entry.S 18 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. /*
  3. * arch/alpha/kernel/entry.S
  4. *
  5. * Kernel entry-points.
  6. */
  7. #include <asm/asm-offsets.h>
  8. #include <asm/thread_info.h>
  9. #include <asm/pal.h>
  10. #include <asm/errno.h>
  11. #include <asm/unistd.h>
  12. .text
  13. .set noat
  14. .cfi_sections .debug_frame
  15. /* Stack offsets. */
  16. #define SP_OFF 184
  17. #define SWITCH_STACK_SIZE 320
  18. .macro CFI_START_OSF_FRAME func
  19. .align 4
  20. .globl \func
  21. .type \func,@function
  22. \func:
  23. .cfi_startproc simple
  24. .cfi_return_column 64
  25. .cfi_def_cfa $sp, 48
  26. .cfi_rel_offset 64, 8
  27. .cfi_rel_offset $gp, 16
  28. .cfi_rel_offset $16, 24
  29. .cfi_rel_offset $17, 32
  30. .cfi_rel_offset $18, 40
  31. .endm
  32. .macro CFI_END_OSF_FRAME func
  33. .cfi_endproc
  34. .size \func, . - \func
  35. .endm
  36. /*
  37. * This defines the normal kernel pt-regs layout.
  38. *
  39. * regs 9-15 preserved by C code
  40. * regs 16-18 saved by PAL-code
  41. * regs 29-30 saved and set up by PAL-code
  42. * JRP - Save regs 16-18 in a special area of the stack, so that
  43. * the palcode-provided values are available to the signal handler.
  44. */
  45. .macro SAVE_ALL
  46. subq $sp, SP_OFF, $sp
  47. .cfi_adjust_cfa_offset SP_OFF
  48. stq $0, 0($sp)
  49. stq $1, 8($sp)
  50. stq $2, 16($sp)
  51. stq $3, 24($sp)
  52. stq $4, 32($sp)
  53. stq $28, 144($sp)
  54. .cfi_rel_offset $0, 0
  55. .cfi_rel_offset $1, 8
  56. .cfi_rel_offset $2, 16
  57. .cfi_rel_offset $3, 24
  58. .cfi_rel_offset $4, 32
  59. .cfi_rel_offset $28, 144
  60. lda $2, alpha_mv
  61. stq $5, 40($sp)
  62. stq $6, 48($sp)
  63. stq $7, 56($sp)
  64. stq $8, 64($sp)
  65. stq $19, 72($sp)
  66. stq $20, 80($sp)
  67. stq $21, 88($sp)
  68. ldq $2, HAE_CACHE($2)
  69. stq $22, 96($sp)
  70. stq $23, 104($sp)
  71. stq $24, 112($sp)
  72. stq $25, 120($sp)
  73. stq $26, 128($sp)
  74. stq $27, 136($sp)
  75. stq $2, 152($sp)
  76. stq $16, 160($sp)
  77. stq $17, 168($sp)
  78. stq $18, 176($sp)
  79. .cfi_rel_offset $5, 40
  80. .cfi_rel_offset $6, 48
  81. .cfi_rel_offset $7, 56
  82. .cfi_rel_offset $8, 64
  83. .cfi_rel_offset $19, 72
  84. .cfi_rel_offset $20, 80
  85. .cfi_rel_offset $21, 88
  86. .cfi_rel_offset $22, 96
  87. .cfi_rel_offset $23, 104
  88. .cfi_rel_offset $24, 112
  89. .cfi_rel_offset $25, 120
  90. .cfi_rel_offset $26, 128
  91. .cfi_rel_offset $27, 136
  92. .endm
  93. .macro RESTORE_ALL
  94. lda $19, alpha_mv
  95. ldq $0, 0($sp)
  96. ldq $1, 8($sp)
  97. ldq $2, 16($sp)
  98. ldq $3, 24($sp)
  99. ldq $21, 152($sp)
  100. ldq $20, HAE_CACHE($19)
  101. ldq $4, 32($sp)
  102. ldq $5, 40($sp)
  103. ldq $6, 48($sp)
  104. ldq $7, 56($sp)
  105. subq $20, $21, $20
  106. ldq $8, 64($sp)
  107. beq $20, 99f
