arch/sparc64/kernel/rtrap.S

   1 /*
   2  * rtrap.S: Preparing for return from trap on Sparc V9.
   3  *
   4  * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
   5  * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
   6  */
   7
   8
   9 #include <asm/asi.h>
  10 #include <asm/pstate.h>
  11 #include <asm/ptrace.h>
  12 #include <asm/spitfire.h>
  13 #include <asm/head.h>
  14 #include <asm/visasm.h>
  15 #include <asm/processor.h>
  16
  17 #define         RTRAP_PSTATE            (PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV|PSTATE_IE)
  18 #define         RTRAP_PSTATE_IRQOFF     (PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV)
  19 #define         RTRAP_PSTATE_AG_IRQOFF  (PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV|PSTATE_AG)
  20
  21                 .text
  22                 .align                  32
  23 __handle_softirq:
  24                 call                    do_softirq
  25                  nop
  26                 ba,a,pt                 %xcc, __handle_softirq_continue
  27                  nop
  28 __handle_preemption:
  29                 call                    schedule
  30                  wrpr                   %g0, RTRAP_PSTATE, %pstate
  31                 ba,pt                   %xcc, __handle_preemption_continue
  32                  wrpr                   %g0, RTRAP_PSTATE_IRQOFF, %pstate
  33
  34 __handle_user_windows:
  35                 call                    fault_in_user_windows
  36                  wrpr                   %g0, RTRAP_PSTATE, %pstate
  37                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
  38                 /* Redo sched+sig checks */
  39                 ldx                     [%g6 + TI_FLAGS], %l0
  40                 andcc                   %l0, _TIF_NEED_RESCHED, %g0
  41
  42                 be,pt                   %xcc, 1f
  43                  nop
  44                 call                    schedule
  45                  wrpr                   %g0, RTRAP_PSTATE, %pstate
  46                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
  47                 ldx                     [%g6 + TI_FLAGS], %l0
  48
  49 1:              andcc                   %l0, _TIF_SIGPENDING, %g0
  50                 be,pt                   %xcc, __handle_user_windows_continue
  51                  nop
  52                 mov                     %l5, %o1
  53                 add                     %sp, PTREGS_OFF, %o0
  54                 mov                     %l0, %o2
  55
  56                 call                    do_notify_resume
  57                  wrpr                   %g0, RTRAP_PSTATE, %pstate
  58                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
  59                 /* Signal delivery can modify pt_regs tstate, so we must
  60                  * reload it.
  61                  */
  62                 ldx                     [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
  63                 sethi                   %hi(0xf << 20), %l4
  64                 and                     %l1, %l4, %l4
  65                 ba,pt                   %xcc, __handle_user_windows_continue
  66
  67                  andn                   %l1, %l4, %l1
  68 __handle_perfctrs:
  69                 call                    update_perfctrs
  70                  wrpr                   %g0, RTRAP_PSTATE, %pstate
  71                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
  72                 ldub                    [%g6 + TI_WSAVED], %o2
  73                 brz,pt                  %o2, 1f
  74                  nop
  75                 /* Redo userwin+sched+sig checks */
  76                 call                    fault_in_user_windows
  77
  78                  wrpr                   %g0, RTRAP_PSTATE, %pstate
  79                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
  80                 ldx                     [%g6 + TI_FLAGS], %l0
  81                 andcc                   %l0, _TIF_NEED_RESCHED, %g0
  82                 be,pt                   %xcc, 1f
  83
  84                  nop
  85                 call                    schedule
  86                  wrpr                   %g0, RTRAP_PSTATE, %pstate
  87                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
  88                 ldx                     [%g6 + TI_FLAGS], %l0
  89 1:              andcc                   %l0, _TIF_SIGPENDING, %g0
  90
  91                 be,pt                   %xcc, __handle_perfctrs_continue
  92                  sethi                  %hi(TSTATE_PEF), %o0
  93                 mov                     %l5, %o1
  94                 add                     %sp, PTREGS_OFF, %o0
  95                 mov                     %l0, %o2
  96                 call                    do_notify_resume
  97
  98                  wrpr                   %g0, RTRAP_PSTATE, %pstate
  99                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
 100                 /* Signal delivery can modify pt_regs tstate, so we must
 101                  * reload it.
