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/offsets.h> 11#include <asm/unistd.h> 12#include <asm/errno.h> 13#include <asm/psw.h> 14#include <asm/thread_info.h> 15 16#include <asm/assembly.h> 17#include <asm/processor.h> 18 19 /* We fill the empty parts of the gateway page with 20 * something that will kill the kernel or a 21 * userspace application. 22 */ 23#define KILL_INSN break 0,0 24 25#include <linux/config.h> /* for CONFIG_SMP */ 26 27#ifdef __LP64__ 28 .level 2.0w 29#else 30 .level 1.1 31#endif 32 33#ifndef __LP64__ 34 .macro fixup_branch,lbl 35 b \lbl 36 .endm 37#else 38 .macro fixup_branch,lbl 39 ldil L%\lbl, %r1 40 ldo R%\lbl(%r1), %r1 41 bv,n %r0(%r1) 42 .endm 43#endif 44 45 .text 46 47 .import syscall_exit,code 48 .import syscall_exit_rfi,code 49 .export linux_gateway_page 50 51 /* Linux gateway page is aliased to virtual page 0 in the kernel 52 * address space. Since it is a gateway page it cannot be 53 * dereferenced, so null pointers will still fault. We start 54 * the actual entry point at 0x100. We put break instructions 55 * at the beginning of the page to trap null indirect function 56 * pointers. 57 */ 58 59 .align 4096 60linux_gateway_page: 61 62 /* ADDRESS 0x00 to 0xb0 = 176 bytes / 4 bytes per insn = 44 insns */ 63 .rept 44 64 KILL_INSN 65 .endr 66 67 /* ADDRESS 0xb0 to 0xb4, lws uses 1 insns for entry */ 68 /* Light-weight-syscall entry must always be located at 0xb0 */ 69 /* WARNING: Keep this number updated with table size changes */ 70#define __NR_lws_entries (2) 71 72lws_entry: 73 /* Unconditional branch to lws_start, located on the 74 same gateway page */ 75 b,n lws_start 76 77 /* Fill from 0xb4 to 0xe0 */ 78 .rept 11 79 KILL_INSN 80 .endr 81 82 /* This function MUST be located at 0xe0 for glibc's threading 83 mechanism to work. DO NOT MOVE THIS CODE EVER! */ 84set_thread_pointer: 85 gate .+8, %r0 /* increase privilege */ 86 depi 3, 31, 2, %r31 /* Ensure we return into user mode. */ 87 be 0(%sr7,%r31) /* return to user space */ 88 mtctl %r26, %cr27 /* move arg0 to the control register */ 89 90 /* Increase the chance of trapping if random jumps occur to this 91 address, fill from 0xf0 to 0x100 */ 92 .rept 4 93 KILL_INSN 94 .endr 95 96/* This address must remain fixed at 0x100 for glibc's syscalls to work */ 97 .align 256 98linux_gateway_entry: 99 gate .+8, %r0 /* become privileged */ 100 mtsp %r0,%sr4 /* get kernel space into sr4 */ 101 mtsp %r0,%sr5 /* get kernel space into sr5 */ 102 mtsp %r0,%sr6 /* get kernel space into sr6 */ 103 mfsp %sr7,%r1 /* save user sr7 */ 104 mtsp %r1,%sr3 /* and store it in sr3 */ 105 106#ifdef __LP64__ 107 /* for now we can *always* set the W bit on entry to the syscall 108 * since we don't support wide userland processes. We could 109 * also save the current SM other than in r0 and restore it on 110 * exit from the syscall, and also use that value to know 111 * whether to do narrow or wide syscalls. -PB 112 */ 113 ssm PSW_SM_W, %r1 114 extrd,u %r1,PSW_W_BIT,1,%r1 115 /* sp must be aligned on 4, so deposit the W bit setting into 116 * the bottom of sp temporarily */ 117 or,ev %r1,%r30,%r30 118 b,n 1f 119 /* The top halves of argument registers must be cleared on syscall 120 * entry from narrow executable. 