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1/*
2 * linux/arch/arm/kernel/iwmmxt.S
3 *
4 * XScale iWMMXt (Concan) context switching and handling
5 *
6 * Initial code:
7 * Copyright (c) 2003, Intel Corporation
8 *
9 * Full lazy switching support, optimizations and more, by Nicolas Pitre
10* Copyright (c) 2003-2004, MontaVista Software, Inc.
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 */
16
17#include <linux/linkage.h>
18#include <asm/ptrace.h>
19#include <asm/thread_info.h>
20#include <asm/asm-offsets.h>
21
22#if defined(CONFIG_CPU_PJ4) || defined(CONFIG_CPU_PJ4B)
23#define PJ4(code...) code
24#define XSC(code...)
25#elif defined(CONFIG_CPU_MOHAWK) || \
26 defined(CONFIG_CPU_XSC3) || \
27 defined(CONFIG_CPU_XSCALE)
28#define PJ4(code...)
29#define XSC(code...) code
30#else
31#error "Unsupported iWMMXt architecture"
32#endif
33
34#define MMX_WR0 (0x00)
35#define MMX_WR1 (0x08)
36#define MMX_WR2 (0x10)
37#define MMX_WR3 (0x18)
38#define MMX_WR4 (0x20)
39#define MMX_WR5 (0x28)
40#define MMX_WR6 (0x30)
41#define MMX_WR7 (0x38)
42#define MMX_WR8 (0x40)
43#define MMX_WR9 (0x48)
44#define MMX_WR10 (0x50)
45#define MMX_WR11 (0x58)
46#define MMX_WR12 (0x60)
47#define MMX_WR13 (0x68)
48#define MMX_WR14 (0x70)
49#define MMX_WR15 (0x78)
50#define MMX_WCSSF (0x80)
51#define MMX_WCASF (0x84)
52#define MMX_WCGR0 (0x88)
53#define MMX_WCGR1 (0x8C)
54#define MMX_WCGR2 (0x90)
55#define MMX_WCGR3 (0x94)
56
57#define MMX_SIZE (0x98)
58
59 .text
60
61/*
62 * Lazy switching of Concan coprocessor context
63 *
64 * r10 = struct thread_info pointer
65 * r9 = ret_from_exception
66 * lr = undefined instr exit
67 *
68 * called from prefetch exception handler with interrupts disabled
69 */
70
71ENTRY(iwmmxt_task_enable)
72
73 XSC(mrc p15, 0, r2, c15, c1, 0)
74 PJ4(mrc p15, 0, r2, c1, c0, 2)
75 @ CP0 and CP1 accessible?
76 XSC(tst r2, #0x3)
77 PJ4(tst r2, #0xf)
78 movne pc, lr @ if so no business here
79 @ enable access to CP0 and CP1
80 XSC(orr r2, r2, #0x3)
81 XSC(mcr p15, 0, r2, c15, c1, 0)
82 PJ4(orr r2, r2, #0xf)
83 PJ4(mcr p15, 0, r2, c1, c0, 2)
84
85 ldr r3, =concan_owner
86 add r0, r10, #TI_IWMMXT_STATE @ get task Concan save area
87 ldr r2, [sp, #60] @ current task pc value
88 ldr r1, [r3] @ get current Concan owner
89 str r0, [r3] @ this task now owns Concan regs
90 sub r2, r2, #4 @ adjust pc back
91 str r2, [sp, #60]
92
93 mrc p15, 0, r2, c2, c0, 0
94 mov r2, r2 @ cpwait
95
96 teq r1, #0 @ test for last ownership
97 mov lr, r9 @ normal exit from exception
98 beq concan_load @ no owner, skip save
99
100concan_save:
101
102 tmrc r2, wCon
103
104 @ CUP? wCx
105 tst r2, #0x1
106 beq 1f
107
108concan_dump:
109
110 wstrw wCSSF, [r1, #MMX_WCSSF]
111 wstrw wCASF, [r1, #MMX_WCASF]
112 wstrw wCGR0, [r1, #MMX_WCGR0]
113 wstrw wCGR1, [r1, #MMX_WCGR1]
114 wstrw wCGR2, [r1, #MMX_WCGR2]
115 wstrw wCGR3, [r1, #MMX_WCGR3]
116
1171: @ MUP? wRn
118 tst r2, #0x2
119 beq 2f
120
121 wstrd wR0, [r1, #MMX_WR0]
122 wstrd wR1, [r1, #MMX_WR1]
123 wstrd wR2, [r1, #MMX_WR2]
124 wstrd wR3, [r1, #MMX_WR3]
125 wstrd wR4, [r1, #MMX_WR4]
126 wstrd wR5, [r1, #MMX_WR5]
127 wstrd wR6, [r1, #MMX_WR6]
128 wstrd wR7, [r1, #MMX_WR7]
129 wstrd wR8, [r1, #MMX_WR8]
130 wstrd wR9, [r1, #MMX_WR9]
131 wstrd wR10, [r1, #MMX_WR10]
132 wstrd wR11, [r1, #MMX_WR11]
133 wstrd wR12, [r1, #MMX_WR12]
134 wstrd wR13, [r1, #MMX_WR13]
135 wstrd wR14, [r1, #MMX_WR14]
136 wstrd wR15, [r1, #MMX_WR15]
137
1382: teq r0, #0 @ anything to load?
