Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
3 *
4 * System call entry code / Linux gateway page
5 * Copyright (c) Matthew Wilcox 1999 <willy@infradead.org>
6 * Licensed under the GNU GPL.
7 * thanks to Philipp Rumpf, Mike Shaver and various others
8 * sorry about the wall, puffin..
9 */
10
11/*
12How does the Linux gateway page on PA-RISC work?
13------------------------------------------------
14The Linux gateway page on PA-RISC is "special".
15It actually has PAGE_GATEWAY bits set (this is linux terminology; in parisc
16terminology it's Execute, promote to PL0) in the page map. So anything
17executing on this page executes with kernel level privilege (there's more to it
18than that: to have this happen, you also have to use a branch with a ,gate
19completer to activate the privilege promotion). The upshot is that everything
20that runs on the gateway page runs at kernel privilege but with the current
21user process address space (although you have access to kernel space via %sr2).
22For the 0x100 syscall entry, we redo the space registers to point to the kernel
23address space (preserving the user address space in %sr3), move to wide mode if
24required, save the user registers and branch into the kernel syscall entry
25point. For all the other functions, we execute at kernel privilege but don't
26flip address spaces. The basic upshot of this is that these code snippets are
27executed atomically (because the kernel can't be pre-empted) and they may
28perform architecturally forbidden (to PL3) operations (like setting control
29registers).
30*/
31
32
33#include <asm/asm-offsets.h>
34#include <asm/unistd.h>
35#include <asm/errno.h>
36#include <asm/page.h>
37#include <asm/psw.h>
38#include <asm/thread_info.h>
39#include <asm/assembly.h>
40#include <asm/processor.h>
41#include <asm/cache.h>
42
43#include <linux/linkage.h>
44
45 /* We fill the empty parts of the gateway page with
46 * something that will kill the kernel or a
47 * userspace application.
48 */
49#define KILL_INSN break 0,0
50
51 .level PA_ASM_LEVEL
52
53 .macro lws_pagefault_disable reg1,reg2
54 mfctl %cr30, \reg2
55 ldo TASK_PAGEFAULT_DISABLED(\reg2), \reg2
56 ldw 0(%sr2,\reg2), \reg1
57 ldo 1(\reg1), \reg1
58 stw \reg1, 0(%sr2,\reg2)
59 .endm
60
61 .macro lws_pagefault_enable reg1,reg2
62 mfctl %cr30, \reg2
63 ldo TASK_PAGEFAULT_DISABLED(\reg2), \reg2
64 ldw 0(%sr2,\reg2), \reg1
65 ldo -1(\reg1), \reg1
66 stw \reg1, 0(%sr2,\reg2)
67 .endm
68
69 .text
70
71 .import syscall_exit,code
72 .import syscall_exit_rfi,code
73
74 /* Linux gateway page is aliased to virtual page 0 in the kernel
75 * address space. Since it is a gateway page it cannot be
76 * dereferenced, so null pointers will still fault. We start
77 * the actual entry point at 0x100. We put break instructions
78 * at the beginning of the page to trap null indirect function
79 * pointers.
80 */
81
82 .align PAGE_SIZE
83ENTRY(linux_gateway_page)
84
85 /* ADDRESS 0x00 to 0xb0 = 176 bytes / 4 bytes per insn = 44 insns */
86 .rept 44
87 KILL_INSN
88 .endr
89
90 /* ADDRESS 0xb0 to 0xb8, lws uses two insns for entry */
91 /* Light-weight-syscall entry must always be located at 0xb0 */
92 /* WARNING: Keep this number updated with table size changes */
93#define __NR_lws_entries (5)
94
95lws_entry:
96 gate lws_start, %r0 /* increase privilege */
97 depi PRIV_USER, 31, 2, %r31 /* Ensure we return into user mode. */
98
99 /* Fill from 0xb8 to 0xe0 */
100 .rept 10
101 KILL_INSN
102 .endr
103
104 /* This function MUST be located at 0xe0 for glibc's threading
105 mechanism to work. DO NOT MOVE THIS CODE EVER! */
106set_thread_pointer:
107 gate .+8, %r0 /* increase privilege */
108 depi PRIV_USER, 31, 2, %r31 /* Ensure we return into user mode. */
109 be 0(%sr7,%r31) /* return to user space */
110 mtctl %r26, %cr27 /* move arg0 to the control register */
111
112 /* Increase the chance of trapping if random jumps occur to this
113 address, fill from 0xf0 to 0x100 */
114 .rept 4
115 KILL_INSN
116 .endr
117
118/* This address must remain fixed at 0x100 for glibc's syscalls to work */
119 .align LINUX_GATEWAY_ADDR
120linux_gateway_entry:
121 gate .+8, %r0 /* become privileged */
122 mtsp %r0,%sr4 /* get kernel space into sr4 */
123 mtsp %r0,%sr5 /* get kernel space into sr5 */
124 mtsp %r0,%sr6 /* get kernel space into sr6 */
125
126#ifdef CONFIG_64BIT
127 /* Store W bit on entry to the syscall in case it's a wide userland
128 * process. */
129 ssm PSW_SM_W, %r1
130 extrd,u %r1,PSW_W_BIT,1,%r1
131 /* sp must be aligned on 4, so deposit the W bit setting into
132 * the bottom of sp temporarily */
133 or,ev %r1,%r30,%r30
134 b,n 1f
135 /* The top halves of argument registers must be cleared on syscall
136 * entry from narrow executable.
137 */
138 depdi 0, 31, 32, %r26
139 depdi 0, 31, 32, %r25
140 depdi 0, 31, 32, %r24
141 depdi 0, 31, 32, %r23
142 depdi 0, 31, 32, %r22
143 depdi 0, 31, 32, %r21
1441:
145#endif
146
147 /* We use a rsm/ssm pair to prevent sr3 from being clobbered
148 * by external interrupts.
