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1/*
2 * arch/arm/kernel/crunch-bits.S
3 * Cirrus MaverickCrunch context switching and handling
4 *
5 * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
6 *
7 * Shamelessly stolen from the iWMMXt code by Nicolas Pitre, which is
8 * Copyright (c) 2003-2004, MontaVista Software, Inc.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14
15#include <linux/linkage.h>
16#include <asm/ptrace.h>
17#include <asm/thread_info.h>
18#include <asm/asm-offsets.h>
19#include <asm/arch/ep93xx-regs.h>
20
21/*
22 * We can't use hex constants here due to a bug in gas.
23 */
24#define CRUNCH_MVDX0 0
25#define CRUNCH_MVDX1 8
26#define CRUNCH_MVDX2 16
27#define CRUNCH_MVDX3 24
28#define CRUNCH_MVDX4 32
29#define CRUNCH_MVDX5 40
30#define CRUNCH_MVDX6 48
31#define CRUNCH_MVDX7 56
32#define CRUNCH_MVDX8 64
33#define CRUNCH_MVDX9 72
34#define CRUNCH_MVDX10 80
35#define CRUNCH_MVDX11 88
36#define CRUNCH_MVDX12 96
37#define CRUNCH_MVDX13 104
38#define CRUNCH_MVDX14 112
39#define CRUNCH_MVDX15 120
40#define CRUNCH_MVAX0L 128
41#define CRUNCH_MVAX0M 132
42#define CRUNCH_MVAX0H 136
43#define CRUNCH_MVAX1L 140
44#define CRUNCH_MVAX1M 144
45#define CRUNCH_MVAX1H 148
46#define CRUNCH_MVAX2L 152
47#define CRUNCH_MVAX2M 156
48#define CRUNCH_MVAX2H 160
49#define CRUNCH_MVAX3L 164
50#define CRUNCH_MVAX3M 168
51#define CRUNCH_MVAX3H 172
52#define CRUNCH_DSPSC 176
53
54#define CRUNCH_SIZE 184
55
56 .text
57
58/*
59 * Lazy switching of crunch coprocessor context
60 *
61 * r10 = struct thread_info pointer
62 * r9 = ret_from_exception
63 * lr = undefined instr exit
64 *
65 * called from prefetch exception handler with interrupts disabled
66 */
67ENTRY(crunch_task_enable)
68 ldr r8, =(EP93XX_APB_VIRT_BASE + 0x00130000) @ syscon addr
69
70 ldr r1, [r8, #0x80]
71 tst r1, #0x00800000 @ access to crunch enabled?
72 movne pc, lr @ if so no business here
73 mov r3, #0xaa @ unlock syscon swlock
74 str r3, [r8, #0xc0]
75 orr r1, r1, #0x00800000 @ enable access to crunch
76 str r1, [r8, #0x80]
77
78 ldr r3, =crunch_owner
79 add r0, r10, #TI_CRUNCH_STATE @ get task crunch save area
80 ldr r2, [sp, #60] @ current task pc value
81 ldr r1, [r3] @ get current crunch owner
82 str r0, [r3] @ this task now owns crunch
83 sub r2, r2, #4 @ adjust pc back
84 str r2, [sp, #60]
85
86 ldr r2, [r8, #0x80]
87 mov r2, r2 @ flush out enable (@@@)
88
89 teq r1, #0 @ test for last ownership
90 mov lr, r9 @ normal exit from exception
91 beq crunch_load @ no owner, skip save
92
93crunch_save:
94 cfstr64 mvdx0, [r1, #CRUNCH_MVDX0] @ save 64b registers
95 cfstr64 mvdx1, [r1, #CRUNCH_MVDX1]
96 cfstr64 mvdx2, [r1, #CRUNCH_MVDX2]
97 cfstr64 mvdx3, [r1, #CRUNCH_MVDX3]
98 cfstr64 mvdx4, [r1, #CRUNCH_MVDX4]
99 cfstr64 mvdx5, [r1, #CRUNCH_MVDX5]
100 cfstr64 mvdx6, [r1, #CRUNCH_MVDX6]
101 cfstr64 mvdx7, [r1, #CRUNCH_MVDX7]
102 cfstr64 mvdx8, [r1, #CRUNCH_MVDX8]
103 cfstr64 mvdx9, [r1, #CRUNCH_MVDX9]
104 cfstr64 mvdx10, [r1, #CRUNCH_MVDX10]
105 cfstr64 mvdx11, [r1, #CRUNCH_MVDX11]
106 cfstr64 mvdx12, [r1, #CRUNCH_MVDX12]
107 cfstr64 mvdx13, [r1, #CRUNCH_MVDX13]
108 cfstr64 mvdx14, [r1, #CRUNCH_MVDX14]
109 cfstr64 mvdx15, [r1, #CRUNCH_MVDX15]
110
111#ifdef __ARMEB__
112#error fix me for ARMEB