139 moveq pc, lr
140
141concan_load:
142
143 @ Load wRn
144 wldrd wR0, [r0, #MMX_WR0]
145 wldrd wR1, [r0, #MMX_WR1]
146 wldrd wR2, [r0, #MMX_WR2]
147 wldrd wR3, [r0, #MMX_WR3]
148 wldrd wR4, [r0, #MMX_WR4]
149 wldrd wR5, [r0, #MMX_WR5]
150 wldrd wR6, [r0, #MMX_WR6]
151 wldrd wR7, [r0, #MMX_WR7]
152 wldrd wR8, [r0, #MMX_WR8]
153 wldrd wR9, [r0, #MMX_WR9]
154 wldrd wR10, [r0, #MMX_WR10]
155 wldrd wR11, [r0, #MMX_WR11]
156 wldrd wR12, [r0, #MMX_WR12]
157 wldrd wR13, [r0, #MMX_WR13]
158 wldrd wR14, [r0, #MMX_WR14]
159 wldrd wR15, [r0, #MMX_WR15]
160
161 @ Load wCx
162 wldrw wCSSF, [r0, #MMX_WCSSF]
163 wldrw wCASF, [r0, #MMX_WCASF]
164 wldrw wCGR0, [r0, #MMX_WCGR0]
165 wldrw wCGR1, [r0, #MMX_WCGR1]
166 wldrw wCGR2, [r0, #MMX_WCGR2]
167 wldrw wCGR3, [r0, #MMX_WCGR3]
168
169 @ clear CUP/MUP (only if r1 != 0)
170 teq r1, #0
171 mov r2, #0
172 moveq pc, lr
173 tmcr wCon, r2
174 mov pc, lr
175
176/*
177 * Back up Concan regs to save area and disable access to them
178 * (mainly for gdb or sleep mode usage)
179 *
180 * r0 = struct thread_info pointer of target task or NULL for any
181 */
182
183ENTRY(iwmmxt_task_disable)
184
185 stmfd sp!, {r4, lr}
186
187 mrs ip, cpsr
188 orr r2, ip, #PSR_I_BIT @ disable interrupts
189 msr cpsr_c, r2
190
191 ldr r3, =concan_owner
192 add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
193 ldr r1, [r3] @ get current Concan owner
194 teq r1, #0 @ any current owner?
195 beq 1f @ no: quit
196 teq r0, #0 @ any owner?
197 teqne r1, r2 @ or specified one?
198 bne 1f @ no: quit
199
200 @ enable access to CP0 and CP1
201 XSC(mrc p15, 0, r4, c15, c1, 0)
202 XSC(orr r4, r4, #0x3)
203 XSC(mcr p15, 0, r4, c15, c1, 0)
204 PJ4(mrc p15, 0, r4, c1, c0, 2)
205 PJ4(orr r4, r4, #0xf)
206 PJ4(mcr p15, 0, r4, c1, c0, 2)
207
208 mov r0, #0 @ nothing to load
209 str r0, [r3] @ no more current owner
210 mrc p15, 0, r2, c2, c0, 0
211 mov r2, r2 @ cpwait
212 bl concan_save
213
214 @ disable access to CP0 and CP1
215 XSC(bic r4, r4, #0x3)
216 XSC(mcr p15, 0, r4, c15, c1, 0)
217 PJ4(bic r4, r4, #0xf)
218 PJ4(mcr p15, 0, r4, c1, c0, 2)
219
220 mrc p15, 0, r2, c2, c0, 0
221 mov r2, r2 @ cpwait
222
2231: msr cpsr_c, ip @ restore interrupt mode
224 ldmfd sp!, {r4, pc}
225
226/*
227 * Copy Concan state to given memory address
228 *
229 * r0 = struct thread_info pointer of target task
230 * r1 = memory address where to store Concan state
231 *
232 * this is called mainly in the creation of signal stack frames
233 */
234
235ENTRY(iwmmxt_task_copy)
236
237 mrs ip, cpsr
238 orr r2, ip, #PSR_I_BIT @ disable interrupts
239 msr cpsr_c, r2
240
241 ldr r3, =concan_owner
242 add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
243 ldr r3, [r3] @ get current Concan owner
244 teq r2, r3 @ does this task own it...
