unsigned long l4x_clear_user(void *address, unsigned long n) { unsigned long clear_size = (unsigned long)address & ~PAGE_MASK; #ifdef DEBUG_MEMCPY_TOFS printk("%s called from: %08lx to: %p, len: %08lx\n", __func__, *((unsigned long *)&address - 1), address, n); #endif if (segment_eq(get_fs(), KERNEL_DS)) { if (L4X_CHECK_IN_KERNEL_ACCESS && l4x_check_kern_region(address, n, 1)) return -EFAULT; memset(address, 0, n); return 0; } if (clear_size) { clear_size = min(PAGE_SIZE - clear_size, n); if (__clear_user_page(address, clear_size) == -EFAULT) return n; n -= clear_size; } while (n) { address += clear_size; clear_size = min(PAGE_SIZE, n); if (__clear_user_page(address, clear_size) == -EFAULT) return n; n -= clear_size; } return 0; }
/* * clear_user_page * @to: kernel logical address * @address: U0 address to be mapped * @page: page (virt_to_page(to)) */ void clear_user_page(void *to, unsigned long address, struct page *page) { void __clear_page_wb(void *to); if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0) __clear_page_wb(to); else { pgprot_t pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_CACHABLE | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_HW_SHARED | _PAGE_FLAGS_HARD); unsigned long phys_addr = virt_to_phys(to); unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS); pgd_t *pgd = pgd_offset_k(p3_addr); pud_t *pud = pud_offset(pgd, p3_addr); pmd_t *pmd = pmd_offset(pud, p3_addr); pte_t *pte = pte_offset_kernel(pmd, p3_addr); pte_t entry; unsigned long flags; entry = pfn_pte(phys_addr >> PAGE_SHIFT, pgprot); inc_preempt_count(); BUG_ON(atomic_inc_return(&concurreny_check[(address & CACHE_ALIAS)>>12]) != 1); set_pte(pte, entry); local_irq_save(flags); flush_tlb_one(get_asid(), p3_addr); local_irq_restore(flags); update_mmu_cache(NULL, p3_addr, entry); __clear_user_page((void *)p3_addr, to); pte_clear(&init_mm, p3_addr, pte); atomic_dec(&concurreny_check[(address & CACHE_ALIAS)>>12]); dec_preempt_count(); } }
/* * clear_user_page * @to: P1 address * @address: U0 address to be mapped * @page: page (virt_to_page(to)) */ void clear_user_page(void *to, unsigned long address, struct page *page) { __set_bit(PG_mapped, &page->flags); if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0) clear_page(to); else { unsigned long phys_addr = PHYSADDR(to); unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS); pgd_t *pgd = pgd_offset_k(p3_addr); pud_t *pud = pud_offset(pgd, p3_addr); pmd_t *pmd = pmd_offset(pud, p3_addr); pte_t *pte = pte_offset_kernel(pmd, p3_addr); pte_t entry; unsigned long flags; entry = pfn_pte(phys_addr >> PAGE_SHIFT, PAGE_KERNEL); mutex_lock(&p3map_mutex[(address & CACHE_ALIAS)>>12]); set_pte(pte, entry); local_irq_save(flags); __flush_tlb_page(get_asid(), p3_addr); local_irq_restore(flags); update_mmu_cache(NULL, p3_addr, entry); __clear_user_page((void *)p3_addr, to); pte_clear(&init_mm, p3_addr, pte); mutex_unlock(&p3map_mutex[(address & CACHE_ALIAS)>>12]); } }
/* * clear_user_page * @to: P1 address * @address: U0 address to be mapped * @page: page (virt_to_page(to)) */ void clear_user_page(void *to, unsigned long address, struct page *page) { __set_bit(PG_mapped, &page->flags); if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0) clear_page(to); else { pgprot_t pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_CACHABLE | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_HW_SHARED | _PAGE_FLAGS_HARD); unsigned long phys_addr = PHYSADDR(to); unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS); pgd_t *dir = pgd_offset_k(p3_addr); pmd_t *pmd = pmd_offset(dir, p3_addr); pte_t *pte = pte_offset_kernel(pmd, p3_addr); pte_t entry; unsigned long flags; entry = pfn_pte(phys_addr >> PAGE_SHIFT, pgprot); down(&p3map_sem[(address & CACHE_ALIAS)>>12]); set_pte(pte, entry); local_irq_save(flags); __flush_tlb_page(get_asid(), p3_addr); local_irq_restore(flags); update_mmu_cache(NULL, p3_addr, entry); __clear_user_page((void *)p3_addr, to); pte_clear(&init_mm, p3_addr, pte); up(&p3map_sem[(address & CACHE_ALIAS)>>12]); } }