From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- arch/powerpc/mm/hugetlbpage.c | 592 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 592 insertions(+) create mode 100644 arch/powerpc/mm/hugetlbpage.c (limited to 'arch/powerpc/mm/hugetlbpage.c') 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 + */ + +#include +#include +#include +#include +#include +#include +#include + +#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)); +} -- cgit v1.2.3