arch/c6x/kernel/entry.S

   1 ; SPDX-License-Identifier: GPL-2.0-only
   2 ;
   3 ;  Port on Texas Instruments TMS320C6x architecture
   4 ;
   5 ;  Copyright (C) 2004-2011 Texas Instruments Incorporated
   6 ;  Author: Aurelien Jacquiot (aurelien.jacquiot@virtuallogix.com)
   7 ;  Updated for 2.6.34: Mark Salter <msalter@redhat.com>
   8 ;
   9
  10 #include <linux/sys.h>
  11 #include <linux/linkage.h>
  12 #include <asm/thread_info.h>
  13 #include <asm/asm-offsets.h>
  14 #include <asm/unistd.h>
  15 #include <asm/errno.h>
  16
  17 ; Registers naming
  18 #define DP      B14
  19 #define SP      B15
  20
  21 #ifndef CONFIG_PREEMPT
  22 #define resume_kernel restore_all
  23 #endif
  24
  25         .altmacro
  26
  27         .macro MASK_INT reg
  28         MVC     .S2     CSR,reg
  29         CLR     .S2     reg,0,0,reg
  30         MVC     .S2     reg,CSR
  31         .endm
  32
  33         .macro UNMASK_INT reg
  34         MVC     .S2     CSR,reg
  35         SET     .S2     reg,0,0,reg
  36         MVC     .S2     reg,CSR
  37         .endm
  38
  39         .macro GET_THREAD_INFO reg
  40         SHR     .S1X    SP,THREAD_SHIFT,reg
  41         SHL     .S1     reg,THREAD_SHIFT,reg
  42         .endm
  43
  44         ;;
  45         ;;  This defines the normal kernel pt_regs layout.
  46         ;;
  47         .macro SAVE_ALL __rp __tsr
  48         STW     .D2T2   B0,*SP--[2]             ; save original B0
  49         MVKL    .S2     current_ksp,B0
  50         MVKH    .S2     current_ksp,B0
  51         LDW     .D2T2   *B0,B1                  ; KSP
  52
  53         NOP     3
  54         STW     .D2T2   B1,*+SP[1]              ; save original B1
  55         XOR     .D2     SP,B1,B0                ; (SP ^ KSP)
  56         LDW     .D2T2   *+SP[1],B1              ; restore B0/B1
  57         LDW     .D2T2   *++SP[2],B0
  58         SHR     .S2     B0,THREAD_SHIFT,B0      ; 0 if already using kstack
  59   [B0]  STDW    .D2T2   SP:DP,*--B1[1]          ; user: save user sp/dp kstack
  60   [B0]  MV      .S2     B1,SP                   ;    and switch to kstack
  61 ||[!B0] STDW    .D2T2   SP:DP,*--SP[1]          ; kernel: save on current stack
  62
  63         SUBAW   .D2     SP,2,SP
  64
  65         ADD     .D1X    SP,-8,A15
  66  ||     STDW    .D2T1   A15:A14,*SP--[16]       ; save A15:A14
  67
  68         STDW    .D2T2   B13:B12,*SP--[1]
  69  ||     STDW    .D1T1   A13:A12,*A15--[1]
  70  ||     MVC     .S2     __rp,B13
  71
  72         STDW    .D2T2   B11:B10,*SP--[1]
  73  ||     STDW    .D1T1   A11:A10,*A15--[1]
  74  ||     MVC     .S2     CSR,B12
  75
  76         STDW    .D2T2   B9:B8,*SP--[1]
  77  ||     STDW    .D1T1   A9:A8,*A15--[1]
  78  ||     MVC     .S2     RILC,B11
  79         STDW    .D2T2   B7:B6,*SP--[1]
  80  ||     STDW    .D1T1   A7:A6,*A15--[1]
  81  ||     MVC     .S2     ILC,B10
  82
  83         STDW    .D2T2   B5:B4,*SP--[1]
  84  ||     STDW    .D1T1   A5:A4,*A15--[1]
  85
  86         STDW    .D2T2   B3:B2,*SP--[1]
  87  ||     STDW    .D1T1   A3:A2,*A15--[1]
  88  ||     MVC     .S2     __tsr,B5
  89
