projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 9994a338 | 1 | /* |
| 9994a338 PM |
2 | * PowerPC version |
| 3 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) | |
| 4 | * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP | |
| 5 | * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu> | |
| 6 | * Adapted for Power Macintosh by Paul Mackerras. | |
| 7 | * Low-level exception handlers and MMU support | |
| 8 | * rewritten by Paul Mackerras. | |
| 9 | * Copyright (C) 1996 Paul Mackerras. | |
| 10 | * MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net). | |
| 11 | * | |
| 12 | * This file contains the system call entry code, context switch | |
| 13 | * code, and exception/interrupt return code for PowerPC. | |
| 14 | * | |
| 15 | * This program is free software; you can redistribute it and/or | |
| 16 | * modify it under the terms of the GNU General Public License | |
| 17 | * as published by the Free Software Foundation; either version | |
| 18 | * 2 of the License, or (at your option) any later version. | |
| 19 | */ | |
| 20 | ||
| 9994a338 PM |
21 | #include <linux/errno.h> |
| 22 | #include <asm/unistd.h> | |
| 23 | #include <asm/processor.h> | |
| 24 | #include <asm/page.h> | |
| 25 | #include <asm/mmu.h> | |
| 26 | #include <asm/thread_info.h> | |
| 27 | #include <asm/ppc_asm.h> | |
| 28 | #include <asm/asm-offsets.h> | |
| 29 | #include <asm/cputable.h> | |
| 30 | ||
| 31 | #ifdef CONFIG_PPC_ISERIES | |
| 32 | #define DO_SOFT_DISABLE | |
| 33 | #endif | |
| 34 | ||
| 35 | /* | |
| 36 | * System calls. | |
| 37 | */ | |
| 38 | .section ".toc","aw" | |
| 39 | .SYS_CALL_TABLE: | |
| 40 | .tc .sys_call_table[TC],.sys_call_table | |
| 41 | ||
| 42 | /* This value is used to mark exception frames on the stack. */ | |
| 43 | exception_marker: | |
| 44 | .tc ID_72656773_68657265[TC],0x7265677368657265 | |
| 45 | ||
| 46 | .section ".text" | |
| 47 | .align 7 | |
| 48 | ||
| 49 | #undef SHOW_SYSCALLS | |
| 50 | ||
| 51 | .globl system_call_common | |
| 52 | system_call_common: | |
| 53 | andi. r10,r12,MSR_PR | |
| 54 | mr r10,r1 | |
| 55 | addi r1,r1,-INT_FRAME_SIZE | |
| 56 | beq- 1f | |
| 57 | ld r1,PACAKSAVE(r13) | |
| 58 | 1: std r10,0(r1) | |
| bd19c899 | 59 | crclr so |
| 9994a338 PM |
60 | std r11,_NIP(r1) |
| 61 | std r12,_MSR(r1) | |
| 62 | std r0,GPR0(r1) | |
| 63 | std r10,GPR1(r1) | |
| c6622f63 | 64 | ACCOUNT_CPU_USER_ENTRY(r10, r11) |
| 9994a338 PM |
65 | std r2,GPR2(r1) |
| 66 | std r3,GPR3(r1) | |
| 67 | std r4,GPR4(r1) | |
| 68 | std r5,GPR5(r1) | |
| 69 | std r6,GPR6(r1) | |
| 70 | std r7,GPR7(r1) | |
| 71 | std r8,GPR8(r1) | |
| 72 | li r11,0 | |
| 73 | std r11,GPR9(r1) | |
| 74 | std r11,GPR10(r1) | |
| 75 | std r11,GPR11(r1) | |
| 76 | std r11,GPR12(r1) | |
| 77 | std r9,GPR13(r1) | |
| 9994a338 PM |
78 | mfcr r9 |
| 79 | mflr r10 | |
| 80 | li r11,0xc01 | |
| 81 | std r9,_CCR(r1) | |
| 82 | std r10,_LINK(r1) | |
| 83 | std r11,_TRAP(r1) | |
| 84 | mfxer r9 | |
| 85 | mfctr r10 | |
| 86 | std r9,_XER(r1) | |
| 87 | std r10,_CTR(r1) | |
| 88 | std r3,ORIG_GPR3(r1) | |
| 89 | ld r2,PACATOC(r13) | |
| 90 | addi r9,r1,STACK_FRAME_OVERHEAD | |
| 91 | ld r11,exception_marker@toc(r2) | |
| 92 | std r11,-16(r9) /* "regshere" marker */ | |
| 93 | #ifdef CONFIG_PPC_ISERIES | |
| 94 | /* Hack for handling interrupts when soft-enabling on iSeries */ | |
| 95 | cmpdi cr1,r0,0x5555 /* syscall 0x5555 */ | |
| 96 | andi. r10,r12,MSR_PR /* from kernel */ | |
| 97 | crand 4*cr0+eq,4*cr1+eq,4*cr0+eq | |
| 98 | beq hardware_interrupt_entry | |
