| /* |
| * 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 <rohit.seth@intel.com> |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/fs.h> |
| #include <linux/mm.h> |
| #include <linux/hugetlb.h> |
| #include <linux/pagemap.h> |
| #include <linux/smp_lock.h> |
| #include <linux/slab.h> |
| #include <linux/err.h> |
| #include <linux/sysctl.h> |
| #include <asm/mman.h> |
| #include <asm/pgalloc.h> |
| #include <asm/tlb.h> |
| #include <asm/tlbflush.h> |
| #include <asm/mmu_context.h> |
| #include <asm/machdep.h> |
| #include <asm/cputable.h> |
| #include <asm/tlb.h> |
| |
| #include <linux/sysctl.h> |
| |
| #define NUM_LOW_AREAS (0x100000000UL >> SID_SHIFT) |
| #define NUM_HIGH_AREAS (PGTABLE_RANGE >> HTLB_AREA_SHIFT) |
| |
| #ifdef CONFIG_PPC_64K_PAGES |
| #define HUGEPTE_INDEX_SIZE (PMD_SHIFT-HPAGE_SHIFT) |
| #else |
| #define HUGEPTE_INDEX_SIZE (PUD_SHIFT-HPAGE_SHIFT) |
| #endif |
| #define PTRS_PER_HUGEPTE (1 << HUGEPTE_INDEX_SIZE) |
| #define HUGEPTE_TABLE_SIZE (sizeof(pte_t) << HUGEPTE_INDEX_SIZE) |
| |
| #define HUGEPD_SHIFT (HPAGE_SHIFT + HUGEPTE_INDEX_SIZE) |
| #define HUGEPD_SIZE (1UL << HUGEPD_SHIFT) |
| #define HUGEPD_MASK (~(HUGEPD_SIZE-1)) |
| |
| #define huge_pgtable_cache (pgtable_cache[HUGEPTE_CACHE_NUM]) |
| |
| /* 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. */ |
| #define HUGEPD_OK 0x1 |
| |
| typedef struct { unsigned long pd; } hugepd_t; |
| |
| #define hugepd_none(hpd) ((hpd).pd == 0) |
| |
| static inline pte_t *hugepd_page(hugepd_t hpd) |
| { |
| BUG_ON(!(hpd.pd & HUGEPD_OK)); |
| return (pte_t *)(hpd.pd & ~HUGEPD_OK); |
| } |
| |
| static inline pte_t *hugepte_offset(hugepd_t *hpdp, unsigned long addr) |
| { |
| unsigned long idx = ((addr >> HPAGE_SHIFT) & (PTRS_PER_HUGEPTE-1)); |
| pte_t *dir = hugepd_page(*hpdp); |
| |
| return dir + idx; |
| } |
| |
| static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp, |
| unsigned long address) |
| { |
| pte_t *new = kmem_cache_alloc(huge_pgtable_cache, |
| GFP_KERNEL|__GFP_REPEAT); |
| |
| if (! new) |
| return -ENOMEM; |
| |
| spin_lock(&mm->page_table_lock); |
| if (!hugepd_none(*hpdp)) |
| kmem_cache_free(huge_pgtable_cache, new); |
| else |
| hpdp->pd = (unsigned long)new | HUGEPD_OK; |
| spin_unlock(&mm->page_table_lock); |
| return 0; |
| } |
| |
| /* Modelled after find_linux_pte() */ |
| pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) |
| { |
| pgd_t *pg; |
| pud_t *pu; |
| |
| BUG_ON(! in_hugepage_area(mm->context, addr)); |
| |
| addr &= HPAGE_MASK; |
| |
| pg = pgd_offset(mm, addr); |
| if (!pgd_none(*pg)) { |
| pu = pud_offset(pg, addr); |
| if (!pud_none(*pu)) { |
| #ifdef CONFIG_PPC_64K_PAGES |
| pmd_t *pm; |
| pm = pmd_offset(pu, addr); |
| if (!pmd_none(*pm)) |
| return hugepte_offset((hugepd_t *)pm, addr); |
| #else |
| return hugepte_offset((hugepd_t *)pu, addr); |
| #endif |
| } |
| } |
| |
| return NULL; |
| } |
| |
| pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr) |
| { |
| pgd_t *pg; |
| pud_t *pu; |
| hugepd_t *hpdp = NULL; |
| |
| BUG_ON(! in_hugepage_area(mm->context, addr)); |
| |
| addr &= HPAGE_MASK; |
| |
| pg = pgd_offset(mm, addr); |
| pu = pud_alloc(mm, pg, addr); |
| |
| if (pu) { |
| #ifdef CONFIG_PPC_64K_PAGES |
| pmd_t *pm; |
| pm = pmd_alloc(mm, pu, addr); |
| if (pm) |
| hpdp = (hugepd_t *)pm; |
| #else |
| hpdp = (hugepd_t *)pu; |
| #endif |
| } |
| |
| if (! hpdp) |
| return NULL; |
| |
| if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr)) |
| return NULL; |
| |
| return hugepte_offset(hpdp, addr); |
