xref: /openbmc/linux/arch/arm/mm/cache-v4wb.S (revision 287dcc2b)
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/memory.h>
11#include <asm/page.h>
12#include "proc-macros.S"
13
14/*
15 * The size of one data cache line.
16 */
17#define CACHE_DLINESIZE	32
18
19/*
20 * The total size of the data cache.
21 */
22#if defined(CONFIG_CPU_SA110)
23# define CACHE_DSIZE	16384
24#elif defined(CONFIG_CPU_SA1100)
25# define CACHE_DSIZE	8192
26#else
27# error Unknown cache size
28#endif
29
30/*
31 * This is the size at which it becomes more efficient to
32 * clean the whole cache, rather than using the individual
33 * cache line maintenance instructions.
34 *
35 *  Size  Clean (ticks) Dirty (ticks)
36 *   4096   21  20  21    53  55  54
37 *   8192   40  41  40   106 100 102
38 *  16384   77  77  76   140 140 138
39 *  32768  150 149 150   214 216 212 <---
40 *  65536  296 297 296   351 358 361
41 * 131072  591 591 591   656 657 651
42 *  Whole  132 136 132   221 217 207 <---
43 */
44#define CACHE_DLIMIT	(CACHE_DSIZE * 4)
45
46	.data
47	.align	2
48flush_base:
49	.long	FLUSH_BASE
50	.text
51
52/*
53 *	flush_icache_all()
54 *
55 *	Unconditionally clean and invalidate the entire icache.
56 */
57ENTRY(v4wb_flush_icache_all)
58	mov	r0, #0
59	mcr	p15, 0, r0, c7, c5, 0		@ invalidate I cache
60	ret	lr
61ENDPROC(v4wb_flush_icache_all)
62
63/*
64 *	flush_user_cache_all()
65 *
66 *	Clean and invalidate all cache entries in a particular address
67 *	space.
68 */
69ENTRY(v4wb_flush_user_cache_all)
70	/* FALLTHROUGH */
71/*
72 *	flush_kern_cache_all()
73 *
74 *	Clean and invalidate the entire cache.
75 */
76ENTRY(v4wb_flush_kern_cache_all)
77	mov	ip, #0
78	mcr	p15, 0, ip, c7, c5, 0		@ invalidate I cache
79__flush_whole_cache:
80	ldr	r3, =flush_base
81	ldr	r1, [r3, #0]
82	eor	r1, r1, #CACHE_DSIZE
83	str	r1, [r3, #0]
84	add	r2, r1, #CACHE_DSIZE
851:	ldr	r3, [r1], #32
86	cmp	r1, r2
87	blo	1b
88#ifdef FLUSH_BASE_MINICACHE
89	add	r2, r2, #FLUSH_BASE_MINICACHE - FLUSH_BASE
90	sub	r1, r2, #512			@ only 512 bytes
911:	ldr	r3, [r1], #32
92	cmp	r1, r2
93	blo	1b
94#endif
95	mcr	p15, 0, ip, c7, c10, 4		@ drain write buffer
96	ret	lr
97
98/*
99 *	flush_user_cache_range(start, end, flags)
100 *
101 *	Invalidate a range of cache entries in the specified
102 *	address space.
103 *
104 *	- start - start address (inclusive, page aligned)
105 *	- end	- end address (exclusive, page aligned)
106 *	- flags	- vma_area_struct flags describing address space
107 */
108ENTRY(v4wb_flush_user_cache_range)
109	mov	ip, #0
110	sub	r3, r1, r0			@ calculate total size
111	tst	r2, #VM_EXEC			@ executable region?
112	mcrne	p15, 0, ip, c7, c5, 0		@ invalidate I cache
113
114	cmp	r3, #CACHE_DLIMIT		@ total size >= limit?
115	bhs	__flush_whole_cache		@ flush whole D cache
116
1171:	mcr	p15, 0, r0, c7, c10, 1		@ clean D entry
118	mcr	p15, 0, r0, c7, c6, 1		@ invalidate D entry
119	add	r0, r0, #CACHE_DLINESIZE
120	cmp	r0, r1
121	blo	1b
122	tst	r2, #VM_EXEC
123	mcrne	p15, 0, ip, c7, c10, 4		@ drain write buffer
124	ret	lr
125
126/*
127 *	flush_kern_dcache_area(void *addr, size_t size)
128 *
129 *	Ensure no D cache aliasing occurs, either with itself or
130 *	the I cache
131 *
132 *	- addr	- kernel address
133 *	- size	- region size
134 */
135ENTRY(v4wb_flush_kern_dcache_area)
136	add	r1, r0, r1
137	/* fall through */
138
139/*
140 *	coherent_kern_range(start, end)
141 *
142 *	Ensure coherency between the Icache and the Dcache in the
143 *	region described by start.  If you have non-snooping
144 *	Harvard caches, you need to implement this function.
