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#include <linux/config.h> /* for CONFIG_SMP */ 10 11#include <asm/asm-offsets.h> 12#include <asm/unistd.h> 13#include <asm/errno.h> 14#include <asm/psw.h> 15#include <asm/thread_info.h> 16 17#include <asm/assembly.h> 18#include <asm/processor.h> 19 20 /* We fill the empty parts of the gateway page with 21 * something that will kill the kernel or a 22 * userspace application. 23 */ 24#define KILL_INSN break 0,0 25 26#ifdef CONFIG_64BIT 27 .level 2.0w 28#else 29 .level 1.1 30#endif 31 32#ifndef CONFIG_64BIT 33 .macro fixup_branch,lbl 34 b \lbl 35 .endm 36#else 37 .macro fixup_branch,lbl 38 ldil L%\lbl, %r1 39 ldo R%\lbl(%r1), %r1 40 bv,n %r0(%r1) 41 .endm 42#endif 43 44 .text 45 46 .import syscall_exit,code 47 .import syscall_exit_rfi,code 48 .export linux_gateway_page 49 50 /* Linux gateway page is aliased to virtual page 0 in the kernel 51 * address space. Since it is a gateway page it cannot be 52 * dereferenced, so null pointers will still fault. We start 53 * the actual entry point at 0x100. We put break instructions 54 * at the beginning of the page to trap null indirect function 55 * pointers. 56 */ 57 58 .align 4096 59linux_gateway_page: 60 61 /* ADDRESS 0x00 to 0xb0 = 176 bytes / 4 bytes per insn = 44 insns */ 62 .rept 44 63 KILL_INSN 64 .endr 65 66 /* ADDRESS 0xb0 to 0xb4, lws uses 1 insns for entry */ 67 /* Light-weight-syscall entry must always be located at 0xb0 */ 68 /* WARNING: Keep this number updated with table size changes */ 69#define __NR_lws_entries (2) 70 71lws_entry: 72 /* Unconditional branch to lws_start, located on the 73 same gateway page */ 74 b,n lws_start 75 76 /* Fill from 0xb4 to 0xe0 */ 77 .rept 11 78 KILL_INSN 79 .endr 80 81 /* This function MUST be located at 0xe0 for glibc's threading 82 mechanism to work. DO NOT MOVE THIS CODE EVER! */ 83set_thread_pointer: 84 gate .+8, %r0 /* increase privilege */ 85 depi 3, 31, 2, %r31 /* Ensure we return into user mode. */ 86 be 0(%sr7,%r31) /* return to user space */ 87 mtctl %r26, %cr27 /* move arg0 to the control register */ 88 89 /* Increase the chance of trapping if random jumps occur to this 90 address, fill from 0xf0 to 0x100 */ 91 .rept 4 92 KILL_INSN 93 .endr 94 95/* This address must remain fixed at 0x100 for glibc's syscalls to work */ 96 .align 256 97linux_gateway_entry: 98 gate .+8, %r0 /* become privileged */ 99 mtsp %r0,%sr4 /* get kernel space into sr4 */ 100 mtsp %r0,%sr5 /* get kernel space into sr5 */ 101 mtsp %r0,%sr6 /* get kernel space into sr6 */ 102 mfsp %sr7,%r1 /* save user sr7 */ 103 mtsp %r1,%sr3 /* and store it in sr3 */ 104 105#ifdef CONFIG_64BIT 106 /* for now we can *always* set the W bit on entry to the syscall 107 * since we don't support wide userland processes. We could 108 * also save the current SM other than in r0 and restore it on 109 * exit from the syscall, and also use that value to know 110 * whether to do narrow or wide syscalls. -PB 111 */ 112 ssm PSW_SM_W, %r1 113 extrd,u %r1,PSW_W_BIT,1,%r1 114 /* sp must be aligned on 4, so deposit the W bit setting into 115 * the bottom of sp temporarily */ 116 or,ev %r1,%r30,%r30 117 b,n 1f 118 /* The top halves of argument registers must be cleared on syscall 119 * entry from narrow executable. 