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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 <mach/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  */
  67 ENTRY(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
  93 crunch_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
 147 crunch_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  */
 201 ENTRY(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
 238 1:      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  */
 249 ENTRY(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
 267 1:      @ 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  */
 282 ENTRY(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
 299 1:      @ 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