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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)
23#define PJ4(code...) code
24#define XSC(code...)
25#else
26#define PJ4(code...)
27#define XSC(code...) code
28#endif
29
30#define MMX_WR0 (0x00)
31#define MMX_WR1 (0x08)
32#define MMX_WR2 (0x10)
33#define MMX_WR3 (0x18)
34#define MMX_WR4 (0x20)
35#define MMX_WR5 (0x28)
36#define MMX_WR6 (0x30)
37#define MMX_WR7 (0x38)
38#define MMX_WR8 (0x40)
39#define MMX_WR9 (0x48)
40#define MMX_WR10 (0x50)
41#define MMX_WR11 (0x58)
42#define MMX_WR12 (0x60)
43#define MMX_WR13 (0x68)
44#define MMX_WR14 (0x70)
45#define MMX_WR15 (0x78)
46#define MMX_WCSSF (0x80)
47#define MMX_WCASF (0x84)
48#define MMX_WCGR0 (0x88)
49#define MMX_WCGR1 (0x8C)
50#define MMX_WCGR2 (0x90)
51#define MMX_WCGR3 (0x94)
52
53#define MMX_SIZE (0x98)
54
55 .text
56
57/*
58 * Lazy switching of Concan coprocessor context
59 *
60 * r10 = struct thread_info pointer
61 * r9 = ret_from_exception
62 * lr = undefined instr exit
63 *
64 * called from prefetch exception handler with interrupts disabled
65 */
66
67ENTRY(iwmmxt_task_enable)
68
69 XSC(mrc p15, 0, r2, c15, c1, 0)
70 PJ4(mrc p15, 0, r2, c1, c0, 2)
71 @ CP0 and CP1 accessible?
72 XSC(tst r2, #0x3)
73 PJ4(tst r2, #0xf)
74 movne pc, lr @ if so no business here
75 @ enable access to CP0 and CP1
76 XSC(orr r2, r2, #0x3)
77 XSC(mcr p15, 0, r2, c15, c1, 0)
78 PJ4(orr r2, r2, #0xf)
79 PJ4(mcr p15, 0, r2, c1, c0, 2)
80
81 ldr r3, =concan_owner
82 add r0, r10, #TI_IWMMXT_STATE @ get task Concan save area
83 ldr r2, [sp, #60] @ current task pc value
84 ldr r1, [r3] @ get current Concan owner
85 str r0, [r3] @ this task now owns Concan regs
86 sub r2, r2, #4 @ adjust pc back
87 str r2, [sp, #60]
88
89 mrc p15, 0, r2, c2, c0, 0
90 mov r2, r2 @ cpwait
91
92 teq r1, #0 @ test for last ownership
93 mov lr, r9 @ normal exit from exception
94 beq concan_load @ no owner, skip save
95
96concan_save:
97
98 tmrc r2, wCon
99
100 @ CUP? wCx
101 tst r2, #0x1
102 beq 1f
103
104concan_dump:
105
106 wstrw wCSSF, [r1, #MMX_WCSSF]
107 wstrw wCASF, [r1, #MMX_WCASF]
108 wstrw wCGR0, [r1, #MMX_WCGR0]
109 wstrw wCGR1, [r1, #MMX_WCGR1]
110 wstrw wCGR2, [r1, #MMX_WCGR2]
111 wstrw wCGR3, [r1, #MMX_WCGR3]
112
1131: @ MUP? wRn
114 tst r2, #0x2
115 beq 2f
116
117 wstrd wR0, [r1, #MMX_WR0]
118 wstrd wR1, [r1, #MMX_WR1]
119 wstrd wR2, [r1, #MMX_WR2]
120 wstrd wR3, [r1, #MMX_WR3]
121 wstrd wR4, [r1, #MMX_WR4]
122 wstrd wR5, [r1, #MMX_WR5]
123 wstrd wR6, [r1, #MMX_WR6]
124 wstrd wR7, [r1, #MMX_WR7]
125 wstrd wR8, [r1, #MMX_WR8]
126 wstrd wR9, [r1, #MMX_WR9]
127 wstrd wR10, [r1, #MMX_WR10]
128 wstrd wR11, [r1, #MMX_WR11]
129 wstrd wR12, [r1, #MMX_WR12]
130 wstrd wR13, [r1, #MMX_WR13]
131 wstrd wR14, [r1, #MMX_WR14]
132 wstrd wR15, [r1, #MMX_WR15]
133
1342: teq r0, #0 @ anything to load?