120 */ 121 depdi 0, 31, 32, %r26 122 depdi 0, 31, 32, %r25 123 depdi 0, 31, 32, %r24 124 depdi 0, 31, 32, %r23 125 depdi 0, 31, 32, %r22 126 depdi 0, 31, 32, %r21 1271: 128#endif 129 mfctl %cr30,%r1 130 xor %r1,%r30,%r30 /* ye olde xor trick */ 131 xor %r1,%r30,%r1 132 xor %r1,%r30,%r30 133 134 ldo THREAD_SZ_ALGN+FRAME_SIZE(%r30),%r30 /* set up kernel stack */ 135 136 /* N.B.: It is critical that we don't set sr7 to 0 until r30 137 * contains a valid kernel stack pointer. It is also 138 * critical that we don't start using the kernel stack 139 * until after sr7 has been set to 0. 140 */ 141 142 mtsp %r0,%sr7 /* get kernel space into sr7 */ 143 STREGM %r1,FRAME_SIZE(%r30) /* save r1 (usp) here for now */ 144 mfctl %cr30,%r1 /* get task ptr in %r1 */ 145 LDREG TI_TASK(%r1),%r1 146 147 /* Save some registers for sigcontext and potential task 148 switch (see entry.S for the details of which ones are 149 saved/restored). TASK_PT_PSW is zeroed so we can see whether 150 a process is on a syscall or not. For an interrupt the real 151 PSW value is stored. This is needed for gdb and sys_ptrace. */ 152 STREG %r0, TASK_PT_PSW(%r1) 153 STREG %r2, TASK_PT_GR2(%r1) /* preserve rp */ 154 STREG %r19, TASK_PT_GR19(%r1) 155 156 LDREGM -FRAME_SIZE(%r30), %r2 /* get users sp back */ 157#ifdef CONFIG_64BIT 158 extrd,u %r2,63,1,%r19 /* W hidden in bottom bit */ 159#if 0 160 xor %r19,%r2,%r2 /* clear bottom bit */ 161 depd,z %r19,1,1,%r19 162 std %r19,TASK_PT_PSW(%r1) 163#endif 164#endif 165 STREG %r2, TASK_PT_GR30(%r1) /* ... and save it */ 166 167 STREG %r20, TASK_PT_GR20(%r1) 168 STREG %r21, TASK_PT_GR21(%r1) 169 STREG %r22, TASK_PT_GR22(%r1) 170 STREG %r23, TASK_PT_GR23(%r1) /* 4th argument */ 171 STREG %r24, TASK_PT_GR24(%r1) /* 3rd argument */ 172 STREG %r25, TASK_PT_GR25(%r1) /* 2nd argument */ 173 STREG %r26, TASK_PT_GR26(%r1) /* 1st argument */ 174 STREG %r27, TASK_PT_GR27(%r1) /* user dp */ 175 STREG %r28, TASK_PT_GR28(%r1) /* return value 0 */ 176 STREG %r28, TASK_PT_ORIG_R28(%r1) /* return value 0 (saved for signals) */ 177 STREG %r29, TASK_PT_GR29(%r1) /* return value 1 */ 178 STREG %r31, TASK_PT_GR31(%r1) /* preserve syscall return ptr */ 179 180 ldo TASK_PT_FR0(%r1), %r27 /* save fpregs from the kernel */ 181 save_fp %r27 /* or potential task switch */ 182 183 mfctl %cr11, %r27 /* i.e. SAR */ 184 STREG %r27, TASK_PT_SAR(%r1) 185 186 loadgp 187 188#ifdef CONFIG_64BIT 189 ldo -16(%r30),%r29 /* Reference param save area */ 190 copy %r19,%r2 /* W bit back to r2 */ 191#else 192 /* no need to