1/* 2 * Linux/PA-RISC Project (http://www.parisc-linux.org/) 3 * 4 * System call entry code Copyright (c) Matthew Wilcox 1999 <willy@bofh.ai> 5 * Licensed under the GNU GPL. 6 * thanks to Philipp Rumpf, Mike Shaver and various others 7 * sorry about the wall, puffin.. 8 */ 9 10#include <asm/asm-offsets.h> 11#include <asm/unistd.h> 12#include <asm/errno.h> 13#include <asm/page.h> 14#include <asm/psw.h> 15#include <asm/thread_info.h> 16#include <asm/assembly.h> 17#include <asm/processor.h> 18 19#include <linux/linkage.h> 20 21 /* We fill the empty parts of the gateway page with 22 * something that will kill the kernel or a 23 * userspace application. 24 */ 25#define KILL_INSN break 0,0 26 27 .level LEVEL 28 29 .text 30 31 .import syscall_exit,code 32 .import syscall_exit_rfi,code 33 34 /* Linux gateway page is aliased to virtual page 0 in the kernel 35 * address space. Since it is a gateway page it cannot be 36 * dereferenced, so null pointers will still fault. We start 37 * the actual entry point at 0x100. We put break instructions 38 * at the beginning of the page to trap null indirect function 39 * pointers. 40 */ 41 42 .align PAGE_SIZE 43ENTRY(linux_gateway_page) 44 45 /* ADDRESS 0x00 to 0xb0 = 176 bytes / 4 bytes per insn = 44 insns */ 46 .rept 44 47 KILL_INSN 48 .endr 49 50 /* ADDRESS 0xb0 to 0xb4, lws uses 1 insns for entry */ 51 /* Light-weight-syscall entry must always be located at 0xb0 */ 52 /* WARNING: Keep this number updated with table size changes */ 53#define __NR_lws_entries (2) 54 55lws_entry: 56 /* Unconditional branch to lws_start, located on the 57 same gateway page */ 58 b,n lws_start 59 60 /* Fill from 0xb4 to 0xe0 */ 61 .rept 11 62 KILL_INSN 63 .endr 64 65 /* This function MUST be located at 0xe0 for glibc's threading 66 mechanism to work. DO NOT MOVE THIS CODE EVER! */ 67set_thread_pointer: 68 gate .+8, %r0 /* increase privilege */ 69 depi 3, 31, 2, %r31 /* Ensure we return into user mode. */ 70 be 0(%sr7,%r31) /* return to user space */ 71 mtctl %r26, %cr27 /* move arg0 to the control register */ 72 73 /* Increase the chance of trapping if random jumps occur to this 74 address, fill from 0xf0 to 0x100 */ 75 .rept 4 76 KILL_INSN 77 .endr 78 79/* This address must remain fixed at 0x100 for glibc's syscalls to work */ 80 .align 256 81linux_gateway_entry: 82 gate .+8, %r0 /* become privileged */ 83 mtsp %r0,%sr4 /* get kernel space into sr4 */ 84 mtsp %r0,%sr5 /* get kernel space into sr5 */ 85 mtsp %r0,%sr6 /* get kernel space into sr6 */ 86 mfsp %sr7,%r1 /* save user sr7 */ 87 mtsp %r1,%sr3 /* and store it in sr3 */ 88 89#ifdef CONFIG_64BIT 90 /* for now we can *always* set the W bit on entry to the syscall 91 * since we don't support wide userland processes. We could 92 * also save the current SM other than in r0 and restore it on 93 * exit from the syscall, and also use that value to know 94 * whether to do narrow or wide syscalls. -PB 95 */ 96 ssm PSW_SM_W, %r1 97 extrd,u %r1,PSW_W_BIT,1,%r1 98 /* sp must be aligned on 4, so deposit the W bit setting into 99 * the bottom of sp temporarily */ 100 or,ev %r1,%r30,%r30 101 b,n 1f 102 /* The top halves of argument registers must be cleared on syscall 103 * entry from narrow executable. 