149 */
150 mfsp %sr7,%r1 /* save user sr7 */
151 rsm PSW_SM_I, %r0 /* disable interrupts */
152 mtsp %r1,%sr3 /* and store it in sr3 */
153
154 mfctl %cr30,%r1
155 xor %r1,%r30,%r30 /* ye olde xor trick */
156 xor %r1,%r30,%r1
157 xor %r1,%r30,%r30
158
159 LDREG TASK_STACK(%r30),%r30 /* set up kernel stack */
160 ldo FRAME_SIZE(%r30),%r30
161 /* N.B.: It is critical that we don't set sr7 to 0 until r30
162 * contains a valid kernel stack pointer. It is also
163 * critical that we don't start using the kernel stack
164 * until after sr7 has been set to 0.
165 */
166
167 mtsp %r0,%sr7 /* get kernel space into sr7 */
168 ssm PSW_SM_I, %r0 /* enable interrupts */
169 STREGM %r1,FRAME_SIZE(%r30) /* save r1 (usp) here for now */
170 mfctl %cr30,%r1 /* get task ptr in %r1 */
171
172 /* Save some registers for sigcontext and potential task
173 switch (see entry.S for the details of which ones are
174 saved/restored). TASK_PT_PSW is zeroed so we can see whether
175 a process is on a syscall or not. For an interrupt the real
176 PSW value is stored. This is needed for gdb and sys_ptrace. */
177 STREG %r0, TASK_PT_PSW(%r1)
178 STREG %r2, TASK_PT_GR2(%r1) /* preserve rp */
179 STREG %r19, TASK_PT_GR19(%r1)
180
181 LDREGM -FRAME_SIZE(%r30), %r2 /* get users sp back */
182#ifdef CONFIG_64BIT
183 extrd,u %r2,63,1,%r19 /* W hidden in bottom bit */
184#if 0
185 xor %r19,%r2,%r2 /* clear bottom bit */
186 depd,z %r19,1,1,%r19
187 std %r19,TASK_PT_PSW(%r1)
188#endif
189#endif
190 STREG %r2, TASK_PT_GR30(%r1) /* ... and save it */
191
192 STREG %r20, TASK_PT_GR20(%r1) /* Syscall number */
193 STREG %r21, TASK_PT_GR21(%r1)
194 STREG %r22, TASK_PT_GR22(%r1)
195 STREG %r23, TASK_PT_GR23(%r1) /* 4th argument */
196 STREG %r24, TASK_PT_GR24(%r1) /* 3rd argument */
197 STREG %r25, TASK_PT_GR25(%r1) /* 2nd argument */
198 STREG %r26, TASK_PT_GR26(%r1) /* 1st argument */
199 STREG %r27, TASK_PT_GR27(%r1) /* user dp */
200 STREG %r28, TASK_PT_GR28(%r1) /* return value 0 */
201 STREG %r0, TASK_PT_ORIG_R28(%r1) /* don't prohibit restarts */
202 STREG %r29, TASK_PT_GR29(%r1) /* return value 1 */
203 STREG %r31, TASK_PT_GR31(%r1) /* preserve syscall return ptr */
204
205 ldo TASK_PT_FR0(%r1), %r27 /* save fpregs from the kernel */
206 save_fp %r27 /* or potential task switch */
207
208 mfctl %cr11, %r27 /* i.e. SAR */
209 STREG %r27, TASK_PT_SAR(%r1)
210
211 loadgp
212
213#ifdef CONFIG_64BIT
214 ldo -16(%r30),%r29 /* Reference param save area */
215 copy %r19,%r2 /* W bit back to r2 */
216#else
217 /* no need to save these on stack in wide mode because the first 8
218 * args are passed in registers */
219 stw %r22, -52(%r30) /* 5th argument */
220 stw %r21, -56(%r30) /* 6th argument */
221#endif
222
223 /* Are we being ptraced? */
224 mfctl %cr30, %r1
225 LDREG TASK_TI_FLAGS(%r1),%r1
226 ldi _TIF_SYSCALL_TRACE_MASK, %r19
227 and,COND(=) %r1, %r19, %r0
228 b,n .Ltracesys
229
230 /* Note! We cannot use the syscall table that is mapped
231 nearby since the gateway page is mapped execute-only. */
232
233#ifdef CONFIG_64BIT
234 ldil L%sys_call_table, %r1
235 or,= %r2,%r2,%r2
236 addil L%(sys_call_table64-sys_call_table), %r1
237 ldo R%sys_call_table(%r1), %r19
238 or,= %r2,%r2,%r2
239 ldo R%sys_call_table64(%r1), %r19
240#else
241 load32 sys_call_table, %r19
242#endif
243 comiclr,>> __NR_Linux_syscalls, %r20, %r0
244 b,n .Lsyscall_nosys
245
246 LDREGX %r20(%r19), %r19
247
248 /* If this is a sys_rt_sigreturn call, and the signal was received
249 * when not in_syscall, then we want to return via syscall_exit_rfi,
250 * not syscall_exit. Signal no. in r20, in_syscall in r25 (see
251 * trampoline code in signal.c).
252 */
253 ldi __NR_rt_sigreturn,%r2
254 comb,= %r2,%r20,.Lrt_sigreturn
255.Lin_syscall:
256 ldil L%syscall_exit,%r2
257 be 0(%sr7,%r19)
258 ldo R%syscall_exit(%r2),%r2
259.Lrt_sigreturn:
260 comib,<> 0,%r25,.Lin_syscall
261 ldil L%syscall_exit_rfi,%r2
262 be 0(%sr7,%r19)
263 ldo R%syscall_exit_rfi(%r2),%r2
264
265 /* Note! Because we are not running where we were linked, any
266 calls to functions external to this file must be indirect. To
267 be safe, we apply the opposite rule to functions within this
268 file, with local labels given to them to ensure correctness. */
269
270.Lsyscall_nosys:
271syscall_nosys:
272 ldil L%syscall_exit,%r1
273 be R%syscall_exit(%sr7,%r1)
274 ldo -ENOSYS(%r0),%r28 /* set errno */
275
276
277/* Warning! This trace code is a virtual duplicate of the code above so be
278 * sure to maintain both! */
279.Ltracesys:
280tracesys:
281 /* Need to save more registers so the debugger can see where we
282 * are. This saves only the lower 8 bits of PSW, so that the C
283 * bit is still clear on syscalls, and the D bit is set if this
284 * full register save path has been executed. We check the D
285 * bit on syscall_return_rfi to determine which registers to
286 * restore. An interrupt results in a full PSW saved with the
287 * C bit set, a non-straced syscall entry results in C and D clear
288 * in the saved PSW.
