1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * S390 low-level entry points. 4 * 5 * Copyright IBM Corp. 1999, 2012 6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), 7 * Hartmut Penner (hp@de.ibm.com), 8 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), 9 */ 10 11#include <linux/export.h> 12#include <linux/init.h> 13#include <linux/linkage.h> 14#include <asm/asm-extable.h> 15#include <asm/alternative.h> 16#include <asm/processor.h> 17#include <asm/cache.h> 18#include <asm/dwarf.h> 19#include <asm/errno.h> 20#include <asm/ptrace.h> 21#include <asm/thread_info.h> 22#include <asm/asm-offsets.h> 23#include <asm/unistd.h> 24#include <asm/page.h> 25#include <asm/sigp.h> 26#include <asm/irq.h> 27#include <asm/fpu-insn.h> 28#include <asm/setup.h> 29#include <asm/nmi.h> 30#include <asm/nospec-insn.h> 31#include <asm/lowcore.h> 32 33_LPP_OFFSET = __LC_LPP 34 35 .macro STBEAR address 36 ALTERNATIVE "nop", ".insn s,0xb2010000,\address", ALT_FACILITY(193) 37 .endm 38 39 .macro LBEAR address 40 ALTERNATIVE "nop", ".insn s,0xb2000000,\address", ALT_FACILITY(193) 41 .endm 42 43 .macro LPSWEY address, lpswe 44 ALTERNATIVE_2 "b \lpswe;nopr", \ 45 ".insn siy,0xeb0000000071,\address,0", ALT_FACILITY(193), \ 46 __stringify(.insn siy,0xeb0000000071,LOWCORE_ALT_ADDRESS+\address,0), \ 47 ALT_LOWCORE 48 .endm 49 50 .macro MBEAR reg, lowcore 51 ALTERNATIVE "brcl 0,0", __stringify(mvc __PT_LAST_BREAK(8,\reg),__LC_LAST_BREAK(\lowcore)),\ 52 ALT_FACILITY(193) 53 .endm 54 55 .macro CHECK_STACK savearea, lowcore 56#ifdef CONFIG_CHECK_STACK 57 tml %r15,THREAD_SIZE - CONFIG_STACK_GUARD 58 la %r14,\savearea(\lowcore) 59 jz stack_overflow 60#endif 61 .endm 62 63 .macro CHECK_VMAP_STACK savearea, lowcore, oklabel 64#ifdef CONFIG_VMAP_STACK 65 lgr %r14,%r15 66 nill %r14,0x10000 - THREAD_SIZE 67 oill %r14,STACK_INIT_OFFSET 68 clg %r14,__LC_KERNEL_STACK(\lowcore) 69 je \oklabel 70 clg %r14,__LC_ASYNC_STACK(\lowcore) 71 je \oklabel 72 clg %r14,__LC_MCCK_STACK(\lowcore) 73 je \oklabel 74 clg %r14,__LC_NODAT_STACK(\lowcore) 75 je \oklabel 76 clg %r14,__LC_RESTART_STACK(\lowcore) 77 je \oklabel 78 la %r14,\savearea(\lowcore) 79 j stack_overflow 80#else 81 j \oklabel 82#endif 83 .endm 84 85 /* 86 * The TSTMSK macro generates a test-under-mask instruction by 87 * calculating the memory offset for the specified mask value. 88 * Mask value can be any constant. The macro shifts the mask 89 * value to calculate the memory offset for the test-under-mask 90 * instruction. 91 */ 92 .macro TSTMSK addr, mask, size=8, bytepos=0 93 .if (\bytepos < \size) && (\mask >> 8) 94 .if (\mask & 0xff) 95 .error "Mask exceeds byte boundary" 96 .endif 97 TSTMSK \addr, "(\mask >> 8)", \size, "(\bytepos + 1)" 98 .exitm 99 .endif 100 .ifeq \mask 101 .error "Mask must not be zero" 102 .endif 103 off = \size - \bytepos - 1 104 tm off+\addr, \mask 105 .endm 106 107 .macro BPOFF 108 ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,12,0", ALT_SPEC(82) 109 .endm 110 111 .macro BPON 112 ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,13,0", ALT_SPEC(82) 113 .endm 114 115 .macro BPENTER tif_ptr,tif_mask 116 ALTERNATIVE "TSTMSK \tif_ptr,\tif_mask; jz .