  90         STDW    .D2T2   B1:B0,*SP--[1]
  91  ||     STDW    .D1T1   A1:A0,*A15--[1]
  92  ||     MV      .S1X    B5,A5
  93
  94         STDW    .D2T2   B31:B30,*SP--[1]
  95  ||     STDW    .D1T1   A31:A30,*A15--[1]
  96         STDW    .D2T2   B29:B28,*SP--[1]
  97  ||     STDW    .D1T1   A29:A28,*A15--[1]
  98         STDW    .D2T2   B27:B26,*SP--[1]
  99  ||     STDW    .D1T1   A27:A26,*A15--[1]
 100         STDW    .D2T2   B25:B24,*SP--[1]
 101  ||     STDW    .D1T1   A25:A24,*A15--[1]
 102         STDW    .D2T2   B23:B22,*SP--[1]
 103  ||     STDW    .D1T1   A23:A22,*A15--[1]
 104         STDW    .D2T2   B21:B20,*SP--[1]
 105  ||     STDW    .D1T1   A21:A20,*A15--[1]
 106         STDW    .D2T2   B19:B18,*SP--[1]
 107  ||     STDW    .D1T1   A19:A18,*A15--[1]
 108         STDW    .D2T2   B17:B16,*SP--[1]
 109  ||     STDW    .D1T1   A17:A16,*A15--[1]
 110
 111         STDW    .D2T2   B13:B12,*SP--[1]        ; save PC and CSR
 112
 113         STDW    .D2T2   B11:B10,*SP--[1]        ; save RILC and ILC
 114         STDW    .D2T1   A5:A4,*SP--[1]          ; save TSR and orig A4
 115
 116         ;; We left an unused word on the stack just above pt_regs.
 117         ;; It is used to save whether or not this frame is due to
 118         ;; a syscall. It is cleared here, but the syscall handler
 119         ;; sets it to a non-zero value.
 120         MVK     .L2     0,B1
 121         STW     .D2T2   B1,*+SP(REGS__END+8)    ; clear syscall flag
 122         .endm
 123
 124         .macro RESTORE_ALL __rp __tsr
 125         LDDW    .D2T2   *++SP[1],B9:B8          ; get TSR (B9)
 126         LDDW    .D2T2   *++SP[1],B11:B10        ; get RILC (B11) and ILC (B10)
 127         LDDW    .D2T2   *++SP[1],B13:B12        ; get PC (B13) and CSR (B12)
 128
 129         ADDAW   .D1X    SP,30,A15
 130
 131         LDDW    .D1T1   *++A15[1],A17:A16
 132  ||     LDDW    .D2T2   *++SP[1],B17:B16
 133         LDDW    .D1T1   *++A15[1],A19:A18
 134  ||     LDDW    .D2T2   *++SP[1],B19:B18
 135         LDDW    .D1T1   *++A15[1],A21:A20
 136  ||     LDDW    .D2T2   *++SP[1],B21:B20
 137         LDDW    .D1T1   *++A15[1],A23:A22
 138  ||     LDDW    .D2T2   *++SP[1],B23:B22
 139         LDDW    .D1T1   *++A15[1],A25:A24
 140  ||     LDDW    .D2T2   *++SP[1],B25:B24
 141         LDDW    .D1T1   *++A15[1],A27:A26
 142  ||     LDDW    .D2T2   *++SP[1],B27:B26
 143         LDDW    .D1T1   *++A15[1],A29:A28
 144  ||     LDDW    .D2T2   *++SP[1],B29:B28
 145         LDDW    .D1T1   *++A15[1],A31:A30
 146  ||     LDDW    .D2T2   *++SP[1],B31:B30
 147
 148         LDDW    .D1T1   *++A15[1],A1:A0
 149  ||     LDDW    .D2T2   *++SP[1],B1:B0
 150
 151         LDDW    .D1T1   *++A15[1],A3:A2
 152  ||     LDDW    .D2T2   *++SP[1],B3:B2
 153  ||     MVC     .S2     B9,__tsr
 154         LDDW    .D1T1   *++A15[1],A5:A4
 155  ||     LDDW    .D2T2   *++SP[1],B5:B4
 156  ||     MVC     .S2     B11,RILC
 157         LDDW    .D1T1   *++A15[1],A7:A6
 158  ||     LDDW    .D2T2   *++SP[1],B7:B6
 159  ||     MVC     .S2     B10,ILC
 160
 161         LDDW    .D1T1   *++A15[1],A9:A8
