xref: /openbmc/linux/arch/arm64/mm/flush.c (revision f7d84fa7)
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/cache.h>
26 #include <asm/tlbflush.h>
27 
28 void sync_icache_aliases(void *kaddr, unsigned long len)
29 {
30 	unsigned long addr = (unsigned long)kaddr;
31 
32 	if (icache_is_aliasing()) {
33 		__clean_dcache_area_pou(kaddr, len);
34 		__flush_icache_all();
35 	} else {
36 		flush_icache_range(addr, addr + len);
37 	}
38 }
39 
40 static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
41 				unsigned long uaddr, void *kaddr,
42 				unsigned long len)
43 {
44 	if (vma->vm_flags & VM_EXEC)
45 		sync_icache_aliases(kaddr, len);
46 }
47 
48 /*
49  * Copy user data from/to a page which is mapped into a different processes
50  * address space.  Really, we want to allow our "user space" model to handle
51  * this.
52  */
53 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
54 		       unsigned long uaddr, void *dst, const void *src,
55 		       unsigned long len)
56 {
57 	memcpy(dst, src, len);
58 	flush_ptrace_access(vma, page, uaddr, dst, len);
59 }
60 
61 void __sync_icache_dcache(pte_t pte, unsigned long addr)
62 {
63 	struct page *page = pte_page(pte);
64 
65 	if (!test_and_set_bit(PG_dcache_clean, &page->flags))
66 		sync_icache_aliases(page_address(page),
67 				    PAGE_SIZE << compound_order(page));
68 }
69 
70 /*
71  * This function is called when a page has been modified by the kernel. Mark
72  * it as dirty for later flushing when mapped in user space (if executable,
73  * see __sync_icache_dcache).
74  */
75 void flush_dcache_page(struct page *page)
76 {
77 	if (test_bit(PG_dcache_clean, &page->flags))
78 		clear_bit(PG_dcache_clean, &page->flags);
79 }
80 EXPORT_SYMBOL(flush_dcache_page);
81 
82 /*
83  * Additional functions defined in assembly.
84  */
85 EXPORT_SYMBOL(flush_icache_range);
86