245 beq 1f
246
247 @ current Concan values are in the task save area
248 msr cpsr_c, ip @ restore interrupt mode
249 mov r0, r1
250 mov r1, r2
251 mov r2, #MMX_SIZE
252 b memcpy
253
2541: @ this task owns Concan regs -- grab a copy from there
255 mov r0, #0 @ nothing to load
256 mov r2, #3 @ save all regs
257 mov r3, lr @ preserve return address
258 bl concan_dump
259 msr cpsr_c, ip @ restore interrupt mode
260 mov pc, r3
261
262/*
263 * Restore Concan state from given memory address
264 *
265 * r0 = struct thread_info pointer of target task
266 * r1 = memory address where to get Concan state from
267 *
268 * this is used to restore Concan state when unwinding a signal stack frame
269 */
270
271ENTRY(iwmmxt_task_restore)
272
273 mrs ip, cpsr
274 orr r2, ip, #PSR_I_BIT @ disable interrupts
275 msr cpsr_c, r2
276
277 ldr r3, =concan_owner
278 add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
279 ldr r3, [r3] @ get current Concan owner
280 bic r2, r2, #0x7 @ 64-bit alignment
281 teq r2, r3 @ does this task own it...
282 beq 1f
283
284 @ this task doesn't own Concan regs -- use its save area
285 msr cpsr_c, ip @ restore interrupt mode
286 mov r0, r2
287 mov r2, #MMX_SIZE
288 b memcpy
289
2901: @ this task owns Concan regs -- load them directly
291 mov r0, r1
292 mov r1, #0 @ don't clear CUP/MUP
293 mov r3, lr @ preserve return address
294 bl concan_load
295 msr cpsr_c, ip @ restore interrupt mode
296 mov pc, r3
297
298/*
299 * Concan handling on task switch
300 *
301 * r0 = next thread_info pointer
302 *
303 * Called only from the iwmmxt notifier with task preemption disabled.
304 */
305ENTRY(iwmmxt_task_switch)
306
307 XSC(mrc p15, 0, r1, c15, c1, 0)
308 PJ4(mrc p15, 0, r1, c1, c0, 2)
309 @ CP0 and CP1 accessible?
310 XSC(tst r1, #0x3)
311 PJ4(tst r1, #0xf)
312 bne 1f @ yes: block them for next task
313
314 ldr r2, =concan_owner
315 add r3, r0, #TI_IWMMXT_STATE @ get next task Concan save area
316 ldr r2, [r2] @ get current Concan owner
317 teq r2, r3 @ next task owns it?
318 movne pc, lr @ no: leave Concan disabled
319
3201: @ flip Concan access
321 XSC(eor r1, r1, #0x3)
322 XSC(mcr p15, 0, r1, c15, c1, 0)
323 PJ4(eor r1, r1, #0xf)
324 PJ4(mcr p15, 0, r1, c1, c0, 2)
325
326 mrc p15, 0, r1, c2, c0, 0
327 sub pc, lr, r1, lsr #32 @ cpwait and return
328
329/*
330 * Remove Concan ownership of given task
331 *
332 * r0 = struct thread_info pointer
333 */
334ENTRY(iwmmxt_task_release)
335
336 mrs r2, cpsr
337 orr ip, r2, #PSR_I_BIT @ disable interrupts
338 msr cpsr_c, ip
339 ldr r3, =concan_owner
340 add r0, r0, #TI_IWMMXT_STATE @ get task Concan save area
341 ldr r1, [r3] @ get current Concan owner
342 eors r0, r0, r1 @ if equal...
343 streq r0, [r3] @ then clear ownership
344 msr cpsr_c, r2 @ restore interrupts
345 mov pc, lr
346
347 .data
348concan_owner:
349 .word 0
350
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * linux/arch/arm/kernel/iwmmxt.S
4 *
5 * XScale iWMMXt (Concan) context switching and handling
6 *
7 * Initial code:
8 * Copyright (c) 2003, Intel Corporation
9 *
10 * Full lazy switching support, optimizations and more, by Nicolas Pitre
11* Copyright (c) 2003-2004, MontaVista Software, Inc.
