entry.
This patch:
* removes #ifdefs in favor of if/else based on the range sizes
* merges the two huge_pte_alloc() functions as they are pretty similar
* merges the two hugetlbpage_init() functions as they are pretty similar
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> (v3)
---
v2: This part is new and results from a split of last patch of v1 serie in
two parts
v3:
- Only allocate hugepte_cache on FSL_BOOKE. Not needed on BOOK3S_64
- Removed the BUG in the unused hugepd_free(), made it
static inline {} instead.
v4:
- Fixing pdshift calculation on FSL_BOOK3E in hugetlbpage_init() by
using HUGEPD_PxD_SHIFT instead of PyD_SHIFT.
- Fixing default hugepage size selection on FSL_BOOK3E by spliting decision
based on #ifdefs in order to keep previous behaviour.
arch/powerpc/mm/hugetlbpage.c | 195 ++++++++++++++++++------------------------
1 file changed, 81 insertions(+), 114 deletions(-)
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index a5d3ecd..53245aa 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -64,14 +64,16 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
{
struct kmem_cache *cachep;
pte_t *new;
-
-#ifdef CONFIG_PPC_FSL_BOOK3E
int i;
- int num_hugepd = 1 << (pshift - pdshift);
- cachep = hugepte_cache;
-#else
- cachep = PGT_CACHE(pdshift - pshift);
-#endif
+ int num_hugepd;
+
+ if (pshift >= pdshift) {
+ cachep = hugepte_cache;
+ num_hugepd = 1 << (pshift - pdshift);
+ } else {
+ cachep = PGT_CACHE(pdshift - pshift);
+ num_hugepd = 1;
+ }
new = kmem_cache_zalloc(cachep, GFP_KERNEL);
@@ -89,7 +91,7 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
smp_wmb();
spin_lock(&mm->page_table_lock);
-#ifdef CONFIG_PPC_FSL_BOOK3E
+
/*
* We have multiple higher-level entries that point to the same
* actual pte location. Fill in each as we go and backtrack on error.
@@ -100,8 +102,13 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
if (unlikely(!hugepd_none(*hpdp)))
break;
else
+#ifdef CONFIG_PPC_BOOK3S_64
+ hpdp->pd = __pa(new) |
+ (shift_to_mmu_psize(pshift) << 2);
+#else
/* We use the old format for PPC_FSL_BOOK3E */
hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift;
+#endif
}
/* If we bailed from the for loop early, an error occurred, clean up */
if (i < num_hugepd) {
@@ -109,17 +116,6 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
hpdp->pd = 0;
kmem_cache_free(cachep, new);
}
-#else
- if (!hugepd_none(*hpdp))
- kmem_cache_free(cachep, new);
- else {
-#ifdef CONFIG_PPC_BOOK3S_64
- hpdp->pd = __pa(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;
}
@@ -136,7 +132,6 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
#define HUGEPD_PUD_SHIFT PMD_SHIFT
#endif
-#ifdef CONFIG_PPC_BOOK3S_64
/*
* At this point we do the placement change only for BOOK3S 64. This would
* possibly work on other subarchs.
@@ -153,6 +148,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz
addr &= ~(sz-1);
pg = pgd_offset(mm, addr);
+#ifdef CONFIG_PPC_BOOK3S_64
if (pshift == PGDIR_SHIFT)
/* 16GB huge page */
return (pte_t *) pg;
@@ -178,32 +174,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz
hpdp = (hugepd_t *)pm;
}
}
- if (!hpdp)
- return NULL;
-
- BUG_ON(!hugepd_none(*hpdp) && !hugepd_ok(*hpdp));
-
- if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr, pdshift, pshift))
- return NULL;
-
- return hugepte_offset(*hpdp, addr, pdshift);
-}
-
#else
-
-pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
-{
- pgd_t *pg;
- pud_t *pu;
- pmd_t *pm;
- hugepd_t *hpdp = NULL;
- unsigned pshift = __ffs(sz);
- unsigned pdshift = PGDIR_SHIFT;
-
- addr &= ~(sz-1);
-
- pg = pgd_offset(mm, addr);
-
if (pshift >= HUGEPD_PGD_SHIFT) {
hpdp = (hugepd_t *)pg;
} else {
@@ -217,7 +188,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz
hpdp = (hugepd_t *)pm;