121 */ 122 depdi 0, 31, 32, %r26 123 depdi 0, 31, 32, %r25 124 depdi 0, 31, 32, %r24 125 depdi 0, 31, 32, %r23 126 depdi 0, 31, 32, %r22 127 depdi 0, 31, 32, %r21 1281: 129#endif 130 mfctl %cr30,%r1 131 xor %r1,%r30,%r30 /* ye olde xor trick */ 132 xor %r1,%r30,%r1 133 xor %r1,%r30,%r30 134 135 ldo THREAD_SZ_ALGN+FRAME_SIZE(%r30),%r30 /* set up kernel stack */ 136 137 /* N.B.: It is critical that we don't set sr7 to 0 until r30 138 * contains a valid kernel stack pointer. It is also 139 * critical that we don't start using the kernel stack 140 * until after sr7 has been set to 0. 141 */ 142 143 mtsp %r0,%sr7 /* get kernel space into sr7 */ 144 STREGM %r1,FRAME_SIZE(%r30) /* save r1 (usp) here for now */ 145 mfctl %cr30,%r1 /* get task ptr in %r1 */ 146 LDREG TI_TASK(%r1),%r1 147 148 /* Save some registers for sigcontext and potential task 149 switch (see entry.S for the details of which ones are 150 saved/restored). TASK_PT_PSW is zeroed so we can see whether 151 a process is on a syscall or not. For an interrupt the real 152 PSW value is stored. This is needed for gdb and sys_ptrace. */ 153 STREG %r0, TASK_PT_PSW(%r1) 154 STREG %r2, TASK_PT_GR2(%r1) /* preserve rp */ 155 STREG %r19, TASK_PT_GR19(%r1) 156 157 LDREGM -FRAME_SIZE(%r30), %r2 /* get users sp back */ 158#ifdef __LP64__ 159 extrd,u %r2,63,1,%r19 /* W hidden in bottom bit */ 160#if 0 161 xor %r19,%r2,%r2 /* clear bottom bit */ 162 depd,z %r19,1,1,%r19 163 std %r19,TASK_PT_PSW(%r1) 164#endif 165#endif 166 STREG %r2, TASK_PT_GR30(%r1) /* ... and save it */ 167 168 STREG %r20, TASK_PT_GR20(%r1) 169 STREG %r21, TASK_PT_GR21(%r1) 170 STREG %r22, TASK_PT_GR22(%r1) 171 STREG %r23, TASK_PT_GR23(%r1) /* 4th argument */ 172 STREG %r24, TASK_PT_GR24(%r1) /* 3rd argument */ 173 STREG %r25, TASK_PT_GR25(%r1) /* 2nd argument */ 174 STREG %r26, TASK_PT_GR26(%r1) /* 1st argument */ 175 STREG %r27, TASK_PT_GR27(%r1) /* user dp */ 176 STREG %r28, TASK_PT_GR28(%r1) /* return value 0 */ 177 STREG %r28, TASK_PT_ORIG_R28(%r1) /* return value 0 (saved for signals) */ 178 STREG %r29, TASK_PT_GR29(%r1) /* return value 1 */ 179 STREG %r31, TASK_PT_GR31(%r1) /* preserve syscall return ptr */ 180 181 ldo TASK_PT_FR0(%r1), %r27 /* save fpregs from the kernel */ 182 save_fp %r27 /* or potential task switch */ 183 184 mfctl %cr11, %r27 /* i.e. SAR */ 185 STREG %r27, TASK_PT_SAR(%r1) 186 187 loadgp 188 189#ifdef __LP64__ 190 ldo -16(%r30),%r29 /* Reference param save area */ 191 copy %r19,%r2 /* W bit back to r2 */ 192#else 193 /* no need to save these on stack in wide mode because the first 8 194 * args are passed in registers */ 195 stw %r22, -52(%r30) /* 5th argument */ 196 stw %r21, -56(%r30) /* 6th argument */ 197#endif 198 199 /* Are we being ptraced? */ 200 mfctl %cr30, %r1 201 LDREG TI_TASK(%r1),%r1 202 LDREG TASK_PTRACE(%r1), %r1 203 bb,<,n %r1,31,.Ltracesys 204 205 /* Note! We cannot use the syscall table that is mapped 206 nearby since the gateway page is mapped execute-only. */ 207 208#ifdef __LP64__ 209 ldil L%sys_call_table, %r1 210 or,= %r2,%r2,%r2 211 addil L%(sys_call_table64-sys_call_table), %r1 212 ldo R%sys_call_table(%r1), %r19 213 or,= %r2,%r2,%r2 214 ldo R%sys_call_table64(%r1), %r19 215#else 216 ldil L%sys_call_table, %r1 217 ldo R%sys_call_table(%r1), %r19 218#endif 219 comiclr,>>= __NR_Linux_syscalls, %r20, %r0 220 b,n .Lsyscall_nosys 221 222 LDREGX %r20(%r19), %r19 223 224 /* If this is a sys_rt_sigreturn call, and the signal was received 225 * when not in_syscall, then we want to return via syscall_exit_rfi, 226 * not syscall_exit. Signal no. in r20, in_syscall in r25 (see 227 * trampoline code in signal.c). 