  108. ldq $20, HAE_REG($19)
  109. stq $21, HAE_CACHE($19)
  110. stq $21, 0($20)
  111. 99: ldq $19, 72($sp)
  112. ldq $20, 80($sp)
  113. ldq $21, 88($sp)
  114. ldq $22, 96($sp)
  115. ldq $23, 104($sp)
  116. ldq $24, 112($sp)
  117. ldq $25, 120($sp)
  118. ldq $26, 128($sp)
  119. ldq $27, 136($sp)
  120. ldq $28, 144($sp)
  121. addq $sp, SP_OFF, $sp
  122. .cfi_restore $0
  123. .cfi_restore $1
  124. .cfi_restore $2
  125. .cfi_restore $3
  126. .cfi_restore $4
  127. .cfi_restore $5
  128. .cfi_restore $6
  129. .cfi_restore $7
  130. .cfi_restore $8
  131. .cfi_restore $19
  132. .cfi_restore $20
  133. .cfi_restore $21
  134. .cfi_restore $22
  135. .cfi_restore $23
  136. .cfi_restore $24
  137. .cfi_restore $25
  138. .cfi_restore $26
  139. .cfi_restore $27
  140. .cfi_restore $28
  141. .cfi_adjust_cfa_offset -SP_OFF
  142. .endm
  143. .macro DO_SWITCH_STACK
  144. bsr $1, do_switch_stack
  145. .cfi_adjust_cfa_offset SWITCH_STACK_SIZE
  146. .cfi_rel_offset $9, 0
  147. .cfi_rel_offset $10, 8
  148. .cfi_rel_offset $11, 16
  149. .cfi_rel_offset $12, 24
  150. .cfi_rel_offset $13, 32
  151. .cfi_rel_offset $14, 40
  152. .cfi_rel_offset $15, 48
  153. /* We don't really care about the FP registers for debugging. */
  154. .endm
  155. .macro UNDO_SWITCH_STACK
  156. bsr $1, undo_switch_stack
  157. .cfi_restore $9
  158. .cfi_restore $10
  159. .cfi_restore $11
  160. .cfi_restore $12
  161. .cfi_restore $13
  162. .cfi_restore $14
  163. .cfi_restore $15
  164. .cfi_adjust_cfa_offset -SWITCH_STACK_SIZE
  165. .endm
  166. /*
  167. * Non-syscall kernel entry points.
  168. */
  169. CFI_START_OSF_FRAME entInt
  170. SAVE_ALL
  171. lda $8, 0x3fff
  172. lda $26, ret_from_sys_call
  173. bic $sp, $8, $8
  174. mov $sp, $19
  175. jsr $31, do_entInt
  176. CFI_END_OSF_FRAME entInt
  177. CFI_START_OSF_FRAME entArith
  178. SAVE_ALL
  179. lda $8, 0x3fff
  180. lda $26, ret_from_sys_call
  181. bic $sp, $8, $8
  182. mov $sp, $18
  183. jsr $31, do_entArith
  184. CFI_END_OSF_FRAME entArith
  185. CFI_START_OSF_FRAME entMM
  186. SAVE_ALL
  187. /* save $9 - $15 so the inline exception code can manipulate them. */
  188. subq $sp, 56, $sp
  189. .cfi_adjust_cfa_offset 56
  190. stq $9, 0($sp)
  191. stq $10, 8($sp)
  192. stq $11, 16($sp)
  193. stq $12, 24($sp)
  194. stq $13, 32($sp)
  195. stq $14, 40($sp)
  196. stq $15, 48($sp)
  197. .cfi_rel_offset $9, 0
  198. .cfi_rel_offset $10, 8
  199. .cfi_rel_offset $11, 16
  200. .cfi_rel_offset $12, 24
  201. .cfi_rel_offset $13, 32
  202. .cfi_rel_offset $14, 40
  203. .cfi_rel_offset $15, 48
  204. addq $sp, 56, $19
  205. /* handle the fault */
  206. lda $8, 0x3fff
  207. bic $sp, $8, $8
  208. jsr $26, do_page_fault
  209. /* reload the registers after the exception code played. */
  210. ldq $9, 0($sp)
  211. ldq $10, 8($sp)