| 99 | lbz r10,PACAPROCENABLED(r13) | |
| 100 | std r10,SOFTE(r1) | |
| 101 | #endif | |
| 102 | mfmsr r11 | |
| 103 | ori r11,r11,MSR_EE | |
| 104 | mtmsrd r11,1 | |
| 105 | ||
| 106 | #ifdef SHOW_SYSCALLS | |
| 107 | bl .do_show_syscall | |
| 108 | REST_GPR(0,r1) | |
| 109 | REST_4GPRS(3,r1) | |
| 110 | REST_2GPRS(7,r1) | |
| 111 | addi r9,r1,STACK_FRAME_OVERHEAD | |
| 112 | #endif | |
| 113 | clrrdi r11,r1,THREAD_SHIFT | |
| 9994a338 | 114 | ld r10,TI_FLAGS(r11) |
| 9994a338 PM |
115 | andi. r11,r10,_TIF_SYSCALL_T_OR_A |
| 116 | bne- syscall_dotrace | |
| 117 | syscall_dotrace_cont: | |
| 118 | cmpldi 0,r0,NR_syscalls | |
| 119 | bge- syscall_enosys | |
| 120 | ||
| 121 | system_call: /* label this so stack traces look sane */ | |
| 122 | /* | |
| 123 | * Need to vector to 32 Bit or default sys_call_table here, | |
| 124 | * based on caller's run-mode / personality. | |
| 125 | */ | |
| 126 | ld r11,.SYS_CALL_TABLE@toc(2) | |
| 127 | andi. r10,r10,_TIF_32BIT | |
| 128 | beq 15f | |
| 129 | addi r11,r11,8 /* use 32-bit syscall entries */ | |
| 130 | clrldi r3,r3,32 | |
| 131 | clrldi r4,r4,32 | |
| 132 | clrldi r5,r5,32 | |
| 133 | clrldi r6,r6,32 | |
| 134 | clrldi r7,r7,32 | |
| 135 | clrldi r8,r8,32 | |
| 136 | 15: | |
| 137 | slwi r0,r0,4 | |
| 138 | ldx r10,r11,r0 /* Fetch system call handler [ptr] */ | |
| 139 | mtctr r10 | |
| 140 | bctrl /* Call handler */ | |
| 141 | ||
| 142 | syscall_exit: | |
| 401d1f02 | 143 | std r3,RESULT(r1) |
| 9994a338 | 144 | #ifdef SHOW_SYSCALLS |
| 9994a338 | 145 | bl .do_show_syscall_exit |
| 401d1f02 | 146 | ld r3,RESULT(r1) |
| 9994a338 | 147 | #endif |
| 9994a338 | 148 | clrrdi r12,r1,THREAD_SHIFT |
| 9994a338 PM |
149 | |
| 150 | /* disable interrupts so current_thread_info()->flags can't change, | |
| 151 | and so that we don't get interrupted after loading SRR0/1. */ | |
| 152 | ld r8,_MSR(r1) | |
| 153 | andi. r10,r8,MSR_RI | |
| 154 | beq- unrecov_restore | |
| 155 | mfmsr r10 | |
| 156 | rldicl r10,r10,48,1 | |
| 157 | rotldi r10,r10,16 | |
| 158 | mtmsrd r10,1 | |
| 159 | ld r9,TI_FLAGS(r12) | |
| 401d1f02 | 160 | li r11,-_LAST_ERRNO |
| 1bd79336 | 161 | andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK) |
| 9994a338 | 162 | bne- syscall_exit_work |
| 401d1f02 DW |
163 | cmpld r3,r11 |
| 164 | ld r5,_CCR(r1) | |
| 165 | bge- syscall_error | |
| 166 | syscall_error_cont: | |
| 9994a338 PM |
167 | ld r7,_NIP(r1) |
| 168 | stdcx. r0,0,r1 /* to clear the reservation */ | |
| 169 | andi. r6,r8,MSR_PR | |
| 170 | ld r4,_LINK(r1) | |
| c6622f63 PM |
171 | beq- 1f |
| 172 | ACCOUNT_CPU_USER_EXIT(r11, r12) | |
| 173 | ld r13,GPR13(r1) /* only restore r13 if returning to usermode */ | |
| 9994a338 PM |
174 | 1: ld r2,GPR2(r1) |
| 175 | li r12,MSR_RI | |
| 3eb6f26b PM |
176 | andc r11,r10,r12 |
| 177 | mtmsrd r11,1 /* clear MSR.RI */ | |
| 9994a338 PM |
178 | ld r1,GPR1(r1) |
| 179 | mtlr r4 | |
| 180 | mtcr r5 | |
| 181 | mtspr SPRN_SRR0,r7 | |
| 182 | mtspr SPRN_SRR1,r8 | |
| 183 | rfid | |
| 184 | b . /* prevent speculative execution */ | |
| 185 | ||
| 401d1f02 | 186 | syscall_error: |
| 9994a338 | 187 | oris r5,r5,0x1000 /* Set SO bit in CR */ |
| 401d1f02 | 188 | neg r3,r3 |
| 9994a338 PM |
189 | std r5,_CCR(r1) |
| 190 | b syscall_error_cont | |
| 401d1f02 | 191 | |
| 9994a338 PM |
192 | /* Traced system call support */ |
| 193 | syscall_dotrace: | |
| 194 | bl .save_nvgprs | |
| 195 | addi r3,r1,STACK_FRAME_OVERHEAD | |
| 196 | bl .do_syscall_trace_enter | |
| 197 | ld r0,GPR0(r1) /* Restore original registers */ | |
| 198 | ld r3,GPR3(r1) | |