+8; .insn rrf,0xb2e80000,0,0,13,0", \ 117 "j .+12; nop; nop", ALT_SPEC(82) 118 .endm 119 120 .macro BPEXIT tif_ptr,tif_mask 121 TSTMSK \tif_ptr,\tif_mask 122 ALTERNATIVE "jz .+8; .insn rrf,0xb2e80000,0,0,12,0", \ 123 "jnz .+8; .insn rrf,0xb2e80000,0,0,13,0", ALT_SPEC(82) 124 .endm 125 126#if IS_ENABLED(CONFIG_KVM) 127 .macro SIEEXIT sie_control,lowcore 128 lg %r9,\sie_control # get control block pointer 129 ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE 130 lctlg %c1,%c1,__LC_KERNEL_ASCE(\lowcore) # load primary asce 131 lg %r9,__LC_CURRENT(\lowcore) 132 mvi __TI_sie(%r9),0 133 larl %r9,sie_exit # skip forward to sie_exit 134 .endm 135#endif 136 137 .macro STACKLEAK_ERASE 138#ifdef CONFIG_GCC_PLUGIN_STACKLEAK 139 brasl %r14,stackleak_erase_on_task_stack 140#endif 141 .endm 142 143 GEN_BR_THUNK %r14 144 145 .section .kprobes.text, "ax" 146.Ldummy: 147 /* 148 * The following nop exists only in order to avoid that the next 149 * symbol starts at the beginning of the kprobes text section. 150 * In that case there would be several symbols at the same address. 151 * E.g. objdump would take an arbitrary symbol when disassembling 152 * the code. 153 * With the added nop in between this cannot happen. 154 */ 155 nop 0 156 157/* 158 * Scheduler resume function, called by __switch_to 159 * gpr2 = (task_struct *)prev 160 * gpr3 = (task_struct *)next 161 * Returns: 162 * gpr2 = prev 163 */ 164SYM_FUNC_START(__switch_to_asm) 165 stmg %r6,%r15,__SF_GPRS(%r15) # store gprs of prev task 166 lghi %r4,__TASK_stack 167 lghi %r1,__TASK_thread 168 llill %r5,STACK_INIT_OFFSET 169 stg %r15,__THREAD_ksp(%r1,%r2) # store kernel stack of prev 170 lg %r15,0(%r4,%r3) # start of kernel stack of next 171 agr %r15,%r5 # end of kernel stack of next 172 GET_LC %r13 173 stg %r3,__LC_CURRENT(%r13) # store task struct of next 174 stg %r15,__LC_KERNEL_STACK(%r13) # store end of kernel stack 175 lg %r15,__THREAD_ksp(%r1,%r3) # load kernel stack of next 176 aghi %r3,__TASK_pid 177 mvc __LC_CURRENT_PID(4,%r13),0(%r3) # store pid of next 178 ALTERNATIVE "nop", "lpp _LPP_OFFSET(%r13)", ALT_FACILITY(40) 179 lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task 180 BR_EX %r14 181SYM_FUNC_END(__switch_to_asm) 182 183#if IS_ENABLED(CONFIG_KVM) 184/* 185 * __sie64a calling convention: 186 * %r2 pointer to sie control block phys 187 * %r3 pointer to sie control block virt 188 * %r4 guest register save area 189 * %r5 guest asce 190 */ 191SYM_FUNC_START(__sie64a) 192 stmg %r6,%r14,__SF_GPRS(%r15) # save kernel registers 193 GET_LC %r13 194 lg %r14,__LC_CURRENT(%r13) 195 stg %r2,__SF_SIE_CONTROL_PHYS(%r15) # save sie block physical.. 