12 */
13
14#include <linux/linkage.h>
15#include <asm/ptrace.h>
16#include <asm/thread_info.h>
17#include <asm/asm-offsets.h>
18#include <asm/assembler.h>
19#include "iwmmxt.h"
20
21#if defined(CONFIG_CPU_PJ4) || defined(CONFIG_CPU_PJ4B)
22#define PJ4(code...) code
23#define XSC(code...)
24#elif defined(CONFIG_CPU_MOHAWK) || \
25 defined(CONFIG_CPU_XSC3) || \
26 defined(CONFIG_CPU_XSCALE)
27#define PJ4(code...)
28#define XSC(code...) code
29#else
30#error "Unsupported iWMMXt architecture"
31#endif
32
33#define MMX_WR0 (0x00)
34#define MMX_WR1 (0x08)
35#define MMX_WR2 (0x10)
36#define MMX_WR3 (0x18)
37#define MMX_WR4 (0x20)
38#define MMX_WR5 (0x28)
39#define MMX_WR6 (0x30)
40#define MMX_WR7 (0x38)
41#define MMX_WR8 (0x40)
42#define MMX_WR9 (0x48)
43#define MMX_WR10 (0x50)
44#define MMX_WR11 (0x58)
45#define MMX_WR12 (0x60)
46#define MMX_WR13 (0x68)
47#define MMX_WR14 (0x70)
48#define MMX_WR15 (0x78)
49#define MMX_WCSSF (0x80)
50#define MMX_WCASF (0x84)
51#define MMX_WCGR0 (0x88)
52#define MMX_WCGR1 (0x8C)
53#define MMX_WCGR2 (0x90)
54#define MMX_WCGR3 (0x94)
55
56#define MMX_SIZE (0x98)
57
58 .text
59 .arm
60
61/*
62 * Lazy switching of Concan coprocessor context
63 *
64 * r10 = struct thread_info pointer
65 * r9 = ret_from_exception
66 * lr = undefined instr exit
67 *
68 * called from prefetch exception handler with interrupts enabled
69 */
70
71ENTRY(iwmmxt_task_enable)
72 inc_preempt_count r10, r3
73
74 XSC(mrc p15, 0, r2, c15, c1, 0)
75 PJ4(mrc p15, 0, r2, c1, c0, 2)
76 @ CP0 and CP1 accessible?
77 XSC(tst r2, #0x3)
78 PJ4(tst r2, #0xf)
79 bne 4f @ if so no business here
80 @ enable access to CP0 and CP1
81 XSC(orr r2, r2, #0x3)
82 XSC(mcr p15, 0, r2, c15, c1, 0)
83 PJ4(orr r2, r2, #0xf)
84 PJ4(mcr p15, 0, r2, c1, c0, 2)
85
86 ldr r3, =concan_owner
87 add r0, r10, #TI_IWMMXT_STATE @ get task Concan save area
88 ldr r2, [sp, #60] @ current task pc value
89 ldr r1, [r3] @ get current Concan owner
90 str r0, [r3] @ this task now owns Concan regs
91 sub r2, r2, #4 @ adjust pc back
92 str r2, [sp, #60]
93
94 mrc p15, 0, r2, c2, c0, 0
95 mov r2, r2 @ cpwait
96 bl concan_save
97
98#ifdef CONFIG_PREEMPT_COUNT
99 get_thread_info r10
100#endif
1014: dec_preempt_count r10, r3
102 ret r9 @ normal exit from exception
103
104concan_save:
105
106 teq r1, #0 @ test for last ownership
107 beq concan_load @ no owner, skip save
108
109 tmrc r2, wCon
110
111 @ CUP? wCx
112 tst r2, #0x1
113 beq 1f
114
115concan_dump:
116
117 wstrw wCSSF, r1, MMX_WCSSF
118 wstrw wCASF, r1, MMX_WCASF
119 wstrw wCGR0, r1, MMX_WCGR0
120 wstrw wCGR1, r1, MMX_WCGR1
121 wstrw wCGR2, r1, MMX_WCGR2
122 wstrw wCGR3, r1, MMX_WCGR3
123
1241: @ MUP? wRn
125 tst r2, #0x2
126 beq 2f
127
128 wstrd wR0, r1, MMX_WR0
129 wstrd wR1, r1, MMX_WR1
130 wstrd wR2, r1, MMX_WR2
131 wstrd wR3, r1, MMX_WR3
132 wstrd wR4, r1, MMX_WR4
133 wstrd wR5, r1, MMX_WR5
134 wstrd wR6, r1, MMX_WR6
135 wstrd wR7, r1, MMX_WR7
136 wstrd wR8, r1, MMX_WR8
137 wstrd wR9, r1, MMX_WR9
138 wstrd wR10, r1, MMX_WR10
139 wstrd wR11, r1, MMX_WR11
140 wstrd wR12, r1, MMX_WR12
141 wstrd wR13, r1, MMX_WR13
142 wstrd wR14, r1, MMX_WR14
143 wstrd wR15, r1, MMX_WR15
144
1452: teq r0, #0 @ anything to load?