| } |
| |
| int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) |
| { |
| return 0; |
| } |
| |
| static void free_hugepte_range(struct mmu_gather *tlb, hugepd_t *hpdp) |
| { |
| pte_t *hugepte = hugepd_page(*hpdp); |
| |
| hpdp->pd = 0; |
| tlb->need_flush = 1; |
| pgtable_free_tlb(tlb, pgtable_free_cache(hugepte, HUGEPTE_CACHE_NUM, |
| PGF_CACHENUM_MASK)); |
| } |
| |
| #ifdef CONFIG_PPC_64K_PAGES |
| 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_hugepte_range(tlb, (hugepd_t *)pmd); |
| } 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); |
| } |
| #endif |
| |
| 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); |
| #ifdef CONFIG_PPC_64K_PAGES |
| if (pud_none_or_clear_bad(pud)) |
| continue; |
| hugetlb_free_pmd_range(tlb, pud, addr, next, floor, ceiling); |
| #else |
| if (pud_none(*pud)) |
| continue; |
| free_hugepte_range(tlb, (hugepd_t *)pud); |
| #endif |
| } 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); |
| } |
| |
| /* |
| * 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; |
| unsigned long start; |
| |
| /* |
| * Comments below take from the normal free_pgd_range(). They |
| * apply here too. The tests against HUGEPD_MASK below are |
| * essential, because we *don't* test for this at the bottom |
| * level. Without them we'll attempt to free a hugepte table |
| * when we unmap just part of it, even if there are other |
| * active mappings using it. |
| * |
| * The next few lines have given us lots of grief... |
| * |
| * Why are we testing HUGEPD* at this top level? Because |
| * often there will be no work to do at all, and we'd prefer |
| * not to go all the way down to the bottom just to discover |
| * that. |
| * |
| * Why all these "- 1"s? Because 0 represents both the bottom |
| * of the address space and the top of it (using -1 for the |
| * top wouldn't help much: the masks would do the wrong thing). |
| * The rule is that addr 0 and floor 0 refer to the bottom of |
| * the address space, but end 0 and ceiling 0 refer to the top |
| * Comparisons need to use "end - 1" and "ceiling - 1" (though |
| * that end 0 case should be mythical). |
| * |
| * Wherever addr is brought up or ceiling brought down, we |
| * must be careful to reject "the opposite 0" before it |
| * confuses the subsequent tests. But what about where end is |
| * brought down by HUGEPD_SIZE below? no, end can't go down to |
| * 0 there. |
| * |
| * Whereas we round start (addr) and ceiling down, by different |
| * masks at different levels, in order to test whether a table |
| * now has no other vmas using it, so can be freed, we don't |
| * bother to round floor or end up - the tests don't need that. |
| */ |
| |
| addr &= HUGEPD_MASK; |
| if (addr < floor) { |
| addr += HUGEPD_SIZE; |
| if (!addr) |
| return; |
| } |
| if (ceiling) { |
| ceiling &= HUGEPD_MASK; |
| if (!ceiling) |
| return; |
| } |
| if (end - 1 > ceiling - 1) |
| end -= HUGEPD_SIZE; |
| if (addr > end - 1) |
| return; |
| |
| start = addr; |
| pgd = pgd_offset((*tlb)->mm, addr); |
| do { |
| BUG_ON(! in_hugepage_area((*tlb)->mm->context, addr)); |
| next = pgd_addr_end(addr, end); |
| if (pgd_none_or_clear_bad(pgd)) |
| continue; |
| hugetlb_free_pud_range(*tlb, pgd, addr, next, floor, ceiling); |
| } while (pgd++, addr = next, addr != end); |
| } |
| |
| void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, |
| pte_t *ptep, pte_t pte) |
| { |
| if (pte_present(*ptep)) { |
| /* We open-code pte_clear because we need to pass the right |
