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-rw-r--r--arch/powerpc/mm/hugetlbpage.c592
1 files changed, 592 insertions, 0 deletions
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
new file mode 100644
index 00000000..da5eb388
--- /dev/null
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -0,0 +1,592 @@
+/*
+ * PPC64 (POWER4) Huge TLB Page Support for Kernel.
+ *
+ * Copyright (C) 2003 David Gibson, IBM Corporation.
+ *
+ * Based on the IA-32 version:
+ * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
+ */
+
+#include <linux/mm.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/hugetlb.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+
+#define PAGE_SHIFT_64K 16
+#define PAGE_SHIFT_16M 24
+#define PAGE_SHIFT_16G 34
+
+#define MAX_NUMBER_GPAGES 1024
+
+/* Tracks the 16G pages after the device tree is scanned and before the
+ * huge_boot_pages list is ready. */
+static unsigned long gpage_freearray[MAX_NUMBER_GPAGES];
+static unsigned nr_gpages;
+
+/* 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. */
+
+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)
+
+static inline pte_t *hugepd_page(hugepd_t hpd)
+{
+ BUG_ON(!hugepd_ok(hpd));
+ return (pte_t *)((hpd.pd & ~HUGEPD_SHIFT_MASK) | 0xc000000000000000);
+}
+
+static inline unsigned int hugepd_shift(hugepd_t hpd)
+{
+ return hpd.pd & HUGEPD_SHIFT_MASK;
+}
+
+static inline pte_t *hugepte_offset(hugepd_t *hpdp, unsigned long addr, unsigned pdshift)
+{
+ unsigned long idx = (addr & ((1UL << pdshift) - 1)) >> hugepd_shift(*hpdp);
+ pte_t *dir = hugepd_page(*hpdp);
+
+ return dir + idx;
+}
+
+pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift)
+{
+ pgd_t *pg;
+ pud_t *pu;
+ pmd_t *pm;
+ hugepd_t *hpdp = NULL;
+ unsigned pdshift = PGDIR_SHIFT;
+
+ if (shift)
+ *shift = 0;
+
+ pg = pgdir + pgd_index(ea);
+ if (is_hugepd(pg)) {
+ hpdp = (hugepd_t *)pg;
+ } else if (!pgd_none(*pg)) {
+ pdshift = PUD_SHIFT;
+ pu = pud_offset(pg, ea);
+ if (is_hugepd(pu))
+ hpdp = (hugepd_t *)pu;
+ else if (!pud_none(*pu)) {
+ pdshift = PMD_SHIFT;
+ pm = pmd_offset(pu, ea);
+ if (is_hugepd(pm))
+ hpdp = (hugepd_t *)pm;
+ else if (!pmd_none(*pm)) {
+ return pte_offset_map(pm, ea);
+ }
+ }
+ }
+
+ if (!hpdp)
+ return NULL;
+
+ if (shift)
+ *shift = hugepd_shift(*hpdp);
+ return hugepte_offset(hpdp, ea, pdshift);
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
+{
+ return find_linux_pte_or_hugepte(mm->pgd, addr, NULL);
+}
+
+static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
+ unsigned long address, unsigned pdshift, unsigned pshift)
+{
+ pte_t *new = kmem_cache_zalloc(PGT_CACHE(pdshift - pshift),
+ GFP_KERNEL|__GFP_REPEAT);
+
+ BUG_ON(pshift > HUGEPD_SHIFT_MASK);
+ BUG_ON((unsigned long)new & HUGEPD_SHIFT_MASK);
+
+ if (! new)
+ return -ENOMEM;
+
+ spin_lock(&mm->page_table_lock);
+ if (!hugepd_none(*hpdp))
+ kmem_cache_free(PGT_CACHE(pdshift - pshift), new);
+ else
+ hpdp->pd = ((unsigned long)new & ~0x8000000000000000) | pshift;
+ spin_unlock(&mm->page_table_lock);
+ return 0;
+}
+
+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 >= PUD_SHIFT) {
+ hpdp = (hugepd_t *)pg;
+ } else {
+ pdshift = PUD_SHIFT;
+ pu = pud_alloc(mm, pg, addr);
+ if (pshift >= PMD_SHIFT) {
+ hpdp = (hugepd_t *)pu;
+ } else {
+ pdshift = PMD_SHIFT;
+ pm = pmd_alloc(mm, pu, addr);
+ 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);
+}
+
+/* Build list of addresses of gigantic pages. This function is used in early
+ * boot before the buddy or bootmem allocator is setup.
+ */
+void add_gpage(unsigned long addr, unsigned long page_size,
+ unsigned long number_of_pages)
+{
+ if (!addr)
+ return;
+ while (number_of_pages > 0) {
+ gpage_freearray[nr_gpages] = addr;
+ nr_gpages++;
+ number_of_pages--;
+ addr += page_size;
+ }
+}
+
+/* Moves the gigantic page addresses from the temporary list to the
+ * huge_boot_pages list.