135 moveq pc, lr
136
137concan_load:
138
139 @ Load wRn
140 wldrd wR0, [r0, #MMX_WR0]
141 wldrd wR1, [r0, #MMX_WR1]
142 wldrd wR2, [r0, #MMX_WR2]
143 wldrd wR3, [r0, #MMX_WR3]
144 wldrd wR4, [r0, #MMX_WR4]
145 wldrd wR5, [r0, #MMX_WR5]
146 wldrd wR6, [r0, #MMX_WR6]
147 wldrd wR7, [r0, #MMX_WR7]
148 wldrd wR8, [r0, #MMX_WR8]
149 wldrd wR9, [r0, #MMX_WR9]
150 wldrd wR10, [r0, #MMX_WR10]
151 wldrd wR11, [r0, #MMX_WR11]
152 wldrd wR12, [r0, #MMX_WR12]
153 wldrd wR13, [r0, #MMX_WR13]
154 wldrd wR14, [r0, #MMX_WR14]
155 wldrd wR15, [r0, #MMX_WR15]
156
157 @ Load wCx
158 wldrw wCSSF, [r0, #MMX_WCSSF]
159 wldrw wCASF, [r0, #MMX_WCASF]
160 wldrw wCGR0, [r0, #MMX_WCGR0]
161 wldrw wCGR1, [r0, #MMX_WCGR1]
162 wldrw wCGR2, [r0, #MMX_WCGR2]
163 wldrw wCGR3, [r0, #MMX_WCGR3]
164
165 @ clear CUP/MUP (only if r1 != 0)
166 teq r1, #0
167 mov r2, #0
168 moveq pc, lr
169 tmcr wCon, r2
170 mov pc, lr
171
172/*
173 * Back up Concan regs to save area and disable access to them
174 * (mainly for gdb or sleep mode usage)
175 *
176 * r0 = struct thread_info pointer of target task or NULL for any
177 */
178
179ENTRY(iwmmxt_task_disable)
180
181 stmfd sp!, {r4, lr}
182
183 mrs ip, cpsr
184 orr r2, ip, #PSR_I_BIT @ disable interrupts
185 msr cpsr_c, r2
186
187 ldr r3, =concan_owner
188 add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
189 ldr r1, [r3] @ get current Concan owner
190 teq r1, #0 @ any current owner?
191 beq 1f @ no: quit
192 teq r0, #0 @ any owner?
193 teqne r1, r2 @ or specified one?
194 bne 1f @ no: quit
195
196 @ enable access to CP0 and CP1
197 XSC(mrc p15, 0, r4, c15, c1, 0)
198 XSC(orr r4, r4, #0x3)
199 XSC(mcr p15, 0, r4, c15, c1, 0)
200 PJ4(mrc p15, 0, r4, c1, c0, 2)
201 PJ4(orr r4, r4, #0xf)
202 PJ4(mcr p15, 0, r4, c1, c0, 2)
203
204 mov r0, #0 @ nothing to load
205 str r0, [r3] @ no more current owner
206 mrc p15, 0, r2, c2, c0, 0
207 mov r2, r2 @ cpwait
208 bl concan_save
209
210 @ disable access to CP0 and CP1
211 XSC(bic r4, r4, #0x3)
212 XSC(mcr p15, 0, r4, c15, c1, 0)
213 PJ4(bic r4, r4, #0xf)
214 PJ4(mcr p15, 0, r4, c1, c0, 2)
215
216 mrc p15, 0, r2, c2, c0, 0
217 mov r2, r2 @ cpwait
218
2191: msr cpsr_c, ip @ restore interrupt mode
220 ldmfd sp!, {r4, pc}
221
222/*
223 * Copy Concan state to given memory address
224 *
225 * r0 = struct thread_info pointer of target task
226 * r1 = memory address where to store Concan state
227 *
228 * this is called mainly in the creation of signal stack frames
229 */
230
231ENTRY(iwmmxt_task_copy)
232
233 mrs ip, cpsr
234 orr r2, ip, #PSR_I_BIT @ disable interrupts
235 msr cpsr_c, r2
236
237 ldr r3, =concan_owner
238 add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
239 ldr r3, [r3] @ get current Concan owner
240 teq r2, r3 @ does this task own it...