| * argument to hpte_update (huge / !huge) |
| */ |
| unsigned long old = pte_update(ptep, ~0UL); |
| if (old & _PAGE_HASHPTE) |
| hpte_update(mm, addr & HPAGE_MASK, ptep, old, 1); |
| flush_tlb_pending(); |
| } |
| *ptep = __pte(pte_val(pte) & ~_PAGE_HPTEFLAGS); |
| } |
| |
| pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, |
| pte_t *ptep) |
| { |
| unsigned long old = pte_update(ptep, ~0UL); |
| |
| if (old & _PAGE_HASHPTE) |
| hpte_update(mm, addr & HPAGE_MASK, ptep, old, 1); |
| *ptep = __pte(0); |
| |
| return __pte(old); |
| } |
| |
| struct slb_flush_info { |
| struct mm_struct *mm; |
| u16 newareas; |
| }; |
| |
| static void flush_low_segments(void *parm) |
| { |
| struct slb_flush_info *fi = parm; |
| unsigned long i; |
| |
| BUILD_BUG_ON((sizeof(fi->newareas)*8) != NUM_LOW_AREAS); |
| |
| if (current->active_mm != fi->mm) |
| return; |
| |
| /* Only need to do anything if this CPU is working in the same |
| * mm as the one which has changed */ |
| |
| /* update the paca copy of the context struct */ |
| get_paca()->context = current->active_mm->context; |
| |
| asm volatile("isync" : : : "memory"); |
| for (i = 0; i < NUM_LOW_AREAS; i++) { |
| if (! (fi->newareas & (1U << i))) |
| continue; |
| asm volatile("slbie %0" |
| : : "r" ((i << SID_SHIFT) | SLBIE_C)); |
| } |
| asm volatile("isync" : : : "memory"); |
| } |
| |
| static void flush_high_segments(void *parm) |
| { |
| struct slb_flush_info *fi = parm; |
| unsigned long i, j; |
| |
| |
| BUILD_BUG_ON((sizeof(fi->newareas)*8) != NUM_HIGH_AREAS); |
| |
| if (current->active_mm != fi->mm) |
| return; |
| |
| /* Only need to do anything if this CPU is working in the same |
| * mm as the one which has changed */ |
| |
| /* update the paca copy of the context struct */ |
| get_paca()->context = current->active_mm->context; |
| |
| asm volatile("isync" : : : "memory"); |
| for (i = 0; i < NUM_HIGH_AREAS; i++) { |
| if (! (fi->newareas & (1U << i))) |
| continue; |
| for (j = 0; j < (1UL << (HTLB_AREA_SHIFT-SID_SHIFT)); j++) |
| asm volatile("slbie %0" |
| :: "r" (((i << HTLB_AREA_SHIFT) |
| + (j << SID_SHIFT)) | SLBIE_C)); |
| } |
| asm volatile("isync" : : : "memory"); |
| } |
| |
| static int prepare_low_area_for_htlb(struct mm_struct *mm, unsigned long area) |
| { |
| unsigned long start = area << SID_SHIFT; |
| unsigned long end = (area+1) << SID_SHIFT; |
| struct vm_area_struct *vma; |
| |
| BUG_ON(area >= NUM_LOW_AREAS); |
| |
| /* Check no VMAs are in the region */ |
| vma = find_vma(mm, start); |
| if (vma && (vma->vm_start < end)) |
| return -EBUSY; |
| |
| return 0; |
| } |
| |
| static int prepare_high_area_for_htlb(struct mm_struct *mm, unsigned long area) |
| { |
| unsigned long start = area << HTLB_AREA_SHIFT; |
| unsigned long end = (area+1) << HTLB_AREA_SHIFT; |
| struct vm_area_struct *vma; |
| |
| BUG_ON(area >= NUM_HIGH_AREAS); |
| |
| /* Hack, so that each addresses is controlled by exactly one |
| * of the high or low area bitmaps, the first high area starts |
| * at 4GB, not 0 */ |
| if (start == 0) |
| start = 0x100000000UL; |
| |
| /* Check no VMAs are in the region */ |
| vma = find_vma(mm, start); |
| if (vma && (vma->vm_start < end)) |
| return -EBUSY; |
| |
| return 0; |
| } |
| |
| static int open_low_hpage_areas(struct mm_struct *mm, u16 newareas) |
| { |
| unsigned long i; |
| struct slb_flush_info fi; |
| |
| BUILD_BUG_ON((sizeof(newareas)*8) != NUM_LOW_AREAS); |
| BUILD_BUG_ON((sizeof(mm->context.low_htlb_areas)*8) != NUM_LOW_AREAS); |
| |
| newareas &= ~(mm->context.low_htlb_areas); |