 162  ||     LDDW    .D2T2   *++SP[1],B9:B8
 163  ||     MVC     .S2     B13,__rp
 164
 165         LDDW    .D1T1   *++A15[1],A11:A10
 166  ||     LDDW    .D2T2   *++SP[1],B11:B10
 167  ||     MVC     .S2     B12,CSR
 168
 169         LDDW    .D1T1   *++A15[1],A13:A12
 170  ||     LDDW    .D2T2   *++SP[1],B13:B12
 171
 172         MV      .D2X    A15,SP
 173  ||     MVKL    .S1     current_ksp,A15
 174         MVKH    .S1     current_ksp,A15
 175  ||     ADDAW   .D1X    SP,6,A14
 176         STW     .D1T1   A14,*A15        ; save kernel stack pointer
 177
 178         LDDW    .D2T1   *++SP[1],A15:A14
 179
 180         B       .S2     __rp            ; return from interruption
 181         LDDW    .D2T2   *+SP[1],SP:DP
 182         NOP     4
 183         .endm
 184
 185         .section .text
 186
 187         ;;
 188         ;; Jump to schedule() then return to ret_from_exception
 189         ;;
 190 _reschedule:
 191 #ifdef CONFIG_C6X_BIG_KERNEL
 192         MVKL    .S1     schedule,A0
 193         MVKH    .S1     schedule,A0
 194         B       .S2X    A0
 195 #else
 196         B       .S1     schedule
 197 #endif
 198         ADDKPC  .S2     ret_from_exception,B3,4
 199
 200         ;;
 201         ;; Called before syscall handler when process is being debugged
 202         ;;
 203 tracesys_on:
 204 #ifdef CONFIG_C6X_BIG_KERNEL
 205         MVKL    .S1     syscall_trace_entry,A0
 206         MVKH    .S1     syscall_trace_entry,A0
 207         B       .S2X    A0
 208 #else
 209         B       .S1     syscall_trace_entry
 210 #endif
 211         ADDKPC  .S2     ret_from_syscall_trace,B3,3
 212         ADD     .S1X    8,SP,A4
 213
 214 ret_from_syscall_trace:
 215         ;; tracing returns (possibly new) syscall number
 216         MV      .D2X    A4,B0
 217  ||     MVK     .S2     __NR_syscalls,B1
 218         CMPLTU  .L2     B0,B1,B1
 219
 220  [!B1]  BNOP    .S2     ret_from_syscall_function,5
 221  ||     MVK     .S1     -ENOSYS,A4
 222
 223         ;; reload syscall args from (possibly modified) stack frame
 224         ;; and get syscall handler addr from sys_call_table:
 225         LDW     .D2T2   *+SP(REGS_B4+8),B4
 226  ||     MVKL    .S2     sys_call_table,B1
 227         LDW     .D2T1   *+SP(REGS_A6+8),A6
 228  ||     MVKH    .S2     sys_call_table,B1
 229         LDW     .D2T2   *+B1[B0],B0
 230  ||     MVKL    .S2     ret_from_syscall_function,B3
 231         LDW     .D2T2   *+SP(REGS_B6+8),B6
 232  ||     MVKH    .S2     ret_from_syscall_function,B3
 233         LDW     .D2T1   *+SP(REGS_A8+8),A8
 234         LDW     .D2T2   *+SP(REGS_B8+8),B8
 235         NOP
 236         ; B0 = sys_call_table[__NR_*]
 237         BNOP    .S2     B0,5                    ; branch to syscall handler
 238  ||     LDW     .D2T1   *+SP(REGS_ORIG_A4+8),A4
 239
 240 syscall_exit_work:
 241         AND     .D1     _TIF_SYSCALL_TRACE,A2,A0
 242  [!A0]  BNOP    .S1     work_pending,5
 243  [A0]   B       .S2     syscall_trace_exit
 244         ADDKPC  .S2     resume_userspace,B3,1
 245         MVC     .S2     CSR,B1
 246         SET     .S2     B1,0,0,B1
