Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Sam Ravnborg | e6ae744 | 2005-09-09 21:08:59 +0200 | [diff] [blame] | 20 | #include <asm/asm-offsets.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | |
| 22 | #define MMX_WR0 (0x00) |
| 23 | #define MMX_WR1 (0x08) |
| 24 | #define MMX_WR2 (0x10) |
| 25 | #define MMX_WR3 (0x18) |
| 26 | #define MMX_WR4 (0x20) |
| 27 | #define MMX_WR5 (0x28) |
| 28 | #define MMX_WR6 (0x30) |
| 29 | #define MMX_WR7 (0x38) |
| 30 | #define MMX_WR8 (0x40) |
| 31 | #define MMX_WR9 (0x48) |
| 32 | #define MMX_WR10 (0x50) |
| 33 | #define MMX_WR11 (0x58) |
| 34 | #define MMX_WR12 (0x60) |
| 35 | #define MMX_WR13 (0x68) |
| 36 | #define MMX_WR14 (0x70) |
| 37 | #define MMX_WR15 (0x78) |
| 38 | #define MMX_WCSSF (0x80) |
| 39 | #define MMX_WCASF (0x84) |
| 40 | #define MMX_WCGR0 (0x88) |
| 41 | #define MMX_WCGR1 (0x8C) |
| 42 | #define MMX_WCGR2 (0x90) |
| 43 | #define MMX_WCGR3 (0x94) |
| 44 | |
| 45 | #define MMX_SIZE (0x98) |
| 46 | |
| 47 | .text |
| 48 | |
| 49 | /* |
| 50 | * Lazy switching of Concan coprocessor context |
| 51 | * |
| 52 | * r10 = struct thread_info pointer |
| 53 | * r9 = ret_from_exception |
| 54 | * lr = undefined instr exit |
| 55 | * |
| 56 | * called from prefetch exception handler with interrupts disabled |
| 57 | */ |
| 58 | |
| 59 | ENTRY(iwmmxt_task_enable) |
| 60 | |
| 61 | mrc p15, 0, r2, c15, c1, 0 |
| 62 | tst r2, #0x3 @ CP0 and CP1 accessible? |
| 63 | movne pc, lr @ if so no business here |
| 64 | orr r2, r2, #0x3 @ enable access to CP0 and CP1 |
| 65 | mcr p15, 0, r2, c15, c1, 0 |
| 66 | |
| 67 | ldr r3, =concan_owner |
| 68 | add r0, r10, #TI_IWMMXT_STATE @ get task Concan save area |
| 69 | ldr r2, [sp, #60] @ current task pc value |
| 70 | ldr r1, [r3] @ get current Concan owner |
| 71 | str r0, [r3] @ this task now owns Concan regs |
| 72 | sub r2, r2, #4 @ adjust pc back |
| 73 | str r2, [sp, #60] |
| 74 | |
| 75 | mrc p15, 0, r2, c2, c0, 0 |
| 76 | mov r2, r2 @ cpwait |
| 77 | |
| 78 | teq r1, #0 @ test for last ownership |
| 79 | mov lr, r9 @ normal exit from exception |
| 80 | beq concan_load @ no owner, skip save |
| 81 | |
| 82 | concan_save: |
| 83 | |
| 84 | tmrc r2, wCon |
| 85 | |
| 86 | @ CUP? wCx |
| 87 | tst r2, #0x1 |
| 88 | beq 1f |
| 89 | |
| 90 | concan_dump: |
| 91 | |
| 92 | wstrw wCSSF, [r1, #MMX_WCSSF] |
| 93 | wstrw wCASF, [r1, #MMX_WCASF] |
| 94 | wstrw wCGR0, [r1, #MMX_WCGR0] |
| 95 | wstrw wCGR1, [r1, #MMX_WCGR1] |
| 96 | wstrw wCGR2, [r1, #MMX_WCGR2] |
| 97 | wstrw wCGR3, [r1, #MMX_WCGR3] |
| 98 | |
| 99 | 1: @ MUP? wRn |
| 100 | tst r2, #0x2 |
| 101 | beq 2f |
| 102 | |
| 103 | wstrd wR0, [r1, #MMX_WR0] |
| 104 | wstrd wR1, [r1, #MMX_WR1] |
| 105 | wstrd wR2, [r1, #MMX_WR2] |
| 106 | wstrd wR3, [r1, #MMX_WR3] |
| 107 | wstrd wR4, [r1, #MMX_WR4] |
| 108 | wstrd wR5, [r1, #MMX_WR5] |
| 109 | wstrd wR6, [r1, #MMX_WR6] |
| 110 | wstrd wR7, [r1, #MMX_WR7] |
| 111 | wstrd wR8, [r1, #MMX_WR8] |
| 112 | wstrd wR9, [r1, #MMX_WR9] |
| 113 | wstrd wR10, [r1, #MMX_WR10] |
| 114 | wstrd wR11, [r1, #MMX_WR11] |
| 115 | wstrd wR12, [r1, #MMX_WR12] |
| 116 | wstrd wR13, [r1, #MMX_WR13] |
| 117 | wstrd wR14, [r1, #MMX_WR14] |
| 118 | wstrd wR15, [r1, #MMX_WR15] |
| 119 | |
| 120 | 2: teq r0, #0 @ anything to load? |
| 121 | moveq pc, lr |
| 122 | |
