diff options
Diffstat (limited to 'arch/powerpc/mm/hugetlbpage.c')
| -rw-r--r-- | arch/powerpc/mm/hugetlbpage.c | 826 |
1 files changed, 667 insertions, 159 deletions
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index 9bb249c3046..7e70ae968e5 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -1,7 +1,8 @@ /* - * PPC64 (POWER4) Huge TLB Page Support for Kernel. + * 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> @@ -11,127 +12,229 @@ #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 -#define MAX_NUMBER_GPAGES 1024 +unsigned int HPAGE_SHIFT; -/* 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]; +/* + * 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) -/* 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. */ +#ifdef CONFIG_PPC_BOOK3S_64 +/* + * At this point we do the placement change only for BOOK3S 64. This would + * possibly work on other subarchs. + */ -static inline int shift_to_mmu_psize(unsigned int shift) +/* + * 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; + */ +int pmd_huge(pmd_t pmd) { - int psize; + /* + * leaf pte for huge page, bottom two bits != 00 + */ + return ((pmd_val(pmd) & 0x3) != 0x0); +} - for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) - if (mmu_psize_defs[psize].shift == shift) - return psize; - return -1; +int pud_huge(pud_t pud) +{ + /* + * leaf pte for huge page, bottom two bits != 00 + */ + return ((pud_val(pud) & 0x3) != 0x0); } -static inline unsigned int mmu_psize_to_shift(unsigned int mmu_psize) +int pgd_huge(pgd_t pgd) { - if (mmu_psize_defs[mmu_psize].shift) - return mmu_psize_defs[mmu_psize].shift; - BUG(); + /* + * leaf pte for huge page, bottom two bits != 00 + */ + return ((pgd_val(pgd) & 0x3) != 0x0); +} +#else +int pmd_huge(pmd_t pmd) +{ + return 0; } -#define hugepd_none(hpd) ((hpd).pd == 0) +int pud_huge(pud_t pud) +{ + return 0; +} -static inline pte_t *hugepd_page(hugepd_t hpd) +int pgd_huge(pgd_t pgd) { - BUG_ON(!hugepd_ok(hpd)); - return (pte_t *)((hpd.pd & ~HUGEPD_SHIFT_MASK) | 0xc000000000000000); + return 0; } +#endif -static inline unsigned int hugepd_shift(hugepd_t hpd) +pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) { - return hpd.pd & HUGEPD_SHIFT_MASK; + /* Only called for hugetlbfs pages, hence can ignore THP */ + return find_linux_pte_or_hugepte(mm->pgd, addr, NULL); } -static inline pte_t *hugepte_offset(hugepd_t *hpdp, unsigned long addr, unsigned pdshift) +static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp, + unsigned long address, unsigned pdshift, unsigned pshift) { - unsigned long idx = (addr & ((1UL << pdshift) - 1)) >> hugepd_shift(*hpdp); - pte_t *dir = hugepd_page(*hpdp); + 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); - return dir + idx; + 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; } -pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift) +/* + * 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; - if (shift) - *shift = 0; + addr &= ~(sz-1); + pg = pgd_offset(mm, addr); - pg = pgdir + pgd_index(ea); - if (is_hugepd(pg)) { + 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 if (!pgd_none(*pg)) { + else { pdshift = PUD_SHIFT; - pu = pud_offset(pg, ea); - if (is_hugepd(pu)) + pu = pud_alloc(mm, pg, addr); + if (pshift == PUD_SHIFT) + return (pte_t *)pu; + else if (pshift > PMD_SHIFT) hpdp = (hugepd_t *)pu; - else if (!pud_none(*pu)) { + else { pdshift = PMD_SHIFT; - pm = pmd_offset(pu, ea); - if (is_hugepd(pm)) + pm = pmd_alloc(mm, pu, addr); + if (pshift == PMD_SHIFT) + /* 16MB hugepage */ + return (pte_t *)pm; + else 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); + BUG_ON(!hugepd_none(*hpdp) && !hugepd_ok(*hpdp)); - if (! new) - return -ENOMEM; + if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr, pdshift, pshift)) + return NULL; - 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; + 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; @@ -144,12 +247,13 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz addr &= ~(sz-1); pg = pgd_offset(mm, addr); - if (pshift >= PUD_SHIFT) { + + if (pshift >= HUGEPD_PGD_SHIFT) { hpdp = (hugepd_t *)pg; } else { pdshift = PUD_SHIFT; pu = pud_alloc(mm, pg, addr); - if (pshift >= PMD_SHIFT) { + if (pshift >= HUGEPD_PUD_SHIFT) { hpdp = (hugepd_t *)pu; } else { pdshift = PMD_SHIFT; @@ -168,12 +272,136 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz 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 or bootmem 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 = alloc_bootmem(sizeof(struct huge_bootmem_page)); + 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; + 