 102                  */
 103                 ldx                     [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
 104                 sethi                   %hi(0xf << 20), %l4
 105                 and                     %l1, %l4, %l4
 106                 andn                    %l1, %l4, %l1
 107                 ba,pt                   %xcc, __handle_perfctrs_continue
 108
 109                  sethi                  %hi(TSTATE_PEF), %o0
 110 __handle_userfpu:
 111                 rd                      %fprs, %l5
 112                 andcc                   %l5, FPRS_FEF, %g0
 113                 sethi                   %hi(TSTATE_PEF), %o0
 114                 be,a,pn                 %icc, __handle_userfpu_continue
 115                  andn                   %l1, %o0, %l1
 116                 ba,a,pt                 %xcc, __handle_userfpu_continue
 117
 118 __handle_signal:
 119                 mov                     %l5, %o1
 120                 add                     %sp, PTREGS_OFF, %o0
 121                 mov                     %l0, %o2
 122                 call                    do_notify_resume
 123                  wrpr                   %g0, RTRAP_PSTATE, %pstate
 124                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
 125
 126                 /* Signal delivery can modify pt_regs tstate, so we must
 127                  * reload it.
 128                  */
 129                 ldx                     [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
 130                 sethi                   %hi(0xf << 20), %l4
 131                 and                     %l1, %l4, %l4
 132                 ba,pt                   %xcc, __handle_signal_continue
 133                  andn                   %l1, %l4, %l1
 134
 135                 .align                  64
 136                 .globl                  rtrap_irq, rtrap, irqsz_patchme, rtrap_xcall
 137 rtrap_irq:
 138 rtrap:
 139 #ifndef CONFIG_SMP
 140                 sethi                   %hi(per_cpu____cpu_data), %l0
 141                 lduw                    [%l0 + %lo(per_cpu____cpu_data)], %l1
 142 #else
 143                 sethi                   %hi(per_cpu____cpu_data), %l0
 144                 or                      %l0, %lo(per_cpu____cpu_data), %l0
 145                 lduw                    [%l0 + %g5], %l1
 146 #endif
 147                 cmp                     %l1, 0
 148
 149                 /* mm/ultra.S:xcall_report_regs KNOWS about this load. */
 150                 bne,pn                  %icc, __handle_softirq
 151                  ldx                    [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
 152 __handle_softirq_continue:
 153 rtrap_xcall:
 154                 sethi                   %hi(0xf << 20), %l4
 155                 and                     %l1, %l4, %l4
 156                 andn                    %l1, %l4, %l1
 157                 srl                     %l4, 20, %l4
 158 #ifdef CONFIG_TRACE_IRQFLAGS
 159                 brnz,pn                 %l4, rtrap_no_irq_enable
 160                  nop
 161                 call                    trace_hardirqs_on
 162                  nop
 163                 wrpr                    %l4, %pil
 164 rtrap_no_irq_enable:
 165 #endif
 166                 andcc                   %l1, TSTATE_PRIV, %l3
 167                 bne,pn                  %icc, to_kernel
 168                  nop
 169
 170                 /* We must hold IRQs off and atomically test schedule+signal
 171                  * state, then hold them off all the way back to userspace.
 172                  * If we are returning to kernel, none of this matters.  Note
 173                  * that we are disabling interrupts via PSTATE_IE, not using
 174                  * %pil.
 175                  *
 176                  * If we do not do this, there is a window where we would do
 177                  * the tests, later the signal/resched event arrives but we do
 178                  * not process it since we are still in kernel mode.  It would
 179                  * take until the next local IRQ before the signal/resched
 180                  * event would be handled.
 181                  *
 182                  * This also means that if we have to deal with performance
 183                  * counters or user windows, we have to redo all of these
 184                  * sched+signal checks with IRQs disabled.