289 */
290 mfctl %cr30,%r1 /* get task ptr */
291 ssm 0,%r2
292 STREG %r2,TASK_PT_PSW(%r1) /* Lower 8 bits only!! */
293 mfsp %sr0,%r2
294 STREG %r2,TASK_PT_SR0(%r1)
295 mfsp %sr1,%r2
296 STREG %r2,TASK_PT_SR1(%r1)
297 mfsp %sr2,%r2
298 STREG %r2,TASK_PT_SR2(%r1)
299 mfsp %sr3,%r2
300 STREG %r2,TASK_PT_SR3(%r1)
301 STREG %r2,TASK_PT_SR4(%r1)
302 STREG %r2,TASK_PT_SR5(%r1)
303 STREG %r2,TASK_PT_SR6(%r1)
304 STREG %r2,TASK_PT_SR7(%r1)
305 STREG %r2,TASK_PT_IASQ0(%r1)
306 STREG %r2,TASK_PT_IASQ1(%r1)
307 LDREG TASK_PT_GR31(%r1),%r2
308 STREG %r2,TASK_PT_IAOQ0(%r1)
309 ldo 4(%r2),%r2
310 STREG %r2,TASK_PT_IAOQ1(%r1)
311 ldo TASK_REGS(%r1),%r2
312 /* reg_save %r2 */
313 STREG %r3,PT_GR3(%r2)
314 STREG %r4,PT_GR4(%r2)
315 STREG %r5,PT_GR5(%r2)
316 STREG %r6,PT_GR6(%r2)
317 STREG %r7,PT_GR7(%r2)
318 STREG %r8,PT_GR8(%r2)
319 STREG %r9,PT_GR9(%r2)
320 STREG %r10,PT_GR10(%r2)
321 STREG %r11,PT_GR11(%r2)
322 STREG %r12,PT_GR12(%r2)
323 STREG %r13,PT_GR13(%r2)
324 STREG %r14,PT_GR14(%r2)
325 STREG %r15,PT_GR15(%r2)
326 STREG %r16,PT_GR16(%r2)
327 STREG %r17,PT_GR17(%r2)
328 STREG %r18,PT_GR18(%r2)
329 /* Finished saving things for the debugger */
330
331 copy %r2,%r26
332 ldil L%do_syscall_trace_enter,%r1
333 ldil L%tracesys_next,%r2
334 be R%do_syscall_trace_enter(%sr7,%r1)
335 ldo R%tracesys_next(%r2),%r2
336
337tracesys_next:
338 /* do_syscall_trace_enter either returned the syscallno, or -1L,
339 * so we skip restoring the PT_GR20 below, since we pulled it from
340 * task->thread.regs.gr[20] above.
341 */
342 copy %ret0,%r20
343
344 mfctl %cr30,%r1 /* get task ptr */
345 LDREG TASK_PT_GR28(%r1), %r28 /* Restore return value */
346 LDREG TASK_PT_GR26(%r1), %r26 /* Restore the users args */
347 LDREG TASK_PT_GR25(%r1), %r25
348 LDREG TASK_PT_GR24(%r1), %r24
349 LDREG TASK_PT_GR23(%r1), %r23
350 LDREG TASK_PT_GR22(%r1), %r22
351 LDREG TASK_PT_GR21(%r1), %r21
352#ifdef CONFIG_64BIT
353 ldo -16(%r30),%r29 /* Reference param save area */
354#else
355 stw %r22, -52(%r30) /* 5th argument */
356 stw %r21, -56(%r30) /* 6th argument */
357#endif
358
359 cmpib,COND(=),n -1,%r20,tracesys_exit /* seccomp may have returned -1 */
360 comiclr,>> __NR_Linux_syscalls, %r20, %r0
361 b,n .Ltracesys_nosys
362
363 /* Note! We cannot use the syscall table that is mapped
364 nearby since the gateway page is mapped execute-only. */
365
366#ifdef CONFIG_64BIT
367 LDREG TASK_PT_GR30(%r1), %r19 /* get users sp back */
368 extrd,u %r19,63,1,%r2 /* W hidden in bottom bit */
369
370 ldil L%sys_call_table, %r1
371 or,= %r2,%r2,%r2
372 addil L%(sys_call_table64-sys_call_table), %r1
373 ldo R%sys_call_table(%r1), %r19
374 or,= %r2,%r2,%r2
375 ldo R%sys_call_table64(%r1), %r19
376#else
377 load32 sys_call_table, %r19
378#endif
379
380 LDREGX %r20(%r19), %r19
381
382 /* If this is a sys_rt_sigreturn call, and the signal was received
383 * when not in_syscall, then we want to return via syscall_exit_rfi,
384 * not syscall_exit. Signal no. in r20, in_syscall in r25 (see
385 * trampoline code in signal.c).
386 */
387 ldi __NR_rt_sigreturn,%r2
388 comb,= %r2,%r20,.Ltrace_rt_sigreturn
389.Ltrace_in_syscall:
390 ldil L%tracesys_exit,%r2
391 be 0(%sr7,%r19)
392 ldo R%tracesys_exit(%r2),%r2
393
394.Ltracesys_nosys:
395 ldo -ENOSYS(%r0),%r28 /* set errno */
396
397 /* Do *not* call this function on the gateway page, because it
398 makes a direct call to syscall_trace. */
399
400tracesys_exit:
401 mfctl %cr30,%r1 /* get task ptr */
402#ifdef CONFIG_64BIT
403 ldo -16(%r30),%r29 /* Reference param save area */
404#endif
405 ldo TASK_REGS(%r1),%r26
406 BL do_syscall_trace_exit,%r2
407 STREG %r28,TASK_PT_GR28(%r1) /* save return value now */
408 mfctl %cr30,%r1 /* get task ptr */
409 LDREG TASK_PT_GR28(%r1), %r28 /* Restore return val. */
410
411 ldil L%syscall_exit,%r1
412 be,n R%syscall_exit(%sr7,%r1)
413
414.Ltrace_rt_sigreturn:
415 comib,<> 0,%r25,.Ltrace_in_syscall
416 ldil L%tracesys_sigexit,%r2
417 be 0(%sr7,%r19)
418 ldo R%tracesys_sigexit(%r2),%r2
419
420tracesys_sigexit:
421 mfctl %cr30,%r1 /* get task ptr */
422#ifdef CONFIG_64BIT
423 ldo -16(%r30),%r29 /* Reference param save area */
424#endif
425 BL do_syscall_trace_exit,%r2
426 ldo TASK_REGS(%r1),%r26
427
428 ldil L%syscall_exit_rfi,%r1
429 be,n R%syscall_exit_rfi(%sr7,%r1)
430
431
432 /*********************************************************
433 32/64-bit Light-Weight-Syscall ABI
434
435 * - Indicates a hint for userspace inline asm
436 implementations.
