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-rw-r--r--arch/sh/mm/cache-sh7705.c206
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diff --git a/arch/sh/mm/cache-sh7705.c b/arch/sh/mm/cache-sh7705.c
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1/*
2 * arch/sh/mm/cache-sh7705.c
3 *
4 * Copyright (C) 1999, 2000 Niibe Yutaka
5 * Copyright (C) 2004 Alex Song
6 *
7 * This file is subject to the terms and conditions of the GNU General Public
8 * License. See the file "COPYING" in the main directory of this archive
9 * for more details.
10 *
11 */
12
13#include <linux/init.h>
14#include <linux/mman.h>
15#include <linux/mm.h>
16#include <linux/threads.h>
17#include <asm/addrspace.h>
18#include <asm/page.h>
19#include <asm/pgtable.h>
20#include <asm/processor.h>
21#include <asm/cache.h>
22#include <asm/io.h>
23#include <asm/uaccess.h>
24#include <asm/pgalloc.h>
25#include <asm/mmu_context.h>
26#include <asm/cacheflush.h>
27
28/* The 32KB cache on the SH7705 suffers from the same synonym problem
29 * as SH4 CPUs */
30
31#define __pte_offset(address) \
32 ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
33#define pte_offset(dir, address) ((pte_t *) pmd_page_kernel(*(dir)) + \
34 __pte_offset(address))
35
36static inline void cache_wback_all(void)
37{
38 unsigned long ways, waysize, addrstart;
39
40 ways = cpu_data->dcache.ways;
41 waysize = cpu_data->dcache.sets;
42 waysize <<= cpu_data->dcache.entry_shift;
43
44 addrstart = CACHE_OC_ADDRESS_ARRAY;
45
46 do {
47 unsigned long addr;
48
49 for (addr = addrstart;
50 addr < addrstart + waysize;
51 addr += cpu_data->dcache.linesz) {
52 unsigned long data;
53 int v = SH_CACHE_UPDATED | SH_CACHE_VALID;
54
55 data = ctrl_inl(addr);
56
57 if ((data & v) == v)
58 ctrl_outl(data & ~v, addr);
59
60 }
61
62 addrstart += cpu_data->dcache.way_incr;
63 } while (--ways);
64}
65
66/*
67 * Write back the range of D-cache, and purge the I-cache.
68 *
69 * Called from kernel/module.c:sys_init_module and routine for a.out format.
70 */
71void flush_icache_range(unsigned long start, unsigned long end)
72{
73 __flush_wback_region((void *)start, end - start);
74}
75
76
77/*
78 * Writeback&Invalidate the D-cache of the page
79 */
80static void __flush_dcache_page(unsigned long phys)
81{
82 unsigned long ways, waysize, addrstart;
83 unsigned long flags;
84
85 phys |= SH_CACHE_VALID;
86
87 /*
88 * Here, phys is the physical address of the page. We check all the
89 * tags in the cache for those with the same page number as this page
90 * (by masking off the lowest 2 bits of the 19-bit tag; these bits are
91 * derived from the offset within in the 4k page). Matching valid
92 * entries are invalidated.
93 *
94 * Since 2 bits of the cache index are derived from the virtual page
95 * number, knowing this would reduce the number of cache entries to be
96 * searched by a factor of 4. However this function exists to deal with
97 * potential cache aliasing, therefore the optimisation is probably not
98 * possible.
99 */
100 local_irq_save(flags);
101 jump_to_P2();
102
103 ways = cpu_data->dcache.ways;
104 waysize = cpu_data->dcache.sets;
105 waysize <<= cpu_data->dcache.entry_shift;
106
107 addrstart = CACHE_OC_ADDRESS_ARRAY;
108
109 do {
110 unsigned long addr;
111
112 for (addr = addrstart;
113 addr < addrstart + waysize;
114 addr += cpu_data->dcache.linesz) {
115 unsigned long data;
116
117 data = ctrl_inl(addr) & (0x1ffffC00 | SH_CACHE_VALID);
118 if (data == phys) {
119 data &= ~(SH_CACHE_VALID | SH_CACHE_UPDATED);
120 ctrl_outl(data, addr);
121 }
122 }
123
124 addrstart += cpu_data->dcache.way_incr;
125 } while (--ways);
126
127 back_to_P1();
128 local_irq_restore(flags);
129}
130
131
132/*
133 * Write back & invalidate the D-cache of the page.
134 * (To avoid "alias" issues)
135 */
136void flush_dcache_page(struct page *page)
137{
138 if (test_bit(PG_mapped, &page->flags))
139 __flush_dcache_page(PHYSADDR(page_address(page)));
140}
141
142void flush_cache_all(void)
143{
144 unsigned long flags;
145
146 local_irq_save(flags);
147 jump_to_P2();
148
149 cache_wback_all();
150 back_to_P1();
151 local_irq_restore(flags);
152}
153
154void flush_cache_mm(struct mm_struct *mm)
155{
156 /* Is there any good way? */
157 /* XXX: possibly call flush_cache_range for each vm area */
158 flush_cache_all();
159}
160
161/*
162 * Write back and invalidate D-caches.
163 *
164 * START, END: Virtual Address (U0 address)
165 *
166 * NOTE: We need to flush the _physical_ page entry.
167 * Flushing the cache lines for U0 only isn't enough.
168 * We need to flush for P1 too, which may contain aliases.
169 */
170void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
171 unsigned long end)
172{
173
174 /*
175 * We could call flush_cache_page for the pages of these range,
176 * but it's not efficient (scan the caches all the time...).
177 *
178 * We can't use A-bit magic, as there's the case we don't have
179 * valid entry on TLB.
180 */
181 flush_cache_all();
182}
183
184/*
185 * Write back and invalidate I/D-caches for the page.
186 *
187 * ADDRESS: Virtual Address (U0 address)
188 */
189void flush_cache_page(struct vm_area_struct *vma, unsigned long address, unsigned long pfn)
190{
191 __flush_dcache_page(pfn << PAGE_SHIFT);
192}
193
194/*
195 * This is called when a page-cache page is about to be mapped into a
196 * user process' address space. It offers an opportunity for a
197 * port to ensure d-cache/i-cache coherency if necessary.
198 *
199 * Not entirely sure why this is necessary on SH3 with 32K cache but
200 * without it we get occasional "Memory fault" when loading a program.
201 */
202void flush_icache_page(struct vm_area_struct *vma, struct page *page)
203{
204 __flush_purge_region(page_address(page), PAGE_SIZE);
205}
206