1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * linux/arch/arm/mm/cache-v4wb.S
4 *
5 * Copyright (C) 1997-2002 Russell king
6 */
7#include <linux/linkage.h>
8#include <linux/init.h>
9#include <asm/assembler.h>
10#include <asm/page.h>
11#include "proc-macros.S"
12
13/*
14 * The size of one data cache line.
15 */
16#define CACHE_DLINESIZE 32
17
18/*
19 * The total size of the data cache.
20 */
21#if defined(CONFIG_CPU_SA110)
22# define CACHE_DSIZE 16384
23#elif defined(CONFIG_CPU_SA1100)
24# define CACHE_DSIZE 8192
25#else
26# error Unknown cache size
27#endif
28
29/*
30 * This is the size at which it becomes more efficient to
31 * clean the whole cache, rather than using the individual
32 * cache line maintenance instructions.
33 *
34 * Size Clean (ticks) Dirty (ticks)
35 * 4096 21 20 21 53 55 54
36 * 8192 40 41 40 106 100 102
37 * 16384 77 77 76 140 140 138
38 * 32768 150 149 150 214 216 212 <---
39 * 65536 296 297 296 351 358 361
40 * 131072 591 591 591 656 657 651
41 * Whole 132 136 132 221 217 207 <---
42 */
43#define CACHE_DLIMIT (CACHE_DSIZE * 4)
44
45 .data
46 .align 2
47flush_base:
48 .long FLUSH_BASE
49 .text
50
51/*
52 * flush_icache_all()
53 *
54 * Unconditionally clean and invalidate the entire icache.
55 */
56ENTRY(v4wb_flush_icache_all)
57 mov r0, #0
58 mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
59 ret lr
60ENDPROC(v4wb_flush_icache_all)
61
62/*
63 * flush_user_cache_all()
64 *
65 * Clean and invalidate all cache entries in a particular address
66 * space.
67 */
68ENTRY(v4wb_flush_user_cache_all)
69 /* FALLTHROUGH */
70/*
71 * flush_kern_cache_all()
72 *
73 * Clean and invalidate the entire cache.
74 */
75ENTRY(v4wb_flush_kern_cache_all)
76 mov ip, #0
77 mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
78__flush_whole_cache:
79 ldr r3, =flush_base
80 ldr r1, [r3, #0]
81 eor r1, r1, #CACHE_DSIZE
82 str r1, [r3, #0]
83 add r2, r1, #CACHE_DSIZE
841: ldr r3, [r1], #32
85 cmp r1, r2
86 blo 1b
87#ifdef FLUSH_BASE_MINICACHE
88 add r2, r2, #FLUSH_BASE_MINICACHE - FLUSH_BASE
89 sub r1, r2, #512 @ only 512 bytes
901: ldr r3, [r1], #32
91 cmp r1, r2
92 blo 1b
93#endif
94 mcr p15, 0, ip, c7, c10, 4 @ drain write buffer
95 ret lr
96
97/*
98 * flush_user_cache_range(start, end, flags)
99 *
100 * Invalidate a range of cache entries in the specified
101 * address space.
102 *
103 * - start - start address (inclusive, page aligned)
104 * - end - end address (exclusive, page aligned)
105 * - flags - vma_area_struct flags describing address space
106 */
107ENTRY(v4wb_flush_user_cache_range)
108 mov ip, #0
109 sub r3, r1, r0 @ calculate total size
110 tst r2, #VM_EXEC @ executable region?
111 mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
112
113 cmp r3, #CACHE_DLIMIT @ total size >= limit?
114 bhs __flush_whole_cache @ flush whole D cache
115
1161: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
117 mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
118 add r0, r0, #CACHE_DLINESIZE
119 cmp r0, r1
120 blo 1b
121 tst r2, #VM_EXEC
122 mcrne p15, 0, ip, c7, c10, 4 @ drain write buffer
123 ret lr
124
125/*
126 * flush_kern_dcache_area(void *addr, size_t size)
127 *
128 * Ensure no D cache aliasing occurs, either with itself or
129 * the I cache
130 *
131 * - addr - kernel address
132 * - size - region size
133 */
134ENTRY(v4wb_flush_kern_dcache_area)
135 add r1, r0, r1
136 /* fall through */
137
138/*
139 * coherent_kern_range(start, end)
140 *
141 * Ensure coherency between the Icache and the Dcache in the
142 * region described by start. If you have non-snooping
143 * Harvard caches, you need to implement this function.
