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-rw-r--r--arch/powerpc/mm/hugetlbpage.c919
1 files changed, 919 insertions, 0 deletions
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
new file mode 100644
index 000000000..cef0b7ee1
--- /dev/null
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -0,0 +1,919 @@
+/*
+ * PPC Huge TLB Page Support for Kernel.
+ *
+ * Copyright (C) 2003 David Gibson, IBM Corporation.
+ * Copyright (C) 2011 Becky Bruce, Freescale Semiconductor
+ *
+ * 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 <linux/export.h>
+#include <linux/of_fdt.h>
+#include <linux/memblock.h>
+#include <linux/bootmem.h>
+#include <linux/moduleparam.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/kmemleak.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+#include <asm/setup.h>
+#include <asm/hugetlb.h>
+#include <asm/pte-walk.h>
+
+
+#ifdef CONFIG_HUGETLB_PAGE
+
+#define PAGE_SHIFT_64K 16
+#define PAGE_SHIFT_512K 19
+#define PAGE_SHIFT_8M 23
+#define PAGE_SHIFT_16M 24
+#define PAGE_SHIFT_16G 34
+
+bool hugetlb_disabled = false;
+
+unsigned int HPAGE_SHIFT;
+EXPORT_SYMBOL(HPAGE_SHIFT);
+
+#define hugepd_none(hpd) (hpd_val(hpd) == 0)
+
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr, unsigned long sz)
+{
+ /*
+ * Only called for hugetlbfs pages, hence can ignore THP and the
+ * irq disabled walk.
+ */
+ return __find_linux_pte(mm->pgd, addr, NULL, NULL);
+}
+
+static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
+ unsigned long address, unsigned int pdshift,
+ unsigned int pshift, spinlock_t *ptl)
+{
+ struct kmem_cache *cachep;
+ pte_t *new;
+ int i;
+ 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, pgtable_gfp_flags(mm, GFP_KERNEL));
+
+ BUG_ON(pshift > HUGEPD_SHIFT_MASK);
+ BUG_ON((unsigned long)new & HUGEPD_SHIFT_MASK);
+
+ if (! new)
+ return -ENOMEM;
+
+ /*
+ * Make sure other cpus find the hugepd set only after a
+ * properly initialized page table is visible to them.
+ * For more details look for comment in __pte_alloc().
+ */
+ smp_wmb();
+
+ spin_lock(ptl);
+ /*
+ * We have multiple higher-level entries that point to the same
+ * actual pte location. Fill in each as we go and backtrack on error.
+ * We need all of these so the DTLB pgtable walk code can find the
+ * right higher-level entry without knowing if it's a hugepage or not.
+ */
+ for (i = 0; i < num_hugepd; i++, hpdp++) {
+ if (unlikely(!hugepd_none(*hpdp)))
+ break;
+ else {
+#ifdef CONFIG_PPC_BOOK3S_64
+ *hpdp = __hugepd(__pa(new) |
+ (shift_to_mmu_psize(pshift) << 2));
+#elif defined(CONFIG_PPC_8xx)
+ *hpdp = __hugepd(__pa(new) | _PMD_USER |
+ (pshift == PAGE_SHIFT_8M ? _PMD_PAGE_8M :
+ _PMD_PAGE_512K) | _PMD_PRESENT);
+#else
+ /* We use the old format for PPC_FSL_BOOK3E */
+ *hpdp = __hugepd(((unsigned long)new & ~PD_HUGE) | pshift);
+#endif
+ }
+ }
+ /* If we bailed from the for loop early, an error occurred, clean up */
+ if (i < num_hugepd) {
+ for (i = i - 1 ; i >= 0; i--, hpdp--)
+ *hpdp = __hugepd(0);
+ kmem_cache_free(cachep, new);
+ } else {
+ kmemleak_ignore(new);
+ }
+ spin_unlock(ptl);
+ return 0;
+}
+
+/*
+ * At this point we do the placement change only for BOOK3S 64. This would
+ * possibly work on other subarchs.