228 */ 229 ldi __NR_rt_sigreturn,%r2 230 comb,= %r2,%r20,.Lrt_sigreturn 231.Lin_syscall: 232 ldil L%syscall_exit,%r2 233 be 0(%sr7,%r19) 234 ldo R%syscall_exit(%r2),%r2 235.Lrt_sigreturn: 236 comib,<> 0,%r25,.Lin_syscall 237 ldil L%syscall_exit_rfi,%r2 238 be 0(%sr7,%r19) 239 ldo R%syscall_exit_rfi(%r2),%r2 240 241 /* Note! Because we are not running where we were linked, any 242 calls to functions external to this file must be indirect. To 243 be safe, we apply the opposite rule to functions within this 244 file, with local labels given to them to ensure correctness. */ 245 246.Lsyscall_nosys: 247syscall_nosys: 248 ldil L%syscall_exit,%r1 249 be R%syscall_exit(%sr7,%r1) 250 ldo -ENOSYS(%r0),%r28 /* set errno */ 251 252 253/* Warning! This trace code is a virtual duplicate of the code above so be 254 * sure to maintain both! */ 255.Ltracesys: 256tracesys: 257 /* Need to save more registers so the debugger can see where we 258 * are. This saves only the lower 8 bits of PSW, so that the C 259 * bit is still clear on syscalls, and the D bit is set if this 260 * full register save path has been executed. We check the D 261 * bit on syscall_return_rfi to determine which registers to 262 * restore. An interrupt results in a full PSW saved with the 263 * C bit set, a non-straced syscall entry results in C and D clear 264 * in the saved PSW. 265 */ 266 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 267 LDREG TI_TASK(%r1), %r1 268 ssm 0,%r2 269 STREG %r2,TASK_PT_PSW(%r1) /* Lower 8 bits only!! */ 270 mfsp %sr0,%r2 271 STREG %r2,TASK_PT_SR0(%r1) 272 mfsp %sr1,%r2 273 STREG %r2,TASK_PT_SR1(%r1) 274 mfsp %sr2,%r2 275 STREG %r2,TASK_PT_SR2(%r1) 276 mfsp %sr3,%r2 277 STREG %r2,TASK_PT_SR3(%r1) 278 STREG %r2,TASK_PT_SR4(%r1) 279 STREG %r2,TASK_PT_SR5(%r1) 280 STREG %r2,TASK_PT_SR6(%r1) 281 STREG %r2,TASK_PT_SR7(%r1) 282 STREG %r2,TASK_PT_IASQ0(%r1) 283 STREG %r2,TASK_PT_IASQ1(%r1) 284 LDREG TASK_PT_GR31(%r1),%r2 285 STREG %r2,TASK_PT_IAOQ0(%r1) 286 ldo 4(%r2),%r2 287 STREG %r2,TASK_PT_IAOQ1(%r1) 288 ldo TASK_REGS(%r1),%r2 289 /* reg_save %r2 */ 290 STREG %r3,PT_GR3(%r2) 291 STREG %r4,PT_GR4(%r2) 292 STREG %r5,PT_GR5(%r2) 293 STREG %r6,PT_GR6(%r2) 294 STREG %r7,PT_GR7(%r2) 295 STREG %r8,PT_GR8(%r2) 296 STREG %r9,PT_GR9(%r2) 297 STREG %r10,PT_GR10(%r2) 298 STREG %r11,PT_GR11(%r2) 299 STREG %r12,PT_GR12(%r2) 300 STREG %r13,PT_GR13(%r2) 301 STREG %r14,PT_GR14(%r2) 302 STREG %r15,PT_GR15(%r2) 303 STREG %r16,PT_GR16(%r2) 304 STREG %r17,PT_GR17(%r2) 305 STREG %r18,PT_GR18(%r2) 306 /* Finished saving things for the debugger */ 307 308 ldil L%syscall_trace,%r1 309 ldil L%tracesys_next,%r2 310 be R%syscall_trace(%sr7,%r1) 311 ldo R%tracesys_next(%r2),%r2 312 313tracesys_next: 314 ldil L%sys_call_table,%r1 315 ldo R%sys_call_table(%r1), %r19 316 317 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 318 LDREG TI_TASK(%r1), %r1 319 LDREG TASK_PT_GR20(%r1), %r20 320 LDREG TASK_PT_GR26(%r1), %r26 /* Restore the users args */ 321 LDREG TASK_PT_GR25(%r1), %r25 322 LDREG TASK_PT_GR24(%r1), %r24 323 LDREG TASK_PT_GR23(%r1), %r23 324#ifdef __LP64__ 325 LDREG TASK_PT_GR22(%r1), %r22 326 LDREG TASK_PT_GR21(%r1), %r21 327 ldo -16(%r30),%r29 /* Reference param save area */ 328#endif 329 330 comiclr,>>= __NR_Linux_syscalls, %r20, %r0 331 b,n .Lsyscall_nosys 332 333 LDREGX %r20(%r19), %r19 334 335 /* If this is a sys_rt_sigreturn call, and the signal was received 336 * when not in_syscall, then we want to return via syscall_exit_rfi, 337 * not syscall_exit. Signal no. in r20, in_syscall in r25 (see 338 * trampoline code in signal.c). 