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 or bootmem allocator is setup. */ -void add_gpage(unsigned long addr, unsigned long page_size, - unsigned long number_of_pages) +void add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages) { if (!addr) return; @@ -199,19 +427,81 @@ int alloc_bootmem_huge_page(struct hstate *hstate) 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 = &get_cpu_var(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); - unsigned shift = hugepd_shift(*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) @@ -224,9 +514,16 @@ static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshif if (end - 1 > ceiling - 1) return; - hpdp->pd = 0; + for (i = 0; i < num_hugepd; i++, hpdp++) + hpdp->pd = 0; + tlb->need_flush = 1; + +#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, @@ -238,14 +535,29 @@ static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud, unsigned long start; start = addr; - pmd = pmd_offset(pud, addr); do { + pmd = pmd_offset(pud, addr); next = pmd_addr_end(addr, end); - if (pmd_none(*pmd)) + if (!is_hugepd(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 (pmd++, addr = next, addr != end); + } while (addr = next, addr != end); start &= PUD_MASK; if (start < floor) @@ -272,8 +584,8 @@ static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd, unsigned long start; start = addr; - pud = pud_offset(pgd, addr); do { + pud = pud_offset(pgd, addr); next = pud_addr_end(addr, end); if (!is_hugepd(pud)) { if (pud_none_or_clear_bad(pud)) @@ -281,10 +593,19 @@ static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd, 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 (pud++, addr = next, addr != end); + } while (addr = next, addr != end); start &= PGDIR_MASK; if (start < floor) @@ -304,8 +625,6 @@ static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd, /* * 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, @@ -331,18 +650,27 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb, * too. */ - pgd = pgd_offset(tlb->mm, addr); do { next = pgd_addr_end(addr, end); + pgd = pgd_offset(tlb->mm, addr); if (!is_hugepd(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 (pgd++, addr = next, addr != end); + } while (addr = next, addr != end); } struct page * @@ -352,11 +680,14 @@ follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) 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) + if (!ptep || !shift || pmd_trans_huge(*(pmd_t *)ptep)) return ERR_PTR(-EINVAL); mask = (1UL << shift) - 1; @@ -367,16 +698,6 @@ follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) 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) @@ -385,58 +706,6 @@ follow_huge_pmd(struct mm_struct *mm, unsigned long address, 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; - 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); - 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 */ - while (*nr) { - put_page(page); - (*nr)--; - } - } - - return 1; -} - static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end, unsigned long sz) { @@ -462,6 +731,7 @@ int gup_hugepd(hugepd_t *hugepd, unsigned pdshift, 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) @@ -469,14 +739,29 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 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); + 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) @@ -486,9 +771,14 @@ static int __init add_huge_page_size(unsigned long long size) /* 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; @@ -525,11 +815,51 @@ static int __init hugepage_setup_sz(char *str) } __setup("hugepagesz=", hugepage_setup_sz); +#ifdef CONFIG_PPC_FSL_BOOK3E +struct kmem_cache *hugepte_cache; static int __init hugetlbpage_init(void) { int psize; - if (!cpu_has_feature(CPU_FTR_16M_PAGE)) + 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) { @@ -550,11 +880,16 @@ static int __init hugetlbpage_init(void) 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); + /* + * 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 @@ -567,15 +902,188 @@ static int __init hugetlbpage_init(void) 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++) - __flush_dcache_icache(page_address(page+i)); + 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(&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(&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(&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; + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + /* + * check for splitting here + */ + if (pmd_trans_splitting(pte_pmd(pte))) + return 0; +#endif + + /* 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; } |