145 *
146 *	- start  - virtual start address
147 *	- end	 - virtual end address
148 */
149ENTRY(v4wb_coherent_kern_range)
150	/* fall through */
151
152/*
153 *	coherent_user_range(start, end)
154 *
155 *	Ensure coherency between the Icache and the Dcache in the
156 *	region described by start.  If you have non-snooping
157 *	Harvard caches, you need to implement this function.
158 *
159 *	- start  - virtual start address
160 *	- end	 - virtual end address
161 */
162ENTRY(v4wb_coherent_user_range)
163	bic	r0, r0, #CACHE_DLINESIZE - 1
1641:	mcr	p15, 0, r0, c7, c10, 1		@ clean D entry
165	mcr	p15, 0, r0, c7, c6, 1		@ invalidate D entry
166	add	r0, r0, #CACHE_DLINESIZE
167	cmp	r0, r1
168	blo	1b
169	mov	r0, #0
170	mcr	p15, 0, r0, c7, c5, 0		@ invalidate I cache
171	mcr	p15, 0, r0, c7, c10, 4		@ drain WB
172	ret	lr
173
174
175/*
176 *	dma_inv_range(start, end)
177 *
178 *	Invalidate (discard) the specified virtual address range.
179 *	May not write back any entries.  If 'start' or 'end'
180 *	are not cache line aligned, those lines must be written
181 *	back.
182 *
183 *	- start  - virtual start address
184 *	- end	 - virtual end address
185 */
186v4wb_dma_inv_range:
187	tst	r0, #CACHE_DLINESIZE - 1
188	bic	r0, r0, #CACHE_DLINESIZE - 1
189	mcrne	p15, 0, r0, c7, c10, 1		@ clean D entry
190	tst	r1, #CACHE_DLINESIZE - 1
191	mcrne	p15, 0, r1, c7, c10, 1		@ clean D entry
1921:	mcr	p15, 0, r0, c7, c6, 1		@ invalidate D entry
193	add	r0, r0, #CACHE_DLINESIZE
194	cmp	r0, r1
195	blo	1b
196	mcr	p15, 0, r0, c7, c10, 4		@ drain write buffer
197	ret	lr
198
199/*
200 *	dma_clean_range(start, end)
201 *
202 *	Clean (write back) the specified virtual address range.
203 *
204 *	- start  - virtual start address
205 *	- end	 - virtual end address
206 */
207v4wb_dma_clean_range:
208	bic	r0, r0, #CACHE_DLINESIZE - 1
2091:	mcr	p15, 0, r0, c7, c10, 1		@ clean D entry
210	add	r0, r0, #CACHE_DLINESIZE
211	cmp	r0, r1
212	blo	1b
213	mcr	p15, 0, r0, c7, c10, 4		@ drain write buffer
214	ret	lr
215
216/*
217 *	dma_flush_range(start, end)
218 *
219 *	Clean and invalidate the specified virtual address range.
220 *
221 *	- start  - virtual start address
222 *	- end	 - virtual end address
223 *
224 *	This is actually the same as v4wb_coherent_kern_range()
225 */
226	.globl	v4wb_dma_flush_range
227	.set	v4wb_dma_flush_range, v4wb_coherent_kern_range
228
229/*
230 *	dma_map_area(start, size, dir)
231 *	- start	- kernel virtual start address
232 *	- size	- size of region
233 *	- dir	- DMA direction
234 */
235ENTRY(v4wb_dma_map_area)
236	add	r1, r1, r0
237	cmp	r2, #DMA_TO_DEVICE
238	beq	v4wb_dma_clean_range
239	bcs	v4wb_dma_inv_range
240	b	v4wb_dma_flush_range
241ENDPROC(v4wb_dma_map_area)
242
243/*
244 *	dma_unmap_area(start, size, dir)
245 *	- start	- kernel virtual start address
246 *	- size	- size of region
247 *	- dir	- DMA direction
248 */
249ENTRY(v4wb_dma_unmap_area)
250	ret	lr
251ENDPROC(v4wb_dma_unmap_area)
252
253	.globl	v4wb_flush_kern_cache_louis
254	.equ	v4wb_flush_kern_cache_louis, v4wb_flush_kern_cache_all
255
256	__INITDATA
257
258	@ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
259	define_cache_functions v4wb
260