save these on stack in wide mode because the first 8 193 * args are passed in registers */ 194 stw %r22, -52(%r30) /* 5th argument */ 195 stw %r21, -56(%r30) /* 6th argument */ 196#endif 197 198 /* Are we being ptraced? */ 199 mfctl %cr30, %r1 200 LDREG TI_TASK(%r1),%r1 201 LDREG TASK_PTRACE(%r1), %r1 202 bb,<,n %r1,31,.Ltracesys 203 204 /* Note! We cannot use the syscall table that is mapped 205 nearby since the gateway page is mapped execute-only. */ 206 207#ifdef CONFIG_64BIT 208 ldil L%sys_call_table, %r1 209 or,= %r2,%r2,%r2 210 addil L%(sys_call_table64-sys_call_table), %r1 211 ldo R%sys_call_table(%r1), %r19 212 or,= %r2,%r2,%r2 213 ldo R%sys_call_table64(%r1), %r19 214#else 215 ldil L%sys_call_table, %r1 216 ldo R%sys_call_table(%r1), %r19 217#endif 218 comiclr,>>= __NR_Linux_syscalls, %r20, %r0 219 b,n .Lsyscall_nosys 220 221 LDREGX %r20(%r19), %r19 222 223 /* If this is a sys_rt_sigreturn call, and the signal was received 224 * when not in_syscall, then we want to return via syscall_exit_rfi, 225 * not syscall_exit. Signal no. in r20, in_syscall in r25 (see 226 * trampoline code in signal.c). 227 */ 228 ldi __NR_rt_sigreturn,%r2 229 comb,= %r2,%r20,.Lrt_sigreturn 230.Lin_syscall: 231 ldil L%syscall_exit,%r2 232 be 0(%sr7,%r19) 233 ldo R%syscall_exit(%r2),%r2 234.Lrt_sigreturn: 235 comib,<> 0,%r25,.Lin_syscall 236 ldil L%syscall_exit_rfi,%r2 237 be 0(%sr7,%r19) 238 ldo R%syscall_exit_rfi(%r2),%r2 239 240 /* Note! Because we are not running where we were linked, any 241 calls to functions external to this file must be indirect. To 242 be safe, we apply the opposite rule to functions within this 243 file, with local labels given to them to ensure correctness. */ 244 245.Lsyscall_nosys: 246syscall_nosys: 247 ldil L%syscall_exit,%r1 248 be R%syscall_exit(%sr7,%r1) 249 ldo -ENOSYS(%r0),%r28 /* set errno */ 250 251 252/* Warning! This trace code is a virtual duplicate of the code above so be 253 * sure to maintain both! */ 254.Ltracesys: 255tracesys: 256 /* Need to save more registers so the debugger can see where we 257 * are. This saves only the lower 8 bits of PSW, so that the C 258 * bit is still clear on syscalls, and the D bit is set if this 259 * full register save path has been executed. We check the D 260 * bit on syscall_return_rfi to determine which registers to 261 * restore. An interrupt results in a full PSW saved with the 262 * C bit set, a non-straced syscall entry results in C and D clear 263 * in the saved PSW. 264 */ 265 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 266 LDREG TI_TASK(%r1), %r1 267 ssm 0,%r2 268 STREG %r2,TASK_PT_PSW(%r1) /* Lower 8 bits only!! */ 269 mfsp %sr0,%r2 270 STREG %r2,TASK_PT_SR0(%r1) 271 mfsp %sr1,%r2 272 STREG %r2,TASK_PT_SR1(%r1) 273 mfsp %sr2,%r2 274 STREG %r2,TASK_PT_SR2(%r1) 275 mfsp %sr3,%r2 276 STREG %r2,TASK_PT_SR3(%r1) 277 STREG %r2,TASK_PT_SR4(%r1) 278 STREG %r2,TASK_PT_SR5(%r1) 