196 stg %r3,__SF_SIE_CONTROL(%r15) # ...and virtual addresses 197 stg %r4,__SF_SIE_SAVEAREA(%r15) # save guest register save area 198 stg %r5,__SF_SIE_GUEST_ASCE(%r15) # save guest asce 199 xc __SF_SIE_REASON(8,%r15),__SF_SIE_REASON(%r15) # reason code = 0 200 mvc __SF_SIE_FLAGS(8,%r15),__TI_flags(%r14) # copy thread flags 201 lmg %r0,%r13,0(%r4) # load guest gprs 0-13 202 mvi __TI_sie(%r14),1 203 lctlg %c1,%c1,__SF_SIE_GUEST_ASCE(%r15) # load primary asce 204 lg %r14,__SF_SIE_CONTROL(%r15) # get control block pointer 205 oi __SIE_PROG0C+3(%r14),1 # we are going into SIE now 206 tm __SIE_PROG20+3(%r14),3 # last exit... 207 jnz .Lsie_skip 208 lg %r14,__SF_SIE_CONTROL_PHYS(%r15) # get sie block phys addr 209 BPEXIT __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST 210.Lsie_entry: 211 sie 0(%r14) 212# Let the next instruction be NOP to avoid triggering a machine check 213# and handling it in a guest as result of the instruction execution. 214 nopr 7 215.Lsie_leave: 216 BPOFF 217 BPENTER __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST 218.Lsie_skip: 219 lg %r14,__SF_SIE_CONTROL(%r15) # get control block pointer 220 ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE 221 GET_LC %r14 222 lctlg %c1,%c1,__LC_KERNEL_ASCE(%r14) # load primary asce 223 lg %r14,__LC_CURRENT(%r14) 224 mvi __TI_sie(%r14),0 225SYM_INNER_LABEL(sie_exit, SYM_L_GLOBAL) 226 lg %r14,__SF_SIE_SAVEAREA(%r15) # load guest register save area 227 stmg %r0,%r13,0(%r14) # save guest gprs 0-13 228 xgr %r0,%r0 # clear guest registers to 229 xgr %r1,%r1 # prevent speculative use 230 xgr %r3,%r3 231 xgr %r4,%r4 232 xgr %r5,%r5 233 lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers 234 lg %r2,__SF_SIE_REASON(%r15) # return exit reason code 235 BR_EX %r14 236SYM_FUNC_END(__sie64a) 237EXPORT_SYMBOL(__sie64a) 238EXPORT_SYMBOL(sie_exit) 239#endif 240 241/* 242 * SVC interrupt handler routine. System calls are synchronous events and 243 * are entered with interrupts disabled. 244 */ 245 246SYM_CODE_START(system_call) 247 STMG_LC %r8,%r15,__LC_SAVE_AREA 248 GET_LC %r13 249 stpt __LC_SYS_ENTER_TIMER(%r13) 250 BPOFF 251 lghi %r14,0 252.Lsysc_per: 253 STBEAR __LC_LAST_BREAK(%r13) 254 lctlg %c1,%c1,__LC_KERNEL_ASCE(%r13) 255 lg %r15,__LC_KERNEL_STACK(%r13) 256 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 257 stmg %r0,%r7,STACK_FRAME_OVERHEAD+__PT_R0(%r15) 258 # clear user controlled register to prevent speculative use 259 xgr %r0,%r0 260 xgr %r1,%r1 261 xgr %r4,%r4 262 xgr %r5,%r5 263 xgr %r6,%r6 264 xgr %r7,%r7 265 xgr %r8,%r8 266 xgr %r9,%r9 267 xgr %r10,%r10 268 xgr %r11,%r11 269 la %r2,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs 270 mvc __PT_R8(64,%r2),__LC_SAVE_AREA(%r13) 271 MBEAR %r2,%r13 272 lgr %r3,%r14 273 brasl %r14,__do_syscall 274 STACKLEAK_ERASE 275 lctlg %c1,%c1,__LC_USER_ASCE(%r13) 276 mvc __LC_RETURN_PSW(16,%r13),STACK_FRAME_OVERHEAD+__PT_PSW(%r15) 277 BPON 278 LBEAR STACK_FRAME_OVERHEAD+__PT_LAST_BREAK(%r15) 279 stpt __LC_EXIT_TIMER(%r13) 280 lmg %r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15) 281 LPSWEY __LC_RETURN_PSW,__LC_RETURN_LPSWE 282SYM_CODE_END(system_call) 283 284# 285# a new process