437
438 Syscall number (caller-saves)
439 - %r20
440 * In asm clobber.
441
442 Argument registers (caller-saves)
443 - %r26, %r25, %r24, %r23, %r22
444 * In asm input.
445
446 Return registers (caller-saves)
447 - %r28 (return), %r21 (errno)
448 * In asm output.
449
450 Caller-saves registers
451 - %r1, %r27, %r29
452 - %r2 (return pointer)
453 - %r31 (ble link register)
454 * In asm clobber.
455
456 Callee-saves registers
457 - %r3-%r18
458 - %r30 (stack pointer)
459 * Not in asm clobber.
460
461 If userspace is 32-bit:
462 Callee-saves registers
463 - %r19 (32-bit PIC register)
464
465 Differences from 32-bit calling convention:
466 - Syscall number in %r20
467 - Additional argument register %r22 (arg4)
468 - Callee-saves %r19.
469
470 If userspace is 64-bit:
471 Callee-saves registers
472 - %r27 (64-bit PIC register)
473
474 Differences from 64-bit calling convention:
475 - Syscall number in %r20
476 - Additional argument register %r22 (arg4)
477 - Callee-saves %r27.
478
479 Error codes returned by entry path:
480
481 ENOSYS - r20 was an invalid LWS number.
482
483 *********************************************************/
484lws_start:
485
486#ifdef CONFIG_64BIT
487 ssm PSW_SM_W, %r1
488 extrd,u %r1,PSW_W_BIT,1,%r1
489 /* sp must be aligned on 4, so deposit the W bit setting into
490 * the bottom of sp temporarily */
491 or,od %r1,%r30,%r30
492
493 /* Clip LWS number to a 32-bit value for 32-bit processes */
494 depdi 0, 31, 32, %r20
495#endif
496
497 /* Is the lws entry number valid? */
498 comiclr,>> __NR_lws_entries, %r20, %r0
499 b,n lws_exit_nosys
500
501 /* Load table start */
502 ldil L%lws_table, %r1
503 ldo R%lws_table(%r1), %r28 /* Scratch use of r28 */
504 LDREGX %r20(%sr2,r28), %r21 /* Scratch use of r21 */
505
506 /* Jump to lws, lws table pointers already relocated */
507 be,n 0(%sr2,%r21)
508
509lws_exit_noerror:
510 lws_pagefault_enable %r1,%r21
511 stw,ma %r20, 0(%sr2,%r20)
512 ssm PSW_SM_I, %r0
513 b lws_exit
514 copy %r0, %r21
515
516lws_wouldblock:
517 ssm PSW_SM_I, %r0
518 ldo 2(%r0), %r28
519 b lws_exit
520 ldo -EAGAIN(%r0), %r21
521
522lws_pagefault:
523 lws_pagefault_enable %r1,%r21
524 stw,ma %r20, 0(%sr2,%r20)
525 ssm PSW_SM_I, %r0
526 ldo 3(%r0),%r28
527 b lws_exit
528 ldo -EAGAIN(%r0),%r21
529
530lws_fault:
531 ldo 1(%r0),%r28
532 b lws_exit
533 ldo -EFAULT(%r0),%r21
534
535lws_exit_nosys:
536 ldo -ENOSYS(%r0),%r21
537 /* Fall through: Return to userspace */
538
539lws_exit:
540#ifdef CONFIG_64BIT
541 /* decide whether to reset the wide mode bit
542 *
543 * For a syscall, the W bit is stored in the lowest bit
544 * of sp. Extract it and reset W if it is zero */
545 extrd,u,*<> %r30,63,1,%r1
546 rsm PSW_SM_W, %r0
547 /* now reset the lowest bit of sp if it was set */
548 xor %r30,%r1,%r30
549#endif
550 be,n 0(%sr7, %r31)
551
552
553
554 /***************************************************
555 Implementing 32bit CAS as an atomic operation:
556
557 %r26 - Address to examine
558 %r25 - Old value to check (old)
559 %r24 - New value to set (new)
560 %r28 - Return prev through this register.
561 %r21 - Kernel error code
562
563 %r21 returns the following error codes:
564 EAGAIN - CAS is busy, ldcw failed, try again.
565 EFAULT - Read or write failed.
566
567 If EAGAIN is returned, %r28 indicates the busy reason:
568 r28 == 1 - CAS is busy. lock contended.
569 r28 == 2 - CAS is busy. ldcw failed.
570 r28 == 3 - CAS is busy. page fault.
571
572 Scratch: r20, r28, r1
573
574 ****************************************************/
575
576 /* ELF64 Process entry path */
577lws_compare_and_swap64:
578#ifdef CONFIG_64BIT
579 b,n lws_compare_and_swap
580#else
581 /* If we are not a 64-bit kernel, then we don't
582 * have 64-bit input registers, and calling
583 * the 64-bit LWS CAS returns ENOSYS.
