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
flush_cache_range(struct vm_area_struct * vma,unsigned long start,unsigned long end)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
flush_ptrace_access(struct vm_area_struct * vma,struct page * page,unsigned long uaddr,void * kaddr,unsigned long len)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 */
copy_to_user_page(struct vm_area_struct * vma,struct page * page,unsigned long uaddr,void * dst,const void * src,unsigned long len)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
__sync_icache_dcache(pte_t pte,unsigned long addr)69 void __sync_icache_dcache(pte_t pte, unsigned long addr)
70 {
71 struct page *page = pte_page(pte);
72
73 if (!test_and_set_bit(PG_dcache_clean, &page->flags)) {
74 __flush_dcache_area(page_address(page),
75 PAGE_SIZE << compound_order(page));
76 __flush_icache_all();
77 } else if (icache_is_aivivt()) {
78 __flush_icache_all();
79 }
80 }
81
82 /*
83 * This function is called when a page has been modified by the kernel. Mark
84 * it as dirty for later flushing when mapped in user space (if executable,
85 * see __sync_icache_dcache).
86 */
flush_dcache_page(struct page * page)87 void flush_dcache_page(struct page *page)
88 {
89 if (test_bit(PG_dcache_clean, &page->flags))
90 clear_bit(PG_dcache_clean, &page->flags);
91 }
92 EXPORT_SYMBOL(flush_dcache_page);
93
94 /*
95 * Additional functions defined in assembly.
96 */
97 EXPORT_SYMBOL(flush_icache_range);
98
99 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
100 #ifdef CONFIG_HAVE_RCU_TABLE_FREE
pmdp_splitting_flush(struct vm_area_struct * vma,unsigned long address,pmd_t * pmdp)101 void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
102 pmd_t *pmdp)
103 {
104 pmd_t pmd = pmd_mksplitting(*pmdp);
105
106 VM_BUG_ON(address & ~PMD_MASK);
107 set_pmd_at(vma->vm_mm, address, pmdp, pmd);
108
109 /* dummy IPI to serialise against fast_gup */
110 kick_all_cpus_sync();
111 }
112 #endif /* CONFIG_HAVE_RCU_TABLE_FREE */
113 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
114