339 */ 340 ldi __NR_rt_sigreturn,%r2 341 comb,= %r2,%r20,.Ltrace_rt_sigreturn 342.Ltrace_in_syscall: 343 ldil L%tracesys_exit,%r2 344 be 0(%sr7,%r19) 345 ldo R%tracesys_exit(%r2),%r2 346 347 /* Do *not* call this function on the gateway page, because it 348 makes a direct call to syscall_trace. */ 349 350tracesys_exit: 351 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 352 LDREG TI_TASK(%r1), %r1 353#ifdef __LP64__ 354 ldo -16(%r30),%r29 /* Reference param save area */ 355#endif 356 bl syscall_trace, %r2 357 STREG %r28,TASK_PT_GR28(%r1) /* save return value now */ 358 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 359 LDREG TI_TASK(%r1), %r1 360 LDREG TASK_PT_GR28(%r1), %r28 /* Restore return val. */ 361 362 ldil L%syscall_exit,%r1 363 be,n R%syscall_exit(%sr7,%r1) 364 365.Ltrace_rt_sigreturn: 366 comib,<> 0,%r25,.Ltrace_in_syscall 367 ldil L%tracesys_sigexit,%r2 368 be 0(%sr7,%r19) 369 ldo R%tracesys_sigexit(%r2),%r2 370 371tracesys_sigexit: 372 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 373 LDREG 0(%r1), %r1 374#ifdef __LP64__ 375 ldo -16(%r30),%r29 /* Reference param save area */ 376#endif 377 bl syscall_trace, %r2 378 nop 379 380 ldil L%syscall_exit_rfi,%r1 381 be,n R%syscall_exit_rfi(%sr7,%r1) 382 383 384 /********************************************************* 385 Light-weight-syscall code 386 387 r20 - lws number 388 r26,r25,r24,r23,r22 - Input registers 389 r28 - Function return register 390 r21 - Error code. 391 392 Scracth: Any of the above that aren't being 393 currently used, including r1. 394 395 Return pointer: r31 (Not usable) 396 397 Error codes returned by entry path: 398 399 ENOSYS - r20 was an invalid LWS number. 400 401 *********************************************************/ 402lws_start: 403 /* Gate and ensure we return to userspace */ 404 gate .+8, %r0 405 depi 3, 31, 2, %r31 /* Ensure we return to userspace */ 406 407#ifdef __LP64__ 408 /* FIXME: If we are a 64-bit kernel just 409 * turn this on unconditionally. 410 */ 411 ssm PSW_SM_W, %r1 412 extrd,u %r1,PSW_W_BIT,1,%r1 413 /* sp must be aligned on 4, so deposit the W bit setting into 414 * the bottom of sp temporarily */ 415 or,ev %r1,%r30,%r30 416 417 /* Clip LWS number to a 32-bit value always */ 418 depdi 0, 31, 32, %r20 419#endif 420 421 /* Is the lws entry number valid? */ 422 comiclr,>>= __NR_lws_entries, %r20, %r0 423 b,n lws_exit_nosys 424 425 /* WARNING: Trashing sr2 and sr3 */ 426 mfsp %sr7,%r1 /* get userspace into sr3 */ 427 mtsp %r1,%sr3 428 mtsp %r0,%sr2 /* get kernel space into sr2 */ 429 430 /* Load table start */ 431 ldil L%lws_table, %r1 432 ldo R%lws_table(%r1), %r28 /* Scratch use of r28 */ 433 LDREGX %r20(%sr2,r28), %r21 /* Scratch use of r21 */ 434 435 /* Jump to lws, lws table pointers already relocated */ 436 be,n 0(%sr2,%r21) 437 438lws_exit_nosys: 439 ldo -ENOSYS(%r0),%r21 /* set errno */ 440 /* Fall through: Return to userspace */ 441 442lws_exit: 443#ifdef __LP64__ 444 /* decide whether to reset the wide mode bit 