exits the kernel with ret_from_fork 286# 287SYM_CODE_START(ret_from_fork) 288 lgr %r3,%r11 289 brasl %r14,__ret_from_fork 290 STACKLEAK_ERASE 291 GET_LC %r13 292 lctlg %c1,%c1,__LC_USER_ASCE(%r13) 293 mvc __LC_RETURN_PSW(16,%r13),STACK_FRAME_OVERHEAD+__PT_PSW(%r15) 294 BPON 295 LBEAR STACK_FRAME_OVERHEAD+__PT_LAST_BREAK(%r15) 296 stpt __LC_EXIT_TIMER(%r13) 297 lmg %r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15) 298 LPSWEY __LC_RETURN_PSW,__LC_RETURN_LPSWE 299SYM_CODE_END(ret_from_fork) 300 301/* 302 * Program check handler routine 303 */ 304 305SYM_CODE_START(pgm_check_handler) 306 STMG_LC %r8,%r15,__LC_SAVE_AREA 307 GET_LC %r13 308 stpt __LC_SYS_ENTER_TIMER(%r13) 309 BPOFF 310 lmg %r8,%r9,__LC_PGM_OLD_PSW(%r13) 311 xgr %r10,%r10 312 tmhh %r8,0x0001 # coming from user space? 313 jno .Lpgm_skip_asce 314 lctlg %c1,%c1,__LC_KERNEL_ASCE(%r13) 315 j 3f # -> fault in user space 316.Lpgm_skip_asce: 317#if IS_ENABLED(CONFIG_KVM) 318 lg %r11,__LC_CURRENT(%r13) 319 tm __TI_sie(%r11),0xff 320 jz 1f 321 BPENTER __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST 322 SIEEXIT __SF_SIE_CONTROL(%r15),%r13 323 lghi %r10,_PIF_GUEST_FAULT 324#endif 3251: tmhh %r8,0x4000 # PER bit set in old PSW ? 326 jnz 2f # -> enabled, can't be a double fault 327 tm __LC_PGM_ILC+3(%r13),0x80 # check for per exception 328 jnz .Lpgm_svcper # -> single stepped svc 3292: CHECK_STACK __LC_SAVE_AREA,%r13 330 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 331 # CHECK_VMAP_STACK branches to stack_overflow or 4f 332 CHECK_VMAP_STACK __LC_SAVE_AREA,%r13,4f 3333: lg %r15,__LC_KERNEL_STACK(%r13) 3344: la %r11,STACK_FRAME_OVERHEAD(%r15) 335 stg %r10,__PT_FLAGS(%r11) 336 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 337 stmg %r0,%r7,__PT_R0(%r11) 338 mvc __PT_R8(64,%r11),__LC_SAVE_AREA(%r13) 339 mvc __PT_LAST_BREAK(8,%r11),__LC_PGM_LAST_BREAK(%r13) 340 stmg %r8,%r9,__PT_PSW(%r11) 341 # clear user controlled registers to prevent speculative use 342 xgr %r0,%r0 343 xgr %r1,%r1 344 xgr %r3,%r3 345 xgr %r4,%r4 346 xgr %r5,%r5 347 xgr %r6,%r6 348 xgr %r7,%r7 349 xgr %r12,%r12 350 lgr %r2,%r11 351 brasl %r14,__do_pgm_check 352 tmhh %r8,0x0001 # returning to user space? 353 jno .Lpgm_exit_kernel 354 STACKLEAK_ERASE 355 lctlg %c1,%c1,__LC_USER_ASCE(%r13) 356 BPON 357 stpt __LC_EXIT_TIMER(%r13) 358.Lpgm_exit_kernel: 359 mvc __LC_RETURN_PSW(16,%r13),STACK_FRAME_OVERHEAD+__PT_PSW(%r15) 360 LBEAR STACK_FRAME_OVERHEAD+__PT_LAST_BREAK(%r15) 361 lmg %r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15) 362 LPSWEY __LC_RETURN_PSW,__LC_RETURN_LPSWE 363 364# 365# single stepped system call 366# 367.Lpgm_svcper: 368 mvc __LC_RETURN_PSW(8,%r13),__LC_SVC_NEW_PSW(%r13) 369 larl %r14,.Lsysc_per 370 stg %r14,__LC_RETURN_PSW+8(%r13) 371 lghi %r14,1 372 LBEAR __LC_PGM_LAST_BREAK(%r13) 373 LPSWEY __LC_RETURN_PSW,__LC_RETURN_LPSWE # branch to .Lsysc_per 374SYM_CODE_END(pgm_check_handler) 375 376/* 377 * Interrupt handler macro used for external and IO interrupts. 