#define NUM_LOW_AREAS (0x100000000UL >> SID_SHIFT)
#define NUM_HIGH_AREAS (PGTABLE_RANGE >> HTLB_AREA_SHIFT)
+#ifdef CONFIG_PPC_64K_PAGES
+#define HUGEPTE_INDEX_SIZE (PMD_SHIFT-HPAGE_SHIFT)
+#else
+#define HUGEPTE_INDEX_SIZE (PUD_SHIFT-HPAGE_SHIFT)
+#endif
+#define PTRS_PER_HUGEPTE (1 << HUGEPTE_INDEX_SIZE)
+#define HUGEPTE_TABLE_SIZE (sizeof(pte_t) << HUGEPTE_INDEX_SIZE)
+
+#define HUGEPD_SHIFT (HPAGE_SHIFT + HUGEPTE_INDEX_SIZE)
+#define HUGEPD_SIZE (1UL << HUGEPD_SHIFT)
+#define HUGEPD_MASK (~(HUGEPD_SIZE-1))
+
+#define huge_pgtable_cache (pgtable_cache[HUGEPTE_CACHE_NUM])
+
+/* Flag to mark huge PD pointers. This means pmd_bad() and pud_bad()
+ * will choke on pointers to hugepte tables, which is handy for
+ * catching screwups early. */
+#define HUGEPD_OK 0x1
+
+typedef struct { unsigned long pd; } hugepd_t;
+
+#define hugepd_none(hpd) ((hpd).pd == 0)
+
+static inline pte_t *hugepd_page(hugepd_t hpd)
+{
+ BUG_ON(!(hpd.pd & HUGEPD_OK));
+ return (pte_t *)(hpd.pd & ~HUGEPD_OK);
+}
+
+static inline pte_t *hugepte_offset(hugepd_t *hpdp, unsigned long addr)
+{
+ unsigned long idx = ((addr >> HPAGE_SHIFT) & (PTRS_PER_HUGEPTE-1));
+ pte_t *dir = hugepd_page(*hpdp);
+
+ return dir + idx;
+}
+
+static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
+ unsigned long address)
+{
+ pte_t *new = kmem_cache_alloc(huge_pgtable_cache,
+ GFP_KERNEL|__GFP_REPEAT);
+
+ if (! new)
+ return -ENOMEM;
+
+ spin_lock(&mm->page_table_lock);
+ if (!hugepd_none(*hpdp))
+ kmem_cache_free(huge_pgtable_cache, new);
+ else
+ hpdp->pd = (unsigned long)new | HUGEPD_OK;
+ spin_unlock(&mm->page_table_lock);
+ return 0;
+}
+
/* Modelled after find_linux_pte() */
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
pgd_t *pg;
pud_t *pu;
- pmd_t *pm;
- pte_t *pt;
BUG_ON(! in_hugepage_area(mm->context, addr));
if (!pgd_none(*pg)) {
pu = pud_offset(pg, addr);
if (!pud_none(*pu)) {
- pm = pmd_offset(pu, addr);
#ifdef CONFIG_PPC_64K_PAGES
- /* Currently, we use the normal PTE offset within full
- * size PTE pages, thus our huge PTEs are scattered in
- * the PTE page and we do waste some. We may change
- * that in the future, but the current mecanism keeps
- * things much simpler
- */
- if (!pmd_none(*pm)) {
- /* Note: pte_offset_* are all equivalent on
- * ppc64 as we don't have HIGHMEM
- */
- pt = pte_offset_kernel(pm, addr);
- return pt;
- }
-#else /* CONFIG_PPC_64K_PAGES */
- /* On 4k pages, we put huge PTEs in the PMD page */
- pt = (pte_t *)pm;
- return pt;
-#endif /* CONFIG_PPC_64K_PAGES */
+ pmd_t *pm;
+ pm = pmd_offset(pu, addr);
+ if (!pmd_none(*pm))
+ return hugepte_offset((hugepd_t *)pm, addr);
+#else
+ return hugepte_offset((hugepd_t *)pu, addr);
+#endif
}
}
{
pgd_t *pg;
pud_t *pu;
- pmd_t *pm;
- pte_t *pt;
+ hugepd_t *hpdp = NULL;
BUG_ON(! in_hugepage_area(mm->context, addr));
pu = pud_alloc(mm, pg, addr);
if (pu) {
+#ifdef CONFIG_PPC_64K_PAGES
+ pmd_t *pm;
pm = pmd_alloc(mm, pu, addr);
- if (pm) {
+ if (pm)
+ hpdp = (hugepd_t *)pm;
+#else
+ hpdp = (hugepd_t *)pu;
+#endif
+ }
+
+ if (! hpdp)
+ return NULL;
+
+ if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr))