241 beq 1f
242
243 @ current Concan values are in the task save area
244 msr cpsr_c, ip @ restore interrupt mode
245 mov r0, r1
246 mov r1, r2
247 mov r2, #MMX_SIZE
248 b memcpy
249
2501: @ this task owns Concan regs -- grab a copy from there
251 mov r0, #0 @ nothing to load
252 mov r2, #3 @ save all regs
253 mov r3, lr @ preserve return address
254 bl concan_dump
255 msr cpsr_c, ip @ restore interrupt mode
256 mov pc, r3
257
258/*
259 * Restore Concan state from given memory address
260 *
261 * r0 = struct thread_info pointer of target task
262 * r1 = memory address where to get Concan state from
263 *
264 * this is used to restore Concan state when unwinding a signal stack frame
265 */
266
267ENTRY(iwmmxt_task_restore)
268
269 mrs ip, cpsr
270 orr r2, ip, #PSR_I_BIT @ disable interrupts
271 msr cpsr_c, r2
272
273 ldr r3, =concan_owner
274 add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
275 ldr r3, [r3] @ get current Concan owner
276 bic r2, r2, #0x7 @ 64-bit alignment
277 teq r2, r3 @ does this task own it...
278 beq 1f
279
280 @ this task doesn't own Concan regs -- use its save area
281 msr cpsr_c, ip @ restore interrupt mode
282 mov r0, r2
283 mov r2, #MMX_SIZE
284 b memcpy
285
2861: @ this task owns Concan regs -- load them directly
287 mov r0, r1
288 mov r1, #0 @ don't clear CUP/MUP
289 mov r3, lr @ preserve return address
290 bl concan_load
291 msr cpsr_c, ip @ restore interrupt mode
292 mov pc, r3
293
294/*
295 * Concan handling on task switch
296 *
297 * r0 = next thread_info pointer
298 *
299 * Called only from the iwmmxt notifier with task preemption disabled.
300 */
301ENTRY(iwmmxt_task_switch)
302
303 XSC(mrc p15, 0, r1, c15, c1, 0)
304 PJ4(mrc p15, 0, r1, c1, c0, 2)
305 @ CP0 and CP1 accessible?
306 XSC(tst r1, #0x3)
307 PJ4(tst r1, #0xf)
308 bne 1f @ yes: block them for next task
309
310 ldr r2, =concan_owner
311 add r3, r0, #TI_IWMMXT_STATE @ get next task Concan save area
312 ldr r2, [r2] @ get current Concan owner
313 teq r2, r3 @ next task owns it?
314 movne pc, lr @ no: leave Concan disabled
315
3161: @ flip Concan access
317 XSC(eor r1, r1, #0x3)
318 XSC(mcr p15, 0, r1, c15, c1, 0)
319 PJ4(eor r1, r1, #0xf)
320 PJ4(mcr p15, 0, r1, c1, c0, 2)
321
322 mrc p15, 0, r1, c2, c0, 0
323 sub pc, lr, r1, lsr #32 @ cpwait and return
324
325/*
326 * Remove Concan ownership of given task
327 *
328 * r0 = struct thread_info pointer
329 */
330ENTRY(iwmmxt_task_release)
331
332 mrs r2, cpsr
333 orr ip, r2, #PSR_I_BIT @ disable interrupts
334 msr cpsr_c, ip
335 ldr r3, =concan_owner
336 add r0, r0, #TI_IWMMXT_STATE @ get task Concan save area
337 ldr r1, [r3] @ get current Concan owner
338 eors r0, r0, r1 @ if equal...
339 streq r0, [r3] @ then clear ownership
340 msr cpsr_c, r2 @ restore interrupts
341 mov pc, lr
342
343 .data
344concan_owner:
345 .word 0
346
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#include <asm/assembler.h>
22
23#if defined(CONFIG_CPU_PJ4) || defined(CONFIG_CPU_PJ4B)
24#define PJ4(code...) code
25#define XSC(code...)
26#elif defined(CONFIG_CPU_MOHAWK) || \
27 defined(CONFIG_CPU_XSC3) || \
28 defined(CONFIG_CPU_XSCALE)
29#define PJ4(code...)