378 */ 379.macro INT_HANDLER name,lc_old_psw,handler 380SYM_CODE_START(\name) 381 STMG_LC %r8,%r15,__LC_SAVE_AREA 382 GET_LC %r13 383 stckf __LC_INT_CLOCK(%r13) 384 stpt __LC_SYS_ENTER_TIMER(%r13) 385 STBEAR __LC_LAST_BREAK(%r13) 386 BPOFF 387 lmg %r8,%r9,\lc_old_psw(%r13) 388 tmhh %r8,0x0001 # interrupting from user ? 389 jnz 1f 390#if IS_ENABLED(CONFIG_KVM) 391 lg %r10,__LC_CURRENT(%r13) 392 tm __TI_sie(%r10),0xff 393 jz 0f 394 BPENTER __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST 395 SIEEXIT __SF_SIE_CONTROL(%r15),%r13 396#endif 3970: CHECK_STACK __LC_SAVE_AREA,%r13 398 aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) 399 j 2f 4001: lctlg %c1,%c1,__LC_KERNEL_ASCE(%r13) 401 lg %r15,__LC_KERNEL_STACK(%r13) 4022: xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 403 la %r11,STACK_FRAME_OVERHEAD(%r15) 404 stmg %r0,%r7,__PT_R0(%r11) 405 # clear user controlled registers to prevent speculative use 406 xgr %r0,%r0 407 xgr %r1,%r1 408 xgr %r3,%r3 409 xgr %r4,%r4 410 xgr %r5,%r5 411 xgr %r6,%r6 412 xgr %r7,%r7 413 xgr %r10,%r10 414 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) 415 mvc __PT_R8(64,%r11),__LC_SAVE_AREA(%r13) 416 MBEAR %r11,%r13 417 stmg %r8,%r9,__PT_PSW(%r11) 418 lgr %r2,%r11 # pass pointer to pt_regs 419 brasl %r14,\handler 420 mvc __LC_RETURN_PSW(16,%r13),__PT_PSW(%r11) 421 tmhh %r8,0x0001 # returning to user ? 422 jno 2f 423 STACKLEAK_ERASE 424 lctlg %c1,%c1,__LC_USER_ASCE(%r13) 425 BPON 426 stpt __LC_EXIT_TIMER(%r13) 4272: LBEAR __PT_LAST_BREAK(%r11) 428 lmg %r0,%r15,__PT_R0(%r11) 429 LPSWEY __LC_RETURN_PSW,__LC_RETURN_LPSWE 430SYM_CODE_END(\name) 431.endm 432 433 .section .irqentry.text, "ax" 434 435INT_HANDLER ext_int_handler,__LC_EXT_OLD_PSW,do_ext_irq 436INT_HANDLER io_int_handler,__LC_IO_OLD_PSW,do_io_irq 437 438 .section .kprobes.text, "ax" 439 440/* 441 * Machine check handler routines 442 */ 443SYM_CODE_START(mcck_int_handler) 444 BPOFF 445 GET_LC %r13 446 lmg %r8,%r9,__LC_MCK_OLD_PSW(%r13) 447 TSTMSK __LC_MCCK_CODE(%r13),MCCK_CODE_SYSTEM_DAMAGE 448 jo .Lmcck_panic # yes -> rest of mcck code invalid 449 TSTMSK __LC_MCCK_CODE(%r13),MCCK_CODE_CR_VALID 450 jno .Lmcck_panic # control registers invalid -> panic 451 ptlb 452 lay %r14,__LC_CPU_TIMER_SAVE_AREA(%r13) 453 mvc __LC_MCCK_ENTER_TIMER(8,%r13),0(%r14) 454 TSTMSK __LC_MCCK_CODE(%r13),MCCK_CODE_CPU_TIMER_VALID 455 jo 3f 456 la %r14,__LC_SYS_ENTER_TIMER(%r13) 457 clc 0(8,%r14),__LC_EXIT_TIMER(%r13) 458 jl 1f 459 la %r14,__LC_EXIT_TIMER(%r13) 4601: clc 0(8,%r14),__LC_LAST_UPDATE_TIMER(%r13) 461 jl 2f 462 la %r14,__LC_LAST_UPDATE_TIMER(%r13) 4632: spt 0(%r14) 464 mvc __LC_MCCK_ENTER_TIMER(8,%r13),0(%r14) 4653: TSTMSK __LC_MCCK_CODE(%r13),MCCK_CODE_PSW_MWP_VALID 466 jno .Lmcck_panic 467 tmhh %r8,0x0001 # interrupting from user ? 