| /* |
| * 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 <asm/pgtable.h> |
| #include <asm/pgalloc.h> |
| #include <asm/tlb.h> |
| #include <asm/setup.h> |
| #include <asm/hugetlb.h> |
| |
| #ifdef CONFIG_HUGETLB_PAGE |
| |
| #define PAGE_SHIFT_64K 16 |
| #define PAGE_SHIFT_16M 24 |
| #define PAGE_SHIFT_16G 34 |
| |
| unsigned int HPAGE_SHIFT; |
| |
| /* |
| * Tracks gpages after the device tree is scanned and before the |
| * huge_boot_pages list is ready. On non-Freescale implementations, this is |
| * just used to track 16G pages and so is a single array. FSL-based |
| * implementations may have more than one gpage size, so we need multiple |
| * arrays |
| */ |
| #ifdef CONFIG_PPC_FSL_BOOK3E |
| #define MAX_NUMBER_GPAGES 128 |
| struct psize_gpages { |
| u64 gpage_list[MAX_NUMBER_GPAGES]; |
| unsigned int nr_gpages; |
| }; |
| static struct psize_gpages gpage_freearray[MMU_PAGE_COUNT]; |
| #else |
| #define MAX_NUMBER_GPAGES 1024 |
| static u64 gpage_freearray[MAX_NUMBER_GPAGES]; |
| static unsigned nr_gpages; |
| #endif |
| |
| #define hugepd_none(hpd) ((hpd).pd == 0) |
| |
| #ifdef CONFIG_PPC_BOOK3S_64 |
| /* |
| * At this point we do the placement change only for BOOK3S 64. This would |
| * possibly work on other subarchs. |
| */ |
| |
| /* |
| * We have PGD_INDEX_SIZ = 12 and PTE_INDEX_SIZE = 8, so that we can have |
| * 16GB hugepage pte in PGD and 16MB hugepage pte at PMD; |
| * |
| * Defined in such a way that we can optimize away code block at build time |
| * if CONFIG_HUGETLB_PAGE=n. |
| */ |
| int pmd_huge(pmd_t pmd) |
| { |
| /* |
| * leaf pte for huge page, bottom two bits != 00 |
| */ |
| return ((pmd_val(pmd) & 0x3) != 0x0); |
| } |
| |
| int pud_huge(pud_t pud) |
| { |
| /* |
| * leaf pte for huge page, bottom two bits != 00 |
| */ |
| return ((pud_val(pud) & 0x3) != 0x0); |
| } |
| |
| int pgd_huge(pgd_t pgd) |
| { |
| /* |
| * leaf pte for huge page, bottom two bits != 00 |
| */ |
| return ((pgd_val(pgd) & 0x3) != 0x0); |
| } |
| #else |
| int pmd_huge(pmd_t pmd) |
| { |
| return 0; |
| } |
| |
| int pud_huge(pud_t pud) |
| { |
| return 0; |
| } |
| |
| int pgd_huge(pgd_t pgd) |
| { |
| return 0; |
| } |
| #endif |
| |
| pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) |
| { |
| /* Only called for hugetlbfs pages, hence can ignore THP */ |
| 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) |
| { |
| 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 |
| |
| new = kmem_cache_zalloc(cachep, 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); |
| #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. |
| * 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 |
| /* We use the old format for PPC_FSL_BOOK3E */ |
| hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift; |
| } |
| /* 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->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 = (unsigned long)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; |
| } |
| |
| /* |
| * These macros define how to determine which level of the page table holds |
| * the hpdp. |
| */ |
| #ifdef CONFIG_PPC_FSL_BOOK3E |
| #define HUGEPD_PGD_SHIFT PGDIR_SHIFT |
| #define HUGEPD_PUD_SHIFT PUD_SHIFT |
| #else |
| #define HUGEPD_PGD_SHIFT PUD_SHIFT |
| #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. |
| */ |
| 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 == PGDIR_SHIFT) |
| /* 16GB huge page */ |
| return (pte_t *) pg; |
| else if (pshift > PUD_SHIFT) |
| /* |
| * We need to use hugepd table |
| */ |
| hpdp = (hugepd_t *)pg; |
| else { |
| pdshift = PUD_SHIFT; |
| pu = pud_alloc(mm, pg, addr); |
| if (pshift == PUD_SHIFT) |
| return (pte_t *)pu; |
| else if (pshift > PMD_SHIFT) |
| hpdp = (hugepd_t *)pu; |
| else { |
| pdshift = PMD_SHIFT; |
| pm = pmd_alloc(mm, pu, addr); |
| if (pshift == PMD_SHIFT) |
| /* 16MB hugepage */ |
| return (pte_t *)pm; |
| else |
| 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 { |
| pdshift = PUD_SHIFT; |
| pu = pud_alloc(mm, pg, addr); |
| if (pshift >= HUGEPD_PUD_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); |
| } |
| #endif |
| |
| #ifdef CONFIG_PPC_FSL_BOOK3E |
| /* Build list of addresses of gigantic pages. This function is used in early |
| * boot before the buddy allocator is setup. |
