xref: /openbmc/linux/arch/arm/mm/cache-v4wb.S (revision cfbb9be8)
1/*
2 *  linux/arch/arm/mm/cache-v4wb.S
3 *
4 *  Copyright (C) 1997-2002 Russell king
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/linkage.h>
11#include <linux/init.h>
12#include <asm/assembler.h>
13#include <asm/memory.h>
14#include <asm/page.h>
15#include "proc-macros.S"
16
17/*
18 * The size of one data cache line.
19 */
20#define CACHE_DLINESIZE	32
21
22/*
23 * The total size of the data cache.
24 */
25#if defined(CONFIG_CPU_SA110)
26# define CACHE_DSIZE	16384
27#elif defined(CONFIG_CPU_SA1100)
28# define CACHE_DSIZE	8192
29#else
30# error Unknown cache size
31#endif
32
33/*
34 * This is the size at which it becomes more efficient to
35 * clean the whole cache, rather than using the individual
36 * cache line maintenance instructions.
37 *
38 *  Size  Clean (ticks) Dirty (ticks)
39 *   4096   21  20  21    53  55  54
40 *   8192   40  41  40   106 100 102
41 *  16384   77  77  76   140 140 138
42 *  32768  150 149 150   214 216 212 <---
43 *  65536  296 297 296   351 358 361
44 * 131072  591 591 591   656 657 651
45 *  Whole  132 136 132   221 217 207 <---
46 */
47#define CACHE_DLIMIT	(CACHE_DSIZE * 4)
48
49	.data
50	.align	2
51flush_base:
52	.long	FLUSH_BASE
53	.text
54
55/*
56 *	flush_icache_all()
57 *
58 *	Unconditionally clean and invalidate the entire icache.
59 */
60ENTRY(v4wb_flush_icache_all)
61	mov	r0, #0
62	mcr	p15, 0, r0, c7, c5, 0		@ invalidate I cache
63	ret	lr
64ENDPROC(v4wb_flush_icache_all)
65
66/*
67 *	flush_user_cache_all()
68 *
69 *	Clean and invalidate all cache entries in a particular address
70 *	space.
71 */
72ENTRY(v4wb_flush_user_cache_all)
73	/* FALLTHROUGH */
74/*
75 *	flush_kern_cache_all()
76 *
77 *	Clean and invalidate the entire cache.
78 */
79ENTRY(v4wb_flush_kern_cache_all)
80	mov	ip, #0
81	mcr	p15, 0, ip, c7, c5, 0		@ invalidate I cache
82__flush_whole_cache:
83	ldr	r3, =flush_base
84	ldr	r1, [r3, #0]
85	eor	r1, r1, #CACHE_DSIZE
86	str	r1, [r3, #0]
87	add	r2, r1, #CACHE_DSIZE
881:	ldr	r3, [r1], #32
89	cmp	r1, r2
90	blo	1b
91#ifdef FLUSH_BASE_MINICACHE
92	add	r2, r2, #FLUSH_BASE_MINICACHE - FLUSH_BASE
93	sub	r1, r2, #512			@ only 512 bytes
941:	ldr	r3, [r1], #32
95	cmp	r1, r2
96	blo	1b
97#endif
98	mcr	p15, 0, ip, c7, c10, 4		@ drain write buffer
99	ret	lr
100
101/*
102 *	flush_user_cache_range(start, end, flags)
103 *
104 *	Invalidate a range of cache entries in the specified
105 *	address space.
106 *
107 *	- start - start address (inclusive, page aligned)
108 *	- end	- end address (exclusive, page aligned)
109 *	- flags	- vma_area_struct flags describing address space
110 */
111ENTRY(v4wb_flush_user_cache_range)
112	mov	ip, #0
113	sub	r3, r1, r0			@ calculate total size
114	tst	r2, #VM_EXEC			@ executable region?
115	mcrne	p15, 0, ip, c7, c5, 0		@ invalidate I cache
116
117	cmp	r3, #CACHE_DLIMIT		@ total size >= limit?
118	bhs	__flush_whole_cache		@ flush whole D cache
119
1201:	mcr	p15, 0, r0, c7, c10, 1		@ clean D entry
121	mcr	p15, 0, r0, c7, c6, 1		@ invalidate D entry
122	add	r0, r0, #CACHE_DLINESIZE
123	cmp	r0, r1
124	blo	1b
125	tst	r2, #VM_EXEC
126	mcrne	p15, 0, ip, c7, c10, 4		@ drain write buffer
127	ret	lr
128
129/*
130 *	flush_kern_dcache_area(void *addr, size_t size)
131 *
132 *	Ensure no D cache aliasing occurs, either with itself or
133 *	the I cache
134 *
135 *	- addr	- kernel address
136 *	- size	- region size
137 */
138ENTRY(v4wb_flush_kern_dcache_area)
139	add	r1, r0, r1
140	/* fall through */
141
142/*
143 *	coherent_kern_range(start, end)
144 *
145 *	Ensure coherency between the Icache and the Dcache in the
146 *	region described by start.  If you have non-snooping
147 *	Harvard caches, you need to implement this function.