30#define XSC(code...) code
31#else
32#error "Unsupported iWMMXt architecture"
33#endif
34
35#define MMX_WR0 (0x00)
36#define MMX_WR1 (0x08)
37#define MMX_WR2 (0x10)
38#define MMX_WR3 (0x18)
39#define MMX_WR4 (0x20)
40#define MMX_WR5 (0x28)
41#define MMX_WR6 (0x30)
42#define MMX_WR7 (0x38)
43#define MMX_WR8 (0x40)
44#define MMX_WR9 (0x48)
45#define MMX_WR10 (0x50)
46#define MMX_WR11 (0x58)
47#define MMX_WR12 (0x60)
48#define MMX_WR13 (0x68)
49#define MMX_WR14 (0x70)
50#define MMX_WR15 (0x78)
51#define MMX_WCSSF (0x80)
52#define MMX_WCASF (0x84)
53#define MMX_WCGR0 (0x88)
54#define MMX_WCGR1 (0x8C)
55#define MMX_WCGR2 (0x90)
56#define MMX_WCGR3 (0x94)
57
58#define MMX_SIZE (0x98)
59
60 .text
61 .arm
62
63/*
64 * Lazy switching of Concan coprocessor context
65 *
66 * r10 = struct thread_info pointer
67 * r9 = ret_from_exception
68 * lr = undefined instr exit
69 *
70 * called from prefetch exception handler with interrupts enabled
71 */
72
73ENTRY(iwmmxt_task_enable)
74 inc_preempt_count r10, r3
75
76 XSC(mrc p15, 0, r2, c15, c1, 0)
77 PJ4(mrc p15, 0, r2, c1, c0, 2)
78 @ CP0 and CP1 accessible?
79 XSC(tst r2, #0x3)
80 PJ4(tst r2, #0xf)
81 bne 4f @ if so no business here
82 @ enable access to CP0 and CP1
83 XSC(orr r2, r2, #0x3)
84 XSC(mcr p15, 0, r2, c15, c1, 0)
85 PJ4(orr r2, r2, #0xf)
86 PJ4(mcr p15, 0, r2, c1, c0, 2)
87
88 ldr r3, =concan_owner
89 add r0, r10, #TI_IWMMXT_STATE @ get task Concan save area
90 ldr r2, [sp, #60] @ current task pc value
91 ldr r1, [r3] @ get current Concan owner
92 str r0, [r3] @ this task now owns Concan regs
93 sub r2, r2, #4 @ adjust pc back
94 str r2, [sp, #60]
95
96 mrc p15, 0, r2, c2, c0, 0
97 mov r2, r2 @ cpwait
98 bl concan_save
99
100#ifdef CONFIG_PREEMPT_COUNT
101 get_thread_info r10
102#endif
1034: dec_preempt_count r10, r3
104 ret r9 @ normal exit from exception
105
106concan_save:
107
108 teq r1, #0 @ test for last ownership
109 beq concan_load @ no owner, skip save
110
111 tmrc r2, wCon
112
113 @ CUP? wCx
114 tst r2, #0x1
115 beq 1f
116
117concan_dump:
118
119 wstrw wCSSF, [r1, #MMX_WCSSF]
120 wstrw wCASF, [r1, #MMX_WCASF]
121 wstrw wCGR0, [r1, #MMX_WCGR0]
122 wstrw wCGR1, [r1, #MMX_WCGR1]
123 wstrw wCGR2, [r1, #MMX_WCGR2]
124 wstrw wCGR3, [r1, #MMX_WCGR3]
125
1261: @ MUP? wRn
127 tst r2, #0x2
128 beq 2f
129
130 wstrd wR0, [r1, #MMX_WR0]
131 wstrd wR1, [r1, #MMX_WR1]
132 wstrd wR2, [r1, #MMX_WR2]
133 wstrd wR3, [r1, #MMX_WR3]
134 wstrd wR4, [r1, #MMX_WR4]
135 wstrd wR5, [r1, #MMX_WR5]
136 wstrd wR6, [r1, #MMX_WR6]
137 wstrd wR7, [r1, #MMX_WR7]
138 wstrd wR8, [r1, #MMX_WR8]
139 wstrd wR9, [r1, #MMX_WR9]
140 wstrd wR10, [r1, #MMX_WR10]
141 wstrd wR11, [r1, #MMX_WR11]
142 wstrd wR12, [r1, #MMX_WR12]
143 wstrd wR13, [r1, #MMX_WR13]
144 wstrd wR14, [r1, #MMX_WR14]
145 wstrd wR15, [r1, #MMX_WR15]
146
1472: teq r0, #0 @ anything to load?