+ return NULL;
+
+ return hugepte_offset(hpdp, addr);
+}
+
+static void free_hugepte_range(struct mmu_gather *tlb, hugepd_t *hpdp)
+{
+ pte_t *hugepte = hugepd_page(*hpdp);
+
+ hpdp->pd = 0;
+ tlb->need_flush = 1;
+ pgtable_free_tlb(tlb, pgtable_free_cache(hugepte, HUGEPTE_CACHE_NUM,
+ PGF_CACHENUM_MASK));
+}
+
#ifdef CONFIG_PPC_64K_PAGES
- /* See comment in huge_pte_offset. Note that if we ever
- * want to put the page size in the PMD, we would have
- * to open code our own pte_alloc* function in order
- * to populate and set the size atomically
- */
- pt = pte_alloc_map(mm, pm, addr);
-#else /* CONFIG_PPC_64K_PAGES */
- pt = (pte_t *)pm;
-#endif /* CONFIG_PPC_64K_PAGES */
- return pt;
- }
+static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
+ unsigned long addr, unsigned long end,
+ unsigned long floor, unsigned long ceiling)
+{
+ pmd_t *pmd;
+ unsigned long next;
+ unsigned long start;
+
+ start = addr;
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ if (pmd_none(*pmd))
+ continue;
+ free_hugepte_range(tlb, (hugepd_t *)pmd);
+ } while (pmd++, addr = next, addr != end);
+
+ start &= PUD_MASK;
+ if (start < floor)
+ return;
+ if (ceiling) {
+ ceiling &= PUD_MASK;
+ if (!ceiling)
+ return;
}
+ if (end - 1 > ceiling - 1)
+ return;
- return NULL;
+ pmd = pmd_offset(pud, start);
+ pud_clear(pud);
+ pmd_free_tlb(tlb, pmd);
+}
+#endif
+
+static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
+ unsigned long addr, unsigned long end,
+ unsigned long floor, unsigned long ceiling)
+{
+ pud_t *pud;
+ unsigned long next;
+ unsigned long start;
+
+ start = addr;
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+#ifdef CONFIG_PPC_64K_PAGES
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ hugetlb_free_pmd_range(tlb, pud, addr, next, floor, ceiling);
+#else
+ if (pud_none(*pud))
+ continue;
+ free_hugepte_range(tlb, (hugepd_t *)pud);
+#endif
+ } while (pud++, addr = next, addr != end);
+
+ start &= PGDIR_MASK;
+ if (start < floor)
+ return;
+ if (ceiling) {
+ ceiling &= PGDIR_MASK;
+ if (!ceiling)
+ return;
+ }
+ if (end - 1 > ceiling - 1)
+ return;
+
+ pud = pud_offset(pgd, start);
+ pgd_clear(pgd);
+ pud_free_tlb(tlb, pud);
+}
+
+/*
+ * This function frees user-level page tables of a process.
+ *
+ * Must be called with pagetable lock held.
+ */
+void hugetlb_free_pgd_range(struct mmu_gather **tlb,
+ unsigned long addr, unsigned long end,
+ unsigned long floor, unsigned long ceiling)
+{
+ pgd_t *pgd;
+ unsigned long next;
+ unsigned long start;
+
+ /*
+ * Comments below take from the normal free_pgd_range(). They
+ * apply here too. The tests against HUGEPD_MASK below are
+ * essential, because we *don't* test for this at the bottom
+ * level. Without them we'll attempt to free a hugepte table
+ * when we unmap just part of it, even if there are other
+ * active mappings using it.
+ *
+ * The next few lines have given us lots of grief...
+ *
+ * Why are we testing HUGEPD* at this top level? Because
+ * often there will be no work to do at all, and we'd prefer
+ * not to go all the way down to the bottom just to discover
+ * that.