| 199 | ld r4,GPR4(r1) | |
| 200 | ld r5,GPR5(r1) | |
| 201 | ld r6,GPR6(r1) | |
| 202 | ld r7,GPR7(r1) | |
| 203 | ld r8,GPR8(r1) | |
| 204 | addi r9,r1,STACK_FRAME_OVERHEAD | |
| 205 | clrrdi r10,r1,THREAD_SHIFT | |
| 206 | ld r10,TI_FLAGS(r10) | |
| 207 | b syscall_dotrace_cont | |
| 208 | ||
| 401d1f02 DW |
209 | syscall_enosys: |
| 210 | li r3,-ENOSYS | |
| 211 | b syscall_exit | |
| 212 | ||
| 213 | syscall_exit_work: | |
| 214 | /* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr. | |
| 215 | If TIF_NOERROR is set, just save r3 as it is. */ | |
| 216 | ||
| 217 | andi. r0,r9,_TIF_RESTOREALL | |
| 1bd79336 PM |
218 | beq+ 0f |
| 219 | REST_NVGPRS(r1) | |
| 220 | b 2f | |
| 221 | 0: cmpld r3,r11 /* r10 is -LAST_ERRNO */ | |
| 401d1f02 DW |
222 | blt+ 1f |
| 223 | andi. r0,r9,_TIF_NOERROR | |
| 224 | bne- 1f | |
| 225 | ld r5,_CCR(r1) | |
| 226 | neg r3,r3 | |
| 227 | oris r5,r5,0x1000 /* Set SO bit in CR */ | |
| 228 | std r5,_CCR(r1) | |
| 229 | 1: std r3,GPR3(r1) | |
| 230 | 2: andi. r0,r9,(_TIF_PERSYSCALL_MASK) | |
| 231 | beq 4f | |
| 232 | ||
| 1bd79336 | 233 | /* Clear per-syscall TIF flags if any are set. */ |
| 401d1f02 DW |
234 | |
| 235 | li r11,_TIF_PERSYSCALL_MASK | |
| 236 | addi r12,r12,TI_FLAGS | |
| 237 | 3: ldarx r10,0,r12 | |
| 238 | andc r10,r10,r11 | |
| 239 | stdcx. r10,0,r12 | |
| 240 | bne- 3b | |
| 241 | subi r12,r12,TI_FLAGS | |
| 1bd79336 PM |
242 | |
| 243 | 4: /* Anything else left to do? */ | |
| 244 | andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP) | |
| 401d1f02 DW |
245 | beq .ret_from_except_lite |
| 246 | ||
| 247 | /* Re-enable interrupts */ | |
| 248 | mfmsr r10 | |
| 249 | ori r10,r10,MSR_EE | |
| 250 | mtmsrd r10,1 | |
| 251 | ||
| 1bd79336 | 252 | bl .save_nvgprs |
| 9994a338 PM |
253 | addi r3,r1,STACK_FRAME_OVERHEAD |
| 254 | bl .do_syscall_trace_leave | |
| 1bd79336 | 255 | b .ret_from_except |
| 9994a338 PM |
256 | |
| 257 | /* Save non-volatile GPRs, if not already saved. */ | |
| 258 | _GLOBAL(save_nvgprs) | |
| 259 | ld r11,_TRAP(r1) | |
| 260 | andi. r0,r11,1 | |
| 261 | beqlr- | |
| 262 | SAVE_NVGPRS(r1) | |
| 263 | clrrdi r0,r11,1 | |
| 264 | std r0,_TRAP(r1) | |
| 265 | blr | |
| 266 | ||
| 401d1f02 | 267 | |
| 9994a338 PM |
268 | /* |
| 269 | * The sigsuspend and rt_sigsuspend system calls can call do_signal | |
| 270 | * and thus put the process into the stopped state where we might | |
| 271 | * want to examine its user state with ptrace. Therefore we need | |
| 272 | * to save all the nonvolatile registers (r14 - r31) before calling | |
| 273 | * the C code. Similarly, fork, vfork and clone need the full | |
| 274 | * register state on the stack so that it can be copied to the child. | |
| 275 | */ | |
| 9994a338 PM |
276 | |
| 277 | _GLOBAL(ppc_fork) | |
| 278 | bl .save_nvgprs | |
| 279 | bl .sys_fork | |
| 280 | b syscall_exit | |
| 281 | ||
| 282 | _GLOBAL(ppc_vfork) | |
| 283 | bl .save_nvgprs | |
| 284 | bl .sys_vfork | |
| 285 | b syscall_exit | |
| 286 | ||
| 287 | _GLOBAL(ppc_clone) | |
| 288 | bl .save_nvgprs | |
| 289 | bl .sys_clone | |
| 290 | b syscall_exit | |
| 291 | ||
| 1bd79336 PM |
292 | _GLOBAL(ppc32_swapcontext) |
| 293 | bl .save_nvgprs | |
| 294 | bl .compat_sys_swapcontext | |
| 295 | b syscall_exit | |
| 296 | ||
| 297 | _GLOBAL(ppc64_swapcontext) | |
| 298 | bl .save_nvgprs | |
| 299 | bl .sys_swapcontext | |
| 300 | b syscall_exit | |
| 301 | ||
| 9994a338 PM |
302 | _GLOBAL(ret_from_fork) |
| 303 | bl .schedule_tail | |
| 304 | REST_NVGPRS(r1) | |
| 305 | li r3,0 | |