+ */
+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;
+ spinlock_t *ptl;
+
+ addr &= ~(sz-1);
+ pg = pgd_offset(mm, addr);
+
+#ifdef CONFIG_PPC_BOOK3S_64
+ if (pshift == PGDIR_SHIFT)
+ /* 16GB huge page */
+ return (pte_t *) pg;
+ else if (pshift > PUD_SHIFT) {
+ /*
+ * We need to use hugepd table
+ */
+ ptl = &mm->page_table_lock;
+ hpdp = (hugepd_t *)pg;
+ } else {
+ pdshift = PUD_SHIFT;
+ pu = pud_alloc(mm, pg, addr);
+ if (!pu)
+ return NULL;
+ if (pshift == PUD_SHIFT)
+ return (pte_t *)pu;
+ else if (pshift > PMD_SHIFT) {
+ ptl = pud_lockptr(mm, pu);
+ hpdp = (hugepd_t *)pu;
+ } else {
+ pdshift = PMD_SHIFT;
+ pm = pmd_alloc(mm, pu, addr);
+ if (!pm)
+ return NULL;
+ if (pshift == PMD_SHIFT)
+ /* 16MB hugepage */
+ return (pte_t *)pm;
+ else {
+ ptl = pmd_lockptr(mm, pm);
+ hpdp = (hugepd_t *)pm;
+ }
+ }
+ }
+#else
+ if (pshift >= PGDIR_SHIFT) {
+ ptl = &mm->page_table_lock;
+ hpdp = (hugepd_t *)pg;
+ } else {
+ pdshift = PUD_SHIFT;
+ pu = pud_alloc(mm, pg, addr);
+ if (!pu)
+ return NULL;
+ if (pshift >= PUD_SHIFT) {
+ ptl = pud_lockptr(mm, pu);
+ hpdp = (hugepd_t *)pu;
+ } else {
+ pdshift = PMD_SHIFT;
+ pm = pmd_alloc(mm, pu, addr);
+ if (!pm)
+ return NULL;
+ ptl = pmd_lockptr(mm, pm);
+ hpdp = (hugepd_t *)pm;
+ }
+ }
+#endif
+ if (!hpdp)
+ return NULL;
+
+ BUG_ON(!hugepd_none(*hpdp) && !hugepd_ok(*hpdp));
+
+ if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr,
+ pdshift, pshift, ptl))
+ return NULL;
+
+ return hugepte_offset(*hpdp, addr, pdshift);
+}
+
+#ifdef CONFIG_PPC_BOOK3S_64
+/*
+ * Tracks gpages after the device tree is scanned and before the
+ * huge_boot_pages list is ready on pseries.
+ */
+#define MAX_NUMBER_GPAGES 1024
+__initdata static u64 gpage_freearray[MAX_NUMBER_GPAGES];
+__initdata static unsigned nr_gpages;
+
+/*
+ * Build list of addresses of gigantic pages. This function is used in early
+ * boot before the buddy allocator is setup.
+ */
+void __init pseries_add_gpage(u64 addr, u64 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;
+ }
+}
+
+int __init pseries_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;
+}
+#endif
+
+
+int __init alloc_bootmem_huge_page(struct hstate *h)
+{
+
+#ifdef CONFIG_PPC_BOOK3S_64
+ if (firmware_has_feature(FW_FEATURE_LPAR) && !radix_enabled())
+ return pseries_alloc_bootmem_huge_page(h);
+#endif
+ return __alloc_bootmem_huge_page(h);
+}
+
+#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
+#define HUGEPD_FREELIST_SIZE \
+ ((PAGE_SIZE - sizeof(struct hugepd_freelist)) / sizeof(pte_t))
+
+struct hugepd_freelist {
+ struct rcu_head rcu;
+ unsigned int index;
+ void *ptes[0];
+};
+
+static DEFINE_PER_CPU(struct hugepd_freelist *, hugepd_freelist_cur);
+
+static void hugepd_free_rcu_callback(struct rcu_head *head)
+{
+ struct hugepd_freelist *batch =
+ container_of(head, struct hugepd_freelist, rcu);
+ unsigned int i;
+
+ for (i = 0; i < batch->index; i++)
+ kmem_cache_free(hugepte_cache, batch->ptes[i]);
+
+ free_page((unsigned long)batch);
+}
+
+static void hugepd_free(struct mmu_gather *tlb, void *hugepte)
+{
+ struct hugepd_freelist **batchp;
+
+ batchp = &get_cpu_var(hugepd_freelist_cur);
+
+ if (atomic_read(&tlb->mm->mm_users) < 2 ||
+ mm_is_thread_local(tlb->mm)) {
+ kmem_cache_free(hugepte_cache, hugepte);
+ put_cpu_var(hugepd_freelist_cur);
+ return;
+ }
+
+ if (*batchp == NULL) {
+ *batchp = (struct hugepd_freelist *)__get_free_page(GFP_ATOMIC);
+ (*batchp)->index = 0;
+ }
+
+ (*batchp)->ptes[(*batchp)->index++] = hugepte;
+ if ((*batchp)->index == HUGEPD_FREELIST_SIZE) {
+ call_rcu_sched(&(*batchp)->rcu, hugepd_free_rcu_callback);
+ *batchp = NULL;
+ }
+ 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,
+ unsigned long start, unsigned long end,
+ unsigned long floor, unsigned long ceiling)
+{
