| /* |
| * 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/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) |
| |
| #define PTE_T_ORDER (__builtin_ffs(sizeof(pte_t)) - __builtin_ffs(sizeof(void *))) |
| |
| 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 = PGT_CACHE(PTE_T_ORDER); |
| num_hugepd = 1 << (pshift - pdshift); |
| } else if (IS_ENABLED(CONFIG_PPC_8xx)) { |
| cachep = PGT_CACHE(PTE_INDEX_SIZE); |
| num_hugepd = 1; |
| } else { |
| cachep = PGT_CACHE(pdshift - pshift); |
| num_hugepd = 1; |
| } |
| |
| new = kmem_cache_alloc(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) | HUGEPD_VAL_BITS | |
| (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 (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 (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 (pshift >= PUD_SHIFT) { |
| ptl = pud_lockptr(mm, pu); |
| hpdp = (hugepd_t *)pu; |
| } else { |
| pdshift = PMD_SHIFT; |
| pm = pmd_alloc(mm, pu, addr); |
| 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(PGT_CACHE(PTE_T_ORDER), 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(PGT_CACHE(PTE_T_ORDER), 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(&(*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 if (IS_ENABLED(CONFIG_PPC_8xx)) |
| pgtable_free_tlb(tlb, hugepte, |
| get_hugepd_cache_index(PTE_INDEX_SIZE)); |
| 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); |
| |
| 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 && IS_ENABLED(CONFIG_PPC_8xx)) |
| pgtable_cache_add(PTE_INDEX_SIZE); |
| else if (pdshift > shift) |
| pgtable_cache_add(pdshift - shift); |
| #if defined(CONFIG_PPC_FSL_BOOK3E) || defined(CONFIG_PPC_8xx) |
| else |
| pgtable_cache_add(PTE_T_ORDER); |
| #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; |
| } |
| /* |
| * pmd_large check below will handle the swap pmd pte |
| * we need to do both the check because they are config |
| * dependent. |
| */ |
| 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 (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; |
| } |