1 /* Flush dcache and invalidate icache when the dcache is in writeback mode
2 *
3 * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11 #include <linux/module.h>
12 #include <linux/mm.h>
13 #include <asm/cacheflush.h>
14 #include <asm/smp.h>
15 #include "cache-smp.h"
16
17 /**
18 * flush_icache_page - Flush a page from the dcache and invalidate the icache
19 * @vma: The VMA the page is part of.
20 * @page: The page to be flushed.
21 *
22 * Write a page back from the dcache and invalidate the icache so that we can
23 * run code from it that we've just written into it
24 */
flush_icache_page(struct vm_area_struct * vma,struct page * page)25 void flush_icache_page(struct vm_area_struct *vma, struct page *page)
26 {
27 unsigned long start = page_to_phys(page);
28 unsigned long flags;
29
30 flags = smp_lock_cache();
31
32 mn10300_local_dcache_flush_page(start);
33 mn10300_local_icache_inv_page(start);
34
35 smp_cache_call(SMP_IDCACHE_INV_FLUSH_RANGE, start, start + PAGE_SIZE);
36 smp_unlock_cache(flags);
37 }
38 EXPORT_SYMBOL(flush_icache_page);
39
40 /**
41 * flush_icache_page_range - Flush dcache and invalidate icache for part of a
42 * single page
43 * @start: The starting virtual address of the page part.
44 * @end: The ending virtual address of the page part.
45 *
46 * Flush the dcache and invalidate the icache for part of a single page, as
47 * determined by the virtual addresses given. The page must be in the paged
48 * area.
49 */
flush_icache_page_range(unsigned long start,unsigned long end)50 static void flush_icache_page_range(unsigned long start, unsigned long end)
51 {
52 unsigned long addr, size, off;
53 struct page *page;
54 pgd_t *pgd;
55 pud_t *pud;
56 pmd_t *pmd;
57 pte_t *ppte, pte;
58
59 /* work out how much of the page to flush */
60 off = start & ~PAGE_MASK;
61 size = end - start;
62
63 /* get the physical address the page is mapped to from the page
64 * tables */
65 pgd = pgd_offset(current->mm, start);
66 if (!pgd || !pgd_val(*pgd))
67 return;
68
69 pud = pud_offset(pgd, start);
70 if (!pud || !pud_val(*pud))
71 return;
72
73 pmd = pmd_offset(pud, start);
74 if (!pmd || !pmd_val(*pmd))
75 return;
76
77 ppte = pte_offset_map(pmd, start);
78 if (!ppte)
79 return;
80 pte = *ppte;
81 pte_unmap(ppte);
82
83 if (pte_none(pte))
84 return;
85
86 page = pte_page(pte);
87 if (!page)
88 return;
89
90 addr = page_to_phys(page);
91
92 /* flush the dcache and invalidate the icache coverage on that
93 * region */
94 mn10300_local_dcache_flush_range2(addr + off, size);
95 mn10300_local_icache_inv_range2(addr + off, size);
96 smp_cache_call(SMP_IDCACHE_INV_FLUSH_RANGE, start, end);
97 }
98
99 /**
100 * flush_icache_range - Globally flush dcache and invalidate icache for region
101 * @start: The starting virtual address of the region.
102 * @end: The ending virtual address of the region.
103 *
104 * This is used by the kernel to globally flush some code it has just written
105 * from the dcache back to RAM and then to globally invalidate the icache over
106 * that region so that that code can be run on all CPUs in the system.
107 */
flush_icache_range(unsigned long start,unsigned long end)108 void flush_icache_range(unsigned long start, unsigned long end)
109 {
110 unsigned long start_page, end_page;
111 unsigned long flags;
112
113 flags = smp_lock_cache();
114
115 if (end > 0x80000000UL) {
116 /* addresses above 0xa0000000 do not go through the cache */
117 if (end > 0xa0000000UL) {
118 end = 0xa0000000UL;
119 if (start >= end)
120 goto done;
121 }
122
123 /* kernel addresses between 0x80000000 and 0x9fffffff do not
124 * require page tables, so we just map such addresses
125 * directly */
126 start_page = (start >= 0x80000000UL) ? start : 0x80000000UL;
127 mn10300_local_dcache_flush_range(start_page, end);
128 mn10300_local_icache_inv_range(start_page, end);
129 smp_cache_call(SMP_IDCACHE_INV_FLUSH_RANGE, start_page, end);
130 if (start_page == start)
131 goto done;
132 end = start_page;
133 }
134
135 start_page = start & PAGE_MASK;
136 end_page = (end - 1) & PAGE_MASK;
137
138 if (start_page == end_page) {
139 /* the first and last bytes are on the same page */
140 flush_icache_page_range(start, end);
141 } else if (start_page + 1 == end_page) {
142 /* split over two virtually contiguous pages */
143 flush_icache_page_range(start, end_page);
144 flush_icache_page_range(end_page, end);
145 } else {
146 /* more than 2 pages; just flush the entire cache */
147 mn10300_dcache_flush();
148 mn10300_icache_inv();
149 smp_cache_call(SMP_IDCACHE_INV_FLUSH, 0, 0);
150 }
151
152 done:
153 smp_unlock_cache(flags);
154 }
155 EXPORT_SYMBOL(flush_icache_range);
156