468 jnz .Lmcck_user 469 TSTMSK __LC_MCCK_CODE(%r13),MCCK_CODE_PSW_IA_VALID 470 jno .Lmcck_panic 471#if IS_ENABLED(CONFIG_KVM) 472 lg %r10,__LC_CURRENT(%r13) 473 tm __TI_sie(%r10),0xff 474 jz .Lmcck_user 475 # Need to compare the address instead of __TI_SIE flag. 476 # Otherwise there would be a race between setting the flag 477 # and entering SIE (or leaving and clearing the flag). This 478 # would cause machine checks targeted at the guest to be 479 # handled by the host. 480 larl %r14,.Lsie_entry 481 clgrjl %r9,%r14, 4f 482 larl %r14,.Lsie_leave 483 clgrjhe %r9,%r14, 4f 484 lg %r10,__LC_PCPU 485 oi __PCPU_FLAGS+7(%r10), _CIF_MCCK_GUEST 4864: BPENTER __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST 487 SIEEXIT __SF_SIE_CONTROL(%r15),%r13 488#endif 489.Lmcck_user: 490 lg %r15,__LC_MCCK_STACK(%r13) 491 la %r11,STACK_FRAME_OVERHEAD(%r15) 492 stctg %c1,%c1,__PT_CR1(%r11) 493 lctlg %c1,%c1,__LC_KERNEL_ASCE(%r13) 494 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 495 lay %r14,__LC_GPREGS_SAVE_AREA(%r13) 496 mvc __PT_R0(128,%r11),0(%r14) 497 # clear user controlled registers to prevent speculative use 498 xgr %r0,%r0 499 xgr %r1,%r1 500 xgr %r3,%r3 501 xgr %r4,%r4 502 xgr %r5,%r5 503 xgr %r6,%r6 504 xgr %r7,%r7 505 xgr %r10,%r10 506 stmg %r8,%r9,__PT_PSW(%r11) 507 xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) 508 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 509 lgr %r2,%r11 # pass pointer to pt_regs 510 brasl %r14,s390_do_machine_check 511 lctlg %c1,%c1,__PT_CR1(%r11) 512 lmg %r0,%r10,__PT_R0(%r11) 513 mvc __LC_RETURN_MCCK_PSW(16,%r13),__PT_PSW(%r11) # move return PSW 514 tm __LC_RETURN_MCCK_PSW+1(%r13),0x01 # returning to user ? 515 jno 0f 516 BPON 517 stpt __LC_EXIT_TIMER(%r13) 5180: ALTERNATIVE "brcl 0,0", __stringify(lay %r12,__LC_LAST_BREAK_SAVE_AREA(%r13)),\ 519 ALT_FACILITY(193) 520 LBEAR 0(%r12) 521 lmg %r11,%r15,__PT_R11(%r11) 522 LPSWEY __LC_RETURN_MCCK_PSW,__LC_RETURN_MCCK_LPSWE 523 524.Lmcck_panic: 525 /* 526 * Iterate over all possible CPU addresses in the range 0..0xffff 527 * and stop each CPU using signal processor. Use compare and swap 528 * to allow just one CPU-stopper and prevent concurrent CPUs from 529 * stopping each other while leaving the others running. 530 */ 531 lhi %r5,0 532 lhi %r6,1 533 larl %r7,stop_lock 534 cs %r5,%r6,0(%r7) # single CPU-stopper only 535 jnz 4f 536 larl %r7,this_cpu 537 stap 0(%r7) # this CPU address 538 lh %r4,0(%r7) 539 nilh %r4,0 540 lhi %r0,1 541 sll %r0,16 # CPU counter 542 lhi %r3,0 # next CPU address 5430: cr %r3,%r4 544 je 2f 5451: sigp %r1,%r3,SIGP_STOP # stop next CPU 546 brc SIGP_CC_BUSY,1b 5472: ahi %r3,1 548 brct %r0,0b 5493: sigp %r1,%r4,SIGP_STOP # stop this CPU 550 brc SIGP_CC_BUSY,3b 5514: j 4b 552SYM_CODE_END(mcck_int_handler) 553 554SYM_CODE_START(restart_int_handler) 555 ALTERNATIVE "nop", "lpp _LPP_OFFSET", ALT_FACILITY(40) 556 stg %r15,__LC_SAVE_AREA_RESTART 557 TSTMSK __LC_RESTART_FLAGS,RESTART_FLAG_CTLREGS,4 558 jz 0f 559 lctlg %c0,%c15,__LC_CREGS_SAVE_AREA 5600: larl %r15,daton_psw 561 lpswe 0(%r15) # turn dat on, keep irqs off 562.Ldaton: 563 GET_LC %r15 564 lg %r15,__LC_RESTART_STACK(%r15) 565 xc STACK_FRAME_OVERHEAD(__PT_SIZE,%r15),STACK_FRAME_OVERHEAD(%r15) 