aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/mm/proc-arm940.S
blob: e5212d48937723e8fe711aadfba2ade276d2a442 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
/*
 *  linux/arch/arm/mm/arm940.S: utility functions for ARM940T
 *
 *  Copyright (C) 2004-2006 Hyok S. Choi (hyok.choi@samsung.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/assembler.h>
#include <asm/hwcap.h>
#include <asm/pgtable-hwdef.h>
#include <asm/pgtable.h>
#include <asm/ptrace.h>
#include "proc-macros.S"

/* ARM940T has a 4KB DCache comprising 256 lines of 4 words */
#define CACHE_DLINESIZE	16
#define CACHE_DSEGMENTS	4
#define CACHE_DENTRIES	64

	.text
/*
 * cpu_arm940_proc_init()
 * cpu_arm940_switch_mm()
 *
 * These are not required.
 */
ENTRY(cpu_arm940_proc_init)
ENTRY(cpu_arm940_switch_mm)
	ret	lr

/*
 * cpu_arm940_proc_fin()
 */
ENTRY(cpu_arm940_proc_fin)
	mrc	p15, 0, r0, c1, c0, 0		@ ctrl register
	bic	r0, r0, #0x00001000		@ i-cache
	bic	r0, r0, #0x00000004		@ d-cache
	mcr	p15, 0, r0, c1, c0, 0		@ disable caches
	ret	lr

/*
 * cpu_arm940_reset(loc)
 * Params  : r0 = address to jump to
 * Notes   : This sets up everything for a reset
 */
	.pushsection	.idmap.text, "ax"
ENTRY(cpu_arm940_reset)
	mov	ip, #0
	mcr	p15, 0, ip, c7, c5, 0		@ flush I cache
	mcr	p15, 0, ip, c7, c6, 0		@ flush D cache
	mcr	p15, 0, ip, c7, c10, 4		@ drain WB
	mrc	p15, 0, ip, c1, c0, 0		@ ctrl register
	bic	ip, ip, #0x00000005		@ .............c.p
	bic	ip, ip, #0x00001000		@ i-cache
	mcr	p15, 0, ip, c1, c0, 0		@ ctrl register
	ret	r0
ENDPROC(cpu_arm940_reset)
	.popsection

/*
 * cpu_arm940_do_idle()
 */
	.align	5
ENTRY(cpu_arm940_do_idle)
	mcr	p15, 0, r0, c7, c0, 4		@ Wait for interrupt
	ret	lr

/*
 *	flush_icache_all()
 *
 *	Unconditionally clean and invalidate the entire icache.
 */
ENTRY(arm940_flush_icache_all)
	mov	r0, #0
	mcr	p15, 0, r0, c7, c5, 0		@ invalidate I cache
	ret	lr
ENDPROC(arm940_flush_icache_all)

/*
 *	flush_user_cache_all()
 */
ENTRY(arm940_flush_user_cache_all)
	/* FALLTHROUGH */

/*
 *	flush_kern_cache_all()
 *
 *	Clean and invalidate the entire cache.
 */
ENTRY(arm940_flush_kern_cache_all)
	mov	r2, #VM_EXEC
	/* FALLTHROUGH */

/*
 *	flush_user_cache_range(start, end, flags)
 *
 *	There is no efficient way to flush a range of cache entries
 *	in the specified address range. Thus, flushes all.
 *
 *	- start	- start address (inclusive)
 *	- end	- end address (exclusive)
 *	- flags	- vm_flags describing address space
 */
ENTRY(arm940_flush_user_cache_range)
	mov	ip, #0
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
	mcr	p15, 0, ip, c7, c6, 0		@ flush D cache
#else
	mov	r1, #(CACHE_DSEGMENTS - 1) << 4	@ 4 segments
1:	orr	r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
2:	mcr	p15, 0, r3, c7, c14, 2		@ clean/flush D index
	subs	r3, r3, #1 << 26
	bcs	2b				@ entries 63 to 0
	subs	r1, r1, #1 << 4
	bcs	1b				@ segments 3 to 0
#endif
	tst	r2, #VM_EXEC
	mcrne	p15, 0, ip, c7, c5, 0		@ invalidate I cache
	mcrne	p15, 0, ip, c7, c10, 4		@ drain WB
	ret	lr

/*
 *	coherent_kern_range(start, end)
 *
 *	Ensure coherency between the Icache and the Dcache in the
 *	region described by start, end.  If you have non-snooping
 *	Harvard caches, you need to implement this function.
 *
 *	- start	- virtual start address
 *	- end	- virtual end address
 */
ENTRY(arm940_coherent_kern_range)
	/* FALLTHROUGH */