113#endif
114
115 cfmv32al mvfx0, mvax0 @ save 72b accumulators
116 cfstr32 mvfx0, [r1, #CRUNCH_MVAX0L]
117 cfmv32am mvfx0, mvax0
118 cfstr32 mvfx0, [r1, #CRUNCH_MVAX0M]
119 cfmv32ah mvfx0, mvax0
120 cfstr32 mvfx0, [r1, #CRUNCH_MVAX0H]
121 cfmv32al mvfx0, mvax1
122 cfstr32 mvfx0, [r1, #CRUNCH_MVAX1L]
123 cfmv32am mvfx0, mvax1
124 cfstr32 mvfx0, [r1, #CRUNCH_MVAX1M]
125 cfmv32ah mvfx0, mvax1
126 cfstr32 mvfx0, [r1, #CRUNCH_MVAX1H]
127 cfmv32al mvfx0, mvax2
128 cfstr32 mvfx0, [r1, #CRUNCH_MVAX2L]
129 cfmv32am mvfx0, mvax2
130 cfstr32 mvfx0, [r1, #CRUNCH_MVAX2M]
131 cfmv32ah mvfx0, mvax2
132 cfstr32 mvfx0, [r1, #CRUNCH_MVAX2H]
133 cfmv32al mvfx0, mvax3
134 cfstr32 mvfx0, [r1, #CRUNCH_MVAX3L]
135 cfmv32am mvfx0, mvax3
136 cfstr32 mvfx0, [r1, #CRUNCH_MVAX3M]
137 cfmv32ah mvfx0, mvax3
138 cfstr32 mvfx0, [r1, #CRUNCH_MVAX3H]
139
140 cfmv32sc mvdx0, dspsc @ save status word
141 cfstr64 mvdx0, [r1, #CRUNCH_DSPSC]
142
143 teq r0, #0 @ anything to load?
144 cfldr64eq mvdx0, [r1, #CRUNCH_MVDX0] @ mvdx0 was clobbered
145 moveq pc, lr
146
147crunch_load:
148 cfldr64 mvdx0, [r0, #CRUNCH_DSPSC] @ load status word
149 cfmvsc32 dspsc, mvdx0
150
151 cfldr32 mvfx0, [r0, #CRUNCH_MVAX0L] @ load 72b accumulators
152 cfmval32 mvax0, mvfx0
153 cfldr32 mvfx0, [r0, #CRUNCH_MVAX0M]
154 cfmvam32 mvax0, mvfx0
155 cfldr32 mvfx0, [r0, #CRUNCH_MVAX0H]
156 cfmvah32 mvax0, mvfx0
157 cfldr32 mvfx0, [r0, #CRUNCH_MVAX1L]
158 cfmval32 mvax1, mvfx0
159 cfldr32 mvfx0, [r0, #CRUNCH_MVAX1M]
160 cfmvam32 mvax1, mvfx0
161 cfldr32 mvfx0, [r0, #CRUNCH_MVAX1H]
162 cfmvah32 mvax1, mvfx0
163 cfldr32 mvfx0, [r0, #CRUNCH_MVAX2L]
164 cfmval32 mvax2, mvfx0
165 cfldr32 mvfx0, [r0, #CRUNCH_MVAX2M]
166 cfmvam32 mvax2, mvfx0
167 cfldr32 mvfx0, [r0, #CRUNCH_MVAX2H]
168 cfmvah32 mvax2, mvfx0
169 cfldr32 mvfx0, [r0, #CRUNCH_MVAX3L]
170 cfmval32 mvax3, mvfx0
171 cfldr32 mvfx0, [r0, #CRUNCH_MVAX3M]
172 cfmvam32 mvax3, mvfx0
173 cfldr32 mvfx0, [r0, #CRUNCH_MVAX3H]
174 cfmvah32 mvax3, mvfx0
175
176 cfldr64 mvdx0, [r0, #CRUNCH_MVDX0] @ load 64b registers
177 cfldr64 mvdx1, [r0, #CRUNCH_MVDX1]
178 cfldr64 mvdx2, [r0, #CRUNCH_MVDX2]
179 cfldr64 mvdx3, [r0, #CRUNCH_MVDX3]
180 cfldr64 mvdx4, [r0, #CRUNCH_MVDX4]
181 cfldr64 mvdx5, [r0, #CRUNCH_MVDX5]
182 cfldr64 mvdx6, [r0, #CRUNCH_MVDX6]
183 cfldr64 mvdx7, [r0, #CRUNCH_MVDX7]
184 cfldr64 mvdx8, [r0, #CRUNCH_MVDX8]
185 cfldr64 mvdx9, [r0, #CRUNCH_MVDX9]
186 cfldr64 mvdx10, [r0, #CRUNCH_MVDX10]
187 cfldr64 mvdx11, [r0, #CRUNCH_MVDX11]
188 cfldr64 mvdx12, [r0, #CRUNCH_MVDX12]
189 cfldr64 mvdx13, [r0, #CRUNCH_MVDX13]
190 cfldr64 mvdx14, [r0, #CRUNCH_MVDX14]
191 cfldr64 mvdx15, [r0, #CRUNCH_MVDX15]
192
193 mov pc, lr
194
195/*
196 * Back up crunch regs to save area and disable access to them
197 * (mainly for gdb or sleep mode usage)
198 *
199 * r0 = struct thread_info pointer of target task or NULL for any
200 */
201ENTRY(crunch_task_disable)
202 stmfd sp!, {r4, r5, lr}
203
204 mrs ip, cpsr
205 orr r2, ip, #PSR_I_BIT @ disable interrupts
206 msr cpsr_c, r2
207
208 ldr r4, =(EP93XX_APB_VIRT_BASE + 0x00130000) @ syscon addr
209
210 ldr r3, =crunch_owner
211 add r2, r0, #TI_CRUNCH_STATE @ get task crunch save area
212 ldr r1, [r3] @ get current crunch owner
213 teq r1, #0 @ any current owner?