+ */
+int alloc_bootmem_huge_page(struct hstate *hstate)
+{
+ struct huge_bootmem_page *m;
+ if (nr_gpages == 0)
+ return 0;
+ m = phys_to_virt(gpage_freearray[--nr_gpages]);
+ gpage_freearray[nr_gpages] = 0;
+ list_add(&m->list, &huge_boot_pages);
+ m->hstate = hstate;
+ return 1;
+}
+
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
+{
+ return 0;
+}
+
+static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshift,
+ unsigned long start, unsigned long end,
+ unsigned long floor, unsigned long ceiling)
+{
+ pte_t *hugepte = hugepd_page(*hpdp);
+ unsigned shift = hugepd_shift(*hpdp);
+ unsigned long pdmask = ~((1UL << pdshift) - 1);
+
+ start &= pdmask;
+ if (start < floor)
+ return;
+ if (ceiling) {
+ ceiling &= pdmask;
+ if (! ceiling)
+ return;
+ }
+ if (end - 1 > ceiling - 1)
+ return;
+
+ hpdp->pd = 0;
+ tlb->need_flush = 1;
+ pgtable_free_tlb(tlb, hugepte, pdshift - shift);
+}
+
+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_hugepd_range(tlb, (hugepd_t *)pmd, PMD_SHIFT,
+ addr, next, floor, ceiling);
+ } 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;
+
+ pmd = pmd_offset(pud, start);
+ pud_clear(pud);
+ pmd_free_tlb(tlb, pmd, start);
+}
+
+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);
+ if (!is_hugepd(pud)) {
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
+ ceiling);
+ } else {
+ free_hugepd_range(tlb, (hugepd_t *)pud, PUD_SHIFT,
+ addr, next, floor, ceiling);
+ }
+ } 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, start);
+}
+
+/*
+ * 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;
+
+ /*
+ * Because there are a number of different possible pagetable
+ * layouts for hugepage ranges, we limit knowledge of how
+ * things should be laid out to the allocation path
+ * (huge_pte_alloc(), above). Everything else works out the
+ * structure as it goes from information in the hugepd
+ * pointers. That means that we can't here use the
+ * optimization used in the normal page free_pgd_range(), of
+ * checking whether we're actually covering a large enough
+ * range to have to do anything at the top level of the walk
+ * instead of at the bottom.
+ *
+ * To make sense of this, you should probably go read the big
+ * block comment at the top of the normal free_pgd_range(),
+ * too.
+ */
+
+ pgd = pgd_offset(tlb->mm, addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (!is_hugepd(pgd)) {
+ if (pgd_none_or_clear_bad(pgd))
+ continue;
+ hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);
+ } else {
+ free_hugepd_range(tlb, (hugepd_t *)pgd, PGDIR_SHIFT,
+ addr, next, floor, ceiling);
+ }
+ } while (pgd++, addr = next, addr != end);
+}
+
+struct page *
+follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
+{
+ pte_t *ptep;
+ struct page *page;
+ unsigned shift;
+ unsigned long mask;
+
+ ptep = find_linux_pte_or_hugepte(mm->pgd, address, &shift);
+
+ /* Verify it is a huge page else bail. */
+ if (!ptep || !shift)
+ return ERR_PTR(-EINVAL);
+
+ mask = (1UL << shift) - 1;
+ page = pte_page(*ptep);
+ if (page)
+ page += (address & mask) / PAGE_SIZE;
+
+ return page;
+}
+
+int pmd_huge(pmd_t pmd)
+{
+ return 0;
+}
+
+int pud_huge(pud_t pud)
+{
+ return 0;
+}
+
+struct page *
+follow_huge_pmd(struct mm_struct *mm, unsigned long address,
+ pmd_t *pmd, int write)
+{
+ BUG();
+ return NULL;
+}
+
+static noinline int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
+ unsigned long end, int write, struct page **pages, int *nr)
+{
+ unsigned long mask;
+ unsigned long pte_end;
+ struct page *head, *page, *tail;
+ pte_t pte;
+ int refs;
+
+ pte_end = (addr + sz) & ~(sz-1);
+ if (pte_end < end)
+ end = pte_end;
+
+ pte = *ptep;
+ mask = _PAGE_PRESENT | _PAGE_USER;
+ if (write)
+ mask |= _PAGE_RW;
+
+ if ((pte_val(pte) & mask) != mask)
+ return 0;
+
+ /* hugepages are never "special" */
+ VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
+
+ refs = 0;
+ head = pte_page(pte);
+
+ page = head + ((addr & (sz-1)) >> PAGE_SHIFT);
+ tail = page;
+ do {
+ VM_BUG_ON(compound_head(page) != head);
+ pages[*nr] = page;
+ (*nr)++;
+ page++;
+ refs++;
+ } while (addr += PAGE_SIZE, addr != end);
+
+ if (!page_cache_add_speculative(head, refs)) {
+ *nr -= refs;
+ return 0;
+ }
+
+ if (unlikely(pte_val(pte) != pte_val(*ptep))) {
+ /* Could be optimized better */
+ *nr -= refs;
+ while (refs--)
+ put_page(head);
+ return 0;
+ }
+
+ /*
+ * Any tail page need their mapcount reference taken before we
+ * return.