584 */
585 b,n lws_exit_nosys
586#endif
587
588 /* ELF32/ELF64 Process entry path */
589lws_compare_and_swap32:
590#ifdef CONFIG_64BIT
591 /* Wide mode user process? */
592 bb,<,n %sp, 31, lws_compare_and_swap
593
594 /* Clip all the input registers for 32-bit processes */
595 depdi 0, 31, 32, %r26
596 depdi 0, 31, 32, %r25
597 depdi 0, 31, 32, %r24
598#endif
599
600lws_compare_and_swap:
601 /* Trigger memory reference interruptions without writing to memory */
6021: ldw 0(%r26), %r28
6032: stbys,e %r0, 0(%r26)
604
605 /* Calculate 8-bit hash index from virtual address */
606 extru_safe %r26, 27, 8, %r20
607
608 /* Load start of lock table */
609 ldil L%lws_lock_start, %r28
610 ldo R%lws_lock_start(%r28), %r28
611
612 /* Find lock to use, the hash index is one of 0 to
613 255, multiplied by 16 (keep it 16-byte aligned)
614 and add to the lock table offset. */
615 shlw %r20, 4, %r20
616 add %r20, %r28, %r20
617
618 rsm PSW_SM_I, %r0 /* Disable interrupts */
619
620 /* Try to acquire the lock */
621 LDCW 0(%sr2,%r20), %r28
622 comclr,<> %r0, %r28, %r0
623 b,n lws_wouldblock
624
625 /* Disable page faults to prevent sleeping in critical region */
626 lws_pagefault_disable %r21,%r28
627
628 /*
629 prev = *addr;
630 if ( prev == old )
631 *addr = new;
632 return prev;
633 */
634
635 /* NOTES:
636 This all works because intr_do_signal
637 and schedule both check the return iasq
638 and see that we are on the kernel page
639 so this process is never scheduled off
640 or is ever sent any signal of any sort,
641 thus it is wholly atomic from usrspace's
642 perspective
643 */
644 /* The load and store could fail */
6453: ldw 0(%r26), %r28
646 sub,<> %r28, %r25, %r0
6474: stw %r24, 0(%r26)
648 b,n lws_exit_noerror
649
650 /* A fault occurred on load or stbys,e store */
6515: b,n lws_fault
652 ASM_EXCEPTIONTABLE_ENTRY(1b-linux_gateway_page, 5b-linux_gateway_page)
653 ASM_EXCEPTIONTABLE_ENTRY(2b-linux_gateway_page, 5b-linux_gateway_page)
654
655 /* A page fault occurred in critical region */
6566: b,n lws_pagefault
657 ASM_EXCEPTIONTABLE_ENTRY(3b-linux_gateway_page, 6b-linux_gateway_page)
658 ASM_EXCEPTIONTABLE_ENTRY(4b-linux_gateway_page, 6b-linux_gateway_page)
659
660
661 /***************************************************
662 New CAS implementation which uses pointers and variable size
663 information. The value pointed by old and new MUST NOT change
664 while performing CAS. The lock only protects the value at %r26.
665
666 %r26 - Address to examine
667 %r25 - Pointer to the value to check (old)
668 %r24 - Pointer to the value to set (new)
669 %r23 - Size of the variable (0/1/2/3 for 8/16/32/64 bit)
670 %r28 - Return non-zero on failure
671 %r21 - Kernel error code
672
673 %r21 returns the following error codes:
674 EAGAIN - CAS is busy, ldcw failed, try again.
675 EFAULT - Read or write failed.
676
677 If EAGAIN is returned, %r28 indicates the busy reason:
678 r28 == 1 - CAS is busy. lock contended.
679 r28 == 2 - CAS is busy. ldcw failed.
680 r28 == 3 - CAS is busy. page fault.
681
682 Scratch: r20, r22, r28, r29, r1, fr4 (32bit for 64bit CAS only)
683
684 ****************************************************/
685
686lws_compare_and_swap_2:
687#ifdef CONFIG_64BIT
688 /* Wide mode user process? */
689 bb,<,n %sp, 31, cas2_begin
690
691 /* Clip the input registers for 32-bit processes. We don't
692 need to clip %r23 as we only use it for word operations */
693 depdi 0, 31, 32, %r26
694 depdi 0, 31, 32, %r25
695 depdi 0, 31, 32, %r24
696#endif
697
698cas2_begin:
699 /* Check the validity of the size pointer */
700 subi,>>= 3, %r23, %r0
701 b,n lws_exit_nosys
702
703 /* Jump to the functions which will load the old and new values into
704 registers depending on the their size */
705 shlw %r23, 2, %r29
706 blr %r29, %r0
707 nop
708
709 /* 8-bit load */
7101: ldb 0(%r25), %r25
711 b cas2_lock_start
7122: ldb 0(%r24), %r24
713 nop
714 nop
715 nop
716 nop
717 nop
718
719 /* 16-bit load */
7203: ldh 0(%r25), %r25
721 b cas2_lock_start
7224: ldh 0(%r24), %r24
723 nop
724 nop
725 nop
726 nop
727 nop
728
729 /* 32-bit load */
7305: ldw 0(%r25), %r25
731 b cas2_lock_start
7326: ldw 0(%r24), %r24
733 nop
734 nop
735 nop
736 nop
737 nop
738
739 /* 64-bit load */
740#ifdef CONFIG_64BIT
7417: ldd 0(%r25), %r25
7428: ldd 0(%r24), %r24
743#else
744 /* Load old value into r22/r23 - high/low */
7457: ldw 0(%r25), %r22
7468: ldw 4(%r25), %r23
747 /* Load new value into fr4 for atomic store later */
7489: flddx 0(%r24), %fr4
749#endif
750
751cas2_lock_start:
752 /* Trigger memory reference interruptions without writing to memory */
753 copy %r26, %r28
754 depi_safe 0, 31, 2, %r28
75510: ldw 0(%r28), %r1