  212. ldq $11, 16($sp)
  213. ldq $12, 24($sp)
  214. ldq $13, 32($sp)
  215. ldq $14, 40($sp)
  216. ldq $15, 48($sp)
  217. addq $sp, 56, $sp
  218. .cfi_restore $9
  219. .cfi_restore $10
  220. .cfi_restore $11
  221. .cfi_restore $12
  222. .cfi_restore $13
  223. .cfi_restore $14
  224. .cfi_restore $15
  225. .cfi_adjust_cfa_offset -56
  226. /* finish up the syscall as normal. */
  227. br ret_from_sys_call
  228. CFI_END_OSF_FRAME entMM
  229. CFI_START_OSF_FRAME entIF
  230. SAVE_ALL
  231. lda $8, 0x3fff
  232. lda $26, ret_from_sys_call
  233. bic $sp, $8, $8
  234. mov $sp, $17
  235. jsr $31, do_entIF
  236. CFI_END_OSF_FRAME entIF
  237. CFI_START_OSF_FRAME entUna
  238. lda $sp, -256($sp)
  239. .cfi_adjust_cfa_offset 256
  240. stq $0, 0($sp)
  241. .cfi_rel_offset $0, 0
  242. .cfi_remember_state
  243. ldq $0, 256($sp) /* get PS */
  244. stq $1, 8($sp)
  245. stq $2, 16($sp)
  246. stq $3, 24($sp)
  247. and $0, 8, $0 /* user mode? */
  248. stq $4, 32($sp)
  249. bne $0, entUnaUser /* yup -> do user-level unaligned fault */
  250. stq $5, 40($sp)
  251. stq $6, 48($sp)
  252. stq $7, 56($sp)
  253. stq $8, 64($sp)
  254. stq $9, 72($sp)
  255. stq $10, 80($sp)
  256. stq $11, 88($sp)
  257. stq $12, 96($sp)
  258. stq $13, 104($sp)
  259. stq $14, 112($sp)
  260. stq $15, 120($sp)
  261. /* 16-18 PAL-saved */
  262. stq $19, 152($sp)
  263. stq $20, 160($sp)
  264. stq $21, 168($sp)
  265. stq $22, 176($sp)
  266. stq $23, 184($sp)
  267. stq $24, 192($sp)
  268. stq $25, 200($sp)
  269. stq $26, 208($sp)
  270. stq $27, 216($sp)
  271. stq $28, 224($sp)
  272. mov $sp, $19
  273. stq $gp, 232($sp)
  274. .cfi_rel_offset $1, 1*8
  275. .cfi_rel_offset $2, 2*8
  276. .cfi_rel_offset $3, 3*8
  277. .cfi_rel_offset $4, 4*8
  278. .cfi_rel_offset $5, 5*8
  279. .cfi_rel_offset $6, 6*8
  280. .cfi_rel_offset $7, 7*8
  281. .cfi_rel_offset $8, 8*8
  282. .cfi_rel_offset $9, 9*8
  283. .cfi_rel_offset $10, 10*8
  284. .cfi_rel_offset $11, 11*8
  285. .cfi_rel_offset $12, 12*8
  286. .cfi_rel_offset $13, 13*8
  287. .cfi_rel_offset $14, 14*8
  288. .cfi_rel_offset $15, 15*8
  289. .cfi_rel_offset $19, 19*8
  290. .cfi_rel_offset $20, 20*8
  291. .cfi_rel_offset $21, 21*8
  292. .cfi_rel_offset $22, 22*8
  293. .cfi_rel_offset $23, 23*8
  294. .cfi_rel_offset $24, 24*8
  295. .cfi_rel_offset $25, 25*8
  296. .cfi_rel_offset $26, 26*8
  297. .cfi_rel_offset $27, 27*8
  298. .cfi_rel_offset $28, 28*8
  299. .cfi_rel_offset $29, 29*8
  300. lda $8, 0x3fff
  301. stq $31, 248($sp)
  302. bic $sp, $8, $8
  303. jsr $26, do_entUna
  304. ldq $0, 0($sp)
  305. ldq $1, 8($sp)
  306. ldq $2, 16($sp)
  307. ldq $3, 24($sp)
  308. ldq $4, 32($sp)
  309. ldq $5, 40($sp)
  310. ldq $6, 48($sp)
  311. ldq $7, 56($sp)
  312. ldq $8, 64($sp)
  313. ldq $9, 72($sp)
  314. ldq $10, 80($sp)
  315. ldq $11, 88($sp)
