xref: /openbmc/linux/arch/arm64/mm/flush.c (revision ae213c44)
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 		/*
37 		 * Don't issue kick_all_cpus_sync() after I-cache invalidation
38 		 * for user mappings.
39 		 */
40 		__flush_icache_range(addr, addr + len);
41 	}
42 }
43 
44 static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
45 				unsigned long uaddr, void *kaddr,
46 				unsigned long len)
47 {
48 	if (vma->vm_flags & VM_EXEC)
49 		sync_icache_aliases(kaddr, len);
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 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
58 		       unsigned long uaddr, void *dst, const void *src,
59 		       unsigned long len)
60 {
61 	memcpy(dst, src, len);
62 	flush_ptrace_access(vma, page, uaddr, dst, len);
63 }
64 
65 void __sync_icache_dcache(pte_t pte)
66 {
67 	struct page *page = pte_page(pte);
68 
69 	if (!test_and_set_bit(PG_dcache_clean, &page->flags))
70 		sync_icache_aliases(page_address(page),
71 				    PAGE_SIZE << compound_order(page));
72 }
73 EXPORT_SYMBOL_GPL(__sync_icache_dcache);
74 
75 /*
76  * This function is called when a page has been modified by the kernel. Mark
77  * it as dirty for later flushing when mapped in user space (if executable,
78  * see __sync_icache_dcache).
79  */
80 void flush_dcache_page(struct page *page)
81 {
82 	if (test_bit(PG_dcache_clean, &page->flags))
83 		clear_bit(PG_dcache_clean, &page->flags);
84 }
85 EXPORT_SYMBOL(flush_dcache_page);
86 
87 /*
88  * Additional functions defined in assembly.
89  */
90 EXPORT_SYMBOL(__flush_icache_range);
91 
92 #ifdef CONFIG_ARCH_HAS_PMEM_API
93 void arch_wb_cache_pmem(void *addr, size_t size)
94 {
95 	/* Ensure order against any prior non-cacheable writes */
96 	dmb(osh);
97 	__clean_dcache_area_pop(addr, size);
98 }
99 EXPORT_SYMBOL_GPL(arch_wb_cache_pmem);
100 
101 void arch_invalidate_pmem(void *addr, size_t size)
102 {
103 	__inval_dcache_area(addr, size);
104 }
105 EXPORT_SYMBOL_GPL(arch_invalidate_pmem);
106 #endif
107