75611: stbys,e %r0, 0(%r28)
757
758 /* Calculate 8-bit hash index from virtual address */
759 extru_safe %r26, 27, 8, %r20
760
761 /* Load start of lock table */
762 ldil L%lws_lock_start, %r28
763 ldo R%lws_lock_start(%r28), %r28
764
765 /* Find lock to use, the hash index is one of 0 to
766 255, multiplied by 16 (keep it 16-byte aligned)
767 and add to the lock table offset. */
768 shlw %r20, 4, %r20
769 add %r20, %r28, %r20
770
771 rsm PSW_SM_I, %r0 /* Disable interrupts */
772
773 /* Try to acquire the lock */
774 LDCW 0(%sr2,%r20), %r28
775 comclr,<> %r0, %r28, %r0
776 b,n lws_wouldblock
777
778 /* Disable page faults to prevent sleeping in critical region */
779 lws_pagefault_disable %r21,%r28
780
781 /*
782 prev = *addr;
783 if ( prev == old )
784 *addr = new;
785 return prev;
786 */
787
788 /* NOTES:
789 This all works because intr_do_signal
790 and schedule both check the return iasq
791 and see that we are on the kernel page
792 so this process is never scheduled off
793 or is ever sent any signal of any sort,
794 thus it is wholly atomic from usrspace's
795 perspective
796 */
797
798 /* Jump to the correct function */
799 blr %r29, %r0
800 /* Set %r28 as non-zero for now */
801 ldo 1(%r0),%r28
802
803 /* 8-bit CAS */
80412: ldb 0(%r26), %r29
805 sub,= %r29, %r25, %r0
806 b,n lws_exit_noerror
80713: stb %r24, 0(%r26)
808 b lws_exit_noerror
809 copy %r0, %r28
810 nop
811 nop
812
813 /* 16-bit CAS */
81414: ldh 0(%r26), %r29
815 sub,= %r29, %r25, %r0
816 b,n lws_exit_noerror
81715: sth %r24, 0(%r26)
818 b lws_exit_noerror
819 copy %r0, %r28
820 nop
821 nop
822
823 /* 32-bit CAS */
82416: ldw 0(%r26), %r29
825 sub,= %r29, %r25, %r0
826 b,n lws_exit_noerror
82717: stw %r24, 0(%r26)
828 b lws_exit_noerror
829 copy %r0, %r28
830 nop
831 nop
832
833 /* 64-bit CAS */
834#ifdef CONFIG_64BIT
83518: ldd 0(%r26), %r29
836 sub,*= %r29, %r25, %r0
837 b,n lws_exit_noerror
83819: std %r24, 0(%r26)
839 copy %r0, %r28
840#else
841 /* Compare first word */
84218: ldw 0(%r26), %r29
843 sub,= %r29, %r22, %r0
844 b,n lws_exit_noerror
845 /* Compare second word */
84619: ldw 4(%r26), %r29
847 sub,= %r29, %r23, %r0
848 b,n lws_exit_noerror
849 /* Perform the store */
85020: fstdx %fr4, 0(%r26)
851 copy %r0, %r28
852#endif
853 b lws_exit_noerror
854 copy %r0, %r28
855
856 /* A fault occurred on load or stbys,e store */
85730: b,n lws_fault
858 ASM_EXCEPTIONTABLE_ENTRY(1b-linux_gateway_page, 30b-linux_gateway_page)
859 ASM_EXCEPTIONTABLE_ENTRY(2b-linux_gateway_page, 30b-linux_gateway_page)
860 ASM_EXCEPTIONTABLE_ENTRY(3b-linux_gateway_page, 30b-linux_gateway_page)
861 ASM_EXCEPTIONTABLE_ENTRY(4b-linux_gateway_page, 30b-linux_gateway_page)
862 ASM_EXCEPTIONTABLE_ENTRY(5b-linux_gateway_page, 30b-linux_gateway_page)
863 ASM_EXCEPTIONTABLE_ENTRY(6b-linux_gateway_page, 30b-linux_gateway_page)
864 ASM_EXCEPTIONTABLE_ENTRY(7b-linux_gateway_page, 30b-linux_gateway_page)
865 ASM_EXCEPTIONTABLE_ENTRY(8b-linux_gateway_page, 30b-linux_gateway_page)
866#ifndef CONFIG_64BIT
867 ASM_EXCEPTIONTABLE_ENTRY(9b-linux_gateway_page, 30b-linux_gateway_page)
868#endif
869
870 ASM_EXCEPTIONTABLE_ENTRY(10b-linux_gateway_page, 30b-linux_gateway_page)
871 ASM_EXCEPTIONTABLE_ENTRY(11b-linux_gateway_page, 30b-linux_gateway_page)
872
873 /* A page fault occurred in critical region */
87431: b,n lws_pagefault
875 ASM_EXCEPTIONTABLE_ENTRY(12b-linux_gateway_page, 31b-linux_gateway_page)
876 ASM_EXCEPTIONTABLE_ENTRY(13b-linux_gateway_page, 31b-linux_gateway_page)
877 ASM_EXCEPTIONTABLE_ENTRY(14b-linux_gateway_page, 31b-linux_gateway_page)
878 ASM_EXCEPTIONTABLE_ENTRY(15b-linux_gateway_page, 31b-linux_gateway_page)
879 ASM_EXCEPTIONTABLE_ENTRY(16b-linux_gateway_page, 31b-linux_gateway_page)
880 ASM_EXCEPTIONTABLE_ENTRY(17b-linux_gateway_page, 31b-linux_gateway_page)
881 ASM_EXCEPTIONTABLE_ENTRY(18b-linux_gateway_page, 31b-linux_gateway_page)
882 ASM_EXCEPTIONTABLE_ENTRY(19b-linux_gateway_page, 31b-linux_gateway_page)
883#ifndef CONFIG_64BIT
884 ASM_EXCEPTIONTABLE_ENTRY(20b-linux_gateway_page, 31b-linux_gateway_page)
885#endif
886
887
888 /***************************************************
889 LWS atomic exchange.
890
891 %r26 - Exchange address
892 %r25 - Size of the variable (0/1/2/3 for 8/16/32/64 bit)
893 %r24 - Address of new value
894 %r23 - Address of old value
895 %r28 - Return non-zero on failure
896 %r21 - Kernel error code
897
898 %r21 returns the following error codes:
899 EAGAIN - CAS is busy, ldcw failed, try again.
900 EFAULT - Read or write failed.
901
902 If EAGAIN is returned, %r28 indicates the busy reason:
903 r28 == 1 - CAS is busy. lock contended.
904 r28 == 2 - CAS is busy. ldcw failed.
905 r28 == 3 - CAS is busy. page fault.