| if (! newareas) |
| return 0; /* The segments we want are already open */ |
| |
| for (i = 0; i < NUM_LOW_AREAS; i++) |
| if ((1 << i) & newareas) |
| if (prepare_low_area_for_htlb(mm, i) != 0) |
| return -EBUSY; |
| |
| mm->context.low_htlb_areas |= newareas; |
| |
| /* the context change must make it to memory before the flush, |
| * so that further SLB misses do the right thing. */ |
| mb(); |
| |
| fi.mm = mm; |
| fi.newareas = newareas; |
| on_each_cpu(flush_low_segments, &fi, 0, 1); |
| |
| return 0; |
| } |
| |
| static int open_high_hpage_areas(struct mm_struct *mm, u16 newareas) |
| { |
| struct slb_flush_info fi; |
| unsigned long i; |
| |
| BUILD_BUG_ON((sizeof(newareas)*8) != NUM_HIGH_AREAS); |
| BUILD_BUG_ON((sizeof(mm->context.high_htlb_areas)*8) |
| != NUM_HIGH_AREAS); |
| |
| newareas &= ~(mm->context.high_htlb_areas); |
| if (! newareas) |
| return 0; /* The areas we want are already open */ |
| |
| for (i = 0; i < NUM_HIGH_AREAS; i++) |
| if ((1 << i) & newareas) |
| if (prepare_high_area_for_htlb(mm, i) != 0) |
| return -EBUSY; |
| |
| mm->context.high_htlb_areas |= newareas; |
| |
| /* the context change must make it to memory before the flush, |
| * so that further SLB misses do the right thing. */ |
| mb(); |
| |
| fi.mm = mm; |
| fi.newareas = newareas; |
| on_each_cpu(flush_high_segments, &fi, 0, 1); |
| |
| return 0; |
| } |
| |
| int prepare_hugepage_range(unsigned long addr, unsigned long len, pgoff_t pgoff) |
| { |
| int err = 0; |
| |
| if (pgoff & (~HPAGE_MASK >> PAGE_SHIFT)) |
| return -EINVAL; |
| if (len & ~HPAGE_MASK) |
| return -EINVAL; |
| if (addr & ~HPAGE_MASK) |
| return -EINVAL; |
| |
| if (addr < 0x100000000UL) |
| err = open_low_hpage_areas(current->mm, |
| LOW_ESID_MASK(addr, len)); |
| if ((addr + len) > 0x100000000UL) |
| err = open_high_hpage_areas(current->mm, |
| HTLB_AREA_MASK(addr, len)); |
| if (err) { |
| printk(KERN_DEBUG "prepare_hugepage_range(%lx, %lx)" |
| " failed (lowmask: 0x%04hx, highmask: 0x%04hx)\n", |
| addr, len, |
| LOW_ESID_MASK(addr, len), HTLB_AREA_MASK(addr, len)); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| struct page * |
| follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) |
| { |
| pte_t *ptep; |
| struct page *page; |
| |
| if (! in_hugepage_area(mm->context, address)) |
| return ERR_PTR(-EINVAL); |
| |
| ptep = huge_pte_offset(mm, address); |
| page = pte_page(*ptep); |
| if (page) |
| page += (address % HPAGE_SIZE) / PAGE_SIZE; |
| |
| return page; |
| } |
| |
| int pmd_huge(pmd_t pmd) |
| { |
| return 0; |
| } |
| |
| struct page * |
| follow_huge_pmd(struct mm_struct *mm, unsigned long address, |
| pmd_t *pmd, int write) |
| { |
| BUG(); |
| return NULL; |
| } |
| |
| /* Because we have an exclusive hugepage region which lies within the |
| * normal user address space, we have to take special measures to make |
| * non-huge mmap()s evade the hugepage reserved regions. */ |
| unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, |
| unsigned long len, unsigned long pgoff, |
| unsigned long flags) |
| { |
| struct mm_struct *mm = current->mm; |
| struct vm_area_struct *vma; |
| unsigned long start_addr; |
| |
| if (len > TASK_SIZE) |
| return -ENOMEM; |
| |
| if (addr) { |
| addr = PAGE_ALIGN(addr); |
| vma = find_vma(mm, addr); |
| if (((TASK_SIZE - len) >= addr) |
| && (!vma || (addr+len) <= vma->vm_start) |
| && !is_hugepage_only_range(mm, addr,len)) |
| return addr; |
| } |
| if (len > mm->cached_hole_size) { |
| start_addr = addr = mm->free_area_cache; |
