diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/powerpc/mm/subpage-prot.c')
| -rw-r--r-- | ANDROID_3.4.5/arch/powerpc/mm/subpage-prot.c | 219 |
1 files changed, 0 insertions, 219 deletions
diff --git a/ANDROID_3.4.5/arch/powerpc/mm/subpage-prot.c b/ANDROID_3.4.5/arch/powerpc/mm/subpage-prot.c deleted file mode 100644 index e4f8f1fc..00000000 --- a/ANDROID_3.4.5/arch/powerpc/mm/subpage-prot.c +++ /dev/null @@ -1,219 +0,0 @@ -/* - * Copyright 2007-2008 Paul Mackerras, IBM Corp. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - */ - -#include <linux/errno.h> -#include <linux/kernel.h> -#include <linux/gfp.h> -#include <linux/types.h> -#include <linux/mm.h> -#include <linux/hugetlb.h> - -#include <asm/pgtable.h> -#include <asm/uaccess.h> -#include <asm/tlbflush.h> - -/* - * Free all pages allocated for subpage protection maps and pointers. - * Also makes sure that the subpage_prot_table structure is - * reinitialized for the next user. - */ -void subpage_prot_free(struct mm_struct *mm) -{ - struct subpage_prot_table *spt = &mm->context.spt; - unsigned long i, j, addr; - u32 **p; - - for (i = 0; i < 4; ++i) { - if (spt->low_prot[i]) { - free_page((unsigned long)spt->low_prot[i]); - spt->low_prot[i] = NULL; - } - } - addr = 0; - for (i = 0; i < 2; ++i) { - p = spt->protptrs[i]; - if (!p) - continue; - spt->protptrs[i] = NULL; - for (j = 0; j < SBP_L2_COUNT && addr < spt->maxaddr; - ++j, addr += PAGE_SIZE) - if (p[j]) - free_page((unsigned long)p[j]); - free_page((unsigned long)p); - } - spt->maxaddr = 0; -} - -void subpage_prot_init_new_context(struct mm_struct *mm) -{ - struct subpage_prot_table *spt = &mm->context.spt; - - memset(spt, 0, sizeof(*spt)); -} - -static void hpte_flush_range(struct mm_struct *mm, unsigned long addr, - int npages) -{ - pgd_t *pgd; - pud_t *pud; - pmd_t *pmd; - pte_t *pte; - spinlock_t *ptl; - - pgd = pgd_offset(mm, addr); - if (pgd_none(*pgd)) - return; - pud = pud_offset(pgd, addr); - if (pud_none(*pud)) - return; - pmd = pmd_offset(pud, addr); - if (pmd_none(*pmd)) - return; - pte = pte_offset_map_lock(mm, pmd, addr, &ptl); - arch_enter_lazy_mmu_mode(); - for (; npages > 0; --npages) { - pte_update(mm, addr, pte, 0, 0); - addr += PAGE_SIZE; - ++pte; - } - arch_leave_lazy_mmu_mode(); - pte_unmap_unlock(pte - 1, ptl); -} - -/* - * Clear the subpage protection map for an address range, allowing - * all accesses that are allowed by the pte permissions. - */ -static void subpage_prot_clear(unsigned long addr, unsigned long len) -{ - struct mm_struct *mm = current->mm; - struct subpage_prot_table *spt = &mm->context.spt; - u32 **spm, *spp; - int i, nw; - unsigned long next, limit; - - down_write(&mm->mmap_sem); - limit = addr + len; - if (limit > spt->maxaddr) - limit = spt->maxaddr; - for (; addr < limit; addr = next) { - next = pmd_addr_end(addr, limit); - if (addr < 0x100000000) { - spm = spt->low_prot; - } else { - spm = spt->protptrs[addr >> SBP_L3_SHIFT]; - if (!spm) - continue; - } - spp = spm[(addr >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1)]; - if (!spp) - continue; - spp += (addr >> PAGE_SHIFT) & (SBP_L1_COUNT - 1); - - i = (addr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1); - nw = PTRS_PER_PTE - i; - if (addr + (nw << PAGE_SHIFT) > next) - nw = (next - addr) >> PAGE_SHIFT; - - memset(spp, 0, nw * sizeof(u32)); - - /* now flush any existing HPTEs for the range */ - hpte_flush_range(mm, addr, nw); - } - up_write(&mm->mmap_sem); -} - -/* - * Copy in a subpage protection map for an address range. - * The map has 2 bits per 4k subpage, so 32 bits per 64k page. - * Each 2-bit field is 0 to allow any access, 1 to prevent writes, - * 2 or 3 to prevent all accesses. - * Note that the normal page protections also apply; the subpage - * protection mechanism is an additional constraint, so putting 0 - * in a 2-bit field won't allow writes to a page that is otherwise - * write-protected. - */ -long sys_subpage_prot(unsigned long addr, unsigned long len, u32 __user *map) -{ - struct mm_struct *mm = current->mm; - struct subpage_prot_table *spt = &mm->context.spt; - u32 **spm, *spp; - int i, nw; - unsigned long next, limit; - int err; - - /* Check parameters */ - if ((addr & ~PAGE_MASK) || (len & ~PAGE_MASK) || - addr >= TASK_SIZE || len >= TASK_SIZE || addr + len > TASK_SIZE) - return -EINVAL; - - if (is_hugepage_only_range(mm, addr, len)) - return -EINVAL; - - if (!map) { - /* Clear out the protection map for the address range */ - subpage_prot_clear(addr, len); - return 0; - } - - if (!access_ok(VERIFY_READ, map, (len >> PAGE_SHIFT) * sizeof(u32))) - return -EFAULT; - - down_write(&mm->mmap_sem); - for (limit = addr + len; addr < limit; addr = next) { - next = pmd_addr_end(addr, limit); - err = -ENOMEM; - if (addr < 0x100000000) { - spm = spt->low_prot; - } else { - spm = spt->protptrs[addr >> SBP_L3_SHIFT]; - if (!spm) { - spm = (u32 **)get_zeroed_page(GFP_KERNEL); - if (!spm) - goto out; - spt->protptrs[addr >> SBP_L3_SHIFT] = spm; - } - } - spm += (addr >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1); - spp = *spm; - if (!spp) { - spp = (u32 *)get_zeroed_page(GFP_KERNEL); - if (!spp) - goto out; - *spm = spp; - } - spp += (addr >> PAGE_SHIFT) & (SBP_L1_COUNT - 1); - - local_irq_disable(); - demote_segment_4k(mm, addr); - local_irq_enable(); - - i = (addr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1); - nw = PTRS_PER_PTE - i; - if (addr + (nw << PAGE_SHIFT) > next) - nw = (next - addr) >> PAGE_SHIFT; - - up_write(&mm->mmap_sem); - err = -EFAULT; - if (__copy_from_user(spp, map, nw * sizeof(u32))) - goto out2; - map += nw; - down_write(&mm->mmap_sem); - - /* now flush any existing HPTEs for the range */ - hpte_flush_range(mm, addr, nw); - } - if (limit > spt->maxaddr) - spt->maxaddr = limit; - err = 0; - out: - up_write(&mm->mmap_sem); - out2: - return err; -} |