148 reteq lr @ if not, return
149
150concan_load:
151
152 @ Load wRn
153 wldrd wR0, [r0, #MMX_WR0]
154 wldrd wR1, [r0, #MMX_WR1]
155 wldrd wR2, [r0, #MMX_WR2]
156 wldrd wR3, [r0, #MMX_WR3]
157 wldrd wR4, [r0, #MMX_WR4]
158 wldrd wR5, [r0, #MMX_WR5]
159 wldrd wR6, [r0, #MMX_WR6]
160 wldrd wR7, [r0, #MMX_WR7]
161 wldrd wR8, [r0, #MMX_WR8]
162 wldrd wR9, [r0, #MMX_WR9]
163 wldrd wR10, [r0, #MMX_WR10]
164 wldrd wR11, [r0, #MMX_WR11]
165 wldrd wR12, [r0, #MMX_WR12]
166 wldrd wR13, [r0, #MMX_WR13]
167 wldrd wR14, [r0, #MMX_WR14]
168 wldrd wR15, [r0, #MMX_WR15]
169
170 @ Load wCx
171 wldrw wCSSF, [r0, #MMX_WCSSF]
172 wldrw wCASF, [r0, #MMX_WCASF]
173 wldrw wCGR0, [r0, #MMX_WCGR0]
174 wldrw wCGR1, [r0, #MMX_WCGR1]
175 wldrw wCGR2, [r0, #MMX_WCGR2]
176 wldrw wCGR3, [r0, #MMX_WCGR3]
177
178 @ clear CUP/MUP (only if r1 != 0)
179 teq r1, #0
180 mov r2, #0
181 reteq lr
182
183 tmcr wCon, r2
184 ret lr
185
186ENDPROC(iwmmxt_task_enable)
187
188/*
189 * Back up Concan regs to save area and disable access to them
190 * (mainly for gdb or sleep mode usage)
191 *
192 * r0 = struct thread_info pointer of target task or NULL for any
193 */
194
195ENTRY(iwmmxt_task_disable)
196
197 stmfd sp!, {r4, lr}
198
199 mrs ip, cpsr
200 orr r2, ip, #PSR_I_BIT @ disable interrupts
201 msr cpsr_c, r2
202
203 ldr r3, =concan_owner
204 add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
205 ldr r1, [r3] @ get current Concan owner
206 teq r1, #0 @ any current owner?
207 beq 1f @ no: quit
208 teq r0, #0 @ any owner?
209 teqne r1, r2 @ or specified one?
210 bne 1f @ no: quit
211
212 @ enable access to CP0 and CP1
213 XSC(mrc p15, 0, r4, c15, c1, 0)
214 XSC(orr r4, r4, #0x3)
215 XSC(mcr p15, 0, r4, c15, c1, 0)
216 PJ4(mrc p15, 0, r4, c1, c0, 2)
217 PJ4(orr r4, r4, #0xf)
218 PJ4(mcr p15, 0, r4, c1, c0, 2)
219
220 mov r0, #0 @ nothing to load
221 str r0, [r3] @ no more current owner
222 mrc p15, 0, r2, c2, c0, 0
223 mov r2, r2 @ cpwait
224 bl concan_save
225
226 @ disable access to CP0 and CP1
227 XSC(bic r4, r4, #0x3)
228 XSC(mcr p15, 0, r4, c15, c1, 0)
229 PJ4(bic r4, r4, #0xf)
230 PJ4(mcr p15, 0, r4, c1, c0, 2)
231
232 mrc p15, 0, r2, c2, c0, 0
233 mov r2, r2 @ cpwait
234
2351: msr cpsr_c, ip @ restore interrupt mode
236 ldmfd sp!, {r4, pc}
237
238ENDPROC(iwmmxt_task_disable)
239
240/*
241 * Copy Concan state to given memory address
242 *
243 * r0 = struct thread_info pointer of target task
244 * r1 = memory address where to store Concan state
245 *
246 * this is called mainly in the creation of signal stack frames
247 */
248
249ENTRY(iwmmxt_task_copy)
250
251 mrs ip, cpsr
252 orr r2, ip, #PSR_I_BIT @ disable interrupts
253 msr cpsr_c, r2
254
255 ldr r3, =concan_owner
256 add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
257 ldr r3, [r3] @ get current Concan owner
258 teq r2, r3 @ does this task own it...