104 */ 105 depdi 0, 31, 32, %r26 106 depdi 0, 31, 32, %r25 107 depdi 0, 31, 32, %r24 108 depdi 0, 31, 32, %r23 109 depdi 0, 31, 32, %r22 110 depdi 0, 31, 32, %r21 1111: 112#endif 113 mfctl %cr30,%r1 114 xor %r1,%r30,%r30 /* ye olde xor trick */ 115 xor %r1,%r30,%r1 116 xor %r1,%r30,%r30 117 118 ldo THREAD_SZ_ALGN+FRAME_SIZE(%r30),%r30 /* set up kernel stack */ 119 120 /* N.B.: It is critical that we don't set sr7 to 0 until r30 121 * contains a valid kernel stack pointer. It is also 122 * critical that we don't start using the kernel stack 123 * until after sr7 has been set to 0. 124 */ 125 126 mtsp %r0,%sr7 /* get kernel space into sr7 */ 127 STREGM %r1,FRAME_SIZE(%r30) /* save r1 (usp) here for now */ 128 mfctl %cr30,%r1 /* get task ptr in %r1 */ 129 LDREG TI_TASK(%r1),%r1 130 131 /* Save some registers for sigcontext and potential task 132 switch (see entry.S for the details of which ones are 133 saved/restored). TASK_PT_PSW is zeroed so we can see whether 134 a process is on a syscall or not. For an interrupt the real 135 PSW value is stored. This is needed for gdb and sys_ptrace. */ 136 STREG %r0, TASK_PT_PSW(%r1) 137 STREG %r2, TASK_PT_GR2(%r1) /* preserve rp */ 138 STREG %r19, TASK_PT_GR19(%r1) 139 140 LDREGM -FRAME_SIZE(%r30), %r2 /* get users sp back */ 141#ifdef CONFIG_64BIT 142 extrd,u %r2,63,1,%r19 /* W hidden in bottom bit */ 143#if 0 144 xor %r19,%r2,%r2 /* clear bottom bit */ 145 depd,z %r19,1,1,%r19 146 std %r19,TASK_PT_PSW(%r1) 147#endif 148#endif 149 STREG %r2, TASK_PT_GR30(%r1) /* ... and save it */ 150 151 STREG %r20, TASK_PT_GR20(%r1) /* Syscall number */ 152 STREG %r21, TASK_PT_GR21(%r1) 153 STREG %r22, TASK_PT_GR22(%r1) 154 STREG %r23, TASK_PT_GR23(%r1) /* 4th argument */ 155 STREG %r24, TASK_PT_GR24(%r1) /* 3rd argument */ 156 STREG %r25, TASK_PT_GR25(%r1) /* 2nd argument */ 157 STREG %r26, TASK_PT_GR26(%r1) /* 1st argument */ 158 STREG %r27, TASK_PT_GR27(%r1) /* user dp */ 159 STREG %r28, TASK_PT_GR28(%r1) /* return value 0 */ 160 STREG %r28, TASK_PT_ORIG_R28(%r1) /* return value 0 (saved for signals) */ 161 STREG %r29, TASK_PT_GR29(%r1) /* return value 1 */ 162 STREG %r31, TASK_PT_GR31(%r1) /* preserve syscall return ptr */ 163 164 ldo TASK_PT_FR0(%r1), %r27 /* save fpregs from the kernel */ 165 save_fp %r27 /* or potential task switch */ 166 167 mfctl %cr11, %r27 /* i.e. SAR */ 168 STREG %r27, TASK_PT_SAR(%r1) 169 170 loadgp 171 172#ifdef CONFIG_64BIT 173 ldo -16(%r30),%r29 /* Reference param save area */ 174 copy %r19,%r2 /* W bit back to r2 */ 175#else 176 /* no need to save these on stack in wide mode because the first 8 177 * args are passed in registers */ 