144 *
145 * - start - virtual start address
146 * - end - virtual end address
147 */
148ENTRY(v4wb_coherent_kern_range)
149 /* fall through */
150
151/*
152 * coherent_user_range(start, end)
153 *
154 * Ensure coherency between the Icache and the Dcache in the
155 * region described by start. If you have non-snooping
156 * Harvard caches, you need to implement this function.
157 *
158 * - start - virtual start address
159 * - end - virtual end address
160 */
161ENTRY(v4wb_coherent_user_range)
162 bic r0, r0, #CACHE_DLINESIZE - 1
1631: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
164 mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
165 add r0, r0, #CACHE_DLINESIZE
166 cmp r0, r1
167 blo 1b
168 mov r0, #0
169 mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
170 mcr p15, 0, r0, c7, c10, 4 @ drain WB
171 ret lr
172
173
174/*
175 * dma_inv_range(start, end)
176 *
177 * Invalidate (discard) the specified virtual address range.
178 * May not write back any entries. If 'start' or 'end'
179 * are not cache line aligned, those lines must be written
180 * back.
181 *
182 * - start - virtual start address
183 * - end - virtual end address
184 */
185v4wb_dma_inv_range:
186 tst r0, #CACHE_DLINESIZE - 1
187 bic r0, r0, #CACHE_DLINESIZE - 1
188 mcrne p15, 0, r0, c7, c10, 1 @ clean D entry
189 tst r1, #CACHE_DLINESIZE - 1
190 mcrne p15, 0, r1, c7, c10, 1 @ clean D entry
1911: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
192 add r0, r0, #CACHE_DLINESIZE
193 cmp r0, r1
194 blo 1b
195 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
196 ret lr
197
198/*
199 * dma_clean_range(start, end)
200 *
201 * Clean (write back) the specified virtual address range.
202 *
203 * - start - virtual start address
204 * - end - virtual end address
205 */
206v4wb_dma_clean_range:
207 bic r0, r0, #CACHE_DLINESIZE - 1
2081: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
209 add r0, r0, #CACHE_DLINESIZE
210 cmp r0, r1
211 blo 1b
212 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
213 ret lr
214
215/*
216 * dma_flush_range(start, end)
217 *
218 * Clean and invalidate the specified virtual address range.
219 *
220 * - start - virtual start address
221 * - end - virtual end address
222 *
223 * This is actually the same as v4wb_coherent_kern_range()
224 */
225 .globl v4wb_dma_flush_range
226 .set v4wb_dma_flush_range, v4wb_coherent_kern_range
227
228/*
229 * dma_map_area(start, size, dir)
230 * - start - kernel virtual start address
231 * - size - size of region
232 * - dir - DMA direction
233 */
234ENTRY(v4wb_dma_map_area)
235 add r1, r1, r0
236 cmp r2, #DMA_TO_DEVICE
237 beq v4wb_dma_clean_range
238 bcs v4wb_dma_inv_range
239 b v4wb_dma_flush_range
240ENDPROC(v4wb_dma_map_area)
241
242/*
243 * dma_unmap_area(start, size, dir)
244 * - start - kernel virtual start address
245 * - size - size of region
246 * - dir - DMA direction
247 */
248ENTRY(v4wb_dma_unmap_area)
249 ret lr
250ENDPROC(v4wb_dma_unmap_area)
251
252 .globl v4wb_flush_kern_cache_louis
253 .equ v4wb_flush_kern_cache_louis, v4wb_flush_kern_cache_all
254
255 __INITDATA
256
257 @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
258 define_cache_functions v4wb
259

source code of linux/arch/arm/mm/cache-v4wb.S