| 306 | b syscall_exit | |
| 307 | ||
| 308 | /* | |
| 309 | * This routine switches between two different tasks. The process | |
| 310 | * state of one is saved on its kernel stack. Then the state | |
| 311 | * of the other is restored from its kernel stack. The memory | |
| 312 | * management hardware is updated to the second process's state. | |
| 313 | * Finally, we can return to the second process, via ret_from_except. | |
| 314 | * On entry, r3 points to the THREAD for the current task, r4 | |
| 315 | * points to the THREAD for the new task. | |
| 316 | * | |
| 317 | * Note: there are two ways to get to the "going out" portion | |
| 318 | * of this code; either by coming in via the entry (_switch) | |
| 319 | * or via "fork" which must set up an environment equivalent | |
| 320 | * to the "_switch" path. If you change this you'll have to change | |
| 321 | * the fork code also. | |
| 322 | * | |
| 323 | * The code which creates the new task context is in 'copy_thread' | |
| 2ef9481e | 324 | * in arch/powerpc/kernel/process.c |
| 9994a338 | 325 | */ |
| 2f6093c8 MN |
326 | #define SHADOW_SLB_BOLTED_STACK_ESID \ |
| 327 | (SLBSHADOW_SAVEAREA + 0x10*(SLB_NUM_BOLTED-1)) | |
| 328 | #define SHADOW_SLB_BOLTED_STACK_VSID \ | |
| 329 | (SLBSHADOW_SAVEAREA + 0x10*(SLB_NUM_BOLTED-1) + 8) | |
| 330 | ||
| 9994a338 PM |
331 | .align 7 |
| 332 | _GLOBAL(_switch) | |
| 333 | mflr r0 | |
| 334 | std r0,16(r1) | |
| 335 | stdu r1,-SWITCH_FRAME_SIZE(r1) | |
| 336 | /* r3-r13 are caller saved -- Cort */ | |
| 337 | SAVE_8GPRS(14, r1) | |
| 338 | SAVE_10GPRS(22, r1) | |
| 339 | mflr r20 /* Return to switch caller */ | |
| 340 | mfmsr r22 | |
| 341 | li r0, MSR_FP | |
| 342 | #ifdef CONFIG_ALTIVEC | |
| 343 | BEGIN_FTR_SECTION | |
| 344 | oris r0,r0,MSR_VEC@h /* Disable altivec */ | |
| 345 | mfspr r24,SPRN_VRSAVE /* save vrsave register value */ | |
| 346 | std r24,THREAD_VRSAVE(r3) | |
| 347 | END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) | |
| 348 | #endif /* CONFIG_ALTIVEC */ | |
| 349 | and. r0,r0,r22 | |
| 350 | beq+ 1f | |
| 351 | andc r22,r22,r0 | |
| 352 | mtmsrd r22 | |
| 353 | isync | |
| 354 | 1: std r20,_NIP(r1) | |
| 355 | mfcr r23 | |
| 356 | std r23,_CCR(r1) | |
| 357 | std r1,KSP(r3) /* Set old stack pointer */ | |
| 358 | ||
| 359 | #ifdef CONFIG_SMP | |
| 360 | /* We need a sync somewhere here to make sure that if the | |
| 361 | * previous task gets rescheduled on another CPU, it sees all | |
| 362 | * stores it has performed on this one. | |
| 363 | */ | |
| 364 | sync | |
| 365 | #endif /* CONFIG_SMP */ | |
| 366 | ||
| 367 | addi r6,r4,-THREAD /* Convert THREAD to 'current' */ | |
| 368 | std r6,PACACURRENT(r13) /* Set new 'current' */ | |
| 369 | ||
| 370 | ld r8,KSP(r4) /* new stack pointer */ | |
| 371 | BEGIN_FTR_SECTION | |
| 372 | clrrdi r6,r8,28 /* get its ESID */ | |
| 373 | clrrdi r9,r1,28 /* get current sp ESID */ | |
| 374 | clrldi. r0,r6,2 /* is new ESID c00000000? */ | |
| 375 | cmpd cr1,r6,r9 /* or is new ESID the same as current ESID? */ | |
| 376 | cror eq,4*cr1+eq,eq | |
| 377 | beq 2f /* if yes, don't slbie it */ | |
| 378 | ||
| 379 | /* Bolt in the new stack SLB entry */ | |
| 380 | ld r7,KSP_VSID(r4) /* Get new stack's VSID */ | |
| 381 | oris r0,r6,(SLB_ESID_V)@h | |
| 382 | ori r0,r0,(SLB_NUM_BOLTED-1)@l | |
| 2f6093c8 MN |
383 | |
| 384 | /* Update the last bolted SLB */ | |
| 385 | ld r9,PACA_SLBSHADOWPTR(r13) | |
| 386 | li r12,0 | |
| 387 | std r12,SHADOW_SLB_BOLTED_STACK_ESID(r9) /* Clear ESID */ | |