178 stw %r22, -52(%r30) /* 5th argument */ 179 stw %r21, -56(%r30) /* 6th argument */ 180#endif 181 182 /* Are we being ptraced? */ 183 mfctl %cr30, %r1 184 LDREG TI_TASK(%r1),%r1 185 ldw TASK_PTRACE(%r1), %r1 186 bb,<,n %r1,31,.Ltracesys 187 188 /* Note! We cannot use the syscall table that is mapped 189 nearby since the gateway page is mapped execute-only. */ 190 191#ifdef CONFIG_64BIT 192 ldil L%sys_call_table, %r1 193 or,= %r2,%r2,%r2 194 addil L%(sys_call_table64-sys_call_table), %r1 195 ldo R%sys_call_table(%r1), %r19 196 or,= %r2,%r2,%r2 197 ldo R%sys_call_table64(%r1), %r19 198#else 199 ldil L%sys_call_table, %r1 200 ldo R%sys_call_table(%r1), %r19 201#endif 202 comiclr,>> __NR_Linux_syscalls, %r20, %r0 203 b,n .Lsyscall_nosys 204 205 LDREGX %r20(%r19), %r19 206 207 /* If this is a sys_rt_sigreturn call, and the signal was received 208 * when not in_syscall, then we want to return via syscall_exit_rfi, 209 * not syscall_exit. Signal no. in r20, in_syscall in r25 (see 210 * trampoline code in signal.c). 211 */ 212 ldi __NR_rt_sigreturn,%r2 213 comb,= %r2,%r20,.Lrt_sigreturn 214.Lin_syscall: 215 ldil L%syscall_exit,%r2 216 be 0(%sr7,%r19) 217 ldo R%syscall_exit(%r2),%r2 218.Lrt_sigreturn: 219 comib,<> 0,%r25,.Lin_syscall 220 ldil L%syscall_exit_rfi,%r2 221 be 0(%sr7,%r19) 222 ldo R%syscall_exit_rfi(%r2),%r2 223 224 /* Note! Because we are not running where we were linked, any 225 calls to functions external to this file must be indirect. To 226 be safe, we apply the opposite rule to functions within this 227 file, with local labels given to them to ensure correctness. */ 228 229.Lsyscall_nosys: 230syscall_nosys: 231 ldil L%syscall_exit,%r1 232 be R%syscall_exit(%sr7,%r1) 233 ldo -ENOSYS(%r0),%r28 /* set errno */ 234 235 236/* Warning! This trace code is a virtual duplicate of the code above so be 237 * sure to maintain both! */ 238.Ltracesys: 239tracesys: 240 /* Need to save more registers so the debugger can see where we 241 * are. This saves only the lower 8 bits of PSW, so that the C 242 * bit is still clear on syscalls, and the D bit is set if this 243 * full register save path has been executed. We check the D 244 * bit on syscall_return_rfi to determine which registers to 245 * restore. An interrupt results in a full PSW saved with the 246 * C bit set, a non-straced syscall entry results in C and D clear 247 * in the saved PSW. 248 */ 249 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 250 LDREG TI_TASK(%r1), %r1 251 ssm 0,%r2 252 STREG %r2,TASK_PT_PSW(%r1) /* Lower 8 bits only!! */ 253 mfsp %sr0,%r2 254 STREG %r2,TASK_PT_SR0(%r1) 255 mfsp %sr1,%r2 256 STREG %r2,TASK_PT_SR1(%r1) 257 mfsp %sr2,%r2 258 STREG %r2,TASK_PT_SR2(%r1) 259 mfsp %sr3,%r2 260 STREG %r2,TASK_PT_SR3(%r1) 261 STREG %r2,TASK_PT_SR4(%r1) 262 STREG %r2,TASK_PT_SR5(%r1) 263 STREG %r2,TASK_PT_SR6(%r1) 264 STREG %r2,TASK_PT_SR7(%r1) 265 STREG %r2,TASK_PT_IASQ0(%r1) 266 STREG %r2,TASK_PT_IASQ1(%r1) 