259 beq 1f
260
261 @ current Concan values are in the task save area
262 msr cpsr_c, ip @ restore interrupt mode
263 mov r0, r1
264 mov r1, r2
265 mov r2, #MMX_SIZE
266 b memcpy
267
2681: @ this task owns Concan regs -- grab a copy from there
269 mov r0, #0 @ nothing to load
270 mov r2, #3 @ save all regs
271 mov r3, lr @ preserve return address
272 bl concan_dump
273 msr cpsr_c, ip @ restore interrupt mode
274 ret r3
275
276ENDPROC(iwmmxt_task_copy)
277
278/*
279 * Restore Concan state from given memory address
280 *
281 * r0 = struct thread_info pointer of target task
282 * r1 = memory address where to get Concan state from
283 *
284 * this is used to restore Concan state when unwinding a signal stack frame
285 */
286
287ENTRY(iwmmxt_task_restore)
288
289 mrs ip, cpsr
290 orr r2, ip, #PSR_I_BIT @ disable interrupts
291 msr cpsr_c, r2
292
293 ldr r3, =concan_owner
294 add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
295 ldr r3, [r3] @ get current Concan owner
296 bic r2, r2, #0x7 @ 64-bit alignment
297 teq r2, r3 @ does this task own it...
298 beq 1f
299
300 @ this task doesn't own Concan regs -- use its save area
301 msr cpsr_c, ip @ restore interrupt mode
302 mov r0, r2
303 mov r2, #MMX_SIZE
304 b memcpy
305
3061: @ this task owns Concan regs -- load them directly
307 mov r0, r1
308 mov r1, #0 @ don't clear CUP/MUP
309 mov r3, lr @ preserve return address
310 bl concan_load
311 msr cpsr_c, ip @ restore interrupt mode
312 ret r3
313
314ENDPROC(iwmmxt_task_restore)
315
316/*
317 * Concan handling on task switch
318 *
319 * r0 = next thread_info pointer
320 *
321 * Called only from the iwmmxt notifier with task preemption disabled.
322 */
323ENTRY(iwmmxt_task_switch)
324
325 XSC(mrc p15, 0, r1, c15, c1, 0)
326 PJ4(mrc p15, 0, r1, c1, c0, 2)
327 @ CP0 and CP1 accessible?
328 XSC(tst r1, #0x3)
329 PJ4(tst r1, #0xf)
330 bne 1f @ yes: block them for next task
331
332 ldr r2, =concan_owner
333 add r3, r0, #TI_IWMMXT_STATE @ get next task Concan save area
334 ldr r2, [r2] @ get current Concan owner
335 teq r2, r3 @ next task owns it?
336 retne lr @ no: leave Concan disabled
337
3381: @ flip Concan access
339 XSC(eor r1, r1, #0x3)
340 XSC(mcr p15, 0, r1, c15, c1, 0)
341 PJ4(eor r1, r1, #0xf)
342 PJ4(mcr p15, 0, r1, c1, c0, 2)
343
344 mrc p15, 0, r1, c2, c0, 0
345 sub pc, lr, r1, lsr #32 @ cpwait and return
346
347ENDPROC(iwmmxt_task_switch)
348
349/*
350 * Remove Concan ownership of given task
351 *
352 * r0 = struct thread_info pointer
353 */
354ENTRY(iwmmxt_task_release)
355
356 mrs r2, cpsr
357 orr ip, r2, #PSR_I_BIT @ disable interrupts
358 msr cpsr_c, ip
359 ldr r3, =concan_owner
360 add r0, r0, #TI_IWMMXT_STATE @ get task Concan save area
361 ldr r1, [r3] @ get current Concan owner
362 eors r0, r0, r1 @ if equal...
363 streq r0, [r3] @ then clear ownership
364 msr cpsr_c, r2 @ restore interrupts
365 ret lr
366
367ENDPROC(iwmmxt_task_release)
368
369 .data
370concan_owner:
371 .word 0
372