 185                  */
 186 to_user:        wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
 187                 wrpr                    0, %pil
 188 __handle_preemption_continue:
 189                 ldx                     [%g6 + TI_FLAGS], %l0
 190                 sethi                   %hi(_TIF_USER_WORK_MASK), %o0
 191                 or                      %o0, %lo(_TIF_USER_WORK_MASK), %o0
 192                 andcc                   %l0, %o0, %g0
 193                 sethi                   %hi(TSTATE_PEF), %o0
 194                 be,pt                   %xcc, user_nowork
 195                  andcc                  %l1, %o0, %g0
 196                 andcc                   %l0, _TIF_NEED_RESCHED, %g0
 197                 bne,pn                  %xcc, __handle_preemption
 198                  andcc                  %l0, _TIF_SIGPENDING, %g0
 199                 bne,pn                  %xcc, __handle_signal
 200 __handle_signal_continue:
 201                  ldub                   [%g6 + TI_WSAVED], %o2
 202                 brnz,pn                 %o2, __handle_user_windows
 203                  nop
 204 __handle_user_windows_continue:
 205                 ldx                     [%g6 + TI_FLAGS], %l5
 206                 andcc                   %l5, _TIF_PERFCTR, %g0
 207                 sethi                   %hi(TSTATE_PEF), %o0
 208                 bne,pn                  %xcc, __handle_perfctrs
 209 __handle_perfctrs_continue:
 210                  andcc                  %l1, %o0, %g0
 211
 212                 /* This fpdepth clear is necessary for non-syscall rtraps only */
 213 user_nowork:
 214                 bne,pn                  %xcc, __handle_userfpu
 215                  stb                    %g0, [%g6 + TI_FPDEPTH]
 216 __handle_userfpu_continue:
 217
 218 rt_continue:    ldx                     [%sp + PTREGS_OFF + PT_V9_G1], %g1
 219                 ldx                     [%sp + PTREGS_OFF + PT_V9_G2], %g2
 220
 221                 ldx                     [%sp + PTREGS_OFF + PT_V9_G3], %g3
 222                 ldx                     [%sp + PTREGS_OFF + PT_V9_G4], %g4
 223                 ldx                     [%sp + PTREGS_OFF + PT_V9_G5], %g5
 224                 brz,pt                  %l3, 1f
 225                 mov                     %g6, %l2
 226
 227                 /* Must do this before thread reg is clobbered below.  */
 228                 LOAD_PER_CPU_BASE(%g5, %g6, %i0, %i1, %i2)
 229 1:
 230                 ldx                     [%sp + PTREGS_OFF + PT_V9_G6], %g6
 231                 ldx                     [%sp + PTREGS_OFF + PT_V9_G7], %g7
 232
 233                 /* Normal globals are restored, go to trap globals.  */
 234 661:            wrpr                    %g0, RTRAP_PSTATE_AG_IRQOFF, %pstate
 235                 nop
 236                 .section                .sun4v_2insn_patch, "ax"
 237                 .word                   661b
 238                 wrpr                    %g0, RTRAP_PSTATE_IRQOFF, %pstate
 239                 SET_GL(1)
 240                 .previous
 241
 242                 mov                     %l2, %g6
 243
 244                 ldx                     [%sp + PTREGS_OFF + PT_V9_I0], %i0
 245                 ldx                     [%sp + PTREGS_OFF + PT_V9_I1], %i1
 246
 247                 ldx                     [%sp + PTREGS_OFF + PT_V9_I2], %i2
 248                 ldx                     [%sp + PTREGS_OFF + PT_V9_I3], %i3
 249                 ldx                     [%sp + PTREGS_OFF + PT_V9_I4], %i4
 250                 ldx                     [%sp + PTREGS_OFF + PT_V9_I5], %i5
 251                 ldx                     [%sp + PTREGS_OFF + PT_V9_I6], %i6
 252                 ldx                     [%sp + PTREGS_OFF + PT_V9_I7], %i7
 253                 ldx                     [%sp + PTREGS_OFF + PT_V9_TPC], %l2
 254                 ldx                     [%sp + PTREGS_OFF + PT_V9_TNPC], %o2
 255
 256                 ld                      [%sp + PTREGS_OFF + PT_V9_Y], %o3
 257                 wr                      %o3, %g0, %y
 258                 wrpr                    %l4, 0x0, %pil
 259                 wrpr                    %g0, 0x1, %tl