| 123 | concan_load: |
| 124 | |
| 125 | @ Load wRn |
| 126 | wldrd wR0, [r0, #MMX_WR0] |
| 127 | wldrd wR1, [r0, #MMX_WR1] |
| 128 | wldrd wR2, [r0, #MMX_WR2] |
| 129 | wldrd wR3, [r0, #MMX_WR3] |
| 130 | wldrd wR4, [r0, #MMX_WR4] |
| 131 | wldrd wR5, [r0, #MMX_WR5] |
| 132 | wldrd wR6, [r0, #MMX_WR6] |
| 133 | wldrd wR7, [r0, #MMX_WR7] |
| 134 | wldrd wR8, [r0, #MMX_WR8] |
| 135 | wldrd wR9, [r0, #MMX_WR9] |
| 136 | wldrd wR10, [r0, #MMX_WR10] |
| 137 | wldrd wR11, [r0, #MMX_WR11] |
| 138 | wldrd wR12, [r0, #MMX_WR12] |
| 139 | wldrd wR13, [r0, #MMX_WR13] |
| 140 | wldrd wR14, [r0, #MMX_WR14] |
| 141 | wldrd wR15, [r0, #MMX_WR15] |
| 142 | |
| 143 | @ Load wCx |
| 144 | wldrw wCSSF, [r0, #MMX_WCSSF] |
| 145 | wldrw wCASF, [r0, #MMX_WCASF] |
| 146 | wldrw wCGR0, [r0, #MMX_WCGR0] |
| 147 | wldrw wCGR1, [r0, #MMX_WCGR1] |
| 148 | wldrw wCGR2, [r0, #MMX_WCGR2] |
| 149 | wldrw wCGR3, [r0, #MMX_WCGR3] |
| 150 | |
| 151 | @ clear CUP/MUP (only if r1 != 0) |
| 152 | teq r1, #0 |
| 153 | mov r2, #0 |
| 154 | moveq pc, lr |
| 155 | tmcr wCon, r2 |
| 156 | mov pc, lr |
| 157 | |
| 158 | /* |
| 159 | * Back up Concan regs to save area and disable access to them |
| 160 | * (mainly for gdb or sleep mode usage) |
| 161 | * |
| 162 | * r0 = struct thread_info pointer of target task or NULL for any |
| 163 | */ |
| 164 | |
| 165 | ENTRY(iwmmxt_task_disable) |
| 166 | |
| 167 | stmfd sp!, {r4, lr} |
| 168 | |
| 169 | mrs ip, cpsr |
| 170 | orr r2, ip, #PSR_I_BIT @ disable interrupts |
| 171 | msr cpsr_c, r2 |
| 172 | |
| 173 | ldr r3, =concan_owner |
| 174 | add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area |
| 175 | ldr r1, [r3] @ get current Concan owner |
| 176 | teq r1, #0 @ any current owner? |
| 177 | beq 1f @ no: quit |
| 178 | teq r0, #0 @ any owner? |
| 179 | teqne r1, r2 @ or specified one? |
| 180 | bne 1f @ no: quit |
| 181 | |
| 182 | mrc p15, 0, r4, c15, c1, 0 |
| 183 | orr r4, r4, #0x3 @ enable access to CP0 and CP1 |
| 184 | mcr p15, 0, r4, c15, c1, 0 |
| 185 | mov r0, #0 @ nothing to load |
| 186 | str r0, [r3] @ no more current owner |
| 187 | mrc p15, 0, r2, c2, c0, 0 |
| 188 | mov r2, r2 @ cpwait |
| 189 | bl concan_save |
| 190 | |
| 191 | bic r4, r4, #0x3 @ disable access to CP0 and CP1 |
| 192 | mcr p15, 0, r4, c15, c1, 0 |
| 193 | mrc p15, 0, r2, c2, c0, 0 |
| 194 | mov r2, r2 @ cpwait |
| 195 | |
| 196 | 1: msr cpsr_c, ip @ restore interrupt mode |
| 197 | ldmfd sp!, {r4, pc} |
| 198 | |
| 199 | /* |
| 200 | * Copy Concan state to given memory address |
| 201 | * |
| 202 | * r0 = struct thread_info pointer of target task |
| 203 | * r1 = memory address where to store Concan state |
| 204 | * |
| 205 | * this is called mainly in the creation of signal stack frames |
| 206 | */ |
| 207 | |
| 208 | ENTRY(iwmmxt_task_copy) |
| 209 | |
| 210 | mrs ip, cpsr |
| 211 | orr r2, ip, #PSR_I_BIT @ disable interrupts |
| 212 | msr cpsr_c, r2 |
| 213 | |
| 214 | ldr r3, =concan_owner |
| 215 | add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area |
| 216 | ldr r3, [r3] @ get current Concan owner |
| 217 | teq r2, r3 @ does this task own it... |
| 218 | beq 1f |
| 219 | |
| 220 | @ current Concan values are in the task save area |
| 221 | msr cpsr_c, ip @ restore interrupt mode |
| 222 | mov r0, r1 |
| 223 | mov r1, r2 |
| 224 | mov r2, #MMX_SIZE |