  316. ldq $12, 96($sp)
  317. ldq $13, 104($sp)
  318. ldq $14, 112($sp)
  319. ldq $15, 120($sp)
  320. /* 16-18 PAL-saved */
  321. ldq $19, 152($sp)
  322. ldq $20, 160($sp)
  323. ldq $21, 168($sp)
  324. ldq $22, 176($sp)
  325. ldq $23, 184($sp)
  326. ldq $24, 192($sp)
  327. ldq $25, 200($sp)
  328. ldq $26, 208($sp)
  329. ldq $27, 216($sp)
  330. ldq $28, 224($sp)
  331. ldq $gp, 232($sp)
  332. lda $sp, 256($sp)
  333. .cfi_restore $1
  334. .cfi_restore $2
  335. .cfi_restore $3
  336. .cfi_restore $4
  337. .cfi_restore $5
  338. .cfi_restore $6
  339. .cfi_restore $7
  340. .cfi_restore $8
  341. .cfi_restore $9
  342. .cfi_restore $10
  343. .cfi_restore $11
  344. .cfi_restore $12
  345. .cfi_restore $13
  346. .cfi_restore $14
  347. .cfi_restore $15
  348. .cfi_restore $19
  349. .cfi_restore $20
  350. .cfi_restore $21
  351. .cfi_restore $22
  352. .cfi_restore $23
  353. .cfi_restore $24
  354. .cfi_restore $25
  355. .cfi_restore $26
  356. .cfi_restore $27
  357. .cfi_restore $28
  358. .cfi_restore $29
  359. .cfi_adjust_cfa_offset -256
  360. call_pal PAL_rti
  361. .align 4
  362. entUnaUser:
  363. .cfi_restore_state
  364. ldq $0, 0($sp) /* restore original $0 */
  365. lda $sp, 256($sp) /* pop entUna's stack frame */
  366. .cfi_restore $0
  367. .cfi_adjust_cfa_offset -256
  368. SAVE_ALL /* setup normal kernel stack */
  369. lda $sp, -56($sp)
  370. .cfi_adjust_cfa_offset 56
  371. stq $9, 0($sp)
  372. stq $10, 8($sp)
  373. stq $11, 16($sp)
  374. stq $12, 24($sp)
  375. stq $13, 32($sp)
  376. stq $14, 40($sp)
  377. stq $15, 48($sp)
  378. .cfi_rel_offset $9, 0
  379. .cfi_rel_offset $10, 8
  380. .cfi_rel_offset $11, 16
  381. .cfi_rel_offset $12, 24
  382. .cfi_rel_offset $13, 32
  383. .cfi_rel_offset $14, 40
  384. .cfi_rel_offset $15, 48
  385. lda $8, 0x3fff
  386. addq $sp, 56, $19
  387. bic $sp, $8, $8
  388. jsr $26, do_entUnaUser
  389. ldq $9, 0($sp)
  390. ldq $10, 8($sp)
  391. ldq $11, 16($sp)
  392. ldq $12, 24($sp)
  393. ldq $13, 32($sp)
  394. ldq $14, 40($sp)
  395. ldq $15, 48($sp)
  396. lda $sp, 56($sp)
  397. .cfi_restore $9
  398. .cfi_restore $10
  399. .cfi_restore $11
  400. .cfi_restore $12
  401. .cfi_restore $13
  402. .cfi_restore $14
  403. .cfi_restore $15
  404. .cfi_adjust_cfa_offset -56
  405. br ret_from_sys_call
  406. CFI_END_OSF_FRAME entUna
  407. CFI_START_OSF_FRAME entDbg
  408. SAVE_ALL
  409. lda $8, 0x3fff
  410. lda $26, ret_from_sys_call
  411. bic $sp, $8, $8
  412. mov $sp, $16
  413. jsr $31, do_entDbg
  414. CFI_END_OSF_FRAME entDbg
  415. /*
  416. * The system call entry point is special. Most importantly, it looks
  417. * like a function call to userspace as far as clobbered registers. We
  418. * do preserve the argument registers (for syscall restarts) and $26
  419. * (for leaf syscall functions).