267 LDREG TASK_PT_GR31(%r1),%r2 268 STREG %r2,TASK_PT_IAOQ0(%r1) 269 ldo 4(%r2),%r2 270 STREG %r2,TASK_PT_IAOQ1(%r1) 271 ldo TASK_REGS(%r1),%r2 272 /* reg_save %r2 */ 273 STREG %r3,PT_GR3(%r2) 274 STREG %r4,PT_GR4(%r2) 275 STREG %r5,PT_GR5(%r2) 276 STREG %r6,PT_GR6(%r2) 277 STREG %r7,PT_GR7(%r2) 278 STREG %r8,PT_GR8(%r2) 279 STREG %r9,PT_GR9(%r2) 280 STREG %r10,PT_GR10(%r2) 281 STREG %r11,PT_GR11(%r2) 282 STREG %r12,PT_GR12(%r2) 283 STREG %r13,PT_GR13(%r2) 284 STREG %r14,PT_GR14(%r2) 285 STREG %r15,PT_GR15(%r2) 286 STREG %r16,PT_GR16(%r2) 287 STREG %r17,PT_GR17(%r2) 288 STREG %r18,PT_GR18(%r2) 289 /* Finished saving things for the debugger */ 290 291 ldil L%syscall_trace,%r1 292 ldil L%tracesys_next,%r2 293 be R%syscall_trace(%sr7,%r1) 294 ldo R%tracesys_next(%r2),%r2 295 296tracesys_next: 297 ldil L%sys_call_table,%r1 298 ldo R%sys_call_table(%r1), %r19 299 300 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 301 LDREG TI_TASK(%r1), %r1 302 LDREG TASK_PT_GR20(%r1), %r20 303 LDREG TASK_PT_GR26(%r1), %r26 /* Restore the users args */ 304 LDREG TASK_PT_GR25(%r1), %r25 305 LDREG TASK_PT_GR24(%r1), %r24 306 LDREG TASK_PT_GR23(%r1), %r23 307#ifdef CONFIG_64BIT 308 LDREG TASK_PT_GR22(%r1), %r22 309 LDREG TASK_PT_GR21(%r1), %r21 310 ldo -16(%r30),%r29 /* Reference param save area */ 311#endif 312 313 comiclr,>>= __NR_Linux_syscalls, %r20, %r0 314 b,n .Lsyscall_nosys 315 316 LDREGX %r20(%r19), %r19 317 318 /* If this is a sys_rt_sigreturn call, and the signal was received 319 * when not in_syscall, then we want to return via syscall_exit_rfi, 320 * not syscall_exit. Signal no. in r20, in_syscall in r25 (see 321 * trampoline code in signal.c). 322 */ 323 ldi __NR_rt_sigreturn,%r2 324 comb,= %r2,%r20,.Ltrace_rt_sigreturn 325.Ltrace_in_syscall: 326 ldil L%tracesys_exit,%r2 327 be 0(%sr7,%r19) 328 ldo R%tracesys_exit(%r2),%r2 329 330 /* Do *not* call this function on the gateway page, because it 331 makes a direct call to syscall_trace. */ 332 333tracesys_exit: 334 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 335 LDREG TI_TASK(%r1), %r1 336#ifdef CONFIG_64BIT 337 ldo -16(%r30),%r29 /* Reference param save area */ 338#endif 339 bl syscall_trace, %r2 340 STREG %r28,TASK_PT_GR28(%r1) /* save return value now */ 341 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 342 LDREG TI_TASK(%r1), %r1 343 LDREG TASK_PT_GR28(%r1), %r28 /* Restore return val. */ 344 345 ldil L%syscall_exit,%r1 346 be,n R%syscall_exit(%sr7,%r1) 347 348.Ltrace_rt_sigreturn: 349 comib,<> 0,%r25,.Ltrace_in_syscall 350 ldil L%tracesys_sigexit,%r2 351 be 0(%sr7,%r19) 352 ldo R%tracesys_sigexit(%r2),%r2 353 354tracesys_sigexit: 355 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 356 LDREG 0(%r1), %r1 357#ifdef CONFIG_64BIT 358 ldo -16(%r30),%r29 /* Reference param save area */ 359#endif 360 bl syscall_trace, %r2 361 nop 362 363 ldil L%syscall_exit_rfi,%r1 364 be,n R%syscall_exit_rfi(%sr7,%r1) 365 366 367 /********************************************************* 368 32/64-bit Light-Weight-Syscall ABI 369 370 * - Indicates a hint for userspace inline asm 371 implementations. 