}
}
-
+#endif
if (!hpdp)
return NULL;
@@ -228,7 +199,6 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz
return hugepte_offset(*hpdp, addr, pdshift);
}
-#endif
#ifdef CONFIG_PPC_FSL_BOOK3E
/* Build list of addresses of gigantic pages. This function is used in early
@@ -310,7 +280,11 @@ static int __init do_gpage_early_setup(char *param, char *val,
npages = 0;
if (npages > MAX_NUMBER_GPAGES) {
pr_warn("MMU: %lu pages requested for page "
+#ifdef CONFIG_PHYS_ADDR_T_64BIT
"size %llu KB, limiting to "
+#else
+ "size %u KB, limiting to "
+#endif
__stringify(MAX_NUMBER_GPAGES) "\n",
npages, size / 1024);
npages = MAX_NUMBER_GPAGES;
@@ -442,6 +416,8 @@ static void hugepd_free(struct mmu_gather *tlb, void *hugepte)
}
put_cpu_var(hugepd_freelist_cur);
}
+#else
+static inline void hugepd_free(struct mmu_gather *tlb, void *hugepte) {}
#endif
static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshift,
@@ -453,13 +429,11 @@ static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshif
unsigned long pdmask = ~((1UL << pdshift) - 1);
unsigned int num_hugepd = 1;
+ unsigned int shift = hugepd_shift(*hpdp);
-#ifdef CONFIG_PPC_FSL_BOOK3E
/* Note: On fsl the hpdp may be the first of several */
- num_hugepd = (1 << (hugepd_shift(*hpdp) - pdshift));
-#else
- unsigned int shift = hugepd_shift(*hpdp);
-#endif
+ if (shift > pdshift)
+ num_hugepd = 1 << (shift - pdshift);
start &= pdmask;
if (start < floor)
@@ -475,11 +449,10 @@ static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshif
for (i = 0; i < num_hugepd; i++, hpdp++)
hpdp->pd = 0;
-#ifdef CONFIG_PPC_FSL_BOOK3E
- hugepd_free(tlb, hugepte);
-#else
- pgtable_free_tlb(tlb, hugepte, pdshift - shift);
-#endif
+ if (shift >= pdshift)
+ hugepd_free(tlb, hugepte);
+ else
+ pgtable_free_tlb(tlb, hugepte, pdshift - shift);
}
static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
@@ -492,6 +465,8 @@ static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
start = addr;
do {
+ unsigned long more;
+
pmd = pmd_offset(pud, addr);
next = pmd_addr_end(addr, end);
if (!is_hugepd(__hugepd(pmd_val(*pmd)))) {
@@ -502,15 +477,16 @@ static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
WARN_ON(!pmd_none_or_clear_bad(pmd));
continue;
}
-#ifdef CONFIG_PPC_FSL_BOOK3E
/*
* Increment next by the size of the huge mapping since
* there may be more than one entry at this level for a
* single hugepage, but all of them point to
* the same kmem cache that holds the hugepte.
*/
- next = addr + (1 << hugepd_shift(*(hugepd_t *)pmd));
-#endif
+ more = addr + (1 << hugepd_shift(*(hugepd_t *)pmd));
+ if (more > next)
+ next = more;
+
free_hugepd_range(tlb, (hugepd_t *)pmd, PMD_SHIFT,
addr, next, floor, ceiling);
} while (addr = next, addr != end);
@@ -550,15 +526,17 @@ static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
ceiling);
} else {
-#ifdef CONFIG_PPC_FSL_BOOK3E
+ unsigned long more;
/*
* Increment next by the size of the huge mapping since
* there may be more than one entry at this level for a
* single hugepage, but all of them point to
* the same kmem cache that holds the hugepte.
*/
- next = addr + (1 << hugepd_shift(*(hugepd_t *)pud));
-#endif
+ more = addr + (1 << hugepd_shift(*(hugepd_t *)pud));
+ if (more > next)
+ next = more;
+
free_hugepd_range(tlb, (hugepd_t *)pud, PUD_SHIFT,
addr, next, floor, ceiling);
}
@@ -615,15 +593,17 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb,
continue;
hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);
} else {
-#ifdef CONFIG_PPC_FSL_BOOK3E
+ unsigned long more;
/*
* Increment next by the size of the huge mapping since
* there may be more than one entry at the pgd level
* for a single hugepage, but all of them point to the
* same kmem cache that holds the hugepte.