| 388 | std r7,SHADOW_SLB_BOLTED_STACK_VSID(r9) /* Save VSID */ | |
| 389 | std r0,SHADOW_SLB_BOLTED_STACK_ESID(r9) /* Save ESID */ | |
| 390 | ||
| 9994a338 PM |
391 | slbie r6 |
| 392 | slbie r6 /* Workaround POWER5 < DD2.1 issue */ | |
| 393 | slbmte r7,r0 | |
| 394 | isync | |
| 395 | ||
| 396 | 2: | |
| 397 | END_FTR_SECTION_IFSET(CPU_FTR_SLB) | |
| 398 | clrrdi r7,r8,THREAD_SHIFT /* base of new stack */ | |
| 399 | /* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE | |
| 400 | because we don't need to leave the 288-byte ABI gap at the | |
| 401 | top of the kernel stack. */ | |
| 402 | addi r7,r7,THREAD_SIZE-SWITCH_FRAME_SIZE | |
| 403 | ||
| 404 | mr r1,r8 /* start using new stack pointer */ | |
| 405 | std r7,PACAKSAVE(r13) | |
| 406 | ||
| 407 | ld r6,_CCR(r1) | |
| 408 | mtcrf 0xFF,r6 | |
| 409 | ||
| 410 | #ifdef CONFIG_ALTIVEC | |
| 411 | BEGIN_FTR_SECTION | |
| 412 | ld r0,THREAD_VRSAVE(r4) | |
| 413 | mtspr SPRN_VRSAVE,r0 /* if G4, restore VRSAVE reg */ | |
| 414 | END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) | |
| 415 | #endif /* CONFIG_ALTIVEC */ | |
| 416 | ||
| 417 | /* r3-r13 are destroyed -- Cort */ | |
| 418 | REST_8GPRS(14, r1) | |
| 419 | REST_10GPRS(22, r1) | |
| 420 | ||
| 421 | /* convert old thread to its task_struct for return value */ | |
| 422 | addi r3,r3,-THREAD | |
| 423 | ld r7,_NIP(r1) /* Return to _switch caller in new task */ | |
| 424 | mtlr r7 | |
| 425 | addi r1,r1,SWITCH_FRAME_SIZE | |
| 426 | blr | |
| 427 | ||
| 428 | .align 7 | |
| 429 | _GLOBAL(ret_from_except) | |
| 430 | ld r11,_TRAP(r1) | |
| 431 | andi. r0,r11,1 | |
| 432 | bne .ret_from_except_lite | |
| 433 | REST_NVGPRS(r1) | |
| 434 | ||
| 435 | _GLOBAL(ret_from_except_lite) | |
| 436 | /* | |
| 437 | * Disable interrupts so that current_thread_info()->flags | |
| 438 | * can't change between when we test it and when we return | |
| 439 | * from the interrupt. | |
| 440 | */ | |
| 441 | mfmsr r10 /* Get current interrupt state */ | |
| 442 | rldicl r9,r10,48,1 /* clear MSR_EE */ | |
| 443 | rotldi r9,r9,16 | |
| 444 | mtmsrd r9,1 /* Update machine state */ | |
| 445 | ||
| 446 | #ifdef CONFIG_PREEMPT | |
| 447 | clrrdi r9,r1,THREAD_SHIFT /* current_thread_info() */ | |
| 448 | li r0,_TIF_NEED_RESCHED /* bits to check */ | |
| 449 | ld r3,_MSR(r1) | |
| 450 | ld r4,TI_FLAGS(r9) | |
| 451 | /* Move MSR_PR bit in r3 to _TIF_SIGPENDING position in r0 */ | |
| 452 | rlwimi r0,r3,32+TIF_SIGPENDING-MSR_PR_LG,_TIF_SIGPENDING | |
| 453 | and. r0,r4,r0 /* check NEED_RESCHED and maybe SIGPENDING */ | |
| 454 | bne do_work | |
| 455 | ||
| 456 | #else /* !CONFIG_PREEMPT */ | |
| 457 | ld r3,_MSR(r1) /* Returning to user mode? */ | |
| 458 | andi. r3,r3,MSR_PR | |
| 459 | beq restore /* if not, just restore regs and return */ | |
| 460 | ||
| 461 | /* Check current_thread_info()->flags */ | |
| 462 | clrrdi r9,r1,THREAD_SHIFT | |
| 463 | ld r4,TI_FLAGS(r9) | |
| 464 | andi. r0,r4,_TIF_USER_WORK_MASK | |
| 465 | bne do_work | |
| 466 | #endif | |
| 467 | ||
| 468 | restore: | |
| 469 | #ifdef CONFIG_PPC_ISERIES | |
| 470 | ld r5,SOFTE(r1) | |
| 471 | cmpdi 0,r5,0 | |
| 472 | beq 4f | |
| 473 | /* Check for pending interrupts (iSeries) */ | |
| 3356bb9f DG |
474 | ld r3,PACALPPACAPTR(r13) |
| 475 | ld r3,LPPACAANYINT(r3) | |
| 9994a338 PM |
476 | cmpdi r3,0 |
| 477 | beq+ 4f /* skip do_IRQ if no interrupts */ | |
| 478 | ||
| 479 | li r3,0 | |
| 480 | stb r3,PACAPROCENABLED(r13) /* ensure we are soft-disabled */ | |
| 481 | ori r10,r10,MSR_EE | |
| 482 | mtmsrd r10 /* hard-enable again */ | |