372 373 Syscall number (caller-saves) 374 - %r20 375 * In asm clobber. 376 377 Argument registers (caller-saves) 378 - %r26, %r25, %r24, %r23, %r22 379 * In asm input. 380 381 Return registers (caller-saves) 382 - %r28 (return), %r21 (errno) 383 * In asm output. 384 385 Caller-saves registers 386 - %r1, %r27, %r29 387 - %r2 (return pointer) 388 - %r31 (ble link register) 389 * In asm clobber. 390 391 Callee-saves registers 392 - %r3-%r18 393 - %r30 (stack pointer) 394 * Not in asm clobber. 395 396 If userspace is 32-bit: 397 Callee-saves registers 398 - %r19 (32-bit PIC register) 399 400 Differences from 32-bit calling convention: 401 - Syscall number in %r20 402 - Additional argument register %r22 (arg4) 403 - Callee-saves %r19. 404 405 If userspace is 64-bit: 406 Callee-saves registers 407 - %r27 (64-bit PIC register) 408 409 Differences from 64-bit calling convention: 410 - Syscall number in %r20 411 - Additional argument register %r22 (arg4) 412 - Callee-saves %r27. 413 414 Error codes returned by entry path: 415 416 ENOSYS - r20 was an invalid LWS number. 417 418 *********************************************************/ 419lws_start: 420 /* Gate and ensure we return to userspace */ 421 gate .+8, %r0 422 depi 3, 31, 2, %r31 /* Ensure we return to userspace */ 423 424#ifdef CONFIG_64BIT 425 /* FIXME: If we are a 64-bit kernel just 426 * turn this on unconditionally. 427 */ 428 ssm PSW_SM_W, %r1 429 extrd,u %r1,PSW_W_BIT,1,%r1 430 /* sp must be aligned on 4, so deposit the W bit setting into 431 * the bottom of sp temporarily */ 432 or,ev %r1,%r30,%r30 433 434 /* Clip LWS number to a 32-bit value always */ 435 depdi 0, 31, 32, %r20 436#endif 437 438 /* Is the lws entry number valid? */ 439 comiclr,>>= __NR_lws_entries, %r20, %r0 440 b,n lws_exit_nosys 441 442 /* WARNING: Trashing sr2 and sr3 */ 443 mfsp %sr7,%r1 /* get userspace into sr3 */ 444 mtsp %r1,%sr3 445 mtsp %r0,%sr2 /* get kernel space into sr2 */ 446 447 /* Load table start */ 448 ldil L%lws_table, %r1 449 ldo R%lws_table(%r1), %r28 /* Scratch use of r28 */ 450 LDREGX %r20(%sr2,r28), %r21 /* Scratch use of r21 */ 451 452 /* Jump to lws, lws table pointers already relocated */ 453 be,n 0(%sr2,%r21) 454 455lws_exit_nosys: 456 ldo -ENOSYS(%r0),%r21 /* set errno */ 457 /* Fall through: Return to userspace */ 458 459lws_exit: 460#ifdef CONFIG_64BIT 461 /* decide whether to reset the wide mode bit 462 * 463 * For a syscall, the W bit is stored in the lowest bit 464 * of sp. Extract it and reset W if it is zero */ 465 extrd,u,*<> %r30,63,1,%r1 466 rsm PSW_SM_W, %r0 467 /* now reset the lowest bit of sp if it was set */ 468 xor %r30,%r1,%r30 469#endif 470 be,n 0(%sr3, %r31) 471 472 473 474 /*************************************************** 475 Implementing CAS as an atomic operation: 476 477 %r26 - Address to examine 478 %r25 - Old value to check (old) 479 %r24 - New value to set (new) 480 %r28 - Return prev through this register. 