+ */
+ while (refs--) {
+ if (PageTail(tail))
+ get_huge_page_tail(tail);
+ tail++;
+ }
+
+ return 1;
+}
+
+static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
+ unsigned long sz)
+{
+ unsigned long __boundary = (addr + sz) & ~(sz-1);
+ return (__boundary - 1 < end - 1) ? __boundary : end;
+}
+
+int gup_hugepd(hugepd_t *hugepd, unsigned pdshift,
+ unsigned long addr, unsigned long end,
+ int write, struct page **pages, int *nr)
+{
+ pte_t *ptep;
+ unsigned long sz = 1UL << hugepd_shift(*hugepd);
+ unsigned long next;
+
+ ptep = hugepte_offset(hugepd, addr, pdshift);
+ do {
+ next = hugepte_addr_end(addr, end, sz);
+ if (!gup_hugepte(ptep, sz, addr, end, write, pages, nr))
+ return 0;
+ } while (ptep++, addr = next, addr != end);
+
+ return 1;
+}
+
+unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long pgoff,
+ unsigned long flags)
+{
+ struct hstate *hstate = hstate_file(file);
+ int mmu_psize = shift_to_mmu_psize(huge_page_shift(hstate));
+
+ return slice_get_unmapped_area(addr, len, flags, mmu_psize, 1, 0);
+}
+
+unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
+{
+ unsigned int psize = get_slice_psize(vma->vm_mm, vma->vm_start);
+
+ return 1UL << mmu_psize_to_shift(psize);
+}
+
+static int __init add_huge_page_size(unsigned long long size)
+{
+ int shift = __ffs(size);
+ int mmu_psize;
+
+ /* Check that it is a page size supported by the hardware and
+ * that it fits within pagetable and slice limits. */
+ if (!is_power_of_2(size)
+ || (shift > SLICE_HIGH_SHIFT) || (shift <= PAGE_SHIFT))
+ return -EINVAL;
+
+ if ((mmu_psize = shift_to_mmu_psize(shift)) < 0)
+ return -EINVAL;
+
+#ifdef CONFIG_SPU_FS_64K_LS
+ /* Disable support for 64K huge pages when 64K SPU local store
+ * support is enabled as the current implementation conflicts.
+ */
+ if (shift == PAGE_SHIFT_64K)
+ return -EINVAL;
+#endif /* CONFIG_SPU_FS_64K_LS */
+
+ BUG_ON(mmu_psize_defs[mmu_psize].shift != shift);
+
+ /* Return if huge page size has already been setup */
+ if (size_to_hstate(size))
+ return 0;
+
+ hugetlb_add_hstate(shift - PAGE_SHIFT);
+
+ return 0;
+}
+
+static int __init hugepage_setup_sz(char *str)
+{
+ unsigned long long size;
+
+ size = memparse(str, &str);
+
+ if (add_huge_page_size(size) != 0)
+ printk(KERN_WARNING "Invalid huge page size specified(%llu)\n", size);
+
+ return 1;
+}
+__setup("hugepagesz=", hugepage_setup_sz);
+
+static int __init hugetlbpage_init(void)
+{
+ int psize;
+
+ if (!mmu_has_feature(MMU_FTR_16M_PAGE))
+ return -ENODEV;
+
+ for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
+ unsigned shift;
+ unsigned pdshift;
+
+ if (!mmu_psize_defs[psize].shift)
+ continue;
+
+ shift = mmu_psize_to_shift(psize);
+
+ if (add_huge_page_size(1ULL << shift) < 0)
+ continue;
+
+ if (shift < PMD_SHIFT)
+ pdshift = PMD_SHIFT;
+ else if (shift < PUD_SHIFT)
+ pdshift = PUD_SHIFT;
+ else
+ pdshift = PGDIR_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);
+ }
+
+ /* Set default large page size. Currently, we pick 16M or 1M
+ * depending on what is available
+ */
+ if (mmu_psize_defs[MMU_PAGE_16M].shift)
+ HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_16M].shift;
+ else if (mmu_psize_defs[MMU_PAGE_1M].shift)
+ HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_1M].shift;
+
+ return 0;
+}
+
+module_init(hugetlbpage_init);
+
+void flush_dcache_icache_hugepage(struct page *page)
+{
+ int i;
+
+ BUG_ON(!PageCompound(page));
+
+ for (i = 0; i < (1UL << compound_order(page)); i++)
+ __flush_dcache_icache(page_address(page+i));
+}
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