146 reteq lr @ if not, return
147
148concan_load:
149
150 @ Load wRn
151 wldrd wR0, r0, MMX_WR0
152 wldrd wR1, r0, MMX_WR1
153 wldrd wR2, r0, MMX_WR2
154 wldrd wR3, r0, MMX_WR3
155 wldrd wR4, r0, MMX_WR4
156 wldrd wR5, r0, MMX_WR5
157 wldrd wR6, r0, MMX_WR6
158 wldrd wR7, r0, MMX_WR7
159 wldrd wR8, r0, MMX_WR8
160 wldrd wR9, r0, MMX_WR9
161 wldrd wR10, r0, MMX_WR10
162 wldrd wR11, r0, MMX_WR11
163 wldrd wR12, r0, MMX_WR12
164 wldrd wR13, r0, MMX_WR13
165 wldrd wR14, r0, MMX_WR14
166 wldrd wR15, r0, MMX_WR15
167
168 @ Load wCx
169 wldrw wCSSF, r0, MMX_WCSSF
170 wldrw wCASF, r0, MMX_WCASF
171 wldrw wCGR0, r0, MMX_WCGR0
172 wldrw wCGR1, r0, MMX_WCGR1
173 wldrw wCGR2, r0, MMX_WCGR2
174 wldrw wCGR3, r0, MMX_WCGR3
175
176 @ clear CUP/MUP (only if r1 != 0)
177 teq r1, #0
178 mov r2, #0
179 reteq lr
180
181 tmcr wCon, r2
182 ret lr
183
184ENDPROC(iwmmxt_task_enable)
185
186/*
187 * Back up Concan regs to save area and disable access to them
188 * (mainly for gdb or sleep mode usage)
189 *
190 * r0 = struct thread_info pointer of target task or NULL for any
191 */
192
193ENTRY(iwmmxt_task_disable)
194
195 stmfd sp!, {r4, lr}
196
197 mrs ip, cpsr
198 orr r2, ip, #PSR_I_BIT @ disable interrupts
199 msr cpsr_c, r2
200
201 ldr r3, =concan_owner
202 add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
203 ldr r1, [r3] @ get current Concan owner
204 teq r1, #0 @ any current owner?
205 beq 1f @ no: quit
206 teq r0, #0 @ any owner?
207 teqne r1, r2 @ or specified one?
208 bne 1f @ no: quit
209
210 @ enable access to CP0 and CP1
211 XSC(mrc p15, 0, r4, c15, c1, 0)
212 XSC(orr r4, r4, #0x3)
213 XSC(mcr p15, 0, r4, c15, c1, 0)
214 PJ4(mrc p15, 0, r4, c1, c0, 2)
215 PJ4(orr r4, r4, #0xf)
216 PJ4(mcr p15, 0, r4, c1, c0, 2)
217
218 mov r0, #0 @ nothing to load
219 str r0, [r3] @ no more current owner
220 mrc p15, 0, r2, c2, c0, 0
221 mov r2, r2 @ cpwait
222 bl concan_save
223
224 @ disable access to CP0 and CP1
225 XSC(bic r4, r4, #0x3)
226 XSC(mcr p15, 0, r4, c15, c1, 0)
227 PJ4(bic r4, r4, #0xf)
228 PJ4(mcr p15, 0, r4, c1, c0, 2)
229
230 mrc p15, 0, r2, c2, c0, 0
231 mov r2, r2 @ cpwait
232
2331: msr cpsr_c, ip @ restore interrupt mode
234 ldmfd sp!, {r4, pc}
235
236ENDPROC(iwmmxt_task_disable)
237
238/*
239 * Copy Concan state to given memory address
240 *
241 * r0 = struct thread_info pointer of target task
242 * r1 = memory address where to store Concan state
243 *
244 * this is called mainly in the creation of signal stack frames
245 */
246
247ENTRY(iwmmxt_task_copy)
248
249 mrs ip, cpsr
250 orr r2, ip, #PSR_I_BIT @ disable interrupts
251 msr cpsr_c, r2
252
253 ldr r3, =concan_owner
254 add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
255 ldr r3, [r3] @ get current Concan owner
256 teq r2, r3 @ does this task own it...