 247         MVC     .S2     B1,CSR          ; enable ints
 248
 249 work_pending:
 250         AND     .D1     _TIF_NEED_RESCHED,A2,A0
 251  [!A0]  BNOP    .S1     work_notifysig,5
 252
 253 work_resched:
 254 #ifdef CONFIG_C6X_BIG_KERNEL
 255         MVKL    .S1     schedule,A1
 256         MVKH    .S1     schedule,A1
 257         B       .S2X    A1
 258 #else
 259         B       .S2     schedule
 260 #endif
 261         ADDKPC  .S2     work_rescheduled,B3,4
 262 work_rescheduled:
 263         ;; make sure we don't miss an interrupt setting need_resched or
 264         ;; sigpending between sampling and the rti
 265         MASK_INT B2
 266         GET_THREAD_INFO A12
 267         LDW     .D1T1   *+A12(THREAD_INFO_FLAGS),A2
 268         MVK     .S1     _TIF_WORK_MASK,A1
 269         MVK     .S1     _TIF_NEED_RESCHED,A3
 270         NOP     2
 271         AND     .D1     A1,A2,A0
 272  ||     AND     .S1     A3,A2,A1
 273  [!A0]  BNOP    .S1     restore_all,5
 274  [A1]   BNOP    .S1     work_resched,5
 275
 276 work_notifysig:
 277         ;; enable interrupts for do_notify_resume()
 278         UNMASK_INT B2
 279         B       .S2     do_notify_resume
 280         LDW     .D2T1   *+SP(REGS__END+8),A6 ; syscall flag
 281         ADDKPC  .S2     resume_userspace,B3,1
 282         ADD     .S1X    8,SP,A4         ; pt_regs pointer is first arg
 283         MV      .D2X    A2,B4           ; thread_info flags is second arg
 284
 285         ;;
 286         ;; On C64x+, the return way from exception and interrupt
 287         ;; is a little bit different
 288         ;;
 289 ENTRY(ret_from_exception)
 290 #ifdef CONFIG_PREEMPT
 291         MASK_INT B2
 292 #endif
 293
 294 ENTRY(ret_from_interrupt)
 295         ;;
 296         ;; Check if we are comming from user mode.
 297         ;;
 298         LDW     .D2T2   *+SP(REGS_TSR+8),B0
 299         MVK     .S2     0x40,B1
 300         NOP     3
 301         AND     .D2     B0,B1,B0
 302  [!B0]  BNOP    .S2     resume_kernel,5
 303
 304 resume_userspace:
 305         ;; make sure we don't miss an interrupt setting need_resched or
 306         ;; sigpending between sampling and the rti
 307         MASK_INT B2
 308         GET_THREAD_INFO A12
 309         LDW     .D1T1   *+A12(THREAD_INFO_FLAGS),A2
 310         MVK     .S1     _TIF_WORK_MASK,A1
 311         MVK     .S1     _TIF_NEED_RESCHED,A3
 312         NOP     2
 313         AND     .D1     A1,A2,A0
 314  [A0]   BNOP    .S1     work_pending,5
 315         BNOP    .S1     restore_all,5
 316
 317         ;;
 318         ;; System call handling
 319         ;; B0 = syscall number (in sys_call_table)
 320         ;; A4,B4,A6,B6,A8,B8 = arguments of the syscall function
 321         ;; A4 is the return value register
 322         ;;
 323 system_call_saved:
 324         MVK     .L2     1,B2
 325         STW     .D2T2   B2,*+SP(REGS__END+8)    ; set syscall flag
 326         MVC     .S2     B2,ECR                  ; ack the software exception
 327
 328         UNMASK_INT B2                   ; re-enable global IT
 329
 330 system_call_saved_noack:
 331         ;; Check system call number
