1 /* 2 * Based on arch/arm/mm/flush.c 3 * 4 * Copyright (C) 1995-2002 Russell King 5 * Copyright (C) 2012 ARM Ltd. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include <linux/export.h> 21 #include <linux/mm.h> 22 #include <linux/pagemap.h> 23 24 #include <asm/cacheflush.h> 25 #include <asm/cachetype.h> 26 #include <asm/tlbflush.h> 27 28 #include "mm.h" 29 30 void flush_cache_range(struct vm_area_struct *vma, unsigned long start, 31 unsigned long end) 32 { 33 if (vma->vm_flags & VM_EXEC) 34 __flush_icache_all(); 35 } 36 37 static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page, 38 unsigned long uaddr, void *kaddr, 39 unsigned long len) 40 { 41 if (vma->vm_flags & VM_EXEC) { 42 unsigned long addr = (unsigned long)kaddr; 43 if (icache_is_aliasing()) { 44 __flush_dcache_area(kaddr, len); 45 __flush_icache_all(); 46 } else { 47 flush_icache_range(addr, addr + len); 48 } 49 } 50 } 51 52 /* 53 * Copy user data from/to a page which is mapped into a different processes 54 * address space. Really, we want to allow our "user space" model to handle 55 * this. 56 * 57 * Note that this code needs to run on the current CPU. 58 */ 59 void copy_to_user_page(struct vm_area_struct *vma, struct page *page, 60 unsigned long uaddr, void *dst, const void *src, 61 unsigned long len) 62 { 63 preempt_disable(); 64 memcpy(dst, src, len); 65 flush_ptrace_access(vma, page, uaddr, dst, len); 66 preempt_enable(); 67 } 68 69 void __sync_icache_dcache(pte_t pte, unsigned long addr) 70 { 71 struct page *page = pte_page(pte); 72 73 /* no flushing needed for anonymous pages */ 74 if (!page_mapping(page)) 75 return; 76 77 if (!test_and_set_bit(PG_dcache_clean, &page->flags)) { 78 __flush_dcache_area(page_address(page), 79 PAGE_SIZE << compound_order(page)); 80 __flush_icache_all(); 81 } else if (icache_is_aivivt()) { 82 __flush_icache_all(); 83 } 84 } 85 86 /* 87 * This function is called when a page has been modified by the kernel. Mark 88 * it as dirty for later flushing when mapped in user space (if executable, 89 * see __sync_icache_dcache). 90 */ 91 void flush_dcache_page(struct page *page) 92 { 93 if (test_bit(PG_dcache_clean, &page->flags)) 94 clear_bit(PG_dcache_clean, &page->flags); 95 } 96 EXPORT_SYMBOL(flush_dcache_page); 97 98 /* 99 * Additional functions defined in assembly. 100 */ 101 EXPORT_SYMBOL(flush_icache_range); 102 103 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 104 #ifdef CONFIG_HAVE_RCU_TABLE_FREE 105 void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, 106 pmd_t *pmdp) 107 { 108 pmd_t pmd = pmd_mksplitting(*pmdp); 109 110 VM_BUG_ON(address & ~PMD_MASK); 111 set_pmd_at(vma->vm_mm, address, pmdp, pmd); 112 113 /* dummy IPI to serialise against fast_gup */ 114 kick_all_cpus_sync(); 115 } 116 #endif /* CONFIG_HAVE_RCU_TABLE_FREE */ 117 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 118