  420. *
  421. * So much for theory. We don't take advantage of this yet.
  422. *
  423. * Note that a0-a2 are not saved by PALcode as with the other entry points.
  424. */
  425. .align 4
  426. .globl entSys
  427. .type entSys, @function
  428. .cfi_startproc simple
  429. .cfi_return_column 64
  430. .cfi_def_cfa $sp, 48
  431. .cfi_rel_offset 64, 8
  432. .cfi_rel_offset $gp, 16
  433. entSys:
  434. SAVE_ALL
  435. lda $8, 0x3fff
  436. bic $sp, $8, $8
  437. lda $4, NR_SYSCALLS($31)
  438. stq $16, SP_OFF+24($sp)
  439. lda $5, sys_call_table
  440. lda $27, sys_ni_syscall
  441. cmpult $0, $4, $4
  442. ldl $3, TI_FLAGS($8)
  443. stq $17, SP_OFF+32($sp)
  444. s8addq $0, $5, $5
  445. stq $18, SP_OFF+40($sp)
  446. .cfi_rel_offset $16, SP_OFF+24
  447. .cfi_rel_offset $17, SP_OFF+32
  448. .cfi_rel_offset $18, SP_OFF+40
  449. #ifdef CONFIG_AUDITSYSCALL
  450. lda $6, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT
  451. and $3, $6, $3
  452. bne $3, strace
  453. #else
  454. blbs $3, strace /* check for SYSCALL_TRACE in disguise */
  455. #endif
  456. beq $4, 1f
  457. ldq $27, 0($5)
  458. 1: jsr $26, ($27), sys_ni_syscall
  459. ldgp $gp, 0($26)
  460. blt $0, $syscall_error /* the call failed */
  461. stq $0, 0($sp)
  462. stq $31, 72($sp) /* a3=0 => no error */
  463. .align 4
  464. .globl ret_from_sys_call
  465. ret_from_sys_call:
  466. cmovne $26, 0, $18 /* $18 = 0 => non-restartable */
  467. ldq $0, SP_OFF($sp)
  468. and $0, 8, $0
  469. beq $0, ret_to_kernel
  470. ret_to_user:
  471. /* Make sure need_resched and sigpending don't change between
  472. sampling and the rti. */
  473. lda $16, 7
  474. call_pal PAL_swpipl
  475. ldl $17, TI_FLAGS($8)
  476. and $17, _TIF_WORK_MASK, $2
  477. bne $2, work_pending
  478. restore_all:
  479. .cfi_remember_state
  480. RESTORE_ALL
  481. call_pal PAL_rti
  482. ret_to_kernel:
  483. .cfi_restore_state
  484. lda $16, 7
  485. call_pal PAL_swpipl
  486. br restore_all
  487. .align 3
  488. $syscall_error:
  489. /*
  490. * Some system calls (e.g., ptrace) can return arbitrary
  491. * values which might normally be mistaken as error numbers.
  492. * Those functions must zero $0 (v0) directly in the stack
  493. * frame to indicate that a negative return value wasn't an
  494. * error number..