 332         MVK     .S2     __NR_syscalls,B1
 333 #ifdef CONFIG_C6X_BIG_KERNEL
 334  ||     MVKL    .S1     sys_ni_syscall,A0
 335 #endif
 336         CMPLTU  .L2     B0,B1,B1
 337 #ifdef CONFIG_C6X_BIG_KERNEL
 338  ||     MVKH    .S1     sys_ni_syscall,A0
 339 #endif
 340
 341         ;; Check for ptrace
 342         GET_THREAD_INFO A12
 343
 344 #ifdef CONFIG_C6X_BIG_KERNEL
 345  [!B1]  B       .S2X    A0
 346 #else
 347  [!B1]  B       .S2     sys_ni_syscall
 348 #endif
 349  [!B1]  ADDKPC  .S2     ret_from_syscall_function,B3,4
 350
 351         ;; Get syscall handler addr from sys_call_table
 352         ;; call tracesys_on or call syscall handler
 353         LDW     .D1T1   *+A12(THREAD_INFO_FLAGS),A2
 354  ||     MVKL    .S2     sys_call_table,B1
 355         MVKH    .S2     sys_call_table,B1
 356         LDW     .D2T2   *+B1[B0],B0
 357         NOP     2
 358         ; A2 = thread_info flags
 359         AND     .D1     _TIF_SYSCALL_TRACE,A2,A2
 360  [A2]   BNOP    .S1     tracesys_on,5
 361         ;; B0 = _sys_call_table[__NR_*]
 362         B       .S2     B0
 363         ADDKPC  .S2     ret_from_syscall_function,B3,4
 364
 365 ret_from_syscall_function:
 366         STW     .D2T1   A4,*+SP(REGS_A4+8)      ; save return value in A4
 367                                                 ; original A4 is in orig_A4
 368 syscall_exit:
 369         ;; make sure we don't miss an interrupt setting need_resched or
 370         ;; sigpending between sampling and the rti
 371         MASK_INT B2
 372         LDW     .D1T1   *+A12(THREAD_INFO_FLAGS),A2
 373         MVK     .S1     _TIF_ALLWORK_MASK,A1
 374         NOP     3
 375         AND     .D1     A1,A2,A2 ; check for work to do
 376  [A2]   BNOP    .S1     syscall_exit_work,5
 377
 378 restore_all:
 379         RESTORE_ALL NRP,NTSR
 380
 381         ;;
 382         ;; After a fork we jump here directly from resume,
 383         ;; so that A4 contains the previous task structure.
 384         ;;
 385 ENTRY(ret_from_fork)
 386 #ifdef CONFIG_C6X_BIG_KERNEL
 387         MVKL    .S1     schedule_tail,A0
 388         MVKH    .S1     schedule_tail,A0
 389         B       .S2X    A0
 390 #else
 391         B       .S2     schedule_tail
 392 #endif
 393         ADDKPC  .S2     ret_from_fork_2,B3,4
 394 ret_from_fork_2:
 395         ;; return 0 in A4 for child process
 396         GET_THREAD_INFO A12
 397         BNOP    .S2     syscall_exit,3
 398         MVK     .L2     0,B0
 399         STW     .D2T2   B0,*+SP(REGS_A4+8)
 400 ENDPROC(ret_from_fork)
 401
 402 ENTRY(ret_from_kernel_thread)
 403 #ifdef CONFIG_C6X_BIG_KERNEL
 404         MVKL    .S1     schedule_tail,A0
 405         MVKH    .S1     schedule_tail,A0
 406         B       .S2X    A0
 407 #else
 408         B       .S2     schedule_tail
 409 #endif
 410         LDW     .D2T2   *+SP(REGS_A0+8),B10 /* get fn  */
 411         ADDKPC  .S2     0f,B3,3
 412 0:
 413         B       .S2     B10                /* call fn */
 414         LDW     .D2T1   *+SP(REGS_A1+8),A4 /* get arg */
 415         ADDKPC  .S2     ret_from_fork_2,B3,3
 416 ENDPROC(ret_from_kernel_thread)
