syscall.S 19 KB

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