481 %r21 - Kernel error code 482 483 If debugging is DISabled: 484 485 %r21 has the following meanings: 486 487 EAGAIN - CAS is busy, ldcw failed, try again. 488 EFAULT - Read or write failed. 489 490 If debugging is enabled: 491 492 EDEADLOCK - CAS called recursively. 493 EAGAIN && r28 == 1 - CAS is busy. Lock contended. 494 EAGAIN && r28 == 2 - CAS is busy. ldcw failed. 495 EFAULT - Read or write failed. 496 497 Scratch: r20, r28, r1 498 499 ****************************************************/ 500 501 /* Do not enable LWS debugging */ 502#define ENABLE_LWS_DEBUG 0 503 504 /* ELF64 Process entry path */ 505lws_compare_and_swap64: 506#ifdef CONFIG_64BIT 507 b,n lws_compare_and_swap 508#else 509 /* If we are not a 64-bit kernel, then we don't 510 * have 64-bit input registers, and calling 511 * the 64-bit LWS CAS returns ENOSYS. 512 */ 513 b,n lws_exit_nosys 514#endif 515 516 /* ELF32 Process entry path */ 517lws_compare_and_swap32: 518#ifdef CONFIG_64BIT 519 /* Clip all the input registers */ 520 depdi 0, 31, 32, %r26 521 depdi 0, 31, 32, %r25 522 depdi 0, 31, 32, %r24 523#endif 524 525lws_compare_and_swap: 526#ifdef CONFIG_SMP 527 /* Load start of lock table */ 528 ldil L%lws_lock_start, %r20 529 ldo R%lws_lock_start(%r20), %r28 530 531 /* Extract four bits from r26 and hash lock (Bits 4-7) */ 532 extru %r26, 27, 4, %r20 533 534 /* Find lock to use, the hash is either one of 0 to 535 15, multiplied by 16 (keep it 16-byte aligned) 536 and add to the lock table offset. */ 537 shlw %r20, 4, %r20 538 add %r20, %r28, %r20 539 540# if ENABLE_LWS_DEBUG 541 /* 542 DEBUG, check for deadlock! 543 If the thread register values are the same 544 then we were the one that locked it last and 545 this is a recurisve call that will deadlock. 546 We *must* giveup this call and fail. 547 */ 548 ldw 4(%sr2,%r20), %r28 /* Load thread register */ 549 /* WARNING: If cr27 cycles to the same value we have problems */ 550 mfctl %cr27, %r21 /* Get current thread register */ 551 cmpb,<>,n %r21, %r28, cas_lock /* Called recursive? */ 552 b lws_exit /* Return error! */ 553 ldo -EDEADLOCK(%r0), %r21 554cas_lock: 555 cmpb,=,n %r0, %r28, cas_nocontend /* Is nobody using it? */ 556 ldo 1(%r0), %r28 /* 1st case */ 557 b lws_exit /* Contended... */ 558 ldo -EAGAIN(%r0), %r21 /* Spin in userspace */ 559cas_nocontend: 560# endif 561/* ENABLE_LWS_DEBUG */ 562 563 LDCW 0(%sr2,%r20), %r28 /* Try to acquire the lock */ 564 cmpb,<>,n %r0, %r28, cas_action /* Did we get it? */ 565cas_wouldblock: 566 ldo 2(%r0), %r28 /* 2nd case */ 567 b lws_exit /* Contended... */ 568 ldo -EAGAIN(%r0), %r21 /* Spin in userspace */ 569#endif 570/* CONFIG_SMP */ 571 572 /* 573 prev = *addr; 574 if ( prev == old ) 575 *addr = new; 576 