445 * 446 * For a syscall, the W bit is stored in the lowest bit 447 * of sp. Extract it and reset W if it is zero */ 448 extrd,u,*<> %r30,63,1,%r1 449 rsm PSW_SM_W, %r0 450 /* now reset the lowest bit of sp if it was set */ 451 xor %r30,%r1,%r30 452#endif 453 be,n 0(%sr3, %r31) 454 455 456 457 /*************************************************** 458 Implementing CAS as an atomic operation: 459 460 %r26 - Address to examine 461 %r25 - Old value to check (old) 462 %r24 - New value to set (new) 463 %r28 - Return prev through this register. 464 %r21 - Kernel error code 465 466 If debugging is DISabled: 467 468 %r21 has the following meanings: 469 470 EAGAIN - CAS is busy, ldcw failed, try again. 471 EFAULT - Read or write failed. 472 473 If debugging is enabled: 474 475 EDEADLOCK - CAS called recursively. 476 EAGAIN && r28 == 1 - CAS is busy. Lock contended. 477 EAGAIN && r28 == 2 - CAS is busy. ldcw failed. 478 EFAULT - Read or write failed. 479 480 Scratch: r20, r28, r1 481 482 ****************************************************/ 483 484 /* Do not enable LWS debugging */ 485#define ENABLE_LWS_DEBUG 0 486 487 /* ELF64 Process entry path */ 488lws_compare_and_swap64: 489#ifdef __LP64__ 490 b,n lws_compare_and_swap 491#else 492 /* If we are not a 64-bit kernel, then we don't 493 * implement having 64-bit input registers 494 */ 495 b,n lws_exit_nosys 496#endif 497 498 /* ELF32 Process entry path */ 499lws_compare_and_swap32: 500#ifdef __LP64__ 501 /* Clip all the input registers */ 502 depdi 0, 31, 32, %r26 503 depdi 0, 31, 32, %r25 504 depdi 0, 31, 32, %r24 505#endif 506 507lws_compare_and_swap: 508#ifdef CONFIG_SMP 509 /* Load start of lock table */ 510 ldil L%lws_lock_start, %r20 511 ldo R%lws_lock_start(%r20), %r28 512 513 /* Extract four bits from r26 and hash lock (Bits 4-7) */ 514 extru %r26, 27, 4, %r20 515 516 /* Find lock to use, the hash is either one of 0 to 517 15, multiplied by 16 (keep it 16-byte aligned) 518 and add to the lock table offset. */ 519 shlw %r20, 4, %r20 520 add %r20, %r28, %r20 521 522# ifdef ENABLE_LWS_DEBUG 523 /* 524 DEBUG, check for deadlock! 525 If the thread register values are the same 526 then we were the one that locked it last and 527 this is a recurisve call that will deadlock. 528 We *must* giveup this call and fail. 529 */ 530 ldw 4(%sr2,%r20), %r28 /* Load thread register */ 531 mfctl %cr27, %r21 /* Get current thread register */ 532 cmpb,<>,n %r21, %r28, cas_lock /* Called recursive? */ 533 b lws_exit /* Return error! */ 534 ldo -EDEADLOCK(%r0), %r21 535cas_lock: 536 cmpb,=,n %r0, %r28, cas_nocontend /* Is nobody using it? */ 537 ldo 1(%r0), %r28 /* 1st case */ 538 b lws_exit /* Contended... */ 539 ldo -EAGAIN(%r0), %r21 /* Spin in userspace */ 540cas_nocontend: 541# endif 542/* ENABLE_LWS_DEBUG */ 543 544 ldcw 0(%sr2,%r20), %r28 /* Try to acquire the lock */ 545 cmpb,<>,n %r0, %r28, cas_action /* Did we get it? */ 546cas_wouldblock: 547 ldo 2(%r0), %r28 /* 2nd case */ 548 b lws_exit /* Contended... */ 549 ldo -EAGAIN(%r0), %r21 /* Spin in userspace */ 550#endif 551/* CONFIG_SMP */ 552 553 /* 554 prev = *addr; 555 if ( prev == old ) 556 *addr = new; 557 return prev; 558 */ 559 560 /* NOTES: 561 This all works becuse intr_do_signal 562 and schedule both check the return iasq 563 and see that we are on the kernel page 564 so this process is never scheduled