arch/arc/include/asm/entry.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
   4  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   5  */
   6
   7 #ifndef __ASM_ARC_ENTRY_H
   8 #define __ASM_ARC_ENTRY_H
   9
  10 #include <asm/unistd.h>         /* For NR_syscalls defination */
  11 #include <asm/arcregs.h>
  12 #include <asm/ptrace.h>
  13 #include <asm/processor.h>      /* For VMALLOC_START */
  14 #include <asm/mmu.h>
  15
  16 #ifdef CONFIG_ISA_ARCOMPACT
  17 #include <asm/entry-compact.h>  /* ISA specific bits */
  18 #else
  19 #include <asm/entry-arcv2.h>
  20 #endif
  21
  22 /* Note on the LD/ST addr modes with addr reg wback
  23  *
  24  * LD.a same as LD.aw
  25  *
  26  * LD.a    reg1, [reg2, x]  => Pre Incr
  27  *      Eff Addr for load = [reg2 + x]
  28  *
  29  * LD.ab   reg1, [reg2, x]  => Post Incr
  30  *      Eff Addr for load = [reg2]
  31  */
  32
  33 .macro PUSH reg
  34         st.a    \reg, [sp, -4]
  35 .endm
  36
  37 .macro PUSHAX aux
  38         lr      r9, [\aux]
  39         PUSH    r9
  40 .endm
  41
  42 .macro POP reg
  43         ld.ab   \reg, [sp, 4]
  44 .endm
  45
  46 .macro POPAX aux
  47         POP     r9
  48         sr      r9, [\aux]
  49 .endm
  50
  51 /*--------------------------------------------------------------
  52  * Helpers to save/restore Scratch Regs:
  53  * used by Interrupt/Exception Prologue/Epilogue
  54  *-------------------------------------------------------------*/
  55 .macro  SAVE_R0_TO_R12
  56         PUSH    r0
  57         PUSH    r1
  58         PUSH    r2
  59         PUSH    r3
  60         PUSH    r4
  61         PUSH    r5
  62         PUSH    r6
  63         PUSH    r7
  64         PUSH    r8
  65         PUSH    r9
  66         PUSH    r10
  67         PUSH    r11
  68         PUSH    r12
  69 .endm
  70
  71 .macro RESTORE_R12_TO_R0
  72         POP     r12
  73         POP     r11
  74         POP     r10
  75         POP     r9
  76         POP     r8
  77         POP     r7
  78         POP     r6
  79         POP     r5
  80         POP     r4
  81         POP     r3
  82         POP     r2
  83         POP     r1
  84         POP     r0
  85
  86 .endm
  87
  88 /*--------------------------------------------------------------
  89  * Helpers to save/restore callee-saved regs:
  90  * used by several macros below
  91  *-------------------------------------------------------------*/
  92 .macro SAVE_R13_TO_R24
  93         PUSH    r13
  94         PUSH    r14
  95         PUSH    r15
  96         PUSH    r16
  97         PUSH    r17
  98         PUSH    r18
  99         PUSH    r19
 100         PUSH    r20
 101         PUSH    r21
 102         PUSH    r22
 103         PUSH    r23
 104         PUSH    r24
 105 .endm
 106
 107 .macro RESTORE_R24_TO_R13
 108         POP     r24
 109         POP     r23
 110         POP     r22
 111         POP     r21
 112         POP     r20
 113         POP     r19
 114         POP     r18
 115         POP     r17
 116         POP     r16
 117         POP     r15
 118         POP     r14
 119         POP     r13
 120 .endm
 121
 122 /*--------------------------------------------------------------
 123  * Collect User Mode callee regs as struct callee_regs - needed by
 124  * fork/do_signal/unaligned-access-emulation.
 125  * (By default only scratch regs are saved on entry to kernel)
 126  *
 127  * Special handling for r25 if used for caching Task Pointer.
 128  * It would have been saved in task->thread.user_r25 already, but to keep
 129  * the interface same it is copied into regular r25 placeholder in
 130  * struct callee_regs.
 131  *-------------------------------------------------------------*/
 132 .macro SAVE_CALLEE_SAVED_USER
 133
 134         mov     r12, sp         ; save SP as ref to pt_regs
 135         SAVE_R13_TO_R24
 136
 137 #ifdef CONFIG_ARC_CURR_IN_REG
 138         ; Retrieve orig r25 and save it with rest of callee_regs
 139         ld      r12, [r12, PT_user_r25]
 140         PUSH    r12
 141 #else
 142         PUSH    r25
 143 #endif
 144
 145 .endm
 146
 147 /*--------------------------------------------------------------
 148  * Save kernel Mode callee regs at the time of Contect Switch.
 149  *
 150  * Special handling for r25 if used for caching Task Pointer.