148 *
149 *	- start  - virtual start address
150 *	- end	 - virtual end address
151 */
152ENTRY(v4wb_coherent_kern_range)
153	/* fall through */
154
155/*
156 *	coherent_user_range(start, end)
157 *
158 *	Ensure coherency between the Icache and the Dcache in the
159 *	region described by start.  If you have non-snooping
160 *	Harvard caches, you need to implement this function.
161 *
162 *	- start  - virtual start address
163 *	- end	 - virtual end address
164 */
165ENTRY(v4wb_coherent_user_range)
166	bic	r0, r0, #CACHE_DLINESIZE - 1
1671:	mcr	p15, 0, r0, c7, c10, 1		@ clean D entry
168	mcr	p15, 0, r0, c7, c6, 1		@ invalidate D entry
169	add	r0, r0, #CACHE_DLINESIZE
170	cmp	r0, r1
171	blo	1b
172	mov	r0, #0
173	mcr	p15, 0, r0, c7, c5, 0		@ invalidate I cache
174	mcr	p15, 0, r0, c7, c10, 4		@ drain WB
175	ret	lr
176
177
178/*
179 *	dma_inv_range(start, end)
180 *
181 *	Invalidate (discard) the specified virtual address range.
182 *	May not write back any entries.  If 'start' or 'end'
183 *	are not cache line aligned, those lines must be written
184 *	back.
185 *
186 *	- start  - virtual start address
187 *	- end	 - virtual end address
188 */
189v4wb_dma_inv_range:
190	tst	r0, #CACHE_DLINESIZE - 1
191	bic	r0, r0, #CACHE_DLINESIZE - 1
192	mcrne	p15, 0, r0, c7, c10, 1		@ clean D entry
193	tst	r1, #CACHE_DLINESIZE - 1
194	mcrne	p15, 0, r1, c7, c10, 1		@ clean D entry
1951:	mcr	p15, 0, r0, c7, c6, 1		@ invalidate D entry
196	add	r0, r0, #CACHE_DLINESIZE
197	cmp	r0, r1
198	blo	1b
199	mcr	p15, 0, r0, c7, c10, 4		@ drain write buffer
200	ret	lr
201
202/*
203 *	dma_clean_range(start, end)
204 *
205 *	Clean (write back) the specified virtual address range.
206 *
207 *	- start  - virtual start address
208 *	- end	 - virtual end address
209 */
210v4wb_dma_clean_range:
211	bic	r0, r0, #CACHE_DLINESIZE - 1
2121:	mcr	p15, 0, r0, c7, c10, 1		@ clean D entry
213	add	r0, r0, #CACHE_DLINESIZE
214	cmp	r0, r1
215	blo	1b
216	mcr	p15, 0, r0, c7, c10, 4		@ drain write buffer
217	ret	lr
218
219/*
220 *	dma_flush_range(start, end)
221 *
222 *	Clean and invalidate the specified virtual address range.
223 *
224 *	- start  - virtual start address
225 *	- end	 - virtual end address
226 *
227 *	This is actually the same as v4wb_coherent_kern_range()
228 */
229	.globl	v4wb_dma_flush_range
230	.set	v4wb_dma_flush_range, v4wb_coherent_kern_range
231
232/*
233 *	dma_map_area(start, size, dir)
234 *	- start	- kernel virtual start address
235 *	- size	- size of region
236 *	- dir	- DMA direction
237 */
238ENTRY(v4wb_dma_map_area)
239	add	r1, r1, r0
240	cmp	r2, #DMA_TO_DEVICE
241	beq	v4wb_dma_clean_range
242	bcs	v4wb_dma_inv_range
243	b	v4wb_dma_flush_range
244ENDPROC(v4wb_dma_map_area)
245
246/*
247 *	dma_unmap_area(start, size, dir)
248 *	- start	- kernel virtual start address
249 *	- size	- size of region
250 *	- dir	- DMA direction
251 */
252ENTRY(v4wb_dma_unmap_area)
253	ret	lr
254ENDPROC(v4wb_dma_unmap_area)
255
256	.globl	v4wb_flush_kern_cache_louis
257	.equ	v4wb_flush_kern_cache_louis, v4wb_flush_kern_cache_all
258
259	__INITDATA
260
261	@ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
262	define_cache_functions v4wb
263