off 565 or is ever sent any signal of any sort, 566 thus it is wholly atomic from usrspaces 567 perspective 568 */ 569cas_action: 570#if defined CONFIG_SMP && defined ENABLE_LWS_DEBUG 571 /* DEBUG */ 572 mfctl %cr27, %r1 573 stw %r1, 4(%sr2,%r20) 574#endif 575 /* The load and store could fail */ 5761: ldw 0(%sr3,%r26), %r28 577 sub,<> %r28, %r25, %r0 5782: stw %r24, 0(%sr3,%r26) 579#ifdef CONFIG_SMP 580 /* Free lock */ 581 stw %r20, 0(%sr2,%r20) 582# ifdef ENABLE_LWS_DEBUG 583 /* Clear thread register indicator */ 584 stw %r0, 4(%sr2,%r20) 585# endif 586#endif 587 /* Return to userspace, set no error */ 588 b lws_exit 589 copy %r0, %r21 590 5913: 592 /* Error occured on load or store */ 593#ifdef CONFIG_SMP 594 /* Free lock */ 595 stw %r20, 0(%sr2,%r20) 596# ifdef ENABLE_LWS_DEBUG 597 stw %r0, 4(%sr2,%r20) 598# endif 599#endif 600 b lws_exit 601 ldo -EFAULT(%r0),%r21 /* set errno */ 602 nop 603 nop 604 nop 605 nop 606 607 /* Two exception table entries, one for the load, 608 the other for the store. Either return -EFAULT. 609 Each of the entries must be relocated. */ 610 .section __ex_table,"aw" 611#ifdef __LP64__ 612 /* Pad the address calculation */ 613 .word 0,(2b - linux_gateway_page) 614 .word 0,(3b - linux_gateway_page) 615#else 616 .word (2b - linux_gateway_page) 617 .word (3b - linux_gateway_page) 618#endif 619 .previous 620 621 .section __ex_table,"aw" 622#ifdef __LP64__ 623 /* Pad the address calculation */ 624 .word 0,(1b - linux_gateway_page) 625 .word 0,(3b - linux_gateway_page) 626#else 627 .word (1b - linux_gateway_page) 628 .word (3b - linux_gateway_page) 629#endif 630 .previous 631 632end_compare_and_swap: 633 634 /* Make sure nothing else is placed on this page */ 635 .align 4096 636 .export end_linux_gateway_page 637end_linux_gateway_page: 638 639 /* Relocate symbols assuming linux_gateway_page is mapped 640 to virtual address 0x0 */ 641#ifdef __LP64__ 642 /* FIXME: The code will always be on the gateay page 643 and thus it will be on the first 4k, the 644 assembler seems to think that the final 645 subtraction result is only a word in 646 length, so we pad the value. 647 */ 648#define LWS_ENTRY(_name_) .word 0,(lws_##_name_ - linux_gateway_page) 649#else 650#define LWS_ENTRY(_name_) .word (lws_##_name_ - linux_gateway_page) 651#endif 652 653 .align 4096 654 /* Light-weight-syscall table */ 655 /* Start of lws table. */ 656 .export lws_table 657.Llws_table: 658lws_table: 659 LWS_ENTRY(compare_and_swap32) /* 0 - ELF32 Atomic compare and swap */ 660 LWS_ENTRY(compare_and_swap64) /* 1 - ELF64 Atomic compare and swap */ 661 /* End of lws table */ 662 663 .align 4096 664 .export sys_call_table 665.Lsys_call_table: 666sys_call_table: 667#include "syscall_table.S" 668 669#ifdef __LP64__ 670 .align 4096 671 .export sys_call_table64 672.Lsys_call_table64: 673sys_call_table64: 674#define SYSCALL_TABLE_64BIT 675#include "syscall_table.S" 676#endif 677 678#ifdef CONFIG_SMP 679 /* 680 All light-weight-syscall atomic operations 681 will use this set of locks 682 */ 683 .section .data 684 .align 4096 685 .export lws_lock_start 686.Llws_lock_start: 687lws_lock_start: 688 /* lws locks */ 689 .align 16 690 .rept 16 691 /* Keep locks aligned at 16-bytes */ 692 .word 1 693 .word 0 694 .word 0 695 .word 0 696 .endr 697 .previous 698#endif 699/* CONFIG_SMP for lws_lock_start */ 700 701.end 702 703 704