566 stmg %r0,%r14,STACK_FRAME_OVERHEAD+__PT_R0(%r15) 567 GET_LC %r13 568 mvc STACK_FRAME_OVERHEAD+__PT_R15(8,%r15),__LC_SAVE_AREA_RESTART(%r13) 569 mvc STACK_FRAME_OVERHEAD+__PT_PSW(16,%r15),__LC_RST_OLD_PSW(%r13) 570 xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15) 571 lg %r1,__LC_RESTART_FN(%r13) # load fn, parm & source cpu 572 lg %r2,__LC_RESTART_DATA(%r13) 573 lgf %r3,__LC_RESTART_SOURCE(%r13) 574 ltgr %r3,%r3 # test source cpu address 575 jm 1f # negative -> skip source stop 5760: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu 577 brc 10,0b # wait for status stored 5781: basr %r14,%r1 # call function 579 stap __SF_EMPTY(%r15) # store cpu address 580 llgh %r3,__SF_EMPTY(%r15) 5812: sigp %r4,%r3,SIGP_STOP # sigp stop to current cpu 582 brc 2,2b 5833: j 3b 584SYM_CODE_END(restart_int_handler) 585 586 __INIT 587SYM_CODE_START(early_pgm_check_handler) 588 STMG_LC %r8,%r15,__LC_SAVE_AREA 589 GET_LC %r13 590 aghi %r15,-(STACK_FRAME_OVERHEAD+__PT_SIZE) 591 la %r11,STACK_FRAME_OVERHEAD(%r15) 592 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 593 stmg %r0,%r7,__PT_R0(%r11) 594 mvc __PT_PSW(16,%r11),__LC_PGM_OLD_PSW(%r13) 595 mvc __PT_R8(64,%r11),__LC_SAVE_AREA(%r13) 596 lgr %r2,%r11 597 brasl %r14,__do_early_pgm_check 598 mvc __LC_RETURN_PSW(16,%r13),STACK_FRAME_OVERHEAD+__PT_PSW(%r15) 599 lmg %r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15) 600 LPSWEY __LC_RETURN_PSW,__LC_RETURN_LPSWE 601SYM_CODE_END(early_pgm_check_handler) 602 __FINIT 603 604 .section .kprobes.text, "ax" 605 606#if defined(CONFIG_CHECK_STACK) || defined(CONFIG_VMAP_STACK) 607/* 608 * The synchronous or the asynchronous stack overflowed. We are dead. 609 * No need to properly save the registers, we are going to panic anyway. 610 * Setup a pt_regs so that show_trace can provide a good call trace. 611 */ 612SYM_CODE_START(stack_overflow) 613 GET_LC %r15 614 lg %r15,__LC_NODAT_STACK(%r15) # change to panic stack 615 la %r11,STACK_FRAME_OVERHEAD(%r15) 616 stmg %r0,%r7,__PT_R0(%r11) 617 stmg %r8,%r9,__PT_PSW(%r11) 618 mvc __PT_R8(64,%r11),0(%r14) 619 stg %r10,__PT_ORIG_GPR2(%r11) # store last break to orig_gpr2 620 xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) 621 lgr %r2,%r11 # pass pointer to pt_regs 622 jg kernel_stack_overflow 623SYM_CODE_END(stack_overflow) 624#endif 625 626 .section .data, "aw" 627 .balign 4 628SYM_DATA_LOCAL(stop_lock, .long 0) 629SYM_DATA_LOCAL(this_cpu, .short 0) 630 .balign 8 631SYM_DATA_START_LOCAL(daton_psw) 632 .quad PSW_KERNEL_BITS 633 .quad .Ldaton 634SYM_DATA_END(daton_psw) 635 636 .section .rodata, "a" 637 .balign 8 638#define SYSCALL(esame,emu) .quad __s390x_ ## esame 639SYM_DATA_START(sys_call_table) 640#include "asm/syscall_table.h" 641SYM_DATA_END(sys_call_table) 642#undef SYSCALL 643 644#ifdef CONFIG_COMPAT 645 646#define SYSCALL(esame,emu) .quad __s390_ ## emu 647SYM_DATA_START(sys_call_table_emu) 648#include "asm/syscall_table.h" 649SYM_DATA_END(sys_call_table_emu) 650#undef SYSCALL 651#endif 652