+ pte_t *hugepte = hugepd_page(*hpdp);
+ int i;
+
+ unsigned long pdmask = ~((1UL << pdshift) - 1);
+ unsigned int num_hugepd = 1;
+ unsigned int shift = hugepd_shift(*hpdp);
+
+ /* Note: On fsl the hpdp may be the first of several */
+ if (shift > pdshift)
+ num_hugepd = 1 << (shift - pdshift);
+
+ start &= pdmask;
+ if (start < floor)
+ return;
+ if (ceiling) {
+ ceiling &= pdmask;
+ if (! ceiling)
+ return;
+ }
+ if (end - 1 > ceiling - 1)
+ return;
+
+ for (i = 0; i < num_hugepd; i++, hpdp++)
+ *hpdp = __hugepd(0);
+
+ if (shift >= pdshift)
+ hugepd_free(tlb, hugepte);
+ else
+ pgtable_free_tlb(tlb, hugepte,
+ get_hugepd_cache_index(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;
+ do {
+ unsigned long more;
+
+ pmd = pmd_offset(pud, addr);
+ next = pmd_addr_end(addr, end);
+ if (!is_hugepd(__hugepd(pmd_val(*pmd)))) {
+ /*
+ * if it is not hugepd pointer, we should already find
+ * it cleared.
+ */
+ WARN_ON(!pmd_none_or_clear_bad(pmd));
+ continue;
+ }
+ /*
+ * 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.
+ */
+ 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);
+
+ 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);
+ mm_dec_nr_pmds(tlb->mm);
+}
+
+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;
+ do {
+ pud = pud_offset(pgd, addr);
+ next = pud_addr_end(addr, end);
+ if (!is_hugepd(__hugepd(pud_val(*pud)))) {
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
+ ceiling);
+ } else {
+ 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.
+ */
+ 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);
+ }
+ } while (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);
+ mm_dec_nr_puds(tlb->mm);
+}
+
+/*
+ * This function frees user-level page tables of a process.
+ */
+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.
+ */
+
+ do {
+ next = pgd_addr_end(addr, end);
+ pgd = pgd_offset(tlb->mm, addr);
+ if (!is_hugepd(__hugepd(pgd_val(*pgd)))) {
+ if (pgd_none_or_clear_bad(pgd))
+ continue;
+ hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);
+ } else {
+ 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.
+ */
+ 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);
+ }
+ } while (addr = next, addr != end);
+}
+
+struct page *follow_huge_pd(struct vm_area_struct *vma,
+ unsigned long address, hugepd_t hpd,
+ int flags, int pdshift)
+{
+ pte_t *ptep;
+ spinlock_t *ptl;
+ struct page *page = NULL;
+ unsigned long mask;
+ int shift = hugepd_shift(hpd);
+ struct mm_struct *mm = vma->vm_mm;
+
+retry:
+ /*
+ * hugepage directory entries are protected by mm->page_table_lock
+ * Use this instead of huge_pte_lockptr
+ */
+ ptl = &mm->page_table_lock;
+ spin_lock(ptl);
+
+ ptep = hugepte_offset(hpd, address, pdshift);
+ if (pte_present(*ptep)) {
+ mask = (1UL << shift) - 1;
+ page = pte_page(*ptep);
+ page += ((address & mask) >> PAGE_SHIFT);
+ if (flags & FOLL_GET)
+ get_page(page);
+ } else {
+ if (is_hugetlb_entry_migration(*ptep)) {
+ spin_unlock(ptl);
+ __migration_entry_wait(mm, ptep, ptl);
+ goto retry;
+ }
+ }
+ spin_unlock(ptl);
+ return page;
+}
+
+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_huge_pd(hugepd_t hugepd, unsigned long addr, unsigned pdshift,
+ 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;
+}
+
+#ifdef CONFIG_PPC_MM_SLICES
+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));
+
+#ifdef CONFIG_PPC_RADIX_MMU
+ if (radix_enabled())
+ return radix__hugetlb_get_unmapped_area(file, addr, len,
+ pgoff, flags);
+#endif
+ return slice_get_unmapped_area(addr, len, flags, mmu_psize, 1);
+}
+#endif
+
+unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
+{
+#ifdef CONFIG_PPC_MM_SLICES
+ /* With radix we don't use slice, so derive it from vma*/
+ if (!radix_enabled()) {
+ unsigned int psize = get_slice_psize(vma->vm_mm, vma->vm_start);
+