/*
 *	coherent_user_range(start, end)
 *
 *	Ensure coherency between the Icache and the Dcache in the
 *	region described by start, end.  If you have non-snooping
 *	Harvard caches, you need to implement this function.
 *
 *	- start	- virtual start address
 *	- end	- virtual end address
 */
ENTRY(arm940_coherent_user_range)
	/* FALLTHROUGH */

/*
 *	flush_kern_dcache_area(void *addr, size_t size)
 *
 *	Ensure no D cache aliasing occurs, either with itself or
 *	the I cache
 *
 *	- addr	- kernel address
 *	- size	- region size
 */
ENTRY(arm940_flush_kern_dcache_area)
	mov	r0, #0
	mov	r1, #(CACHE_DSEGMENTS - 1) << 4	@ 4 segments
1:	orr	r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
2:	mcr	p15, 0, r3, c7, c14, 2		@ clean/flush D index
	subs	r3, r3, #1 << 26
	bcs	2b				@ entries 63 to 0
	subs	r1, r1, #1 << 4
	bcs	1b				@ segments 7 to 0
	mcr	p15, 0, r0, c7, c5, 0		@ invalidate I cache
	mcr	p15, 0, r0, c7, c10, 4		@ drain WB
	ret	lr

/*
 *	dma_inv_range(start, end)
 *
 *	There is no efficient way to invalidate a specifid virtual
 *	address range. Thus, invalidates all.
 *
 *	- start	- virtual start address
 *	- end	- virtual end address
 */
arm940_dma_inv_range:
	mov	ip, #0
	mov	r1, #(CACHE_DSEGMENTS - 1) << 4	@ 4 segments
1:	orr	r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
2:	mcr	p15, 0, r3, c7, c6, 2		@ flush D entry
	subs	r3, r3, #1 << 26
	bcs	2b				@ entries 63 to 0
	subs	r1, r1, #1 << 4
	bcs	1b				@ segments 7 to 0
	mcr	p15, 0, ip, c7, c10, 4		@ drain WB
	ret	lr

/*
 *	dma_clean_range(start, end)
 *
 *	There is no efficient way to clean a specifid virtual
 *	address range. Thus, cleans all.
 *
 *	- start	- virtual start address
 *	- end	- virtual end address
 */
arm940_dma_clean_range:
ENTRY(cpu_arm940_dcache_clean_area)
	mov	ip, #0
#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
	mov	r1, #(CACHE_DSEGMENTS - 1) << 4	@ 4 segments
1:	orr	r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
2:	mcr	p15, 0, r3, c7, c10, 2		@ clean D entry
	subs	r3, r3, #1 << 26
	bcs	2b				@ entries 63 to 0
	subs	r1, r1, #1 << 4
	bcs	1b				@ segments 7 to 0
#endif
	mcr	p15, 0, ip, c7, c10, 4		@ drain WB
	ret	lr

/*
 *	dma_flush_range(start, end)
 *
 *	There is no efficient way to clean and invalidate a specifid
 *	virtual address range.
 *
 *	- start	- virtual start address
 *	- end	- virtual end address
 */
ENTRY(arm940_dma_flush_range)
	mov	ip, #0
	mov	r1, #(CACHE_DSEGMENTS - 1) << 4	@ 4 segments
1:	orr	r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
2:
#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
	mcr	p15, 0, r3, c7, c14, 2		@ clean/flush D entry
#else
	mcr	p15, 0, r3, c7, c6, 2		@ invalidate D entry
#endif
	subs	r3, r3, #1 << 26
	bcs	2b				@ entries 63 to 0
	subs	r1, r1, #1 << 4
	bcs	1b				@ segments 7 to 0
	mcr	p15, 0, ip, c7, c10, 4		@ drain WB
	ret	lr

/*
 *	dma_map_area(start, size, dir)
 *	- start	- kernel virtual start address
 *	- size	- size of region
 *	- dir	- DMA direction
 */
ENTRY(arm940_dma_map_area)
	add	r1, r1, r0
	cmp	r2, #DMA_TO_DEVICE
	beq	arm940_dma_clean_range
	bcs	arm940_dma_inv_range
	b	arm940_dma_flush_range
ENDPROC(arm940_dma_map_area)

/*
 *	dma_unmap_area(start, size, dir)
 *	- start	- kernel virtual start address
 *	- size	- size of region
 *	- dir	- DMA direction
 */
ENTRY(arm940_dma_unmap_area)
	ret	lr
ENDPROC(arm940_dma_unmap_area)