+ *
+ * Why all these "- 1"s? Because 0 represents both the bottom
+ * of the address space and the top of it (using -1 for the
+ * top wouldn't help much: the masks would do the wrong thing).
+ * The rule is that addr 0 and floor 0 refer to the bottom of
+ * the address space, but end 0 and ceiling 0 refer to the top
+ * Comparisons need to use "end - 1" and "ceiling - 1" (though
+ * that end 0 case should be mythical).
+ *
+ * Wherever addr is brought up or ceiling brought down, we
+ * must be careful to reject "the opposite 0" before it
+ * confuses the subsequent tests. But what about where end is
+ * brought down by HUGEPD_SIZE below? no, end can't go down to
+ * 0 there.
+ *
+ * Whereas we round start (addr) and ceiling down, by different
+ * masks at different levels, in order to test whether a table
+ * now has no other vmas using it, so can be freed, we don't
+ * bother to round floor or end up - the tests don't need that.
+ */
+
+ addr &= HUGEPD_MASK;
+ if (addr < floor) {
+ addr += HUGEPD_SIZE;
+ if (!addr)
+ return;
+ }
+ if (ceiling) {
+ ceiling &= HUGEPD_MASK;
+ if (!ceiling)
+ return;
+ }
+ if (end - 1 > ceiling - 1)
+ end -= HUGEPD_SIZE;
+ if (addr > end - 1)
+ return;
+
+ start = addr;
+ pgd = pgd_offset((*tlb)->mm, addr);
+ do {
+ BUG_ON(! in_hugepage_area((*tlb)->mm->context, addr));
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_or_clear_bad(pgd))
+ continue;
+ hugetlb_free_pud_range(*tlb, pgd, addr, next, floor, ceiling);
+ } while (pgd++, addr = next, addr != end);
}
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
return __pte(old);
}
-/*
- * This function checks for proper alignment of input addr and len parameters.
- */
-int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
-{
- if (len & ~HPAGE_MASK)
- return -EINVAL;
- if (addr & ~HPAGE_MASK)
- return -EINVAL;
- if (! (within_hugepage_low_range(addr, len)
- || within_hugepage_high_range(addr, len)) )
- return -EINVAL;
- return 0;
-}
+struct slb_flush_info {
+ struct mm_struct *mm;
+ u16 newareas;
+};
static void flush_low_segments(void *parm)
{
- u16 areas = (unsigned long) parm;
+ struct slb_flush_info *fi = parm;
unsigned long i;
- asm volatile("isync" : : : "memory");
+ BUILD_BUG_ON((sizeof(fi->newareas)*8) != NUM_LOW_AREAS);
+
+ if (current->active_mm != fi->mm)
+ return;
- BUILD_BUG_ON((sizeof(areas)*8) != NUM_LOW_AREAS);
+ /* Only need to do anything if this CPU is working in the same
+ * mm as the one which has changed */
+ /* update the paca copy of the context struct */
+ get_paca()->context = current->active_mm->context;
+
+ asm volatile("isync" : : : "memory");
for (i = 0; i < NUM_LOW_AREAS; i++) {
- if (! (areas & (1U << i)))
+ if (! (fi->newareas & (1U << i)))
continue;
asm volatile("slbie %0"
: : "r" ((i << SID_SHIFT) | SLBIE_C));
}
-
asm volatile("isync" : : : "memory");
}
static void flush_high_segments(void *parm)
{
- u16 areas = (unsigned long) parm;
+ struct slb_flush_info *fi = parm;
unsigned long i, j;
- asm volatile("isync" : : : "memory");
- BUILD_BUG_ON((sizeof(areas)*8) != NUM_HIGH_AREAS);
+ BUILD_BUG_ON((sizeof(fi->newareas)*8) != NUM_HIGH_AREAS);
+
+ if (current->active_mm != fi->mm)
+ return;
+
+ /* Only need to do anything if this CPU is working in the same
+ * mm as the one which has changed */
+
+ /* update the paca copy of the context struct */