| } else { |
| start_addr = addr = TASK_UNMAPPED_BASE; |
| mm->cached_hole_size = 0; |
| } |
| |
| full_search: |
| vma = find_vma(mm, addr); |
| while (TASK_SIZE - len >= addr) { |
| BUG_ON(vma && (addr >= vma->vm_end)); |
| |
| if (touches_hugepage_low_range(mm, addr, len)) { |
| addr = ALIGN(addr+1, 1<<SID_SHIFT); |
| vma = find_vma(mm, addr); |
| continue; |
| } |
| if (touches_hugepage_high_range(mm, addr, len)) { |
| addr = ALIGN(addr+1, 1UL<<HTLB_AREA_SHIFT); |
| vma = find_vma(mm, addr); |
| continue; |
| } |
| if (!vma || addr + len <= vma->vm_start) { |
| /* |
| * Remember the place where we stopped the search: |
| */ |
| mm->free_area_cache = addr + len; |
| return addr; |
| } |
| if (addr + mm->cached_hole_size < vma->vm_start) |
| mm->cached_hole_size = vma->vm_start - addr; |
| addr = vma->vm_end; |
| vma = vma->vm_next; |
| } |
| |
| /* Make sure we didn't miss any holes */ |
| if (start_addr != TASK_UNMAPPED_BASE) { |
| start_addr = addr = TASK_UNMAPPED_BASE; |
| mm->cached_hole_size = 0; |
| goto full_search; |
| } |
| return -ENOMEM; |
| } |
| |
| /* |
| * This mmap-allocator allocates new areas top-down from below the |
| * stack's low limit (the base): |
| * |
| * Because we have an exclusive hugepage region which lies within the |
| * normal user address space, we have to take special measures to make |
| * non-huge mmap()s evade the hugepage reserved regions. |
| */ |
| unsigned long |
| arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, |
| const unsigned long len, const unsigned long pgoff, |
| const unsigned long flags) |
| { |
| struct vm_area_struct *vma, *prev_vma; |
| struct mm_struct *mm = current->mm; |
| unsigned long base = mm->mmap_base, addr = addr0; |
| unsigned long largest_hole = mm->cached_hole_size; |
| int first_time = 1; |
| |
| /* requested length too big for entire address space */ |
| if (len > TASK_SIZE) |
| return -ENOMEM; |
| |
| /* dont allow allocations above current base */ |
| if (mm->free_area_cache > base) |
| mm->free_area_cache = base; |
| |
| /* requesting a specific address */ |
| if (addr) { |
| addr = PAGE_ALIGN(addr); |
| vma = find_vma(mm, addr); |
| if (TASK_SIZE - len >= addr && |
| (!vma || addr + len <= vma->vm_start) |
| && !is_hugepage_only_range(mm, addr,len)) |
| return addr; |
| } |
| |
| if (len <= largest_hole) { |
| largest_hole = 0; |
| mm->free_area_cache = base; |
| } |
| try_again: |
| /* make sure it can fit in the remaining address space */ |
| if (mm->free_area_cache < len) |
| goto fail; |
| |
| /* either no address requested or cant fit in requested address hole */ |
| addr = (mm->free_area_cache - len) & PAGE_MASK; |
| do { |
| hugepage_recheck: |
| if (touches_hugepage_low_range(mm, addr, len)) { |
| addr = (addr & ((~0) << SID_SHIFT)) - len; |
| goto hugepage_recheck; |
| } else if (touches_hugepage_high_range(mm, addr, len)) { |
| addr = (addr & ((~0UL) << HTLB_AREA_SHIFT)) - len; |
| goto hugepage_recheck; |
| } |
| |
| /* |
| * Lookup failure means no vma is above this address, |
| * i.e. return with success: |
| */ |
| if (!(vma = find_vma_prev(mm, addr, &prev_vma))) |
| return addr; |
| |
| /* |
| * new region fits between prev_vma->vm_end and |
| * vma->vm_start, use it: |
| */ |
| if (addr+len <= vma->vm_start && |
| (!prev_vma || (addr >= prev_vma->vm_end))) { |
| /* remember the address as a hint for next time */ |
| mm->cached_hole_size = largest_hole; |
| return (mm->free_area_cache = addr); |
| } else { |
