#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,
+ HUGEPTE_TABLE_SIZE-1));
+}
+
#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,
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);
projects / karo-tx-linux.git / commitdiff