+ get_paca()->context = current->active_mm->context;
+ asm volatile("isync" : : : "memory");
for (i = 0; i < NUM_HIGH_AREAS; i++) {
- if (! (areas & (1U << i)))
+ if (! (fi->newareas & (1U << i)))
continue;
for (j = 0; j < (1UL << (HTLB_AREA_SHIFT-SID_SHIFT)); j++)
asm volatile("slbie %0"
:: "r" (((i << HTLB_AREA_SHIFT)
- + (j << SID_SHIFT)) | SLBIE_C));
+ + (j << SID_SHIFT)) | SLBIE_C));
}
-
asm volatile("isync" : : : "memory");
}
BUG_ON(area >= NUM_HIGH_AREAS);
+ /* Hack, so that each addresses is controlled by exactly one
+ * of the high or low area bitmaps, the first high area starts
+ * at 4GB, not 0 */
+ if (start == 0)
+ start = 0x100000000UL;
+
/* Check no VMAs are in the region */
vma = find_vma(mm, start);
if (vma && (vma->vm_start < end))
static int open_low_hpage_areas(struct mm_struct *mm, u16 newareas)
{
unsigned long i;
+ struct slb_flush_info fi;
BUILD_BUG_ON((sizeof(newareas)*8) != NUM_LOW_AREAS);
BUILD_BUG_ON((sizeof(mm->context.low_htlb_areas)*8) != NUM_LOW_AREAS);
mm->context.low_htlb_areas |= newareas;
- /* update the paca copy of the context struct */
- get_paca()->context = mm->context;
-
/* the context change must make it to memory before the flush,
* so that further SLB misses do the right thing. */
mb();
- on_each_cpu(flush_low_segments, (void *)(unsigned long)newareas, 0, 1);
+
+ fi.mm = mm;
+ fi.newareas = newareas;
+ on_each_cpu(flush_low_segments, &fi, 0, 1);
return 0;
}
static int open_high_hpage_areas(struct mm_struct *mm, u16 newareas)
{
+ struct slb_flush_info fi;
unsigned long i;
BUILD_BUG_ON((sizeof(newareas)*8) != NUM_HIGH_AREAS);
/* the context change must make it to memory before the flush,
* so that further SLB misses do the right thing. */
mb();
- on_each_cpu(flush_high_segments, (void *)(unsigned long)newareas, 0, 1);
+
+ fi.mm = mm;
+ fi.newareas = newareas;
+ on_each_cpu(flush_high_segments, &fi, 0, 1);
return 0;
}
int prepare_hugepage_range(unsigned long addr, unsigned long len)
{
- int err;
+ int err = 0;
if ( (addr+len) < addr )
return -EINVAL;
- if ((addr + len) < 0x100000000UL)
+ if (addr < 0x100000000UL)
err = open_low_hpage_areas(current->mm,
LOW_ESID_MASK(addr, len));
- else
+ if ((addr + len) > 0x100000000UL)
err = open_high_hpage_areas(current->mm,
HTLB_AREA_MASK(addr, len));
if (err) {
return addr;
}
+static int htlb_check_hinted_area(unsigned long addr, unsigned long len)
+{
+ struct vm_area_struct *vma;
+
+ vma = find_vma(current->mm, addr);
+ if (!vma || ((addr + len) <= vma->vm_start))
+ return 0;
+
+ return -ENOMEM;
+}
+
static unsigned long htlb_get_low_area(unsigned long len, u16 segmask)
{
unsigned long addr = 0;
if (!cpu_has_feature(CPU_FTR_16M_PAGE))
return -EINVAL;
+ /* Paranoia, caller should have dealt with this */
+ BUG_ON((addr + len) < addr);
+
if (test_thread_flag(TIF_32BIT)) {
+ /* Paranoia, caller should have dealt with this */
+ BUG_ON((addr + len) > 0x100000000UL);
+
curareas = current->mm->context.low_htlb_areas;
- /* First see if we can do the mapping in the existing
- * low areas */
+ /* First see if we can use the hint address */
+ if (addr && (htlb_check_hinted_area(addr, len) == 0)) {
+ areamask = LOW_ESID_MASK(addr, len);
+ if (open_low_hpage_areas(current->mm, areamask) == 0)
+ return addr;
+ }
+
+ /* Next see if we can map in the existing low areas */