 417
 418         ;;
 419         ;; These are the interrupt handlers, responsible for calling c6x_do_IRQ()
 420         ;;
 421         .macro SAVE_ALL_INT
 422         SAVE_ALL IRP,ITSR
 423         .endm
 424
 425         .macro CALL_INT int
 426 #ifdef CONFIG_C6X_BIG_KERNEL
 427         MVKL    .S1     c6x_do_IRQ,A0
 428         MVKH    .S1     c6x_do_IRQ,A0
 429         BNOP    .S2X    A0,1
 430         MVK     .S1     int,A4
 431         ADDAW   .D2     SP,2,B4
 432         MVKL    .S2     ret_from_interrupt,B3
 433         MVKH    .S2     ret_from_interrupt,B3
 434 #else
 435         CALLP   .S2     c6x_do_IRQ,B3
 436  ||     MVK     .S1     int,A4
 437  ||     ADDAW   .D2     SP,2,B4
 438         B       .S1     ret_from_interrupt
 439         NOP     5
 440 #endif
 441         .endm
 442
 443 ENTRY(_int4_handler)
 444         SAVE_ALL_INT
 445         CALL_INT 4
 446 ENDPROC(_int4_handler)
 447
 448 ENTRY(_int5_handler)
 449         SAVE_ALL_INT
 450         CALL_INT 5
 451 ENDPROC(_int5_handler)
 452
 453 ENTRY(_int6_handler)
 454         SAVE_ALL_INT
 455         CALL_INT 6
 456 ENDPROC(_int6_handler)
 457
 458 ENTRY(_int7_handler)
 459         SAVE_ALL_INT
 460         CALL_INT 7
 461 ENDPROC(_int7_handler)
 462
 463 ENTRY(_int8_handler)
 464         SAVE_ALL_INT
 465         CALL_INT 8
 466 ENDPROC(_int8_handler)
 467
 468 ENTRY(_int9_handler)
 469         SAVE_ALL_INT
 470         CALL_INT 9
 471 ENDPROC(_int9_handler)
 472
 473 ENTRY(_int10_handler)
 474         SAVE_ALL_INT
 475         CALL_INT 10
 476 ENDPROC(_int10_handler)
 477
 478 ENTRY(_int11_handler)
 479         SAVE_ALL_INT
 480         CALL_INT 11
 481 ENDPROC(_int11_handler)
 482
 483 ENTRY(_int12_handler)
 484         SAVE_ALL_INT
 485         CALL_INT 12
 486 ENDPROC(_int12_handler)
 487
 488 ENTRY(_int13_handler)
 489         SAVE_ALL_INT
 490         CALL_INT 13
 491 ENDPROC(_int13_handler)
 492
 493 ENTRY(_int14_handler)
 494         SAVE_ALL_INT
 495         CALL_INT 14
 496 ENDPROC(_int14_handler)
 497
 498 ENTRY(_int15_handler)
 499         SAVE_ALL_INT
 500         CALL_INT 15
 501 ENDPROC(_int15_handler)
 502
 503         ;;
 504         ;; Handler for uninitialized and spurious interrupts
 505         ;;
 506 ENTRY(_bad_interrupt)
 507         B       .S2     IRP
 508         NOP     5
 509 ENDPROC(_bad_interrupt)
 510
 511         ;;
 512         ;; Entry for NMI/exceptions/syscall
 513         ;;
 514 ENTRY(_nmi_handler)
 515         SAVE_ALL NRP,NTSR
 516
 517         MVC     .S2     EFR,B2
 518         CMPEQ   .L2     1,B2,B2
 519  ||     MVC     .S2     TSR,B1
 520         CLR     .S2     B1,10,10,B1
 521         MVC     .S2     B1,TSR
 522 #ifdef CONFIG_C6X_BIG_KERNEL
 523  [!B2]  MVKL    .S1     process_exception,A0
 524  [!B2]  MVKH    .S1     process_exception,A0
 525  [!B2]  B       .S2X    A0
 526 #else
 527  [!B2]  B       .S2     process_exception
 528 #endif
 529  [B2]   B       .S2     system_call_saved
 530  [!B2]  ADDAW   .D2     SP,2,B1
 531  [!B2]  MV      .D1X    B1,A4
 532         ADDKPC  .S2     ret_from_trap,B3,2
 533
 534 ret_from_trap:
