|  | /* | 
|  | * SPARC64 Huge TLB page support. | 
|  | * | 
|  | * Copyright (C) 2002, 2003, 2006 David S. Miller (davem@davemloft.net) | 
|  | */ | 
|  |  | 
|  | #include <linux/init.h> | 
|  | #include <linux/module.h> | 
|  | #include <linux/fs.h> | 
|  | #include <linux/mm.h> | 
|  | #include <linux/hugetlb.h> | 
|  | #include <linux/pagemap.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/sysctl.h> | 
|  |  | 
|  | #include <asm/mman.h> | 
|  | #include <asm/pgalloc.h> | 
|  | #include <asm/tlb.h> | 
|  | #include <asm/tlbflush.h> | 
|  | #include <asm/cacheflush.h> | 
|  | #include <asm/mmu_context.h> | 
|  |  | 
|  | /* Slightly simplified from the non-hugepage variant because by | 
|  | * definition we don't have to worry about any page coloring stuff | 
|  | */ | 
|  | #define VA_EXCLUDE_START (0x0000080000000000UL - (1UL << 32UL)) | 
|  | #define VA_EXCLUDE_END   (0xfffff80000000000UL + (1UL << 32UL)) | 
|  |  | 
|  | static unsigned long hugetlb_get_unmapped_area_bottomup(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 task_size = TASK_SIZE; | 
|  | unsigned long start_addr; | 
|  |  | 
|  | if (test_thread_flag(TIF_32BIT)) | 
|  | task_size = STACK_TOP32; | 
|  | if (unlikely(len >= VA_EXCLUDE_START)) | 
|  | return -ENOMEM; | 
|  |  | 
|  | 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; | 
|  | } | 
|  |  | 
|  | task_size -= len; | 
|  |  | 
|  | full_search: | 
|  | addr = ALIGN(addr, HPAGE_SIZE); | 
|  |  | 
|  | for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { | 
|  | /* At this point:  (!vma || addr < vma->vm_end). */ | 
|  | if (addr < VA_EXCLUDE_START && | 
|  | (addr + len) >= VA_EXCLUDE_START) { | 
|  | addr = VA_EXCLUDE_END; | 
|  | vma = find_vma(mm, VA_EXCLUDE_END); | 
|  | } | 
|  | if (unlikely(task_size < addr)) { | 
|  | if (start_addr != TASK_UNMAPPED_BASE) { | 
|  | start_addr = addr = TASK_UNMAPPED_BASE; | 
|  | mm->cached_hole_size = 0; | 
|  | goto full_search; | 
|  | } | 
|  | return -ENOMEM; | 
|  | } | 
|  | if (likely(!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 = ALIGN(vma->vm_end, HPAGE_SIZE); | 
|  | } | 
|  | } | 
|  |  | 
|  | static unsigned long | 
|  | hugetlb_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; | 
|  | struct mm_struct *mm = current->mm; | 
|  | unsigned long addr = addr0; | 
|  |  | 
|  | /* This should only ever run for 32-bit processes.  */ | 
|  | BUG_ON(!test_thread_flag(TIF_32BIT)); | 
|  |  | 
|  | /* check if free_area_cache is useful for us */ | 
|  | if (len <= mm->cached_hole_size) { | 
|  | mm->cached_hole_size = 0; | 
|  | mm->free_area_cache = mm->mmap_base; | 
|  | } | 
|  |  | 
|  | /* either no address requested or can't fit in requested address hole */ | 
|  | addr = mm->free_area_cache & HPAGE_MASK; | 
|  |  | 
|  | /* make sure it can fit in the remaining address space */ | 
|  | if (likely(addr > len)) { | 
|  | vma = find_vma(mm, addr-len); | 
|  | if (!vma || addr <= vma->vm_start) { | 
|  | /* remember the address as a hint for next time */ | 
|  | return (mm->free_area_cache = addr-len); | 
|  | } | 
|  | } | 
|  |  | 
|  | if (unlikely(mm->mmap_base < len)) | 