906
907 Scratch: r20, r1
908
909 ****************************************************/
910
911lws_atomic_xchg:
912#ifdef CONFIG_64BIT
913 /* Wide mode user process? */
914 bb,<,n %sp, 31, atomic_xchg_begin
915
916 /* Clip the input registers for 32-bit processes. We don't
917 need to clip %r23 as we only use it for word operations */
918 depdi 0, 31, 32, %r26
919 depdi 0, 31, 32, %r25
920 depdi 0, 31, 32, %r24
921 depdi 0, 31, 32, %r23
922#endif
923
924atomic_xchg_begin:
925 /* Check the validity of the size pointer */
926 subi,>>= 3, %r25, %r0
927 b,n lws_exit_nosys
928
929 /* Jump to the functions which will load the old and new values into
930 registers depending on the their size */
931 shlw %r25, 2, %r1
932 blr %r1, %r0
933 nop
934
935 /* Perform exception checks */
936
937 /* 8-bit exchange */
9381: ldb 0(%r24), %r20
939 copy %r23, %r20
940 depi_safe 0, 31, 2, %r20
941 b atomic_xchg_start
9422: stbys,e %r0, 0(%r20)
943 nop
944 nop
945 nop
946
947 /* 16-bit exchange */
9483: ldh 0(%r24), %r20
949 copy %r23, %r20
950 depi_safe 0, 31, 2, %r20
951 b atomic_xchg_start
9524: stbys,e %r0, 0(%r20)
953 nop
954 nop
955 nop
956
957 /* 32-bit exchange */
9585: ldw 0(%r24), %r20
959 b atomic_xchg_start
9606: stbys,e %r0, 0(%r23)
961 nop
962 nop
963 nop
964 nop
965 nop
966
967 /* 64-bit exchange */
968#ifdef CONFIG_64BIT
9697: ldd 0(%r24), %r20
9708: stdby,e %r0, 0(%r23)
971#else
9727: ldw 0(%r24), %r20
9738: ldw 4(%r24), %r20
974 copy %r23, %r20
975 depi_safe 0, 31, 2, %r20
9769: stbys,e %r0, 0(%r20)
97710: stbys,e %r0, 4(%r20)
978#endif
979
980atomic_xchg_start:
981 /* Trigger memory reference interruptions without writing to memory */
982 copy %r26, %r28
983 depi_safe 0, 31, 2, %r28
98411: ldw 0(%r28), %r1
98512: stbys,e %r0, 0(%r28)
986
987 /* Calculate 8-bit hash index from virtual address */
988 extru_safe %r26, 27, 8, %r20
989
990 /* Load start of lock table */
991 ldil L%lws_lock_start, %r28
992 ldo R%lws_lock_start(%r28), %r28
993
994 /* Find lock to use, the hash index is one of 0 to
995 255, multiplied by 16 (keep it 16-byte aligned)
996 and add to the lock table offset. */
997 shlw %r20, 4, %r20
998 add %r20, %r28, %r20
999
1000 rsm PSW_SM_I, %r0 /* Disable interrupts */
1001
1002 /* Try to acquire the lock */
1003 LDCW 0(%sr2,%r20), %r28
1004 comclr,<> %r0, %r28, %r0
1005 b,n lws_wouldblock
1006
1007 /* Disable page faults to prevent sleeping in critical region */
1008 lws_pagefault_disable %r21,%r28
1009
1010 /* NOTES:
1011 This all works because intr_do_signal
1012 and schedule both check the return iasq
1013 and see that we are on the kernel page
1014 so this process is never scheduled off
1015 or is ever sent any signal of any sort,
1016 thus it is wholly atomic from userspace's
1017 perspective
1018 */
1019
1020 /* Jump to the correct function */
1021 blr %r1, %r0
1022 /* Set %r28 as non-zero for now */
1023 ldo 1(%r0),%r28
1024
1025 /* 8-bit exchange */
102614: ldb 0(%r26), %r1
102715: stb %r1, 0(%r23)
102815: ldb 0(%r24), %r1
102917: stb %r1, 0(%r26)
1030 b lws_exit_noerror
1031 copy %r0, %r28
1032 nop
1033 nop
1034
1035 /* 16-bit exchange */
103618: ldh 0(%r26), %r1
103719: sth %r1, 0(%r23)
103820: ldh 0(%r24), %r1
103921: sth %r1, 0(%r26)
1040 b lws_exit_noerror
1041 copy %r0, %r28
1042 nop
1043 nop
1044
1045 /* 32-bit exchange */
104622: ldw 0(%r26), %r1
104723: stw %r1, 0(%r23)
104824: ldw 0(%r24), %r1
104925: stw %r1, 0(%r26)
1050 b lws_exit_noerror
1051 copy %r0, %r28
1052 nop
1053 nop
1054
1055 /* 64-bit exchange */
1056#ifdef CONFIG_64BIT
105726: ldd 0(%r26), %r1
105827: std %r1, 0(%r23)
105928: ldd 0(%r24), %r1
106029: std %r1, 0(%r26)
1061#else
106226: flddx 0(%r26), %fr4
106327: fstdx %fr4, 0(%r23)
106428: flddx 0(%r24), %fr4
106529: fstdx %fr4, 0(%r26)
1066#endif
1067 b lws_exit_noerror
1068 copy %r0, %r28
1069
1070 /* A fault occurred on load or stbys,e store */
107130: b,n lws_fault
1072 ASM_EXCEPTIONTABLE_ENTRY(1b-linux_gateway_page, 30b-linux_gateway_page)
1073 ASM_EXCEPTIONTABLE_ENTRY(2b-linux_gateway_page, 30b-linux_gateway_page)
1074 ASM_EXCEPTIONTABLE_ENTRY(3b-linux_gateway_page, 30b-linux_gateway_page)
1075 ASM_EXCEPTIONTABLE_ENTRY(4b-linux_gateway_page, 30b-linux_gateway_page)
1076 ASM_EXCEPTIONTABLE_ENTRY(5b-linux_gateway_page, 30b-linux_gateway_page)
1077 ASM_EXCEPTIONTABLE_ENTRY(6b-linux_gateway_page, 30b-linux_gateway_page)
1078 ASM_EXCEPTIONTABLE_ENTRY(7b-linux_gateway_page, 30b-linux_gateway_page)
1079 ASM_EXCEPTIONTABLE_ENTRY(8b-linux_gateway_page, 30b-linux_gateway_page)
1080#ifndef CONFIG_64BIT
1081 ASM_EXCEPTIONTABLE_ENTRY(9b-linux_gateway_page, 30b-linux_gateway_page)