| 483 | addi r3,r1,STACK_FRAME_OVERHEAD | |
| 484 | bl .do_IRQ | |
| 485 | b .ret_from_except_lite /* loop back and handle more */ | |
| 486 | ||
| 487 | 4: stb r5,PACAPROCENABLED(r13) | |
| 488 | #endif | |
| 489 | ||
| 490 | ld r3,_MSR(r1) | |
| 491 | andi. r0,r3,MSR_RI | |
| 492 | beq- unrecov_restore | |
| 493 | ||
| 494 | andi. r0,r3,MSR_PR | |
| 495 | ||
| 496 | /* | |
| 497 | * r13 is our per cpu area, only restore it if we are returning to | |
| 498 | * userspace | |
| 499 | */ | |
| 500 | beq 1f | |
| c6622f63 | 501 | ACCOUNT_CPU_USER_EXIT(r3, r4) |
| 9994a338 PM |
502 | REST_GPR(13, r1) |
| 503 | 1: | |
| 504 | ld r3,_CTR(r1) | |
| 505 | ld r0,_LINK(r1) | |
| 506 | mtctr r3 | |
| 507 | mtlr r0 | |
| 508 | ld r3,_XER(r1) | |
| 509 | mtspr SPRN_XER,r3 | |
| 510 | ||
| 511 | REST_8GPRS(5, r1) | |
| 512 | ||
| 513 | stdcx. r0,0,r1 /* to clear the reservation */ | |
| 514 | ||
| 515 | mfmsr r0 | |
| 516 | li r2, MSR_RI | |
| 517 | andc r0,r0,r2 | |
| 518 | mtmsrd r0,1 | |
| 519 | ||
| 520 | ld r0,_MSR(r1) | |
| 521 | mtspr SPRN_SRR1,r0 | |
| 522 | ||
| 523 | ld r2,_CCR(r1) | |
| 524 | mtcrf 0xFF,r2 | |
| 525 | ld r2,_NIP(r1) | |
| 526 | mtspr SPRN_SRR0,r2 | |
| 527 | ||
| 528 | ld r0,GPR0(r1) | |
| 529 | ld r2,GPR2(r1) | |
| 530 | ld r3,GPR3(r1) | |
| 531 | ld r4,GPR4(r1) | |
| 532 | ld r1,GPR1(r1) | |
| 533 | ||
| 534 | rfid | |
| 535 | b . /* prevent speculative execution */ | |
| 536 | ||
| 537 | /* Note: this must change if we start using the TIF_NOTIFY_RESUME bit */ | |
| 538 | do_work: | |
| 539 | #ifdef CONFIG_PREEMPT | |
| 540 | andi. r0,r3,MSR_PR /* Returning to user mode? */ | |
| 541 | bne user_work | |
| 542 | /* Check that preempt_count() == 0 and interrupts are enabled */ | |
| 543 | lwz r8,TI_PREEMPT(r9) | |
| 544 | cmpwi cr1,r8,0 | |
| 545 | #ifdef CONFIG_PPC_ISERIES | |
| 546 | ld r0,SOFTE(r1) | |
| 547 | cmpdi r0,0 | |
| 548 | #else | |
| 549 | andi. r0,r3,MSR_EE | |
| 550 | #endif | |
| 551 | crandc eq,cr1*4+eq,eq | |
| 552 | bne restore | |
| 553 | /* here we are preempting the current task */ | |
| 554 | 1: | |
| 555 | #ifdef CONFIG_PPC_ISERIES | |
| 556 | li r0,1 | |
| 557 | stb r0,PACAPROCENABLED(r13) | |
| 558 | #endif | |
| 559 | ori r10,r10,MSR_EE | |
| 560 | mtmsrd r10,1 /* reenable interrupts */ | |
| 561 | bl .preempt_schedule | |
| 562 | mfmsr r10 | |
| 563 | clrrdi r9,r1,THREAD_SHIFT | |
| 564 | rldicl r10,r10,48,1 /* disable interrupts again */ | |
| 565 | rotldi r10,r10,16 | |
| 566 | mtmsrd r10,1 | |
| 567 | ld r4,TI_FLAGS(r9) | |
| 568 | andi. r0,r4,_TIF_NEED_RESCHED | |
| 569 | bne 1b | |
| 570 | b restore | |
| 571 | ||
| 572 | user_work: | |
| 573 | #endif | |
| 574 | /* Enable interrupts */ | |
| 575 | ori r10,r10,MSR_EE | |
| 576 | mtmsrd r10,1 | |
| 577 | ||
| 578 | andi. r0,r4,_TIF_NEED_RESCHED | |
| 579 | beq 1f | |
| 580 | bl .schedule | |
| 581 | b .ret_from_except_lite | |
| 582 | ||
| 583 | 1: bl .save_nvgprs | |
| 584 | li r3,0 | |
| 585 | addi r4,r1,STACK_FRAME_OVERHEAD | |
| 586 | bl .do_signal | |
| 587 | b .ret_from_except | |
| 588 | ||
| 589 | unrecov_restore: | |
| 590 | addi r3,r1,STACK_FRAME_OVERHEAD | |
| 591 | bl .unrecoverable_exception | |
| 592 | b unrecov_restore | |
| 593 | ||
| 594 | #ifdef CONFIG_PPC_RTAS | |
| 595 | /* | |
| 596 | * On CHRP, the Run-Time Abstraction Services (RTAS) have to be | |
| 597 | * called with the MMU off. | |
| 598 | * | |
| 599 | * In addition, we need to be in 32b mode, at least for now. | |
| 600 | * | |
| 601 | * Note: r3 is an input parameter to rtas, so don't trash it... | |
| 602 | */ | |