  495. */
  496. ldq $18, 0($sp) /* old syscall nr (zero if success) */
  497. beq $18, $ret_success
  498. ldq $19, 72($sp) /* .. and this a3 */
  499. subq $31, $0, $0 /* with error in v0 */
  500. addq $31, 1, $1 /* set a3 for errno return */
  501. stq $0, 0($sp)
  502. mov $31, $26 /* tell "ret_from_sys_call" we can restart */
  503. stq $1, 72($sp) /* a3 for return */
  504. br ret_from_sys_call
  505. $ret_success:
  506. stq $0, 0($sp)
  507. stq $31, 72($sp) /* a3=0 => no error */
  508. br ret_from_sys_call
  509. /*
  510. * Do all cleanup when returning from all interrupts and system calls.
  511. *
  512. * Arguments:
  513. * $8: current.
  514. * $17: TI_FLAGS.
  515. * $18: The old syscall number, or zero if this is not a return
  516. * from a syscall that errored and is possibly restartable.
  517. * $19: The old a3 value
  518. */
  519. .align 4
  520. .type work_pending, @function
  521. work_pending:
  522. and $17, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL, $2
  523. bne $2, $work_notifysig
  524. $work_resched:
  525. /*
  526. * We can get here only if we returned from syscall without SIGPENDING
  527. * or got through work_notifysig already. Either case means no syscall
  528. * restarts for us, so let $18 and $19 burn.
  529. */
  530. jsr $26, schedule
  531. mov 0, $18
  532. br ret_to_user
  533. $work_notifysig:
  534. mov $sp, $16
  535. DO_SWITCH_STACK
  536. jsr $26, do_work_pending
  537. UNDO_SWITCH_STACK
  538. br restore_all
  539. /*
  540. * PTRACE syscall handler
  541. */
  542. .align 4
  543. .type strace, @function
  544. strace:
  545. /* set up signal stack, call syscall_trace */
  546. DO_SWITCH_STACK
  547. jsr $26, syscall_trace_enter /* returns the syscall number */
  548. UNDO_SWITCH_STACK
  549. /* get the arguments back.. */
  550. ldq $16, SP_OFF+24($sp)
  551. ldq $17, SP_OFF+32($sp)
  552. ldq $18, SP_OFF+40($sp)
  553. ldq $19, 72($sp)
  554. ldq $20, 80($sp)
  555. ldq $21, 88($sp)
  556. /* get the system call pointer.. */
  557. lda $1, NR_SYSCALLS($31)
  558. lda $2, sys_call_table
  559. lda $27, sys_ni_syscall
  560. cmpult $0, $1, $1
  561. s8addq $0, $2, $2
  562. beq $1, 1f
  563. ldq $27, 0($2)
  564. 1: jsr $26, ($27), sys_gettimeofday
  565. ret_from_straced:
  566. ldgp $gp, 0($26)
  567. /* check return.. */
  568. blt $0, $strace_error /* the call failed */
  569. stq $31, 72($sp) /* a3=0 => no error */
  570. $strace_success:
  571. stq $0, 0($sp) /* save return value */
  572. DO_SWITCH_STACK
  573. jsr $26, syscall_trace_leave
  574. UNDO_SWITCH_STACK
  575. br $31, ret_from_sys_call
  576. .align 3
  577. $strace_error:
  578. ldq $18, 0($sp) /* old syscall nr (zero if success) */
  579. beq $18, $strace_success
  580. ldq $19, 72($sp) /* .. and this a3 */
  581. subq $31, $0, $0 /* with error in v0 */
  582. addq $31, 1, $1 /* set a3 for errno return */
  583. stq $0, 0($sp)
  584. stq $1, 72($sp) /* a3 for return */
  585. DO_SWITCH_STACK
  586. mov $18, $9 /* save old syscall number */
  587. mov $19, $10 /* save old a3 */
  588. jsr $26, syscall_trace_leave
  589. mov $9, $18
  590. mov $10, $19
  591. UNDO_SWITCH_STACK
  592. mov $31, $26 /* tell "ret_from_sys_call" we can restart */
  593. br ret_from_sys_call
  594. CFI_END_OSF_FRAME entSys
  595. /*
  596. * Save and restore the switch stack -- aka the balance of the user context.