279 STREG %r2,TASK_PT_SR6(%r1) 280 STREG %r2,TASK_PT_SR7(%r1) 281 STREG %r2,TASK_PT_IASQ0(%r1) 282 STREG %r2,TASK_PT_IASQ1(%r1) 283 LDREG TASK_PT_GR31(%r1),%r2 284 STREG %r2,TASK_PT_IAOQ0(%r1) 285 ldo 4(%r2),%r2 286 STREG %r2,TASK_PT_IAOQ1(%r1) 287 ldo TASK_REGS(%r1),%r2 288 /* reg_save %r2 */ 289 STREG %r3,PT_GR3(%r2) 290 STREG %r4,PT_GR4(%r2) 291 STREG %r5,PT_GR5(%r2) 292 STREG %r6,PT_GR6(%r2) 293 STREG %r7,PT_GR7(%r2) 294 STREG %r8,PT_GR8(%r2) 295 STREG %r9,PT_GR9(%r2) 296 STREG %r10,PT_GR10(%r2) 297 STREG %r11,PT_GR11(%r2) 298 STREG %r12,PT_GR12(%r2) 299 STREG %r13,PT_GR13(%r2) 300 STREG %r14,PT_GR14(%r2) 301 STREG %r15,PT_GR15(%r2) 302 STREG %r16,PT_GR16(%r2) 303 STREG %r17,PT_GR17(%r2) 304 STREG %r18,PT_GR18(%r2) 305 /* Finished saving things for the debugger */ 306 307 ldil L%syscall_trace,%r1 308 ldil L%tracesys_next,%r2 309 be R%syscall_trace(%sr7,%r1) 310 ldo R%tracesys_next(%r2),%r2 311 312tracesys_next: 313 ldil L%sys_call_table,%r1 314 ldo R%sys_call_table(%r1), %r19 315 316 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 317 LDREG TI_TASK(%r1), %r1 318 LDREG TASK_PT_GR20(%r1), %r20 319 LDREG TASK_PT_GR26(%r1), %r26 /* Restore the users args */ 320 LDREG TASK_PT_GR25(%r1), %r25 321 LDREG TASK_PT_GR24(%r1), %r24 322 LDREG TASK_PT_GR23(%r1), %r23 323#ifdef CONFIG_64BIT 324 LDREG TASK_PT_GR22(%r1), %r22 325 LDREG TASK_PT_GR21(%r1), %r21 326 ldo -16(%r30),%r29 /* Reference param save area */ 327#endif 328 329 comiclr,>>= __NR_Linux_syscalls, %r20, %r0 330 b,n .Lsyscall_nosys 331 332 LDREGX %r20(%r19), %r19 333 334 /* If this is a sys_rt_sigreturn call, and the signal was received 335 * when not in_syscall, then we want to return via syscall_exit_rfi, 336 * not syscall_exit. Signal no. in r20, in_syscall in r25 (see 337 * trampoline code in signal.c). 338 */ 339 ldi __NR_rt_sigreturn,%r2 340 comb,= %r2,%r20,.Ltrace_rt_sigreturn 341.Ltrace_in_syscall: 342 ldil L%tracesys_exit,%r2 343 be 0(%sr7,%r19) 344 ldo R%tracesys_exit(%r2),%r2 345 346 /* Do *not* call this function on the gateway page, because it 347 makes a direct call to syscall_trace. */ 348 349tracesys_exit: 350 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 351 LDREG TI_TASK(%r1), %r1 352#ifdef CONFIG_64BIT 353 ldo -16(%r30),%r29 /* Reference param save area */ 354#endif 355 bl syscall_trace, %r2 356 STREG %r28,TASK_PT_GR28(%r1) /* save return value now */ 357 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 358 LDREG TI_TASK(%r1), %r1 359 LDREG TASK_PT_GR28(%r1), %r28 /* Restore return val. */ 360 361 ldil L%syscall_exit,%r1 362 be,n R%syscall_exit(%sr7,%r1) 363 364.Ltrace_rt_sigreturn: 365 comib,<> 0,%r25,.Ltrace_in_syscall 366 ldil L%tracesys_sigexit,%r2 367 be 0(%sr7,%r19) 368 ldo R%tracesys_sigexit(%r2),%r2 369 370tracesys_sigexit: 371 ldo -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr */ 372 LDREG 0(%r1), %r1 373#ifdef CONFIG_64BIT 