| 603 | _GLOBAL(enter_rtas) | |
| 604 | mflr r0 | |
| 605 | std r0,16(r1) | |
| 606 | stdu r1,-RTAS_FRAME_SIZE(r1) /* Save SP and create stack space. */ | |
| 607 | ||
| 608 | /* Because RTAS is running in 32b mode, it clobbers the high order half | |
| 609 | * of all registers that it saves. We therefore save those registers | |
| 610 | * RTAS might touch to the stack. (r0, r3-r13 are caller saved) | |
| 611 | */ | |
| 612 | SAVE_GPR(2, r1) /* Save the TOC */ | |
| 613 | SAVE_GPR(13, r1) /* Save paca */ | |
| 614 | SAVE_8GPRS(14, r1) /* Save the non-volatiles */ | |
| 615 | SAVE_10GPRS(22, r1) /* ditto */ | |
| 616 | ||
| 617 | mfcr r4 | |
| 618 | std r4,_CCR(r1) | |
| 619 | mfctr r5 | |
| 620 | std r5,_CTR(r1) | |
| 621 | mfspr r6,SPRN_XER | |
| 622 | std r6,_XER(r1) | |
| 623 | mfdar r7 | |
| 624 | std r7,_DAR(r1) | |
| 625 | mfdsisr r8 | |
| 626 | std r8,_DSISR(r1) | |
| 627 | mfsrr0 r9 | |
| 628 | std r9,_SRR0(r1) | |
| 629 | mfsrr1 r10 | |
| 630 | std r10,_SRR1(r1) | |
| 631 | ||
| 9fe901d1 MK |
632 | /* Temporary workaround to clear CR until RTAS can be modified to |
| 633 | * ignore all bits. | |
| 634 | */ | |
| 635 | li r0,0 | |
| 636 | mtcr r0 | |
| 637 | ||
| 9994a338 PM |
638 | /* There is no way it is acceptable to get here with interrupts enabled, |
| 639 | * check it with the asm equivalent of WARN_ON | |
| 640 | */ | |
| 641 | mfmsr r6 | |
| 642 | andi. r0,r6,MSR_EE | |
| 643 | 1: tdnei r0,0 | |
| 644 | .section __bug_table,"a" | |
| 645 | .llong 1b,__LINE__ + 0x1000000, 1f, 2f | |
| 646 | .previous | |
| 647 | .section .rodata,"a" | |
| 648 | 1: .asciz __FILE__ | |
| 649 | 2: .asciz "enter_rtas" | |
| 650 | .previous | |
| 651 | ||
| 652 | /* Unfortunately, the stack pointer and the MSR are also clobbered, | |
| 653 | * so they are saved in the PACA which allows us to restore | |
| 654 | * our original state after RTAS returns. | |
| 655 | */ | |
| 656 | std r1,PACAR1(r13) | |
| 657 | std r6,PACASAVEDMSR(r13) | |
| 658 | ||
| 659 | /* Setup our real return addr */ | |
| e58c3495 DG |
660 | LOAD_REG_ADDR(r4,.rtas_return_loc) |
| 661 | clrldi r4,r4,2 /* convert to realmode address */ | |
| 9994a338 PM |
662 | mtlr r4 |
| 663 | ||
| 664 | li r0,0 | |
| 665 | ori r0,r0,MSR_EE|MSR_SE|MSR_BE|MSR_RI | |
| 666 | andc r0,r6,r0 | |
| 667 | ||
| 668 | li r9,1 | |
| 669 | rldicr r9,r9,MSR_SF_LG,(63-MSR_SF_LG) | |
| 670 | ori r9,r9,MSR_IR|MSR_DR|MSR_FE0|MSR_FE1|MSR_FP | |
| 671 | andc r6,r0,r9 | |
| 672 | ori r6,r6,MSR_RI | |
| 673 | sync /* disable interrupts so SRR0/1 */ | |
| 674 | mtmsrd r0 /* don't get trashed */ | |
| 675 | ||
| e58c3495 | 676 | LOAD_REG_ADDR(r4, rtas) |
| 9994a338 PM |
677 | ld r5,RTASENTRY(r4) /* get the rtas->entry value */ |
| 678 | ld r4,RTASBASE(r4) /* get the rtas->base value */ | |
| 679 | ||
| 680 | mtspr SPRN_SRR0,r5 | |
| 681 | mtspr SPRN_SRR1,r6 | |
| 682 | rfid | |
| 683 | b . /* prevent speculative execution */ | |
| 684 | ||
| 685 | _STATIC(rtas_return_loc) | |
| 686 | /* relocation is off at this point */ | |
| 687 | mfspr r4,SPRN_SPRG3 /* Get PACA */ | |
| e58c3495 | 688 | clrldi r4,r4,2 /* convert to realmode address */ |
| 9994a338 PM |
689 | |
| 690 | mfmsr r6 | |
| 691 | li r0,MSR_RI | |
| 692 | andc r6,r6,r0 | |
| 693 | sync | |
| 694 | mtmsrd r6 | |
| 695 | ||
| 696 | ld r1,PACAR1(r4) /* Restore our SP */ | |
| e58c3495 | 697 | LOAD_REG_IMMEDIATE(r3,.rtas_restore_regs) |
| 9994a338 PM |
698 | ld r4,PACASAVEDMSR(r4) /* Restore our MSR */ |
| 699 | ||
| 700 | mtspr SPRN_SRR0,r3 | |
| 701 | mtspr SPRN_SRR1,r4 | |
| 702 | rfid | |