  597. */
  598. .align 4
  599. .type do_switch_stack, @function
  600. .cfi_startproc simple
  601. .cfi_return_column 64
  602. .cfi_def_cfa $sp, 0
  603. .cfi_register 64, $1
  604. do_switch_stack:
  605. lda $sp, -SWITCH_STACK_SIZE($sp)
  606. .cfi_adjust_cfa_offset SWITCH_STACK_SIZE
  607. stq $9, 0($sp)
  608. stq $10, 8($sp)
  609. stq $11, 16($sp)
  610. stq $12, 24($sp)
  611. stq $13, 32($sp)
  612. stq $14, 40($sp)
  613. stq $15, 48($sp)
  614. stq $26, 56($sp)
  615. stt $f0, 64($sp)
  616. stt $f1, 72($sp)
  617. stt $f2, 80($sp)
  618. stt $f3, 88($sp)
  619. stt $f4, 96($sp)
  620. stt $f5, 104($sp)
  621. stt $f6, 112($sp)
  622. stt $f7, 120($sp)
  623. stt $f8, 128($sp)
  624. stt $f9, 136($sp)
  625. stt $f10, 144($sp)
  626. stt $f11, 152($sp)
  627. stt $f12, 160($sp)
  628. stt $f13, 168($sp)
  629. stt $f14, 176($sp)
  630. stt $f15, 184($sp)
  631. stt $f16, 192($sp)
  632. stt $f17, 200($sp)
  633. stt $f18, 208($sp)
  634. stt $f19, 216($sp)
  635. stt $f20, 224($sp)
  636. stt $f21, 232($sp)
  637. stt $f22, 240($sp)
  638. stt $f23, 248($sp)
  639. stt $f24, 256($sp)
  640. stt $f25, 264($sp)
  641. stt $f26, 272($sp)
  642. stt $f27, 280($sp)
  643. mf_fpcr $f0 # get fpcr
  644. stt $f28, 288($sp)
  645. stt $f29, 296($sp)
  646. stt $f30, 304($sp)
  647. stt $f0, 312($sp) # save fpcr in slot of $f31
  648. ldt $f0, 64($sp) # dont let "do_switch_stack" change fp state.
  649. ret $31, ($1), 1
  650. .cfi_endproc
  651. .size do_switch_stack, .-do_switch_stack
  652. .align 4
  653. .type undo_switch_stack, @function
  654. .cfi_startproc simple
  655. .cfi_def_cfa $sp, 0
  656. .cfi_register 64, $1
  657. undo_switch_stack:
  658. ldq $9, 0($sp)
  659. ldq $10, 8($sp)
  660. ldq $11, 16($sp)
  661. ldq $12, 24($sp)
  662. ldq $13, 32($sp)
  663. ldq $14, 40($sp)
  664. ldq $15, 48($sp)
  665. ldq $26, 56($sp)
  666. ldt $f30, 312($sp) # get saved fpcr
  667. ldt $f0, 64($sp)
  668. ldt $f1, 72($sp)
  669. ldt $f2, 80($sp)
  670. ldt $f3, 88($sp)
  671. mt_fpcr $f30 # install saved fpcr
  672. ldt $f4, 96($sp)
  673. ldt $f5, 104($sp)
  674. ldt $f6, 112($sp)
  675. ldt $f7, 120($sp)
  676. ldt $f8, 128($sp)
  677. ldt $f9, 136($sp)
  678. ldt $f10, 144($sp)
  679. ldt $f11, 152($sp)
  680. ldt $f12, 160($sp)
  681. ldt $f13, 168($sp)
  682. ldt $f14, 176($sp)
  683. ldt $f15, 184($sp)
  684. ldt $f16, 192($sp)
  685. ldt $f17, 200($sp)
  686. ldt $f18, 208($sp)
  687. ldt $f19, 216($sp)
  688. ldt $f20, 224($sp)
  689. ldt $f21, 232($sp)
  690. ldt $f22, 240($sp)
  691. ldt $f23, 248($sp)
  692. ldt $f24, 256($sp)
  693. ldt $f25, 264($sp)
  694. ldt $f26, 272($sp)
  695. ldt $f27, 280($sp)
  696. ldt $f28, 288($sp)
  697. ldt $f29, 296($sp)
  698. ldt $f30, 304($sp)
  699. lda $sp, SWITCH_STACK_SIZE($sp)
  700. ret $31, ($1), 1
  701. .cfi_endproc
  702. .size undo_switch_stack, .-undo_switch_stack
  703. /*
  704. * The meat of the context switch code.