| 225 | b memcpy |
| 226 | |
| 227 | 1: @ this task owns Concan regs -- grab a copy from there |
| 228 | mov r0, #0 @ nothing to load |
| 229 | mov r2, #3 @ save all regs |
| 230 | mov r3, lr @ preserve return address |
| 231 | bl concan_dump |
| 232 | msr cpsr_c, ip @ restore interrupt mode |
| 233 | mov pc, r3 |
| 234 | |
| 235 | /* |
| 236 | * Restore Concan state from given memory address |
| 237 | * |
| 238 | * r0 = struct thread_info pointer of target task |
| 239 | * r1 = memory address where to get Concan state from |
| 240 | * |
| 241 | * this is used to restore Concan state when unwinding a signal stack frame |
| 242 | */ |
| 243 | |
| 244 | ENTRY(iwmmxt_task_restore) |
| 245 | |
| 246 | mrs ip, cpsr |
| 247 | orr r2, ip, #PSR_I_BIT @ disable interrupts |
| 248 | msr cpsr_c, r2 |
| 249 | |
| 250 | ldr r3, =concan_owner |
| 251 | add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area |
| 252 | ldr r3, [r3] @ get current Concan owner |
| 253 | bic r2, r2, #0x7 @ 64-bit alignment |
| 254 | teq r2, r3 @ does this task own it... |
| 255 | beq 1f |
| 256 | |
| 257 | @ this task doesn't own Concan regs -- use its save area |
| 258 | msr cpsr_c, ip @ restore interrupt mode |
| 259 | mov r0, r2 |
| 260 | mov r2, #MMX_SIZE |
| 261 | b memcpy |
| 262 | |
| 263 | 1: @ this task owns Concan regs -- load them directly |
| 264 | mov r0, r1 |
| 265 | mov r1, #0 @ don't clear CUP/MUP |
| 266 | mov r3, lr @ preserve return address |
| 267 | bl concan_load |
| 268 | msr cpsr_c, ip @ restore interrupt mode |
| 269 | mov pc, r3 |
| 270 | |
| 271 | /* |
| 272 | * Concan handling on task switch |
| 273 | * |
| 274 | * r0 = previous task_struct pointer (must be preserved) |
| 275 | * r1 = previous thread_info pointer |
| 276 | * r2 = next thread_info.cpu_domain pointer (must be preserved) |
| 277 | * |
| 278 | * Called only from __switch_to with task preemption disabled. |
| 279 | * No need to care about preserving r4 and above. |
| 280 | */ |
| 281 | ENTRY(iwmmxt_task_switch) |
| 282 | |
| 283 | mrc p15, 0, r4, c15, c1, 0 |
| 284 | tst r4, #0x3 @ CP0 and CP1 accessible? |
| 285 | bne 1f @ yes: block them for next task |
| 286 | |
| 287 | ldr r5, =concan_owner |
| 288 | add r6, r2, #(TI_IWMMXT_STATE - TI_CPU_DOMAIN) @ get next task Concan save area |
| 289 | ldr r5, [r5] @ get current Concan owner |
| 290 | teq r5, r6 @ next task owns it? |
| 291 | movne pc, lr @ no: leave Concan disabled |
| 292 | |
| 293 | 1: eor r4, r4, #3 @ flip Concan access |
| 294 | mcr p15, 0, r4, c15, c1, 0 |
| 295 | |
| 296 | mrc p15, 0, r4, c2, c0, 0 |
| 297 | sub pc, lr, r4, lsr #32 @ cpwait and return |
| 298 | |
| 299 | /* |
| 300 | * Remove Concan ownership of given task |
| 301 | * |
| 302 | * r0 = struct thread_info pointer |
| 303 | */ |
| 304 | ENTRY(iwmmxt_task_release) |
| 305 | |
| 306 | mrs r2, cpsr |
| 307 | orr ip, r2, #PSR_I_BIT @ disable interrupts |
| 308 | msr cpsr_c, ip |
| 309 | ldr r3, =concan_owner |
| 310 | add r0, r0, #TI_IWMMXT_STATE @ get task Concan save area |
| 311 | ldr r1, [r3] @ get current Concan owner |
| 312 | eors r0, r0, r1 @ if equal... |
| 313 | streq r0, [r3] @ then clear ownership |
| 314 | msr cpsr_c, r2 @ restore interrupts |
| 315 | mov pc, lr |
| 316 | |
| 317 | .data |
| 318 | concan_owner: |
| 319 | .word 0 |
| 320 | |