arch/arc/include/asm/entry-arcv2.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 #ifndef __ASM_ARC_ENTRY_ARCV2_H
   4 #define __ASM_ARC_ENTRY_ARCV2_H
   5
   6 #include <asm/asm-offsets.h>
   7 #include <asm/irqflags-arcv2.h>
   8 #include <asm/thread_info.h>    /* For THREAD_SIZE */
   9
  10 /*------------------------------------------------------------------------*/
  11 .macro INTERRUPT_PROLOGUE       called_from
  12
  13         ; Before jumping to Interrupt Vector, hardware micro-ops did following:
  14         ;   1. SP auto-switched to kernel mode stack
  15         ;   2. STATUS32.Z flag set to U mode at time of interrupt (U:1, K:0)
  16         ;   3. Auto saved: r0-r11, blink, LPE,LPS,LPC, JLI,LDI,EI, PC, STAT32
  17         ;
  18         ; Now manually save: r12, sp, fp, gp, r25
  19
  20 #ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE
  21 .ifnc \called_from, exception
  22         st.as   r9, [sp, -10]   ; save r9 in it's final stack slot
  23         sub     sp, sp, 12      ; skip JLI, LDI, EI
  24
  25         PUSH    lp_count
  26         PUSHAX  lp_start
  27         PUSHAX  lp_end
  28         PUSH    blink
  29
  30         PUSH    r11
  31         PUSH    r10
  32
  33         sub     sp, sp, 4       ; skip r9
  34
  35         PUSH    r8
  36         PUSH    r7
  37         PUSH    r6
  38         PUSH    r5
  39         PUSH    r4
  40         PUSH    r3
  41         PUSH    r2
  42         PUSH    r1
  43         PUSH    r0
  44 .endif
  45 #endif
  46
  47 #ifdef CONFIG_ARC_HAS_ACCL_REGS
  48         PUSH    r59
  49         PUSH    r58
  50 #endif
  51
  52         PUSH    r30
  53         PUSH    r12
  54
  55         ; Saving pt_regs->sp correctly requires some extra work due to the way
  56         ; Auto stack switch works
  57         ;  - U mode: retrieve it from AUX_USER_SP
  58         ;  - K mode: add the offset from current SP where H/w starts auto push
  59         ;
  60         ; Utilize the fact that Z bit is set if Intr taken in U mode
  61         mov.nz  r9, sp
  62         add.nz  r9, r9, SZ_PT_REGS - PT_sp - 4
  63         bnz     1f
  64
  65         lr      r9, [AUX_USER_SP]
  66 1:
  67         PUSH    r9      ; SP
  68
  69         PUSH    fp
  70         PUSH    gp
  71
  72 #ifdef CONFIG_ARC_CURR_IN_REG
  73         PUSH    r25                     ; user_r25
  74         GET_CURR_TASK_ON_CPU    r25
  75 #else
  76         sub     sp, sp, 4
  77 #endif
  78
  79 .ifnc \called_from, exception
  80         sub     sp, sp, 12      ; BTA/ECR/orig_r0 placeholder per pt_regs
  81 .endif
  82
  83 .endm
  84
  85 /*------------------------------------------------------------------------*/
  86 .macro INTERRUPT_EPILOGUE       called_from
  87
  88 .ifnc \called_from, exception
  89         add     sp, sp, 12      ; skip BTA/ECR/orig_r0 placeholderss
  90 .endif
  91
  92 #ifdef CONFIG_ARC_CURR_IN_REG
  93         POP     r25
  94 #else
  95         add     sp, sp, 4
  96 #endif
  97
  98         POP     gp
  99         POP     fp
 100
 101         ; Don't touch AUX_USER_SP if returning to K mode (Z bit set)
 102         ; (Z bit set on K mode is inverse of INTERRUPT_PROLOGUE)
 103         add.z   sp, sp, 4
 104         bz      1f
 105
 106         POPAX   AUX_USER_SP
 107 1:
 108         POP     r12
 109         POP     r30
 110
 111 #ifdef CONFIG_ARC_HAS_ACCL_REGS
 112         POP     r58
 113         POP     r59
 114 #endif
 115
 116 #ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE
 117 .ifnc \called_from, exception
 118         POP     r0
 119         POP     r1
 120         POP     r2
 121         POP     r3
 122         POP     r4
 123         POP     r5
 124         POP     r6
 125         POP     r7
 126         POP     r8
 127         POP     r9
 128         POP     r10
 129         POP     r11
 130
 131         POP     blink
 132         POPAX   lp_end
 133         POPAX   lp_start