+ return 1UL << mmu_psize_to_shift(psize);
+ }
+#endif
+ return vma_kernel_pagesize(vma);
+}
+
+static inline bool is_power_of_4(unsigned long x)
+{
+ if (is_power_of_2(x))
+ return (__ilog2(x) % 2) ? false : true;
+ return false;
+}
+
+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 (size <= PAGE_SIZE)
+ return -EINVAL;
+#if defined(CONFIG_PPC_FSL_BOOK3E)
+ if (!is_power_of_4(size))
+ return -EINVAL;
+#elif !defined(CONFIG_PPC_8xx)
+ if (!is_power_of_2(size) || (shift > SLICE_HIGH_SHIFT))
+ return -EINVAL;
+#endif
+
+ if ((mmu_psize = shift_to_mmu_psize(shift)) < 0)
+ return -EINVAL;
+
+#ifdef CONFIG_PPC_BOOK3S_64
+ /*
+ * We need to make sure that for different page sizes reported by
+ * firmware we only add hugetlb support for page sizes that can be
+ * supported by linux page table layout.
+ * For now we have
+ * Radix: 2M and 1G
+ * Hash: 16M and 16G
+ */
+ if (radix_enabled()) {
+ if (mmu_psize != MMU_PAGE_2M && mmu_psize != MMU_PAGE_1G)
+ return -EINVAL;
+ } else {
+ if (mmu_psize != MMU_PAGE_16M && mmu_psize != MMU_PAGE_16G)
+ return -EINVAL;
+ }
+#endif
+
+ 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) {
+ hugetlb_bad_size();
+ pr_err("Invalid huge page size specified(%llu)\n", size);
+ }
+
+ return 1;
+}
+__setup("hugepagesz=", hugepage_setup_sz);
+
+struct kmem_cache *hugepte_cache;
+static int __init hugetlbpage_init(void)
+{
+ int psize;
+
+ if (hugetlb_disabled) {
+ pr_info("HugeTLB support is disabled!\n");
+ return 0;
+ }
+
+#if !defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_PPC_8xx)
+ 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;
+
+ if (!mmu_psize_defs[psize].shift)
+ continue;
+
+ shift = mmu_psize_to_shift(psize);
+
+#ifdef CONFIG_PPC_BOOK3S_64
+ if (shift > PGDIR_SHIFT)
+ continue;
+ else if (shift > PUD_SHIFT)
+ pdshift = PGDIR_SHIFT;
+ else if (shift > PMD_SHIFT)
+ pdshift = PUD_SHIFT;
+ else
+ pdshift = PMD_SHIFT;
+#else
+ if (shift < PUD_SHIFT)
+ pdshift = PMD_SHIFT;
+ else if (shift < PGDIR_SHIFT)
+ pdshift = PUD_SHIFT;
+ else
+ pdshift = PGDIR_SHIFT;
+#endif
+
+ if (add_huge_page_size(1ULL << shift) < 0)
+ continue;
+ /*
+ * if we have pdshift and shift value same, we don't
+ * use pgt cache for hugepd.
+ */
+ if (pdshift > shift)
+ pgtable_cache_add(pdshift - shift, NULL);
+#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
+ 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
+ }
+
+#if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx)
+ /* Default hpage size = 4M on FSL_BOOK3E and 512k on 8xx */
+ if (mmu_psize_defs[MMU_PAGE_4M].shift)
+ HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_4M].shift;
+ else if (mmu_psize_defs[MMU_PAGE_512K].shift)
+ HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_512K].shift;
+#else
+ /* 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;
+ else if (mmu_psize_defs[MMU_PAGE_2M].shift)
+ HPAGE_SHIFT = mmu_psize_defs[MMU_PAGE_2M].shift;
+#endif
+ return 0;
+}
+
+arch_initcall(hugetlbpage_init);
+
+void flush_dcache_icache_hugepage(struct page *page)
+{
+ int i;
+ void *start;
+
+ BUG_ON(!PageCompound(page));
+
+ for (i = 0; i < (1UL << compound_order(page)); i++) {
+ if (!PageHighMem(page)) {
+ __flush_dcache_icache(page_address(page+i));
+ } else {
+ start = kmap_atomic(page+i);
+ __flush_dcache_icache(start);
+ kunmap_atomic(start);
+ }
+ }
+}
+
+#endif /* CONFIG_HUGETLB_PAGE */
+
+/*
+ * We have 4 cases for pgds and pmds:
+ * (1) invalid (all zeroes)
+ * (2) pointer to next table, as normal; bottom 6 bits == 0
+ * (3) leaf pte for huge page _PAGE_PTE set
+ * (4) hugepd pointer, _PAGE_PTE = 0 and bits [2..6] indicate size of table
+ *
+ * So long as we atomically load page table pointers we are safe against teardown,
+ * we can follow the address down to the the page and take a ref on it.