|  | goto bottomup; | 
|  |  | 
|  | addr = (mm->mmap_base-len) & HPAGE_MASK; | 
|  |  | 
|  | do { | 
|  | /* | 
|  | * Lookup failure means no vma is above this address, | 
|  | * else if new region fits below vma->vm_start, | 
|  | * return with success: | 
|  | */ | 
|  | vma = find_vma(mm, addr); | 
|  | if (likely(!vma || addr+len <= vma->vm_start)) { | 
|  | /* remember the address as a hint for next time */ | 
|  | return (mm->free_area_cache = addr); | 
|  | } | 
|  |  | 
|  | /* remember the largest hole we saw so far */ | 
|  | if (addr + mm->cached_hole_size < vma->vm_start) | 
|  | mm->cached_hole_size = vma->vm_start - addr; | 
|  |  | 
|  | /* try just below the current vma->vm_start */ | 
|  | addr = (vma->vm_start-len) & HPAGE_MASK; | 
|  | } while (likely(len < vma->vm_start)); | 
|  |  | 
|  | bottomup: | 
|  | /* | 
|  | * 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->cached_hole_size = ~0UL; | 
|  | mm->free_area_cache = TASK_UNMAPPED_BASE; | 
|  | addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags); | 
|  | /* | 
|  | * Restore the topdown base: | 
|  | */ | 
|  | mm->free_area_cache = mm->mmap_base; | 
|  | mm->cached_hole_size = ~0UL; | 
|  |  | 
|  | return addr; | 
|  | } | 
|  |  | 
|  | unsigned long | 
|  | hugetlb_get_unmapped_area(struct file *file, 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 task_size = TASK_SIZE; | 
|  |  | 
|  | if (test_thread_flag(TIF_32BIT)) | 
|  | task_size = STACK_TOP32; | 
|  |  | 
|  | if (len & ~HPAGE_MASK) | 
|  | return -EINVAL; | 
|  | if (len > task_size) | 
|  | return -ENOMEM; | 
|  |  | 
|  | if (flags & MAP_FIXED) { | 
|  | if (prepare_hugepage_range(addr, len, pgoff)) | 
|  | return -EINVAL; | 
|  | return addr; | 
|  | } | 
|  |  | 
|  | if (addr) { | 
|  | addr = ALIGN(addr, HPAGE_SIZE); | 
|  | vma = find_vma(mm, addr); | 
|  | if (task_size - len >= addr && | 
|  | (!vma || addr + len <= vma->vm_start)) | 
|  | return addr; | 
|  | } | 
|  | if (mm->get_unmapped_area == arch_get_unmapped_area) | 
|  | return hugetlb_get_unmapped_area_bottomup(file, addr, len, | 
|  | pgoff, flags); | 
|  | else | 
|  | return hugetlb_get_unmapped_area_topdown(file, addr, len, | 
|  | pgoff, flags); | 
|  | } | 
|  |  | 
|  | pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr) | 
|  | { | 
|  | pgd_t *pgd; | 
|  | pud_t *pud; | 
|  | pmd_t *pmd; | 
|  | pte_t *pte = NULL; | 
|  |  | 
|  | /* We must align the address, because our caller will run | 
|  | * set_huge_pte_at() on whatever we return, which writes out | 
|  | * all of the sub-ptes for the hugepage range.  So we have | 
|  | * to give it the first such sub-pte. | 
|  | */ | 
|  | addr &= HPAGE_MASK; | 
|  |  | 
|  | pgd = pgd_offset(mm, addr); | 
|  | pud = pud_alloc(mm, pgd, addr); | 
|  | if (pud) { | 
|  | pmd = pmd_alloc(mm, pud, addr); | 
|  | if (pmd) | 
|  | pte = pte_alloc_map(mm, pmd, addr); | 
|  | } | 
|  | return pte; | 
|  | } | 
|  |  | 
|  | pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) | 
|  | { | 
|  | pgd_t *pgd; | 
|  | pud_t *pud; | 
|  | pmd_t *pmd; | 
|  | pte_t *pte = NULL; | 
|  |  | 
|  | addr &= HPAGE_MASK; | 