 535         MV      .D2X    A4,B0
 536  [!B0]  BNOP    .S2     ret_from_exception,5
 537
 538 #ifdef CONFIG_C6X_BIG_KERNEL
 539         MVKL    .S2     system_call_saved_noack,B3
 540         MVKH    .S2     system_call_saved_noack,B3
 541 #endif
 542         LDW     .D2T2   *+SP(REGS_B0+8),B0
 543         LDW     .D2T1   *+SP(REGS_A4+8),A4
 544         LDW     .D2T2   *+SP(REGS_B4+8),B4
 545         LDW     .D2T1   *+SP(REGS_A6+8),A6
 546         LDW     .D2T2   *+SP(REGS_B6+8),B6
 547         LDW     .D2T1   *+SP(REGS_A8+8),A8
 548 #ifdef CONFIG_C6X_BIG_KERNEL
 549  ||     B       .S2     B3
 550 #else
 551  ||     B       .S2     system_call_saved_noack
 552 #endif
 553         LDW     .D2T2   *+SP(REGS_B8+8),B8
 554         NOP     4
 555 ENDPROC(_nmi_handler)
 556
 557         ;;
 558         ;; Jump to schedule() then return to ret_from_isr
 559         ;;
 560 #ifdef  CONFIG_PREEMPT
 561 resume_kernel:
 562         GET_THREAD_INFO A12
 563         LDW     .D1T1   *+A12(THREAD_INFO_PREEMPT_COUNT),A1
 564         NOP     4
 565  [A1]   BNOP    .S2     restore_all,5
 566
 567 preempt_schedule:
 568         GET_THREAD_INFO A2
 569         LDW     .D1T1   *+A2(THREAD_INFO_FLAGS),A1
 570 #ifdef CONFIG_C6X_BIG_KERNEL
 571         MVKL    .S2     preempt_schedule_irq,B0
 572         MVKH    .S2     preempt_schedule_irq,B0
 573         NOP     2
 574 #else
 575         NOP     4
 576 #endif
 577         AND     .D1     _TIF_NEED_RESCHED,A1,A1
 578  [!A1]  BNOP    .S2     restore_all,5
 579 #ifdef CONFIG_C6X_BIG_KERNEL
 580         B       .S2     B0
 581 #else
 582         B       .S2     preempt_schedule_irq
 583 #endif
 584         ADDKPC  .S2     preempt_schedule,B3,4
 585 #endif /* CONFIG_PREEMPT */
 586
 587 ENTRY(enable_exception)
 588         DINT
 589         MVC     .S2     TSR,B0
 590         MVC     .S2     B3,NRP
 591         MVK     .L2     0xc,B1
 592         OR      .D2     B0,B1,B0
 593         MVC     .S2     B0,TSR                  ;  Set GEE and XEN in TSR
 594         B       .S2     NRP
 595         NOP     5
 596 ENDPROC(enable_exception)
 597
 598         ;;
 599         ;; Special system calls
 600         ;; return address is in B3
 601         ;;
 602 ENTRY(sys_rt_sigreturn)
 603         ADD     .D1X    SP,8,A4
 604 #ifdef CONFIG_C6X_BIG_KERNEL
 605  ||     MVKL    .S1     do_rt_sigreturn,A0
 606         MVKH    .S1     do_rt_sigreturn,A0
 607         BNOP    .S2X    A0,5
 608 #else
 609  ||     B       .S2     do_rt_sigreturn
 610         NOP     5
 611 #endif
 612 ENDPROC(sys_rt_sigreturn)
 613
 614 ENTRY(sys_pread_c6x)
 615         MV      .D2X    A8,B7
 616 #ifdef CONFIG_C6X_BIG_KERNEL
 617  ||     MVKL    .S1     sys_pread64,A0
 618         MVKH    .S1     sys_pread64,A0
 619         BNOP    .S2X    A0,5
 620 #else
 621  ||     B       .S2     sys_pread64
 622         NOP     5
 623 #endif
 624 ENDPROC(sys_pread_c6x)
 625
 626 ENTRY(sys_pwrite_c6x)
 627         MV      .D2X    A8,B7
 628 #ifdef CONFIG_C6X_BIG_KERNEL
 629  ||     MVKL    .S1     sys_pwrite64,A0
 630         MVKH    .S1     sys_pwrite64,A0
 631         BNOP    .S2X    A0,5