 260                 andn                    %l1, TSTATE_SYSCALL, %l1
 261                 wrpr                    %l1, %g0, %tstate
 262                 wrpr                    %l2, %g0, %tpc
 263                 wrpr                    %o2, %g0, %tnpc
 264
 265                 brnz,pn                 %l3, kern_rtt
 266                  mov                    PRIMARY_CONTEXT, %l7
 267
 268 661:            ldxa                    [%l7 + %l7] ASI_DMMU, %l0
 269                 .section                .sun4v_1insn_patch, "ax"
 270                 .word                   661b
 271                 ldxa                    [%l7 + %l7] ASI_MMU, %l0
 272                 .previous
 273
 274                 sethi                   %hi(sparc64_kern_pri_nuc_bits), %l1
 275                 ldx                     [%l1 + %lo(sparc64_kern_pri_nuc_bits)], %l1
 276                 or                      %l0, %l1, %l0
 277
 278 661:            stxa                    %l0, [%l7] ASI_DMMU
 279                 .section                .sun4v_1insn_patch, "ax"
 280                 .word                   661b
 281                 stxa                    %l0, [%l7] ASI_MMU
 282                 .previous
 283
 284                 sethi                   %hi(KERNBASE), %l7
 285                 flush                   %l7
 286                 rdpr                    %wstate, %l1
 287                 rdpr                    %otherwin, %l2
 288                 srl                     %l1, 3, %l1
 289
 290                 wrpr                    %l2, %g0, %canrestore
 291                 wrpr                    %l1, %g0, %wstate
 292                 brnz,pt                 %l2, user_rtt_restore
 293                  wrpr                   %g0, %g0, %otherwin
 294
 295                 ldx                     [%g6 + TI_FLAGS], %g3
 296                 wr                      %g0, ASI_AIUP, %asi
 297                 rdpr                    %cwp, %g1
 298                 andcc                   %g3, _TIF_32BIT, %g0
 299                 sub                     %g1, 1, %g1
 300                 bne,pt                  %xcc, user_rtt_fill_32bit
 301                  wrpr                   %g1, %cwp
 302                 ba,a,pt                 %xcc, user_rtt_fill_64bit
 303
 304 user_rtt_fill_fixup:
 305                 rdpr    %cwp, %g1
 306                 add     %g1, 1, %g1
 307                 wrpr    %g1, 0x0, %cwp
 308
 309                 rdpr    %wstate, %g2
 310                 sll     %g2, 3, %g2
 311                 wrpr    %g2, 0x0, %wstate
 312
 313                 /* We know %canrestore and %otherwin are both zero.  */
 314
 315                 sethi   %hi(sparc64_kern_pri_context), %g2
 316                 ldx     [%g2 + %lo(sparc64_kern_pri_context)], %g2
 317                 mov     PRIMARY_CONTEXT, %g1
 318
 319 661:            stxa    %g2, [%g1] ASI_DMMU
 320                 .section .sun4v_1insn_patch, "ax"
 321                 .word   661b
 322                 stxa    %g2, [%g1] ASI_MMU
 323                 .previous
 324
 325                 sethi   %hi(KERNBASE), %g1
 326                 flush   %g1
 327
 328                 or      %g4, FAULT_CODE_WINFIXUP, %g4
 329                 stb     %g4, [%g6 + TI_FAULT_CODE]
 330                 stx     %g5, [%g6 + TI_FAULT_ADDR]
 331
 332                 mov     %g6, %l1
 333                 wrpr    %g0, 0x0, %tl
 334
 335 661:            nop
 336                 .section                .sun4v_1insn_patch, "ax"
 337                 .word                   661b
 338                 SET_GL(0)
 339                 .previous
 340
 341                 wrpr    %g0, RTRAP_PSTATE, %pstate
 342
 343                 mov     %l1, %g6
 344                 ldx     [%g6 + TI_TASK], %g4
 345                 LOAD_PER_CPU_BASE(%g5, %g6, %g1, %g2, %g3)
 346                 call    do_sparc64_fault
 347                  add    %sp, PTREGS_OFF, %o0
 348                 ba,pt   %xcc, rtrap
 349                  nop
 350
 351 user_rtt_pre_restore:
 352                 add                     %g1, 1, %g1
 353                 wrpr                    %g1, 0x0, %cwp
 354
 355 user_rtt_restore:
 356                 restore
 357                 rdpr                    %canrestore, %g1
 358                 wrpr                    %g1, 0x0, %cleanwin