|  |  | 
|  | pgd = pgd_offset(mm, addr); | 
|  | if (!pgd_none(*pgd)) { | 
|  | pud = pud_offset(pgd, addr); | 
|  | if (!pud_none(*pud)) { | 
|  | pmd = pmd_offset(pud, addr); | 
|  | if (!pmd_none(*pmd)) | 
|  | pte = pte_offset_map(pmd, addr); | 
|  | } | 
|  | } | 
|  | return pte; | 
|  | } | 
|  |  | 
|  | int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) | 
|  | { | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, | 
|  | pte_t *ptep, pte_t entry) | 
|  | { | 
|  | int i; | 
|  |  | 
|  | if (!pte_present(*ptep) && pte_present(entry)) | 
|  | mm->context.huge_pte_count++; | 
|  |  | 
|  | addr &= HPAGE_MASK; | 
|  | for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) { | 
|  | set_pte_at(mm, addr, ptep, entry); | 
|  | ptep++; | 
|  | addr += PAGE_SIZE; | 
|  | pte_val(entry) += PAGE_SIZE; | 
|  | } | 
|  | } | 
|  |  | 
|  | pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, | 
|  | pte_t *ptep) | 
|  | { | 
|  | pte_t entry; | 
|  | int i; | 
|  |  | 
|  | entry = *ptep; | 
|  | if (pte_present(entry)) | 
|  | mm->context.huge_pte_count--; | 
|  |  | 
|  | addr &= HPAGE_MASK; | 
|  |  | 
|  | for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) { | 
|  | pte_clear(mm, addr, ptep); | 
|  | addr += PAGE_SIZE; | 
|  | ptep++; | 
|  | } | 
|  |  | 
|  | return entry; | 
|  | } | 
|  |  | 
|  | struct page *follow_huge_addr(struct mm_struct *mm, | 
|  | unsigned long address, int write) | 
|  | { | 
|  | return ERR_PTR(-EINVAL); | 
|  | } | 
|  |  | 
|  | 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) | 
|  | { | 
|  | return NULL; | 
|  | } | 
|  |  | 
|  | static void context_reload(void *__data) | 
|  | { | 
|  | struct mm_struct *mm = __data; | 
|  |  | 
|  | if (mm == current->mm) | 
|  | load_secondary_context(mm); | 
|  | } | 
|  |  | 
|  | void hugetlb_prefault_arch_hook(struct mm_struct *mm) | 
|  | { | 
|  | struct tsb_config *tp = &mm->context.tsb_block[MM_TSB_HUGE]; | 
|  |  | 
|  | if (likely(tp->tsb != NULL)) | 
|  | return; | 
|  |  | 
|  | tsb_grow(mm, MM_TSB_HUGE, 0); | 
|  | tsb_context_switch(mm); | 
|  | smp_tsb_sync(mm); | 
|  |  | 
|  | /* On UltraSPARC-III+ and later, configure the second half of | 
|  | * the Data-TLB for huge pages. | 
|  | */ | 
|  | if (tlb_type == cheetah_plus) { | 
|  | unsigned long ctx; | 
|  |  | 
|  | spin_lock(&ctx_alloc_lock); | 
|  | ctx = mm->context.sparc64_ctx_val; | 
|  | ctx &= ~CTX_PGSZ_MASK; | 
|  | ctx |= CTX_PGSZ_BASE << CTX_PGSZ0_SHIFT; | 
|  | ctx |= CTX_PGSZ_HUGE << CTX_PGSZ1_SHIFT; | 
|  |  | 
|  | if (ctx != mm->context.sparc64_ctx_val) { | 
|  | /* When changing the page size fields, we | 
|  | * must perform a context flush so that no | 
|  | * stale entries match.  This flush must | 
|  | * occur with the original context register | 
|  | * settings. | 
|  | */ | 
|  | do_flush_tlb_mm(mm); | 
|  |  | 
|  | /* Reload the context register of all processors | 
|  | * also executing in this address space. | 
|  | */ | 
|  | mm->context.sparc64_ctx_val = ctx; | 
|  | on_each_cpu(context_reload, mm, 0, 0); | 
|  | } | 
|  | spin_unlock(&ctx_alloc_lock); | 
|  | } | 
|  | } |