	.globl	arm940_flush_kern_cache_louis
	.equ	arm940_flush_kern_cache_louis, arm940_flush_kern_cache_all

	@ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
	define_cache_functions arm940

	.type	__arm940_setup, #function
__arm940_setup:
	mov	r0, #0
	mcr	p15, 0, r0, c7, c5, 0		@ invalidate I cache
	mcr	p15, 0, r0, c7, c6, 0		@ invalidate D cache
	mcr	p15, 0, r0, c7, c10, 4		@ drain WB

	mcr	p15, 0, r0, c6, c3, 0		@ disable data area 3~7
	mcr	p15, 0, r0, c6, c4, 0
	mcr	p15, 0, r0, c6, c5, 0
	mcr	p15, 0, r0, c6, c6, 0
	mcr	p15, 0, r0, c6, c7, 0

	mcr	p15, 0, r0, c6, c3, 1		@ disable instruction area 3~7
	mcr	p15, 0, r0, c6, c4, 1
	mcr	p15, 0, r0, c6, c5, 1
	mcr	p15, 0, r0, c6, c6, 1
	mcr	p15, 0, r0, c6, c7, 1

	mov	r0, #0x0000003F			@ base = 0, size = 4GB
	mcr	p15, 0, r0, c6,	c0, 0		@ set area 0, default
	mcr	p15, 0, r0, c6,	c0, 1

	ldr	r0, =(CONFIG_DRAM_BASE & 0xFFFFF000) @ base[31:12] of RAM
	ldr	r1, =(CONFIG_DRAM_SIZE >> 12)	@ size of RAM (must be >= 4KB)
	mov	r2, #10				@ 11 is the minimum (4KB)
1:	add	r2, r2, #1			@ area size *= 2
	mov	r1, r1, lsr #1
	bne	1b				@ count not zero r-shift
	orr	r0, r0, r2, lsl #1		@ the area register value
	orr	r0, r0, #1			@ set enable bit
	mcr	p15, 0, r0, c6,	c1, 0		@ set area 1, RAM
	mcr	p15, 0, r0, c6,	c1, 1

	ldr	r0, =(CONFIG_FLASH_MEM_BASE & 0xFFFFF000) @ base[31:12] of FLASH
	ldr	r1, =(CONFIG_FLASH_SIZE >> 12)	@ size of FLASH (must be >= 4KB)
	mov	r2, #10				@ 11 is the minimum (4KB)
1:	add	r2, r2, #1			@ area size *= 2
	mov	r1, r1, lsr #1
	bne	1b				@ count not zero r-shift
	orr	r0, r0, r2, lsl #1		@ the area register value
	orr	r0, r0, #1			@ set enable bit
	mcr	p15, 0, r0, c6,	c2, 0		@ set area 2, ROM/FLASH
	mcr	p15, 0, r0, c6,	c2, 1

	mov	r0, #0x06
	mcr	p15, 0, r0, c2, c0, 0		@ Region 1&2 cacheable
	mcr	p15, 0, r0, c2, c0, 1
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
	mov	r0, #0x00			@ disable whole write buffer
#else
	mov	r0, #0x02			@ Region 1 write bufferred
#endif
	mcr	p15, 0, r0, c3, c0, 0

	mov	r0, #0x10000
	sub	r0, r0, #1			@ r0 = 0xffff
	mcr	p15, 0, r0, c5, c0, 0		@ all read/write access
	mcr	p15, 0, r0, c5, c0, 1

	mrc	p15, 0, r0, c1, c0		@ get control register
	orr	r0, r0, #0x00001000		@ I-cache
	orr	r0, r0, #0x00000005		@ MPU/D-cache

	ret	lr

	.size	__arm940_setup, . - __arm940_setup

	__INITDATA

	@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
	define_processor_functions arm940, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1

	.section ".rodata"

	string	cpu_arch_name, "armv4t"
	string	cpu_elf_name, "v4"
	string	cpu_arm940_name, "ARM940T"

	.align

	.section ".proc.info.init", #alloc, #execinstr

	.type	__arm940_proc_info,#object
__arm940_proc_info:
	.long	0x41009400
	.long	0xff00fff0
	.long	0
	b	__arm940_setup
	.long	cpu_arch_name
	.long	cpu_elf_name
	.long	HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB
	.long	cpu_arm940_name
	.long	arm940_processor_functions
	.long	0
	.long	0
	.long	arm940_cache_fns
	.size	__arm940_proc_info, . - __arm940_proc_info