+ * This function need to be called with interrupts disabled. We use this variant
+ * when we have MSR[EE] = 0 but the paca->irq_soft_mask = IRQS_ENABLED
+ */
+pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
+ bool *is_thp, unsigned *hpage_shift)
+{
+ pgd_t pgd, *pgdp;
+ pud_t pud, *pudp;
+ pmd_t pmd, *pmdp;
+ pte_t *ret_pte;
+ hugepd_t *hpdp = NULL;
+ unsigned pdshift = PGDIR_SHIFT;
+
+ if (hpage_shift)
+ *hpage_shift = 0;
+
+ if (is_thp)
+ *is_thp = false;
+
+ pgdp = pgdir + pgd_index(ea);
+ pgd = READ_ONCE(*pgdp);
+ /*
+ * Always operate on the local stack value. This make sure the
+ * value don't get updated by a parallel THP split/collapse,
+ * page fault or a page unmap. The return pte_t * is still not
+ * stable. So should be checked there for above conditions.
+ */
+ if (pgd_none(pgd))
+ return NULL;
+ else if (pgd_huge(pgd)) {
+ ret_pte = (pte_t *) pgdp;
+ goto out;
+ } else if (is_hugepd(__hugepd(pgd_val(pgd))))
+ hpdp = (hugepd_t *)&pgd;
+ else {
+ /*
+ * Even if we end up with an unmap, the pgtable will not
+ * be freed, because we do an rcu free and here we are
+ * irq disabled
+ */
+ pdshift = PUD_SHIFT;
+ pudp = pud_offset(&pgd, ea);
+ pud = READ_ONCE(*pudp);
+
+ if (pud_none(pud))
+ return NULL;
+ else if (pud_huge(pud)) {
+ ret_pte = (pte_t *) pudp;
+ goto out;
+ } else if (is_hugepd(__hugepd(pud_val(pud))))
+ hpdp = (hugepd_t *)&pud;
+ else {
+ pdshift = PMD_SHIFT;
+ pmdp = pmd_offset(&pud, ea);
+ pmd = READ_ONCE(*pmdp);
+ /*
+ * A hugepage collapse is captured by pmd_none, because
+ * it mark the pmd none and do a hpte invalidate.
+ */
+ if (pmd_none(pmd))
+ return NULL;
+
+ if (pmd_trans_huge(pmd) || pmd_devmap(pmd)) {
+ if (is_thp)
+ *is_thp = true;
+ ret_pte = (pte_t *) pmdp;
+ goto out;
+ }
+
+ if (pmd_huge(pmd)) {
+ ret_pte = (pte_t *) pmdp;
+ goto out;
+ } else if (is_hugepd(__hugepd(pmd_val(pmd))))
+ hpdp = (hugepd_t *)&pmd;
+ else
+ return pte_offset_kernel(&pmd, ea);
+ }
+ }
+ if (!hpdp)
+ return NULL;
+
+ ret_pte = hugepte_offset(*hpdp, ea, pdshift);
+ pdshift = hugepd_shift(*hpdp);
+out:
+ if (hpage_shift)
+ *hpage_shift = pdshift;
+ return ret_pte;
+}
+EXPORT_SYMBOL_GPL(__find_linux_pte);
+
+int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
+ unsigned long end, int write, struct page **pages, int *nr)
+{
+ unsigned long pte_end;
+ struct page *head, *page;
+ pte_t pte;
+ int refs;
+
+ pte_end = (addr + sz) & ~(sz-1);
+ if (pte_end < end)
+ end = pte_end;
+
+ pte = READ_ONCE(*ptep);
+
+ if (!pte_access_permitted(pte, write))
+ 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);
+ 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;
+ }
+
+ return 1;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 03:05:19 +0000