| /* pull free_area_cache down to the first hole */ |
| if (mm->free_area_cache == vma->vm_end) { |
| mm->free_area_cache = vma->vm_start; |
| mm->cached_hole_size = largest_hole; |
| } |
| } |
| |
| /* remember the largest hole we saw so far */ |
| if (addr + largest_hole < vma->vm_start) |
| largest_hole = vma->vm_start - addr; |
| |
| /* try just below the current vma->vm_start */ |
| addr = vma->vm_start-len; |
| } while (len <= vma->vm_start); |
| |
| fail: |
| /* |
| * if hint left us with no space for the requested |
| * mapping then try again: |
| */ |
| if (first_time) { |
| mm->free_area_cache = base; |
| largest_hole = 0; |
| first_time = 0; |
| goto try_again; |
| } |
| /* |
| * A failed mmap() very likely causes application failure, |
| * so fall back to the bottom-up function here. This scenario |
| * can happen with large stack limits and large mmap() |
| * allocations. |
| */ |
| mm->free_area_cache = TASK_UNMAPPED_BASE; |
| mm->cached_hole_size = ~0UL; |
| addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags); |
| /* |
| * Restore the topdown base: |
| */ |
| mm->free_area_cache = base; |
| mm->cached_hole_size = ~0UL; |
| |
| return addr; |
| } |
| |
| static int htlb_check_hinted_area(unsigned long addr, unsigned long len) |
| { |
| struct vm_area_struct *vma; |
| |
| vma = find_vma(current->mm, addr); |
| if (TASK_SIZE - len >= addr && |
| (!vma || ((addr + len) <= vma->vm_start))) |
| return 0; |
| |
| return -ENOMEM; |
| } |
| |
| static unsigned long htlb_get_low_area(unsigned long len, u16 segmask) |
| { |
| unsigned long addr = 0; |
| struct vm_area_struct *vma; |
| |
| vma = find_vma(current->mm, addr); |
| while (addr + len <= 0x100000000UL) { |
| BUG_ON(vma && (addr >= vma->vm_end)); /* invariant */ |
| |
| if (! __within_hugepage_low_range(addr, len, segmask)) { |
| addr = ALIGN(addr+1, 1<<SID_SHIFT); |
| vma = find_vma(current->mm, addr); |
| continue; |
| } |
| |
| if (!vma || (addr + len) <= vma->vm_start) |
| return addr; |
| addr = ALIGN(vma->vm_end, HPAGE_SIZE); |
| /* Depending on segmask this might not be a confirmed |
| * hugepage region, so the ALIGN could have skipped |
| * some VMAs */ |
| vma = find_vma(current->mm, addr); |
| } |
| |
| return -ENOMEM; |
| } |
| |
| static unsigned long htlb_get_high_area(unsigned long len, u16 areamask) |
| { |
| unsigned long addr = 0x100000000UL; |
| struct vm_area_struct *vma; |
| |
| vma = find_vma(current->mm, addr); |
| while (addr + len <= TASK_SIZE_USER64) { |
| BUG_ON(vma && (addr >= vma->vm_end)); /* invariant */ |
| |
| if (! __within_hugepage_high_range(addr, len, areamask)) { |
| addr = ALIGN(addr+1, 1UL<<HTLB_AREA_SHIFT); |
| vma = find_vma(current->mm, addr); |
| continue; |
| } |
| |
| if (!vma || (addr + len) <= vma->vm_start) |
| return addr; |
| addr = ALIGN(vma->vm_end, HPAGE_SIZE); |
| /* Depending on segmask this might not be a confirmed |
| * hugepage region, so the ALIGN could have skipped |
| * some VMAs */ |
| vma = find_vma(current->mm, addr); |
| } |
| |
| return -ENOMEM; |
| } |
| |
| unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, |
| unsigned long len, unsigned long pgoff, |
| unsigned long flags) |
| { |
| int lastshift; |
| u16 areamask, curareas; |
| |
| if (HPAGE_SHIFT == 0) |
| return -EINVAL; |
| if (len & ~HPAGE_MASK) |
| return -EINVAL; |
| if (len > TASK_SIZE) |
| return -ENOMEM; |
| |
| if (!cpu_has_feature(CPU_FTR_16M_PAGE)) |
| return -EINVAL; |
| |
| /* Paranoia, caller should have dealt with this */ |
| BUG_ON((addr + len) < addr); |
| |