 632 #else
 633  ||     B       .S2     sys_pwrite64
 634         NOP     5
 635 #endif
 636 ENDPROC(sys_pwrite_c6x)
 637
 638 ;; On Entry
 639 ;;   A4 - path
 640 ;;   B4 - offset_lo (LE), offset_hi (BE)
 641 ;;   A6 - offset_lo (BE), offset_hi (LE)
 642 ENTRY(sys_truncate64_c6x)
 643 #ifdef CONFIG_CPU_BIG_ENDIAN
 644         MV      .S2     B4,B5
 645         MV      .D2X    A6,B4
 646 #else
 647         MV      .D2X    A6,B5
 648 #endif
 649 #ifdef CONFIG_C6X_BIG_KERNEL
 650  ||     MVKL    .S1     sys_truncate64,A0
 651         MVKH    .S1     sys_truncate64,A0
 652         BNOP    .S2X    A0,5
 653 #else
 654  ||     B       .S2     sys_truncate64
 655         NOP     5
 656 #endif
 657 ENDPROC(sys_truncate64_c6x)
 658
 659 ;; On Entry
 660 ;;   A4 - fd
 661 ;;   B4 - offset_lo (LE), offset_hi (BE)
 662 ;;   A6 - offset_lo (BE), offset_hi (LE)
 663 ENTRY(sys_ftruncate64_c6x)
 664 #ifdef CONFIG_CPU_BIG_ENDIAN
 665         MV      .S2     B4,B5
 666         MV      .D2X    A6,B4
 667 #else
 668         MV      .D2X    A6,B5
 669 #endif
 670 #ifdef CONFIG_C6X_BIG_KERNEL
 671  ||     MVKL    .S1     sys_ftruncate64,A0
 672         MVKH    .S1     sys_ftruncate64,A0
 673         BNOP    .S2X    A0,5
 674 #else
 675  ||     B       .S2     sys_ftruncate64
 676         NOP     5
 677 #endif
 678 ENDPROC(sys_ftruncate64_c6x)
 679
 680 ;; On Entry
 681 ;;   A4 - fd
 682 ;;   B4 - offset_lo (LE), offset_hi (BE)
 683 ;;   A6 - offset_lo (BE), offset_hi (LE)
 684 ;;   B6 - len_lo (LE), len_hi (BE)
 685 ;;   A8 - len_lo (BE), len_hi (LE)
 686 ;;   B8 - advice
 687 ENTRY(sys_fadvise64_64_c6x)
 688 #ifdef CONFIG_C6X_BIG_KERNEL
 689         MVKL    .S1     sys_fadvise64_64,A0
 690         MVKH    .S1     sys_fadvise64_64,A0
 691         BNOP    .S2X    A0,2
 692 #else
 693         B       .S2     sys_fadvise64_64
 694         NOP     2
 695 #endif
 696 #ifdef CONFIG_CPU_BIG_ENDIAN
 697         MV      .L2     B4,B5
 698  ||     MV      .D2X    A6,B4
 699         MV      .L1     A8,A6
 700  ||     MV      .D1X    B6,A7
 701 #else
 702         MV      .D2X    A6,B5
 703         MV      .L1     A8,A7
 704  ||     MV      .D1X    B6,A6
 705 #endif
 706         MV      .L2     B8,B6
 707 ENDPROC(sys_fadvise64_64_c6x)
 708
 709 ;; On Entry
 710 ;;   A4 - fd
 711 ;;   B4 - mode
 712 ;;   A6 - offset_hi
 713 ;;   B6 - offset_lo
 714 ;;   A8 - len_hi
 715 ;;   B8 - len_lo
 716 ENTRY(sys_fallocate_c6x)
 717 #ifdef CONFIG_C6X_BIG_KERNEL
 718         MVKL    .S1     sys_fallocate,A0
 719         MVKH    .S1     sys_fallocate,A0
 720         BNOP    .S2X    A0,1
 721 #else
 722         B       .S2     sys_fallocate
 723         NOP
 724 #endif
 725         MV      .D1     A6,A7
 726         MV      .D1X    B6,A6
 727         MV      .D2X    A8,B7
 728         MV      .D2     B8,B6
 729 ENDPROC(sys_fallocate_c6x)
 730
 731         ;; put this in .neardata for faster access when using DSBT mode
 732         .section .neardata,"aw",@progbits
 733         .global current_ksp
 734         .hidden current_ksp
 735 current_ksp:
 736         .word   init_thread_union + THREAD_START_SP