addr = htlb_get_low_area(len, curareas);
if (addr != -ENOMEM)
return addr;
+ /* Finally go looking for areas to open */
lastshift = 0;
for (areamask = LOW_ESID_MASK(0x100000000UL-len, len);
! lastshift; areamask >>=1) {
} else {
curareas = current->mm->context.high_htlb_areas;
- /* First see if we can do the mapping in the existing
- * high areas */
+ /* First see if we can use the hint address */
+ /* We discourage 64-bit processes from doing hugepage
+ * mappings below 4GB (must use MAP_FIXED) */
+ if ((addr >= 0x100000000UL)
+ && (htlb_check_hinted_area(addr, len) == 0)) {
+ areamask = HTLB_AREA_MASK(addr, len);
+ if (open_high_hpage_areas(current->mm, areamask) == 0)
+ return addr;
+ }
+
+ /* Next see if we can map in the existing high areas */
addr = htlb_get_high_area(len, curareas);
if (addr != -ENOMEM)
return addr;
+ /* Finally go looking for areas to open */
lastshift = 0;
for (areamask = HTLB_AREA_MASK(TASK_SIZE_USER64-len, len);
! lastshift; areamask >>=1) {
return -ENOMEM;
}
+/*
+ * Called by asm hashtable.S for doing lazy icache flush
+ */
+static unsigned int hash_huge_page_do_lazy_icache(unsigned long rflags,
+ pte_t pte, int trap)
+{
+ struct page *page;
+ int i;
+
+ if (!pfn_valid(pte_pfn(pte)))
+ return rflags;
+
+ page = pte_page(pte);
+
+ /* page is dirty */
+ if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
+ if (trap == 0x400) {
+ for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++)
+ __flush_dcache_icache(page_address(page+i));
+ set_bit(PG_arch_1, &page->flags);
+ } else {
+ rflags |= HPTE_R_N;
+ }
+ }
+ return rflags;
+}
+
int hash_huge_page(struct mm_struct *mm, unsigned long access,
- unsigned long ea, unsigned long vsid, int local)
+ unsigned long ea, unsigned long vsid, int local,
+ unsigned long trap)
{
pte_t *ptep;
unsigned long old_pte, new_pte;
rflags = 0x2 | (!(new_pte & _PAGE_RW));
/* _PAGE_EXEC -> HW_NO_EXEC since it's inverted */
rflags |= ((new_pte & _PAGE_EXEC) ? 0 : HPTE_R_N);
+ if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
+ /* No CPU has hugepages but lacks no execute, so we
+ * don't need to worry about that case */
+ rflags = hash_huge_page_do_lazy_icache(rflags, __pte(old_pte),
+ trap);
/* Check if pte already has an hpte (case 2) */
if (unlikely(old_pte & _PAGE_HASHPTE)) {
slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
slot += (old_pte & _PAGE_F_GIX) >> 12;
- if (ppc_md.hpte_updatepp(slot, rflags, va, 1, local) == -1)
+ if (ppc_md.hpte_updatepp(slot, rflags, va, mmu_huge_psize,
+ local) == -1)
old_pte &= ~_PAGE_HPTEFLAGS;
}
}
/*
- * No need to use ldarx/stdcx here because all who
- * might be updating the pte will hold the
- * page_table_lock
+ * No need to use ldarx/stdcx here
*/
*ptep = __pte(new_pte & ~_PAGE_BUSY);
out:
return err;
}
+
+static void zero_ctor(void *addr, kmem_cache_t *cache, unsigned long flags)
+{
+ memset(addr, 0, kmem_cache_size(cache));
+}
+
+static int __init hugetlbpage_init(void)
+{
+ if (!cpu_has_feature(CPU_FTR_16M_PAGE))
+ return -ENODEV;
+
+ huge_pgtable_cache = kmem_cache_create("hugepte_cache",
+ HUGEPTE_TABLE_SIZE,
+ HUGEPTE_TABLE_SIZE,
+ SLAB_HWCACHE_ALIGN |
+ SLAB_MUST_HWCACHE_ALIGN,
+ zero_ctor, NULL);
+ if (! huge_pgtable_cache)
+ panic("hugetlbpage_init(): could not create hugepte cache\n");
+
+ return 0;
+}
+
+module_init(hugetlbpage_init);