214 beq 1f @ no: quit
215 teq r0, #0 @ any owner?
216 teqne r1, r2 @ or specified one?
217 bne 1f @ no: quit
218
219 ldr r5, [r4, #0x80] @ enable access to crunch
220 mov r2, #0xaa
221 str r2, [r4, #0xc0]
222 orr r5, r5, #0x00800000
223 str r5, [r4, #0x80]
224
225 mov r0, #0 @ nothing to load
226 str r0, [r3] @ no more current owner
227 ldr r2, [r4, #0x80] @ flush out enable (@@@)
228 mov r2, r2
229 bl crunch_save
230
231 mov r2, #0xaa @ disable access to crunch
232 str r2, [r4, #0xc0]
233 bic r5, r5, #0x00800000
234 str r5, [r4, #0x80]
235 ldr r5, [r4, #0x80] @ flush out enable (@@@)
236 mov r5, r5
237
2381: msr cpsr_c, ip @ restore interrupt mode
239 ldmfd sp!, {r4, r5, pc}
240
241/*
242 * Copy crunch state to given memory address
243 *
244 * r0 = struct thread_info pointer of target task
245 * r1 = memory address where to store crunch state
246 *
247 * this is called mainly in the creation of signal stack frames
248 */
249ENTRY(crunch_task_copy)
250 mrs ip, cpsr
251 orr r2, ip, #PSR_I_BIT @ disable interrupts
252 msr cpsr_c, r2
253
254 ldr r3, =crunch_owner
255 add r2, r0, #TI_CRUNCH_STATE @ get task crunch save area
256 ldr r3, [r3] @ get current crunch owner
257 teq r2, r3 @ does this task own it...
258 beq 1f
259
260 @ current crunch values are in the task save area
261 msr cpsr_c, ip @ restore interrupt mode
262 mov r0, r1
263 mov r1, r2
264 mov r2, #CRUNCH_SIZE
265 b memcpy
266
2671: @ this task owns crunch regs -- grab a copy from there
268 mov r0, #0 @ nothing to load
269 mov r3, lr @ preserve return address
270 bl crunch_save
271 msr cpsr_c, ip @ restore interrupt mode
272 mov pc, r3
273
274/*
275 * Restore crunch state from given memory address
276 *
277 * r0 = struct thread_info pointer of target task
278 * r1 = memory address where to get crunch state from
279 *
280 * this is used to restore crunch state when unwinding a signal stack frame
281 */
282ENTRY(crunch_task_restore)
283 mrs ip, cpsr
284 orr r2, ip, #PSR_I_BIT @ disable interrupts
285 msr cpsr_c, r2
286
287 ldr r3, =crunch_owner
288 add r2, r0, #TI_CRUNCH_STATE @ get task crunch save area
289 ldr r3, [r3] @ get current crunch owner
290 teq r2, r3 @ does this task own it...
291 beq 1f
292
293 @ this task doesn't own crunch regs -- use its save area
294 msr cpsr_c, ip @ restore interrupt mode
295 mov r0, r2
296 mov r2, #CRUNCH_SIZE
297 b memcpy
298
2991: @ this task owns crunch regs -- load them directly
300 mov r0, r1
301 mov r1, #0 @ nothing to save
302 mov r3, lr @ preserve return address
303 bl crunch_load
304 msr cpsr_c, ip @ restore interrupt mode
305 mov pc, r3
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