374 ldo -16(%r30),%r29 /* Reference param save area */ 375#endif 376 bl syscall_trace, %r2 377 nop 378 379 ldil L%syscall_exit_rfi,%r1 380 be,n R%syscall_exit_rfi(%sr7,%r1) 381 382 383 /********************************************************* 384 Light-weight-syscall code 385 386 r20 - lws number 387 r26,r25,r24,r23,r22 - Input registers 388 r28 - Function return register 389 r21 - Error code. 390 391 Scracth: Any of the above that aren't being 392 currently used, including r1. 393 394 Return pointer: r31 (Not usable) 395 396 Error codes returned by entry path: 397 398 ENOSYS - r20 was an invalid LWS number. 399 400 *********************************************************/ 401lws_start: 402 /* Gate and ensure we return to userspace */ 403 gate .+8, %r0 404 depi 3, 31, 2, %r31 /* Ensure we return to userspace */ 405 406#ifdef CONFIG_64BIT 407 /* FIXME: If we are a 64-bit kernel just 408 * turn this on unconditionally. 409 */ 410 ssm PSW_SM_W, %r1 411 extrd,u %r1,PSW_W_BIT,1,%r1 412 /* sp must be aligned on 4, so deposit the W bit setting into 413 * the bottom of sp temporarily */ 414 or,ev %r1,%r30,%r30 415 416 /* Clip LWS number to a 32-bit value always */ 417 depdi 0, 31, 32, %r20 418#endif 419 420 /* Is the lws entry number valid? */ 421 comiclr,>>= __NR_lws_entries, %r20, %r0 422 b,n lws_exit_nosys 423 424 /* WARNING: Trashing sr2 and sr3 */ 425 mfsp %sr7,%r1 /* get userspace into sr3 */ 426 mtsp %r1,%sr3 427 mtsp %r0,%sr2 /* get kernel space into sr2 */ 428 429 /* Load table start */ 430 ldil L%lws_table, %r1 431 ldo R%lws_table(%r1), %r28 /* Scratch use of r28 */ 432 LDREGX %r20(%sr2,r28), %r21 /* Scratch use of r21 */ 433 434 /* Jump to lws, lws table pointers already relocated */ 435 be,n 0(%sr2,%r21) 436 437lws_exit_nosys: 438 ldo -ENOSYS(%r0),%r21 /* set errno */ 439 /* Fall through: Return to userspace */ 440 441lws_exit: 442#ifdef CONFIG_64BIT 443 /* decide whether to reset the wide mode bit 444 * 445 * For a syscall, the W bit is stored in the lowest bit 446 * of sp. Extract it and reset W if it is zero */ 447 extrd,u,*<> %r30,63,1,%r1 448 rsm PSW_SM_W, %r0 449 /* now reset the lowest bit of sp if it was set */ 450 xor %r30,%r1,%r30 451#endif 452 be,n 0(%sr3, %r31) 453 454 455 456 /*************************************************** 457 Implementing CAS as an atomic operation: 458 459 %r26 - Address to examine 460 %r25 - Old value to check (old) 461 %r24 - New value to set (new) 462 %r28 - Return prev through this register. 463 %r21 - Kernel error code 464 465 If debugging is DISabled: 466 467 %r21 has the following meanings: 468 469 EAGAIN - CAS is busy, ldcw failed, try again. 470 EFAULT - Read or write failed. 471 472 If debugging is enabled: 473 474 EDEADLOCK - CAS called recursively. 475 EAGAIN && r28 == 1 - CAS is busy. Lock contended. 476 EAGAIN && r28 == 2 - CAS is busy. ldcw failed. 477 EFAULT - Read or write failed. 