 151  * Kernel simply skips saving it since it will be loaded with
 152  * incoming task pointer anyways
 153  *-------------------------------------------------------------*/
 154 .macro SAVE_CALLEE_SAVED_KERNEL
 155
 156         SAVE_R13_TO_R24
 157
 158 #ifdef CONFIG_ARC_CURR_IN_REG
 159         sub     sp, sp, 4
 160 #else
 161         PUSH    r25
 162 #endif
 163 .endm
 164
 165 /*--------------------------------------------------------------
 166  * Opposite of SAVE_CALLEE_SAVED_KERNEL
 167  *-------------------------------------------------------------*/
 168 .macro RESTORE_CALLEE_SAVED_KERNEL
 169
 170 #ifdef CONFIG_ARC_CURR_IN_REG
 171         add     sp, sp, 4  /* skip usual r25 placeholder */
 172 #else
 173         POP     r25
 174 #endif
 175         RESTORE_R24_TO_R13
 176 .endm
 177
 178 /*--------------------------------------------------------------
 179  * Opposite of SAVE_CALLEE_SAVED_USER
 180  *
 181  * ptrace tracer or unaligned-access fixup might have changed a user mode
 182  * callee reg which is saved back to usual r25 storage location
 183  *-------------------------------------------------------------*/
 184 .macro RESTORE_CALLEE_SAVED_USER
 185
 186 #ifdef CONFIG_ARC_CURR_IN_REG
 187         POP     r12
 188 #else
 189         POP     r25
 190 #endif
 191         RESTORE_R24_TO_R13
 192
 193         ; SP is back to start of pt_regs
 194 #ifdef CONFIG_ARC_CURR_IN_REG
 195         st      r12, [sp, PT_user_r25]
 196 #endif
 197 .endm
 198
 199 /*--------------------------------------------------------------
 200  * Super FAST Restore callee saved regs by simply re-adjusting SP
 201  *-------------------------------------------------------------*/
 202 .macro DISCARD_CALLEE_SAVED_USER
 203         add     sp, sp, SZ_CALLEE_REGS
 204 .endm
 205
 206 /*-------------------------------------------------------------
 207  * given a tsk struct, get to the base of it's kernel mode stack
 208  * tsk->thread_info is really a PAGE, whose bottom hoists stack
 209  * which grows upwards towards thread_info
 210  *------------------------------------------------------------*/
 211
 212 .macro GET_TSK_STACK_BASE tsk, out
 213
 214         /* Get task->thread_info (this is essentially start of a PAGE) */
 215         ld  \out, [\tsk, TASK_THREAD_INFO]
 216
 217         /* Go to end of page where stack begins (grows upwards) */
 218         add2 \out, \out, (THREAD_SIZE)/4
 219
 220 .endm
 221
 222 /*
 223  * @reg [OUT] thread_info->flags of "current"
 224  */
 225 .macro GET_CURR_THR_INFO_FLAGS  reg
 226         GET_CURR_THR_INFO_FROM_SP  \reg
 227         ld  \reg, [\reg, THREAD_INFO_FLAGS]
 228 .endm
 229
 230 #ifdef CONFIG_SMP
 231
 232 /*-------------------------------------------------
 233  * Retrieve the current running task on this CPU
 234  * 1. Determine curr CPU id.
 235  * 2. Use it to index into _current_task[ ]
 236  */
 237 .macro  GET_CURR_TASK_ON_CPU   reg
 238         GET_CPU_ID  \reg
 239         ld.as  \reg, [@_current_task, \reg]
 240 .endm
 241
 242 /*-------------------------------------------------
 243  * Save a new task as the "current" task on this CPU
 244  * 1. Determine curr CPU id.
 245  * 2. Use it to index into _current_task[ ]
 246  *
 247  * Coded differently than GET_CURR_TASK_ON_CPU (which uses LD.AS)
 248  * because ST r0, [r1, offset] can ONLY have s9 @offset
 249  * while   LD can take s9 (4 byte insn) or LIMM (8 byte insn)
 250  */
 251
 252 .macro  SET_CURR_TASK_ON_CPU    tsk, tmp
 253         GET_CPU_ID  \tmp
 254         add2 \tmp, @_current_task, \tmp
 255         st   \tsk, [\tmp]
 256 #ifdef CONFIG_ARC_CURR_IN_REG
 257         mov r25, \tsk
 258 #endif
 259
 260 .endm
 261
 262
 263 #else   /* Uniprocessor implementation of macros */
 264
 265 .macro  GET_CURR_TASK_ON_CPU    reg
 266         ld  \reg, [@_current_task]
 267 .endm
 268
 269 .macro  SET_CURR_TASK_ON_CPU    tsk, tmp
 270         st  \tsk, [@_current_task]
 271 #ifdef CONFIG_ARC_CURR_IN_REG
 272         mov r25, \tsk
 273 #endif
 274 .endm
 275
 276 #endif /* SMP / UNI */
 277
 278 /* ------------------------------------------------------------------
 279  * Get the ptr to some field of Current Task at @off in task struct
 280  *  -Uses r25 for Current task ptr if that is enabled
 281  */
 282
 283 #ifdef CONFIG_ARC_CURR_IN_REG
 284
 285 .macro GET_CURR_TASK_FIELD_PTR  off,  reg
 286         add \reg, r25, \off
 287 .endm
 288
 289 #else
 290
 291 .macro GET_CURR_TASK_FIELD_PTR  off,  reg
 292         GET_CURR_TASK_ON_CPU  \reg
 293         add \reg, \reg, \off
 294 .endm
 295
 296 #endif  /* CONFIG_ARC_CURR_IN_REG */
 297
 298 #endif  /* __ASM_ARC_ENTRY_H */