return prev; 577 */ 578 579 /* NOTES: 580 This all works becuse intr_do_signal 581 and schedule both check the return iasq 582 and see that we are on the kernel page 583 so this process is never scheduled off 584 or is ever sent any signal of any sort, 585 thus it is wholly atomic from usrspaces 586 perspective 587 */ 588cas_action: 589#if defined CONFIG_SMP && ENABLE_LWS_DEBUG 590 /* DEBUG */ 591 mfctl %cr27, %r1 592 stw %r1, 4(%sr2,%r20) 593#endif 594 /* The load and store could fail */ 5951: ldw 0(%sr3,%r26), %r28 596 sub,<> %r28, %r25, %r0 5972: stw %r24, 0(%sr3,%r26) 598#ifdef CONFIG_SMP 599 /* Free lock */ 600 stw %r20, 0(%sr2,%r20) 601# if ENABLE_LWS_DEBUG 602 /* Clear thread register indicator */ 603 stw %r0, 4(%sr2,%r20) 604# endif 605#endif 606 /* Return to userspace, set no error */ 607 b lws_exit 608 copy %r0, %r21 609 6103: 611 /* Error occured on load or store */ 612#ifdef CONFIG_SMP 613 /* Free lock */ 614 stw %r20, 0(%sr2,%r20) 615# if ENABLE_LWS_DEBUG 616 stw %r0, 4(%sr2,%r20) 617# endif 618#endif 619 b lws_exit 620 ldo -EFAULT(%r0),%r21 /* set errno */ 621 nop 622 nop 623 nop 624 nop 625 626 /* Two exception table entries, one for the load, 627 the other for the store. Either return -EFAULT. 628 Each of the entries must be relocated. */ 629 .section __ex_table,"aw" 630 ASM_ULONG_INSN (1b - linux_gateway_page), (3b - linux_gateway_page) 631 ASM_ULONG_INSN (2b - linux_gateway_page), (3b - linux_gateway_page) 632 .previous 633 634 635 /* Make sure nothing else is placed on this page */ 636 .align PAGE_SIZE 637END(linux_gateway_page) 638ENTRY(end_linux_gateway_page) 639 640 /* Relocate symbols assuming linux_gateway_page is mapped 641 to virtual address 0x0 */ 642 643#define LWS_ENTRY(_name_) ASM_ULONG_INSN (lws_##_name_ - linux_gateway_page) 644 645 .section .rodata,"a" 646 647 .align PAGE_SIZE 648 /* Light-weight-syscall table */ 649 /* Start of lws table. */ 650ENTRY(lws_table) 651 LWS_ENTRY(compare_and_swap32) /* 0 - ELF32 Atomic compare and swap */ 652 LWS_ENTRY(compare_and_swap64) /* 1 - ELF64 Atomic compare and swap */ 653END(lws_table) 654 /* End of lws table */ 655 656 .align PAGE_SIZE 657ENTRY(sys_call_table) 658#include "syscall_table.S" 659END(sys_call_table) 660 661#ifdef CONFIG_64BIT 662 .align PAGE_SIZE 663ENTRY(sys_call_table64) 664#define SYSCALL_TABLE_64BIT 665#include "syscall_table.S" 666END(sys_call_table64) 667#endif 668 669#ifdef CONFIG_SMP 670 /* 671 All light-weight-syscall atomic operations 672 will use this set of locks 673 674 NOTE: The lws_lock_start symbol must be 675 at least 16-byte aligned for safe use 676 with ldcw. 677 */ 678 .section .data 679 .align PAGE_SIZE 680ENTRY(lws_lock_start) 681 /* lws locks */ 682 .rept 16 683 /* Keep locks aligned at 16-bytes */ 684 .word 1 685 .word 0 686 .word 0 687 .word 0 688 .endr 689END(lws_lock_start) 690 .previous 691#endif 692/* CONFIG_SMP for lws_lock_start */ 693 694.end 695 696 697