478 479 Scratch: r20, r28, r1 480 481 ****************************************************/ 482 483 /* Do not enable LWS debugging */ 484#define ENABLE_LWS_DEBUG 0 485 486 /* ELF64 Process entry path */ 487lws_compare_and_swap64: 488#ifdef CONFIG_64BIT 489 b,n lws_compare_and_swap 490#else 491 /* If we are not a 64-bit kernel, then we don't 492 * implement having 64-bit input registers 493 */ 494 b,n lws_exit_nosys 495#endif 496 497 /* ELF32 Process entry path */ 498lws_compare_and_swap32: 499#ifdef CONFIG_64BIT 500 /* Clip all the input registers */ 501 depdi 0, 31, 32, %r26 502 depdi 0, 31, 32, %r25 503 depdi 0, 31, 32, %r24 504#endif 505 506lws_compare_and_swap: 507#ifdef CONFIG_SMP 508 /* Load start of lock table */ 509 ldil L%lws_lock_start, %r20 510 ldo R%lws_lock_start(%r20), %r28 511 512 /* Extract four bits from r26 and hash lock (Bits 4-7) */ 513 extru %r26, 27, 4, %r20 514 515 /* Find lock to use, the hash is either one of 0 to 516 15, multiplied by 16 (keep it 16-byte aligned) 517 and add to the lock table offset. */ 518 shlw %r20, 4, %r20 519 add %r20, %r28, %r20 520 521# ifdef ENABLE_LWS_DEBUG 522 /* 523 DEBUG, check for deadlock! 524 If the thread register values are the same 525 then we were the one that locked it last and 526 this is a recurisve call that will deadlock. 527 We *must* giveup this call and fail. 528 */ 529 ldw 4(%sr2,%r20), %r28 /* Load thread register */ 530 mfctl %cr27, %r21 /* Get current thread register */ 531 cmpb,<>,n %r21, %r28, cas_lock /* Called recursive? */ 532 b lws_exit /* Return error! */ 533 ldo -EDEADLOCK(%r0), %r21 534cas_lock: 535 cmpb,=,n %r0, %r28, cas_nocontend /* Is nobody using it? */ 536 ldo 1(%r0), %r28 /* 1st case */ 537 b lws_exit /* Contended... */ 538 ldo -EAGAIN(%r0), %r21 /* Spin in userspace */ 539cas_nocontend: 540# endif 541/* ENABLE_LWS_DEBUG */ 542 543 ldcw 0(%sr2,%r20), %r28 /* Try to acquire the lock */ 544 cmpb,<>,n %r0, %r28, cas_action /* Did we get it? */ 545cas_wouldblock: 546 ldo 2(%r0), %r28 /* 2nd case */ 547 b lws_exit /* Contended... */ 548 ldo -EAGAIN(%r0), %r21 /* Spin in userspace */ 549#endif 550/* CONFIG_SMP */ 551 552 /* 553 prev = *addr; 554 if ( prev == old ) 555 *addr = new; 556 return prev; 557 */ 558 559 /* NOTES: 560 This all works becuse intr_do_signal 561 and schedule both check the return iasq 562 and see that we are on the kernel page 563 so this process is never scheduled off 564 or is ever sent any signal of any sort, 565 thus it is wholly atomic from usrspaces 566 perspective 567 */ 568cas_action: 569#if defined CONFIG_SMP && defined ENABLE_LWS_DEBUG 570 /* DEBUG */ 571 mfctl %cr27, %r1 572 stw %r1, 4(%sr2,%r20) 573#endif 574 /* The load and store could fail */ 5751: ldw 0(%sr3,%r26), %r28 576 sub,<> %r28, %r25, %r0 5772: stw %r24, 0(%sr3,%r26) 578#ifdef CONFIG_SMP 579 /* Free lock */ 580 stw %r20, 0(%sr2,%r20) 581# ifdef ENABLE_LWS_DEBUG 582 /* Clear thread register indicator */ 583 stw %r0, 4(%sr2,%r20) 584# endif 585#endif 586 /* Return to userspace, set no error */ 587 b lws_exit 588 copy %r0, %r21 589 5903: 591 /* Error occured on load or store */ 592#ifdef CONFIG_SMP 593 /* Free lock */ 594 stw %r20, 0(%sr2,%r20) 595# ifdef ENABLE_LWS_DEBUG 596 stw %r0, 4(%sr2,%r20) 597# endif 598#endif 599 b lws_exit 600 ldo -EFAULT(%r0),%r21 /* set errno */ 601 nop 602 nop 603 nop 604 nop 605 606 /* Two exception table entries, one for the load, 607 the other for the store. Either return -EFAULT. 608 Each of the entries must be relocated. */ 609 .section __ex_table,"aw" 610#ifdef CONFIG_64BIT 611 /* Pad the address calculation */ 612 .word 0,(2b - linux_gateway_page) 613 .word 0,(3b - linux_gateway_page) 614#else 615 .word (2b - linux_gateway_page) 616 .word (3b - linux_gateway_page) 617#endif 618 .previous 619 620 .section __ex_table,"aw" 621#ifdef CONFIG_64BIT 622 /* Pad the address calculation */ 623 .word 0,(1b - linux_gateway_page) 624 .word 0,(3b - linux_gateway_page) 625#else 626 .word (1b - linux_gateway_page) 627 .word (3b - linux_gateway_page) 628#endif 629 .previous 630 631end_compare_and_swap: 632 633 /* Make sure nothing else is placed on this page */ 634 .align 4096 635 .export end_linux_gateway_page 636end_linux_gateway_page: 637 638 /* Relocate symbols assuming linux_gateway_page is mapped 639 to virtual address 0x0 */ 640#ifdef CONFIG_64BIT 641 /* FIXME: The code will always be on the gateay page 642 and thus it will be on the first 4k, the 643 assembler seems to think that the final 644 subtraction result is only a word in 645 length, so we pad the value. 646 */ 647#define LWS_ENTRY(_name_) .word 0,(lws_##_name_ - linux_gateway_page) 648#else 649#define LWS_ENTRY(_name_) .word (lws_##_name_ - linux_gateway_page) 650#endif 651 652 .align 4096 653 /* Light-weight-syscall table */ 654 /* Start of lws table. */ 655 .export lws_table 656.Llws_table: 657lws_table: 658 LWS_ENTRY(compare_and_swap32) /* 0 - ELF32 Atomic compare and swap */ 659 LWS_ENTRY(compare_and_swap64) /* 1 - ELF64 Atomic compare and swap */ 660 /* End of lws table */ 661 662 .align 4096 663 .export sys_call_table 664.Lsys_call_table: 665sys_call_table: 666#include "syscall_table.S" 667 668#ifdef CONFIG_64BIT 669 .align 4096 670 .export sys_call_table64 671.Lsys_call_table64: 672sys_call_table64: 673#define SYSCALL_TABLE_64BIT 674#include "syscall_table.S" 675#endif 676 677#ifdef CONFIG_SMP 678 /* 679 All light-weight-syscall atomic operations 680 will use this set of locks 681 */ 682 .section .data 683 .align 4096 684 .export lws_lock_start 685.Llws_lock_start: 686lws_lock_start: 687 /* lws locks */ 688 .align 16 689 .rept 16 690 /* Keep locks aligned at 16-bytes */ 691 .word 1 692 .word 0 693 .word 0 694 .word 0 695 .endr 696 .previous 697#endif 698/* CONFIG_SMP for lws_lock_start */ 699 700.end 701 702 703