*/
- next = addr + (1 << hugepd_shift(*(hugepd_t *)pgd));
-#endif
+ more = addr + (1 << hugepd_shift(*(hugepd_t *)pgd));
+ if (more > next)
+ next = more;
+
free_hugepd_range(tlb, (hugepd_t *)pgd, PGDIR_SHIFT,
addr, next, floor, ceiling);
}
@@ -753,12 +733,13 @@ static int __init add_huge_page_size(unsigned long long size)
/* Check that it is a page size supported by the hardware and
* that it fits within pagetable and slice limits. */
+ if (size <= PAGE_SIZE)
+ return -EINVAL;
#ifdef CONFIG_PPC_FSL_BOOK3E
- if ((size < PAGE_SIZE) || !is_power_of_4(size))
+ if (!is_power_of_4(size))
return -EINVAL;
#else
- if (!is_power_of_2(size)
- || (shift > SLICE_HIGH_SHIFT) || (shift <= PAGE_SHIFT))
+ if (!is_power_of_2(size) || (shift > SLICE_HIGH_SHIFT))
return -EINVAL;
#endif
@@ -791,53 +772,15 @@ static int __init hugepage_setup_sz(char *str)
}
__setup("hugepagesz=", hugepage_setup_sz);
-#ifdef CONFIG_PPC_FSL_BOOK3E
struct kmem_cache *hugepte_cache;
static int __init hugetlbpage_init(void)
{
int psize;
- for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
- unsigned shift;
-
- if (!mmu_psize_defs[psize].shift)
- continue;
-
- shift = mmu_psize_to_shift(psize);
-
- /* Don't treat normal page sizes as huge... */
- if (shift != PAGE_SHIFT)
- if (add_huge_page_size(1ULL << shift) < 0)
- continue;
- }
-
- /*
- * Create a kmem cache for hugeptes. The bottom bits in the pte have
- * size information encoded in them, so align them to allow this
- */
- hugepte_cache = kmem_cache_create("hugepte-cache", sizeof(pte_t),
- HUGEPD_SHIFT_MASK + 1, 0, NULL);
- if (hugepte_cache == NULL)
- panic("%s: Unable to create kmem cache for hugeptes\n",
- __func__);
-
- /* Default hpage size = 4M */
- if (mmu_psize_defs[MMU_PAGE_4M].shift)
- HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_4M].shift;
- else
- panic("%s: Unable to set default huge page size\n", __func__);
-
-
- return 0;
-}
-#else
-static int __init hugetlbpage_init(void)
-{
- int psize;
-
+#if !defined(CONFIG_PPC_FSL_BOOK3E)
if (!radix_enabled() && !mmu_has_feature(MMU_FTR_16M_PAGE))
return -ENODEV;
-
+#endif
for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
unsigned shift;
unsigned pdshift;
@@ -850,9 +793,9 @@ static int __init hugetlbpage_init(void)
if (add_huge_page_size(1ULL << shift) < 0)
continue;
- if (shift < PMD_SHIFT)
+ if (shift < HUGEPD_PUD_SHIFT)
pdshift = PMD_SHIFT;
- else if (shift < PUD_SHIFT)
+ else if (shift < HUGEPD_PGD_SHIFT)
pdshift = PUD_SHIFT;
else
pdshift = PGDIR_SHIFT;
@@ -860,14 +803,36 @@ static int __init hugetlbpage_init(void)
* if we have pdshift and shift value same, we don't
* use pgt cache for hugepd.
*/
- if (pdshift != shift) {
+ if (pdshift > shift) {
pgtable_cache_add(pdshift - shift, NULL);
if (!PGT_CACHE(pdshift - shift))
panic("hugetlbpage_init(): could not create "
"pgtable cache for %d bit pagesize\n", shift);
}
+#ifdef CONFIG_PPC_FSL_BOOK3E
+ else if (!hugepte_cache) {
+ /*
+ * Create a kmem cache for hugeptes. The bottom bits in
+ * the pte have size information encoded in them, so
+ * align them to allow this
+ */
+ hugepte_cache = kmem_cache_create("hugepte-cache",
+ sizeof(pte_t),
+ HUGEPD_SHIFT_MASK + 1,
+ 0, NULL);
+ if (hugepte_cache == NULL)
+ panic("%s: Unable to create kmem cache "
+ "for hugeptes\n", __func__);
+
+ }
+#endif
}
+#ifdef CONFIG_PPC_FSL_BOOK3E
+ /* Default hpage size = 4M */
+ if (mmu_psize_defs[MMU_PAGE_4M].shift)
+ HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_4M].shift;
+#else
/* Set default large page size. Currently, we pick 16M or 1M
* depending on what is available
*/
@@ -877,11 +842,13 @@ static int __init hugetlbpage_init(void)
HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_1M].shift;
else if (mmu_psize_defs[MMU_PAGE_2M].shift)
HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_2M].shift;
-
+#endif
+ else
+ panic("%s: Unable to set default huge page size\n", __func__);
return 0;
}
-#endif
+
arch_initcall(hugetlbpage_init);
void flush_dcache_icache_hugepage(struct page *page)
--
2.10.1