| 703 | b . /* prevent speculative execution */ | |
| 704 | ||
| 705 | _STATIC(rtas_restore_regs) | |
| 706 | /* relocation is on at this point */ | |
| 707 | REST_GPR(2, r1) /* Restore the TOC */ | |
| 708 | REST_GPR(13, r1) /* Restore paca */ | |
| 709 | REST_8GPRS(14, r1) /* Restore the non-volatiles */ | |
| 710 | REST_10GPRS(22, r1) /* ditto */ | |
| 711 | ||
| 712 | mfspr r13,SPRN_SPRG3 | |
| 713 | ||
| 714 | ld r4,_CCR(r1) | |
| 715 | mtcr r4 | |
| 716 | ld r5,_CTR(r1) | |
| 717 | mtctr r5 | |
| 718 | ld r6,_XER(r1) | |
| 719 | mtspr SPRN_XER,r6 | |
| 720 | ld r7,_DAR(r1) | |
| 721 | mtdar r7 | |
| 722 | ld r8,_DSISR(r1) | |
| 723 | mtdsisr r8 | |
| 724 | ld r9,_SRR0(r1) | |
| 725 | mtsrr0 r9 | |
| 726 | ld r10,_SRR1(r1) | |
| 727 | mtsrr1 r10 | |
| 728 | ||
| 729 | addi r1,r1,RTAS_FRAME_SIZE /* Unstack our frame */ | |
| 730 | ld r0,16(r1) /* get return address */ | |
| 731 | ||
| 732 | mtlr r0 | |
| 733 | blr /* return to caller */ | |
| 734 | ||
| 735 | #endif /* CONFIG_PPC_RTAS */ | |
| 736 | ||
| 737 | #ifdef CONFIG_PPC_MULTIPLATFORM | |
| 738 | ||
| 739 | _GLOBAL(enter_prom) | |
| 740 | mflr r0 | |
| 741 | std r0,16(r1) | |
| 742 | stdu r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */ | |
| 743 | ||
| 744 | /* Because PROM is running in 32b mode, it clobbers the high order half | |
| 745 | * of all registers that it saves. We therefore save those registers | |
| 746 | * PROM might touch to the stack. (r0, r3-r13 are caller saved) | |
| 747 | */ | |
| 748 | SAVE_8GPRS(2, r1) | |
| 749 | SAVE_GPR(13, r1) | |
| 750 | SAVE_8GPRS(14, r1) | |
| 751 | SAVE_10GPRS(22, r1) | |
| 752 | mfcr r4 | |
| 753 | std r4,_CCR(r1) | |
| 754 | mfctr r5 | |
| 755 | std r5,_CTR(r1) | |
| 756 | mfspr r6,SPRN_XER | |
| 757 | std r6,_XER(r1) | |
| 758 | mfdar r7 | |
| 759 | std r7,_DAR(r1) | |
| 760 | mfdsisr r8 | |
| 761 | std r8,_DSISR(r1) | |
| 762 | mfsrr0 r9 | |
| 763 | std r9,_SRR0(r1) | |
| 764 | mfsrr1 r10 | |
| 765 | std r10,_SRR1(r1) | |
| 766 | mfmsr r11 | |
| 767 | std r11,_MSR(r1) | |
| 768 | ||
| 769 | /* Get the PROM entrypoint */ | |
| 770 | ld r0,GPR4(r1) | |
| 771 | mtlr r0 | |
| 772 | ||
| 773 | /* Switch MSR to 32 bits mode | |
| 774 | */ | |
| 775 | mfmsr r11 | |
| 776 | li r12,1 | |
| 777 | rldicr r12,r12,MSR_SF_LG,(63-MSR_SF_LG) | |
| 778 | andc r11,r11,r12 | |
| 779 | li r12,1 | |
| 780 | rldicr r12,r12,MSR_ISF_LG,(63-MSR_ISF_LG) | |
| 781 | andc r11,r11,r12 | |
| 782 | mtmsrd r11 | |
| 783 | isync | |
| 784 | ||
| 785 | /* Restore arguments & enter PROM here... */ | |
| 786 | ld r3,GPR3(r1) | |
| 787 | blrl | |
| 788 | ||
| 789 | /* Just make sure that r1 top 32 bits didn't get | |
| 790 | * corrupt by OF | |
| 791 | */ | |
| 792 | rldicl r1,r1,0,32 | |
| 793 | ||
| 794 | /* Restore the MSR (back to 64 bits) */ | |
| 795 | ld r0,_MSR(r1) | |
| 796 | mtmsrd r0 | |
| 797 | isync | |
| 798 | ||
| 799 | /* Restore other registers */ | |
| 800 | REST_GPR(2, r1) | |
| 801 | REST_GPR(13, r1) | |
| 802 | REST_8GPRS(14, r1) | |
| 803 | REST_10GPRS(22, r1) | |
| 804 | ld r4,_CCR(r1) | |
| 805 | mtcr r4 | |
| 806 | ld r5,_CTR(r1) | |
| 807 | mtctr r5 | |
| 808 | ld r6,_XER(r1) | |
| 809 | mtspr SPRN_XER,r6 | |
| 810 | ld r7,_DAR(r1) | |
| 811 | mtdar r7 | |
| 812 | ld r8,_DSISR(r1) | |
| 813 | mtdsisr r8 | |
| 814 | ld r9,_SRR0(r1) | |
| 815 | mtsrr0 r9 | |
| 816 | ld r10,_SRR1(r1) | |
| 817 | mtsrr1 r10 | |
| 818 | ||
| 819 | addi r1,r1,PROM_FRAME_SIZE | |
| 820 | ld r0,16(r1) | |
| 821 | mtlr r0 | |
| 822 | blr | |
| 823 | ||
| 824 | #endif /* CONFIG_PPC_MULTIPLATFORM */ |