| if (test_thread_flag(TIF_32BIT)) { |
| curareas = current->mm->context.low_htlb_areas; |
| |
| /* First see if we can use the hint address */ |
| if (addr && (htlb_check_hinted_area(addr, len) == 0)) { |
| areamask = LOW_ESID_MASK(addr, len); |
| if (open_low_hpage_areas(current->mm, areamask) == 0) |
| return addr; |
| } |
| |
| /* Next see if we can map in the existing low areas */ |
| addr = htlb_get_low_area(len, curareas); |
| if (addr != -ENOMEM) |
| return addr; |
| |
| /* Finally go looking for areas to open */ |
| lastshift = 0; |
| for (areamask = LOW_ESID_MASK(0x100000000UL-len, len); |
| ! lastshift; areamask >>=1) { |
| if (areamask & 1) |
| lastshift = 1; |
| |
| addr = htlb_get_low_area(len, curareas | areamask); |
| if ((addr != -ENOMEM) |
| && open_low_hpage_areas(current->mm, areamask) == 0) |
| return addr; |
| } |
| } else { |
| curareas = current->mm->context.high_htlb_areas; |
| |
| /* First see if we can use the hint address */ |
| /* We discourage 64-bit processes from doing hugepage |
| * mappings below 4GB (must use MAP_FIXED) */ |
| if ((addr >= 0x100000000UL) |
| && (htlb_check_hinted_area(addr, len) == 0)) { |
| areamask = HTLB_AREA_MASK(addr, len); |
| if (open_high_hpage_areas(current->mm, areamask) == 0) |
| return addr; |
| } |
| |
| /* Next see if we can map in the existing high areas */ |
| addr = htlb_get_high_area(len, curareas); |
| if (addr != -ENOMEM) |
| return addr; |
| |
| /* Finally go looking for areas to open */ |
| lastshift = 0; |
| for (areamask = HTLB_AREA_MASK(TASK_SIZE_USER64-len, len); |
| ! lastshift; areamask >>=1) { |
| if (areamask & 1) |
| lastshift = 1; |
| |
| addr = htlb_get_high_area(len, curareas | areamask); |
| if ((addr != -ENOMEM) |
| && open_high_hpage_areas(current->mm, areamask) == 0) |
| return addr; |
| } |
| } |
| printk(KERN_DEBUG "hugetlb_get_unmapped_area() unable to open" |
| " enough areas\n"); |
| return -ENOMEM; |
| } |
| |
| /* |
| * Called by asm hashtable.S for doing lazy icache flush |
| */ |
| static unsigned int hash_huge_page_do_lazy_icache(unsigned long rflags, |
| pte_t pte, int trap) |
| { |
| struct page *page; |
| int i; |
| |
| if (!pfn_valid(pte_pfn(pte))) |
| return rflags; |
| |
| page = pte_page(pte); |
| |
| /* page is dirty */ |
| if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) { |
| if (trap == 0x400) { |
| for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) |
| __flush_dcache_icache(page_address(page+i)); |
| set_bit(PG_arch_1, &page->flags); |
| } else { |
| rflags |= HPTE_R_N; |
| } |
| } |
| return rflags; |
| } |
| |
| int hash_huge_page(struct mm_struct *mm, unsigned long access, |
| unsigned long ea, unsigned long vsid, int local, |
| unsigned long trap) |
| { |
| pte_t *ptep; |
| unsigned long old_pte, new_pte; |
| unsigned long va, rflags, pa; |
| long slot; |
| int err = 1; |
| |
| ptep = huge_pte_offset(mm, ea); |
| |
| /* Search the Linux page table for a match with va */ |
| va = (vsid << 28) | (ea & 0x0fffffff); |
| |
| /* |
| * If no pte found or not present, send the problem up to |
| * do_page_fault |
| */ |
| if (unlikely(!ptep || pte_none(*ptep))) |
| goto out; |
| |
| /* |
| * Check the user's access rights to the page. If access should be |
| * prevented then send the problem up to do_page_fault. |
| */ |
| if (unlikely(access & ~pte_val(*ptep))) |
| goto out; |
| /* |
| * At this point, we have a pte (old_pte) which can be used to build |
| * or update an HPTE. There are 2 cases: |
| * |