257 beq 1f
258
259 @ current Concan values are in the task save area
260 msr cpsr_c, ip @ restore interrupt mode
261 mov r0, r1
262 mov r1, r2
263 mov r2, #MMX_SIZE
264 b memcpy
265
2661: @ this task owns Concan regs -- grab a copy from there
267 mov r0, #0 @ nothing to load
268 mov r2, #3 @ save all regs
269 mov r3, lr @ preserve return address
270 bl concan_dump
271 msr cpsr_c, ip @ restore interrupt mode
272 ret r3
273
274ENDPROC(iwmmxt_task_copy)
275
276/*
277 * Restore Concan state from given memory address
278 *
279 * r0 = struct thread_info pointer of target task
280 * r1 = memory address where to get Concan state from
281 *
282 * this is used to restore Concan state when unwinding a signal stack frame
283 */
284
285ENTRY(iwmmxt_task_restore)
286
287 mrs ip, cpsr
288 orr r2, ip, #PSR_I_BIT @ disable interrupts
289 msr cpsr_c, r2
290
291 ldr r3, =concan_owner
292 add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
293 ldr r3, [r3] @ get current Concan owner
294 bic r2, r2, #0x7 @ 64-bit alignment
295 teq r2, r3 @ does this task own it...
296 beq 1f
297
298 @ this task doesn't own Concan regs -- use its save area
299 msr cpsr_c, ip @ restore interrupt mode
300 mov r0, r2
301 mov r2, #MMX_SIZE
302 b memcpy
303
3041: @ this task owns Concan regs -- load them directly
305 mov r0, r1
306 mov r1, #0 @ don't clear CUP/MUP
307 mov r3, lr @ preserve return address
308 bl concan_load
309 msr cpsr_c, ip @ restore interrupt mode
310 ret r3
311
312ENDPROC(iwmmxt_task_restore)
313
314/*
315 * Concan handling on task switch
316 *
317 * r0 = next thread_info pointer
318 *
319 * Called only from the iwmmxt notifier with task preemption disabled.
320 */
321ENTRY(iwmmxt_task_switch)
322
323 XSC(mrc p15, 0, r1, c15, c1, 0)
324 PJ4(mrc p15, 0, r1, c1, c0, 2)
325 @ CP0 and CP1 accessible?
326 XSC(tst r1, #0x3)
327 PJ4(tst r1, #0xf)
328 bne 1f @ yes: block them for next task
329
330 ldr r2, =concan_owner
331 add r3, r0, #TI_IWMMXT_STATE @ get next task Concan save area
332 ldr r2, [r2] @ get current Concan owner
333 teq r2, r3 @ next task owns it?
334 retne lr @ no: leave Concan disabled
335
3361: @ flip Concan access
337 XSC(eor r1, r1, #0x3)
338 XSC(mcr p15, 0, r1, c15, c1, 0)
339 PJ4(eor r1, r1, #0xf)
340 PJ4(mcr p15, 0, r1, c1, c0, 2)
341
342 mrc p15, 0, r1, c2, c0, 0
343 sub pc, lr, r1, lsr #32 @ cpwait and return
344
345ENDPROC(iwmmxt_task_switch)
346
347/*
348 * Remove Concan ownership of given task
349 *
350 * r0 = struct thread_info pointer
351 */
352ENTRY(iwmmxt_task_release)
353
354 mrs r2, cpsr
355 orr ip, r2, #PSR_I_BIT @ disable interrupts
356 msr cpsr_c, ip
357 ldr r3, =concan_owner
358 add r0, r0, #TI_IWMMXT_STATE @ get task Concan save area
359 ldr r1, [r3] @ get current Concan owner
360 eors r0, r0, r1 @ if equal...
361 streq r0, [r3] @ then clear ownership
362 msr cpsr_c, r2 @ restore interrupts
363 ret lr
364
365ENDPROC(iwmmxt_task_release)
366
367 .data
368 .align 2
369concan_owner:
370 .word 0
371