  705. */
  706. .align 4
  707. .globl alpha_switch_to
  708. .type alpha_switch_to, @function
  709. .cfi_startproc
  710. alpha_switch_to:
  711. DO_SWITCH_STACK
  712. call_pal PAL_swpctx
  713. lda $8, 0x3fff
  714. UNDO_SWITCH_STACK
  715. bic $sp, $8, $8
  716. mov $17, $0
  717. ret
  718. .cfi_endproc
  719. .size alpha_switch_to, .-alpha_switch_to
  720. /*
  721. * New processes begin life here.
  722. */
  723. .globl ret_from_fork
  724. .align 4
  725. .ent ret_from_fork
  726. ret_from_fork:
  727. lda $26, ret_from_sys_call
  728. mov $17, $16
  729. jmp $31, schedule_tail
  730. .end ret_from_fork
  731. /*
  732. * ... and new kernel threads - here
  733. */
  734. .align 4
  735. .globl ret_from_kernel_thread
  736. .ent ret_from_kernel_thread
  737. ret_from_kernel_thread:
  738. mov $17, $16
  739. jsr $26, schedule_tail
  740. mov $9, $27
  741. mov $10, $16
  742. jsr $26, ($9)
  743. br $31, ret_to_user
  744. .end ret_from_kernel_thread
  745. /*
  746. * Special system calls. Most of these are special in that they either
  747. * have to play switch_stack games.
  748. */
  749. .macro fork_like name
  750. .align 4
  751. .globl alpha_\name
  752. .ent alpha_\name
  753. alpha_\name:
  754. .prologue 0
  755. bsr $1, do_switch_stack
  756. jsr $26, sys_\name
  757. ldq $26, 56($sp)
  758. lda $sp, SWITCH_STACK_SIZE($sp)
  759. ret
  760. .end alpha_\name
  761. .endm
  762. fork_like fork
  763. fork_like vfork
  764. fork_like clone
  765. .macro sigreturn_like name
  766. .align 4
  767. .globl sys_\name
  768. .ent sys_\name
  769. sys_\name:
  770. .prologue 0
  771. lda $9, ret_from_straced
  772. cmpult $26, $9, $9
  773. lda $sp, -SWITCH_STACK_SIZE($sp)
  774. jsr $26, do_\name
  775. bne $9, 1f
  776. jsr $26, syscall_trace_leave
  777. 1: br $1, undo_switch_stack
  778. br ret_from_sys_call
  779. .end sys_\name
  780. .endm
  781. sigreturn_like sigreturn
  782. sigreturn_like rt_sigreturn
  783. .align 4
  784. .globl alpha_syscall_zero
  785. .ent alpha_syscall_zero
  786. alpha_syscall_zero:
  787. .prologue 0
  788. /* Special because it needs to do something opposite to
  789. force_successful_syscall_return(). We use the saved
  790. syscall number for that, zero meaning "not an error".
  791. That works nicely, but for real syscall 0 we need to
  792. make sure that this logics doesn't get confused.
  793. Store a non-zero there - -ENOSYS we need in register
  794. for our return value will do just fine.
  795. */
  796. lda $0, -ENOSYS
  797. unop
  798. stq $0, 0($sp)
  799. ret
  800. .end alpha_syscall_zero