| * 1. There is a valid (present) pte with no associated HPTE (this is |
| * the most common case) |
| * 2. There is a valid (present) pte with an associated HPTE. The |
| * current values of the pp bits in the HPTE prevent access |
| * because we are doing software DIRTY bit management and the |
| * page is currently not DIRTY. |
| */ |
| |
| |
| do { |
| old_pte = pte_val(*ptep); |
| if (old_pte & _PAGE_BUSY) |
| goto out; |
| new_pte = old_pte | _PAGE_BUSY | |
| _PAGE_ACCESSED | _PAGE_HASHPTE; |
| } while(old_pte != __cmpxchg_u64((unsigned long *)ptep, |
| old_pte, new_pte)); |
| |
| rflags = 0x2 | (!(new_pte & _PAGE_RW)); |
| /* _PAGE_EXEC -> HW_NO_EXEC since it's inverted */ |
| rflags |= ((new_pte & _PAGE_EXEC) ? 0 : HPTE_R_N); |
| if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) |
| /* No CPU has hugepages but lacks no execute, so we |
| * don't need to worry about that case */ |
| rflags = hash_huge_page_do_lazy_icache(rflags, __pte(old_pte), |
| trap); |
| |
| /* Check if pte already has an hpte (case 2) */ |
| if (unlikely(old_pte & _PAGE_HASHPTE)) { |
| /* There MIGHT be an HPTE for this pte */ |
| unsigned long hash, slot; |
| |
| hash = hpt_hash(va, HPAGE_SHIFT); |
| if (old_pte & _PAGE_F_SECOND) |
| hash = ~hash; |
| slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; |
| slot += (old_pte & _PAGE_F_GIX) >> 12; |
| |
| if (ppc_md.hpte_updatepp(slot, rflags, va, mmu_huge_psize, |
| local) == -1) |
| old_pte &= ~_PAGE_HPTEFLAGS; |
| } |
| |
| if (likely(!(old_pte & _PAGE_HASHPTE))) { |
| unsigned long hash = hpt_hash(va, HPAGE_SHIFT); |
| unsigned long hpte_group; |
| |
| pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT; |
| |
| repeat: |
| hpte_group = ((hash & htab_hash_mask) * |
| HPTES_PER_GROUP) & ~0x7UL; |
| |
| /* clear HPTE slot informations in new PTE */ |
| new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HASHPTE; |
| |
| /* Add in WIMG bits */ |
| /* XXX We should store these in the pte */ |
| /* --BenH: I think they are ... */ |
| rflags |= _PAGE_COHERENT; |
| |
| /* Insert into the hash table, primary slot */ |
| slot = ppc_md.hpte_insert(hpte_group, va, pa, rflags, 0, |
| mmu_huge_psize); |
| |
| /* Primary is full, try the secondary */ |
| if (unlikely(slot == -1)) { |
| new_pte |= _PAGE_F_SECOND; |
| hpte_group = ((~hash & htab_hash_mask) * |
| HPTES_PER_GROUP) & ~0x7UL; |
| slot = ppc_md.hpte_insert(hpte_group, va, pa, rflags, |
| HPTE_V_SECONDARY, |
| mmu_huge_psize); |
| if (slot == -1) { |
| if (mftb() & 0x1) |
| hpte_group = ((hash & htab_hash_mask) * |
| HPTES_PER_GROUP)&~0x7UL; |
| |
| ppc_md.hpte_remove(hpte_group); |
| goto repeat; |
| } |
| } |
| |
| if (unlikely(slot == -2)) |
| panic("hash_huge_page: pte_insert failed\n"); |
| |
| new_pte |= (slot << 12) & _PAGE_F_GIX; |
| } |
| |
| /* |
| * No need to use ldarx/stdcx here |
| */ |
| *ptep = __pte(new_pte & ~_PAGE_BUSY); |
| |
| err = 0; |
| |
| out: |
| return err; |
| } |
| |
| static void zero_ctor(void *addr, struct kmem_cache *cache, unsigned long flags) |
| { |
| memset(addr, 0, kmem_cache_size(cache)); |
| } |
| |
| static int __init hugetlbpage_init(void) |
| { |
| if (!cpu_has_feature(CPU_FTR_16M_PAGE)) |
| return -ENODEV; |
| |
| huge_pgtable_cache = kmem_cache_create("hugepte_cache", |
| HUGEPTE_TABLE_SIZE, |
| HUGEPTE_TABLE_SIZE, |
| SLAB_HWCACHE_ALIGN | |
| SLAB_MUST_HWCACHE_ALIGN, |
| zero_ctor, NULL); |
| if (! huge_pgtable_cache) |
| panic("hugetlbpage_init(): could not create hugepte cache\n"); |
| |
| return 0; |
| } |
| |
| module_init(hugetlbpage_init); |