| */ |
| void add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages) |
| { |
| unsigned int idx = shift_to_mmu_psize(__ffs(page_size)); |
| int i; |
| |
| if (addr == 0) |
| return; |
| |
| gpage_freearray[idx].nr_gpages = number_of_pages; |
| |
| for (i = 0; i < number_of_pages; i++) { |
| gpage_freearray[idx].gpage_list[i] = addr; |
| 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; |
| int idx = shift_to_mmu_psize(huge_page_shift(hstate)); |
| int nr_gpages = gpage_freearray[idx].nr_gpages; |
| |
| if (nr_gpages == 0) |
| return 0; |
| |
| #ifdef CONFIG_HIGHMEM |
| /* |
| * If gpages can be in highmem we can't use the trick of storing the |
| * data structure in the page; allocate space for this |
| */ |
| m = memblock_virt_alloc(sizeof(struct huge_bootmem_page), 0); |
| m->phys = gpage_freearray[idx].gpage_list[--nr_gpages]; |
| #else |
| m = phys_to_virt(gpage_freearray[idx].gpage_list[--nr_gpages]); |
| #endif |
| |
| list_add(&m->list, &huge_boot_pages); |
| gpage_freearray[idx].nr_gpages = nr_gpages; |
| gpage_freearray[idx].gpage_list[nr_gpages] = 0; |
| m->hstate = hstate; |
| |
| return 1; |
| } |
| /* |
| * Scan the command line hugepagesz= options for gigantic pages; store those in |
| * a list that we use to allocate the memory once all options are parsed. |
| */ |
| |
| unsigned long gpage_npages[MMU_PAGE_COUNT]; |
| |
| static int __init do_gpage_early_setup(char *param, char *val, |
| const char *unused) |
| { |
| static phys_addr_t size; |
| unsigned long npages; |
| |
| /* |
| * The hugepagesz and hugepages cmdline options are interleaved. We |
| * use the size variable to keep track of whether or not this was done |
| * properly and skip over instances where it is incorrect. Other |
| * command-line parsing code will issue warnings, so we don't need to. |
| * |
| */ |
| if ((strcmp(param, "default_hugepagesz") == 0) || |
| (strcmp(param, "hugepagesz") == 0)) { |
| size = memparse(val, NULL); |
| } else if (strcmp(param, "hugepages") == 0) { |
| if (size != 0) { |
| if (sscanf(val, "%lu", &npages) <= 0) |
| npages = 0; |
| if (npages > MAX_NUMBER_GPAGES) { |
| pr_warn("MMU: %lu pages requested for page " |
| "size %llu KB, limiting to " |
| __stringify(MAX_NUMBER_GPAGES) "\n", |
| npages, size / 1024); |
| npages = MAX_NUMBER_GPAGES; |
| } |
| gpage_npages[shift_to_mmu_psize(__ffs(size))] = npages; |
| size = 0; |
| } |
| } |
| return 0; |
| } |
| |
| |
| /* |
| * This function allocates physical space for pages that are larger than the |
| * buddy allocator can handle. We want to allocate these in highmem because |
| * the amount of lowmem is limited. This means that this function MUST be |
| * called before lowmem_end_addr is set up in MMU_init() in order for the lmb |
| * allocate to grab highmem. |
| */ |
| void __init reserve_hugetlb_gpages(void) |
| { |
| static __initdata char cmdline[COMMAND_LINE_SIZE]; |
| phys_addr_t size, base; |
| int i; |
| |
| strlcpy(cmdline, boot_command_line, COMMAND_LINE_SIZE); |
| parse_args("hugetlb gpages", cmdline, NULL, 0, 0, 0, |
| &do_gpage_early_setup); |
| |
| /* |
| * Walk gpage list in reverse, allocating larger page sizes first. |
| * Skip over unsupported sizes, or sizes that have 0 gpages allocated. |
| * When we reach the point in the list where pages are no longer |
| * considered gpages, we're done. |
| */ |
| for (i = MMU_PAGE_COUNT-1; i >= 0; i--) { |
| if (mmu_psize_defs[i].shift == 0 || gpage_npages[i] == 0) |
| continue; |
| else if (mmu_psize_to_shift(i) < (MAX_ORDER + PAGE_SHIFT)) |
| break; |
| |
| size = (phys_addr_t)(1ULL << mmu_psize_to_shift(i)); |
| base = memblock_alloc_base(size * gpage_npages[i], size, |
| MEMBLOCK_ALLOC_ANYWHERE); |
| add_gpage(base, size, gpage_npages[i]); |
| } |
| } |
| |
| #else /* !PPC_FSL_BOOK3E */ |
| |
| /* Build list of addresses of gigantic pages. This function is used in early |
| * boot before the buddy allocator is setup. |
| */ |
| void 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; |
| } |
| } |
| |
| /* 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; |
| } |
| #endif |
| |
| int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) |
| { |
| return 0; |
| } |
| |
| #ifdef CONFIG_PPC_FSL_BOOK3E |