 134
 135         POP     r9
 136         mov     lp_count, r9
 137
 138         add     sp, sp, 12      ; skip JLI, LDI, EI
 139         ld.as   r9, [sp, -10]   ; reload r9 which got clobbered
 140 .endif
 141 #endif
 142
 143 .endm
 144
 145 /*------------------------------------------------------------------------*/
 146 .macro EXCEPTION_PROLOGUE
 147
 148         ; Before jumping to Exception Vector, hardware micro-ops did following:
 149         ;   1. SP auto-switched to kernel mode stack
 150         ;   2. STATUS32.Z flag set to U mode at time of interrupt (U:1,K:0)
 151         ;
 152         ; Now manually save the complete reg file
 153
 154         PUSH    r9              ; freeup a register: slot of erstatus
 155
 156         PUSHAX  eret
 157         sub     sp, sp, 12      ; skip JLI, LDI, EI
 158         PUSH    lp_count
 159         PUSHAX  lp_start
 160         PUSHAX  lp_end
 161         PUSH    blink
 162
 163         PUSH    r11
 164         PUSH    r10
 165
 166         ld.as   r9,  [sp, 10]   ; load stashed r9 (status32 stack slot)
 167         lr      r10, [erstatus]
 168         st.as   r10, [sp, 10]   ; save status32 at it's right stack slot
 169
 170         PUSH    r9
 171         PUSH    r8
 172         PUSH    r7
 173         PUSH    r6
 174         PUSH    r5
 175         PUSH    r4
 176         PUSH    r3
 177         PUSH    r2
 178         PUSH    r1
 179         PUSH    r0
 180
 181         ; -- for interrupts, regs above are auto-saved by h/w in that order --
 182         ; Now do what ISR prologue does (manually save r12, sp, fp, gp, r25)
 183         ;
 184         ; Set Z flag if this was from U mode (expected by INTERRUPT_PROLOGUE)
 185         ; Although H/w exception micro-ops do set Z flag for U mode (just like
 186         ; for interrupts), it could get clobbered in case we soft land here from
 187         ; a TLB Miss exception handler (tlbex.S)
 188
 189         and     r10, r10, STATUS_U_MASK
 190         xor.f   0, r10, STATUS_U_MASK
 191
 192         INTERRUPT_PROLOGUE  exception
 193
 194         PUSHAX  erbta
 195         PUSHAX  ecr             ; r9 contains ECR, expected by EV_Trap
 196
 197         PUSH    r0              ; orig_r0
 198 .endm
 199
 200 /*------------------------------------------------------------------------*/
 201 .macro EXCEPTION_EPILOGUE
 202
 203         ; Assumes r0 has PT_status32
 204         btst   r0, STATUS_U_BIT ; Z flag set if K, used in INTERRUPT_EPILOGUE
 205
 206         add     sp, sp, 8       ; orig_r0/ECR don't need restoring
 207         POPAX   erbta
 208
 209         INTERRUPT_EPILOGUE  exception
 210
 211         POP     r0
 212         POP     r1
 213         POP     r2
 214         POP     r3
 215         POP     r4
 216         POP     r5
 217         POP     r6
 218         POP     r7
 219         POP     r8
 220         POP     r9
 221         POP     r10
 222         POP     r11
 223
 224         POP     blink
 225         POPAX   lp_end
 226         POPAX   lp_start
 227
 228         POP     r9
 229         mov     lp_count, r9
 230
 231         add     sp, sp, 12      ; skip JLI, LDI, EI
 232         POPAX   eret
 233         POPAX   erstatus
 234
 235         ld.as   r9, [sp, -12]   ; reload r9 which got clobbered
 236 .endm
 237
 238 .macro FAKE_RET_FROM_EXCPN
 239         lr      r9, [status32]
 240         bic     r9, r9, (STATUS_U_MASK|STATUS_DE_MASK|STATUS_AE_MASK)
 241         or      r9, r9, (STATUS_L_MASK|STATUS_IE_MASK)
 242         kflag   r9
 243 .endm
 244
 245 /* Get thread_info of "current" tsk */
 246 .macro GET_CURR_THR_INFO_FROM_SP  reg
 247         bmskn \reg, sp, THREAD_SHIFT - 1
 248 .endm
 249
 250 /* Get CPU-ID of this core */
 251 .macro  GET_CPU_ID  reg
 252         lr  \reg, [identity]
 253         xbfu \reg, \reg, 0xE8   /* 00111    01000 */
 254                                 /* M = 8-1  N = 8 */
 255 .endm
 256
 257 #endif