xref: /linux/arch/arm/mm/cache-v4wb.S (revision f4738f56d1dc62aaba69b33702a5ab098f1b8c63)
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