xref: /openbmc/linux/arch/arm64/mm/flush.c (revision 78700c0a)
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 sync_icache_aliases(void *kaddr, unsigned long len)
38 {
39 	unsigned long addr = (unsigned long)kaddr;
40 
41 	if (icache_is_aliasing()) {
42 		__clean_dcache_area_pou(kaddr, len);
43 		__flush_icache_all();
44 	} else {
45 		flush_icache_range(addr, addr + len);
46 	}
47 }
48 
49 static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
50 				unsigned long uaddr, void *kaddr,
51 				unsigned long len)
52 {
53 	if (vma->vm_flags & VM_EXEC)
54 		sync_icache_aliases(kaddr, len);
55 }
56 
57 /*
58  * Copy user data from/to a page which is mapped into a different processes
59  * address space.  Really, we want to allow our "user space" model to handle
60  * this.
61  */
62 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
63 		       unsigned long uaddr, void *dst, const void *src,
64 		       unsigned long len)
65 {
66 	memcpy(dst, src, len);
67 	flush_ptrace_access(vma, page, uaddr, dst, len);
68 }
69 
70 void __sync_icache_dcache(pte_t pte, unsigned long addr)
71 {
72 	struct page *page = pte_page(pte);
73 
74 	/* no flushing needed for anonymous pages */
75 	if (!page_mapping(page))
76 		return;
77 
78 	if (!test_and_set_bit(PG_dcache_clean, &page->flags))
79 		sync_icache_aliases(page_address(page),
80 				    PAGE_SIZE << compound_order(page));
81 	else if (icache_is_aivivt())
82 		__flush_icache_all();
83 }
84 
85 /*
86  * This function is called when a page has been modified by the kernel. Mark
87  * it as dirty for later flushing when mapped in user space (if executable,
88  * see __sync_icache_dcache).
89  */
90 void flush_dcache_page(struct page *page)
91 {
92 	if (test_bit(PG_dcache_clean, &page->flags))
93 		clear_bit(PG_dcache_clean, &page->flags);
94 }
95 EXPORT_SYMBOL(flush_dcache_page);
96 
97 /*
98  * Additional functions defined in assembly.
99  */
100 EXPORT_SYMBOL(flush_icache_range);
101