 359                 retry
 360                 nop
 361
 362 kern_rtt:       rdpr                    %canrestore, %g1
 363                 brz,pn                  %g1, kern_rtt_fill
 364                  nop
 365 kern_rtt_restore:
 366                 stw                     %g0, [%sp + PTREGS_OFF + PT_V9_MAGIC]
 367                 restore
 368                 retry
 369
 370 to_kernel:
 371 #ifdef CONFIG_PREEMPT
 372                 ldsw                    [%g6 + TI_PRE_COUNT], %l5
 373                 brnz                    %l5, kern_fpucheck
 374                  ldx                    [%g6 + TI_FLAGS], %l5
 375                 andcc                   %l5, _TIF_NEED_RESCHED, %g0
 376                 be,pt                   %xcc, kern_fpucheck
 377                  nop
 378                 cmp                     %l4, 0
 379                 bne,pn                  %xcc, kern_fpucheck
 380                  sethi                  %hi(PREEMPT_ACTIVE), %l6
 381                 stw                     %l6, [%g6 + TI_PRE_COUNT]
 382                 call                    schedule
 383                  nop
 384                 ba,pt                   %xcc, rtrap
 385                  stw                    %g0, [%g6 + TI_PRE_COUNT]
 386 #endif
 387 kern_fpucheck:  ldub                    [%g6 + TI_FPDEPTH], %l5
 388                 brz,pt                  %l5, rt_continue
 389                  srl                    %l5, 1, %o0
 390                 add                     %g6, TI_FPSAVED, %l6
 391                 ldub                    [%l6 + %o0], %l2
 392                 sub                     %l5, 2, %l5
 393
 394                 add                     %g6, TI_GSR, %o1
 395                 andcc                   %l2, (FPRS_FEF|FPRS_DU), %g0
 396                 be,pt                   %icc, 2f
 397                  and                    %l2, FPRS_DL, %l6
 398                 andcc                   %l2, FPRS_FEF, %g0
 399                 be,pn                   %icc, 5f
 400                  sll                    %o0, 3, %o5
 401                 rd                      %fprs, %g1
 402
 403                 wr                      %g1, FPRS_FEF, %fprs
 404                 ldx                     [%o1 + %o5], %g1
 405                 add                     %g6, TI_XFSR, %o1
 406                 sll                     %o0, 8, %o2
 407                 add                     %g6, TI_FPREGS, %o3
 408                 brz,pn                  %l6, 1f
 409                  add                    %g6, TI_FPREGS+0x40, %o4
 410
 411                 membar                  #Sync
 412                 ldda                    [%o3 + %o2] ASI_BLK_P, %f0
 413                 ldda                    [%o4 + %o2] ASI_BLK_P, %f16
 414                 membar                  #Sync
 415 1:              andcc                   %l2, FPRS_DU, %g0
 416                 be,pn                   %icc, 1f
 417                  wr                     %g1, 0, %gsr
 418                 add                     %o2, 0x80, %o2
 419                 membar                  #Sync
 420                 ldda                    [%o3 + %o2] ASI_BLK_P, %f32
 421                 ldda                    [%o4 + %o2] ASI_BLK_P, %f48
 422 1:              membar                  #Sync
 423                 ldx                     [%o1 + %o5], %fsr
 424 2:              stb                     %l5, [%g6 + TI_FPDEPTH]
 425                 ba,pt                   %xcc, rt_continue
 426                  nop
 427 5:              wr                      %g0, FPRS_FEF, %fprs
 428                 sll                     %o0, 8, %o2
 429
 430                 add                     %g6, TI_FPREGS+0x80, %o3
 431                 add                     %g6, TI_FPREGS+0xc0, %o4
 432                 membar                  #Sync
 433                 ldda                    [%o3 + %o2] ASI_BLK_P, %f32
 434                 ldda                    [%o4 + %o2] ASI_BLK_P, %f48
 435                 membar                  #Sync
 436                 wr                      %g0, FPRS_DU, %fprs
 437                 ba,pt                   %xcc, rt_continue
 438                  stb                    %l5, [%g6 + TI_FPDEPTH]