| #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 = this_cpu_ptr(&hugepd_freelist_cur); |
| |
| if (atomic_read(&tlb->mm->mm_users) < 2 || |
| cpumask_equal(mm_cpumask(tlb->mm), |
| cpumask_of(smp_processor_id()))) { |
| 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); |
| } |
| #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; |
| |
| #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 |
| |
| 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->pd = 0; |
| |
| #ifdef CONFIG_PPC_FSL_BOOK3E |
| hugepd_free(tlb, hugepte); |
| #else |
| pgtable_free_tlb(tlb, hugepte, pdshift - shift); |
| #endif |
| } |
| |
| 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 { |
| 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; |
| } |
| #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 |
| 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); |
| } |
| |
| 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 { |
| #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 *)pud)); |
| #endif |
| 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); |
| } |
| |
| /* |
| * 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 { |
| #ifdef CONFIG_PPC_FSL_BOOK3E |
| /* |
| * 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 |
| free_hugepd_range(tlb, (hugepd_t *)pgd, PGDIR_SHIFT, |
| addr, next, floor, ceiling); |
| } |
| } while (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; |
| /* |
| * Transparent hugepages are handled by generic code. We can skip them |
| * here. |
| */ |
| ptep = find_linux_pte_or_hugepte(mm->pgd, address, &shift); |
| |
| /* Verify it is a huge page else bail. */ |
| if (!ptep || !shift || pmd_trans_huge(*(pmd_t *)ptep)) |
| return ERR_PTR(-EINVAL); |
| |
| mask = (1UL << shift) - 1; |
| page = pte_page(*ptep); |
| if (page) |
| page += (address & mask) / PAGE_SIZE; |
| |
| return page; |
| } |
| |
| struct page * |
| follow_huge_pmd(struct mm_struct *mm, unsigned long address, |
| pmd_t *pmd, int write) |
| { |
| BUG(); |
| return NULL; |
| } |
| |
| 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)); |
| |
| 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 |
| unsigned int psize = get_slice_psize(vma->vm_mm, vma->vm_start); |
| |
| return 1UL << mmu_psize_to_shift(psize); |
| #else |
| if (!is_vm_hugetlb_page(vma)) |
| return PAGE_SIZE; |
| |
| return huge_page_size(hstate_vma(vma)); |
| #endif |
| } |
| |
| 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. */ |
| #ifdef CONFIG_PPC_FSL_BOOK3E |
| if ((size < PAGE_SIZE) || !is_power_of_4(size)) |
| return -EINVAL; |
| #else |
| if (!is_power_of_2(size) |
| || (shift > SLICE_HIGH_SHIFT) || (shift <= PAGE_SHIFT)) |
| return -EINVAL; |
| #endif |
| |
| 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); |
| |
| #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 (!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; |
| /* |
| * 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 (!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; |
| } |
| #endif |
| module_init(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, bottom two bits != 00 |
| * (4) hugepd pointer, bottom two bits == 00, next 4 bits 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. |
| */ |
| |
| pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *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 (shift) |
| *shift = 0; |
| |
| pgdp = pgdir + pgd_index(ea); |
| pgd = ACCESS_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 = ACCESS_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 = ACCESS_ONCE(*pmdp); |
| /* |
| * A hugepage collapse is captured by pmd_none, because |
| * it mark the pmd none and do a hpte invalidate. |
| * |
| * A hugepage split is captured by pmd_trans_splitting |
| * because we mark the pmd trans splitting and do a |
| * hpte invalidate |
| * |
| */ |
| if (pmd_none(pmd) || pmd_trans_splitting(pmd)) |
| return NULL; |
| |
| if (pmd_huge(pmd) || pmd_large(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 (shift) |
| *shift = pdshift; |
| return ret_pte; |
| } |
| EXPORT_SYMBOL_GPL(find_linux_pte_or_hugepte); |
| |
| 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 = ACCESS_ONCE(*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; |
| } |