1082 ASM_EXCEPTIONTABLE_ENTRY(10b-linux_gateway_page, 30b-linux_gateway_page)
1083#endif
1084
1085 ASM_EXCEPTIONTABLE_ENTRY(11b-linux_gateway_page, 30b-linux_gateway_page)
1086 ASM_EXCEPTIONTABLE_ENTRY(12b-linux_gateway_page, 30b-linux_gateway_page)
1087
1088 /* A page fault occurred in critical region */
108931: b,n lws_pagefault
1090 ASM_EXCEPTIONTABLE_ENTRY(14b-linux_gateway_page, 31b-linux_gateway_page)
1091 ASM_EXCEPTIONTABLE_ENTRY(15b-linux_gateway_page, 31b-linux_gateway_page)
1092 ASM_EXCEPTIONTABLE_ENTRY(16b-linux_gateway_page, 31b-linux_gateway_page)
1093 ASM_EXCEPTIONTABLE_ENTRY(17b-linux_gateway_page, 31b-linux_gateway_page)
1094 ASM_EXCEPTIONTABLE_ENTRY(18b-linux_gateway_page, 31b-linux_gateway_page)
1095 ASM_EXCEPTIONTABLE_ENTRY(19b-linux_gateway_page, 31b-linux_gateway_page)
1096 ASM_EXCEPTIONTABLE_ENTRY(20b-linux_gateway_page, 31b-linux_gateway_page)
1097 ASM_EXCEPTIONTABLE_ENTRY(21b-linux_gateway_page, 31b-linux_gateway_page)
1098 ASM_EXCEPTIONTABLE_ENTRY(22b-linux_gateway_page, 31b-linux_gateway_page)
1099 ASM_EXCEPTIONTABLE_ENTRY(23b-linux_gateway_page, 31b-linux_gateway_page)
1100 ASM_EXCEPTIONTABLE_ENTRY(24b-linux_gateway_page, 31b-linux_gateway_page)
1101 ASM_EXCEPTIONTABLE_ENTRY(25b-linux_gateway_page, 31b-linux_gateway_page)
1102 ASM_EXCEPTIONTABLE_ENTRY(26b-linux_gateway_page, 31b-linux_gateway_page)
1103 ASM_EXCEPTIONTABLE_ENTRY(27b-linux_gateway_page, 31b-linux_gateway_page)
1104 ASM_EXCEPTIONTABLE_ENTRY(28b-linux_gateway_page, 31b-linux_gateway_page)
1105 ASM_EXCEPTIONTABLE_ENTRY(29b-linux_gateway_page, 31b-linux_gateway_page)
1106
1107 /***************************************************
1108 LWS atomic store.
1109
1110 %r26 - Address to store
1111 %r25 - Size of the variable (0/1/2/3 for 8/16/32/64 bit)
1112 %r24 - Address of value to store
1113 %r28 - Return non-zero on failure
1114 %r21 - Kernel error code
1115
1116 %r21 returns the following error codes:
1117 EAGAIN - CAS is busy, ldcw failed, try again.
1118 EFAULT - Read or write failed.
1119
1120 If EAGAIN is returned, %r28 indicates the busy reason:
1121 r28 == 1 - CAS is busy. lock contended.
1122 r28 == 2 - CAS is busy. ldcw failed.
1123 r28 == 3 - CAS is busy. page fault.
1124
1125 Scratch: r20, r1
1126
1127 ****************************************************/
1128
1129lws_atomic_store:
1130#ifdef CONFIG_64BIT
1131 /* Wide mode user process? */
1132 bb,<,n %sp, 31, atomic_store_begin
1133
1134 /* Clip the input registers for 32-bit processes. We don't
1135 need to clip %r23 as we only use it for word operations */
1136 depdi 0, 31, 32, %r26
1137 depdi 0, 31, 32, %r25
1138 depdi 0, 31, 32, %r24
1139#endif
1140
1141atomic_store_begin:
1142 /* Check the validity of the size pointer */
1143 subi,>>= 3, %r25, %r0
1144 b,n lws_exit_nosys
1145
1146 shlw %r25, 1, %r1
1147 blr %r1, %r0
1148 nop
1149
1150 /* Perform exception checks */
1151
1152 /* 8-bit store */
11531: ldb 0(%r24), %r20
1154 b,n atomic_store_start
1155 nop
1156 nop
1157
1158 /* 16-bit store */
11592: ldh 0(%r24), %r20
1160 b,n atomic_store_start
1161 nop
1162 nop
1163
1164 /* 32-bit store */
11653: ldw 0(%r24), %r20
1166 b,n atomic_store_start
1167 nop
1168 nop
1169
1170 /* 64-bit store */
1171#ifdef CONFIG_64BIT
11724: ldd 0(%r24), %r20
1173#else
11744: ldw 0(%r24), %r20
11755: ldw 4(%r24), %r20
1176#endif
1177
1178atomic_store_start:
1179 /* Trigger memory reference interruptions without writing to memory */
1180 copy %r26, %r28
1181 depi_safe 0, 31, 2, %r28
11826: ldw 0(%r28), %r1
11837: stbys,e %r0, 0(%r28)
1184
1185 /* Calculate 8-bit hash index from virtual address */
1186 extru_safe %r26, 27, 8, %r20
1187
1188 /* Load start of lock table */
1189 ldil L%lws_lock_start, %r28
1190 ldo R%lws_lock_start(%r28), %r28
1191
1192 /* Find lock to use, the hash index is one of 0 to
1193 255, multiplied by 16 (keep it 16-byte aligned)
1194 and add to the lock table offset. */
1195 shlw %r20, 4, %r20
1196 add %r20, %r28, %r20
1197
1198 rsm PSW_SM_I, %r0 /* Disable interrupts */
1199
1200 /* Try to acquire the lock */
1201 LDCW 0(%sr2,%r20), %r28
1202 comclr,<> %r0, %r28, %r0
1203 b,n lws_wouldblock
1204
1205 /* Disable page faults to prevent sleeping in critical region */
1206 lws_pagefault_disable %r21,%r28
1207
1208 /* NOTES:
1209 This all works because intr_do_signal
1210 and schedule both check the return iasq
1211 and see that we are on the kernel page
1212 so this process is never scheduled off
1213 or is ever sent any signal of any sort,
1214 thus it is wholly atomic from userspace's
1215 perspective
1216 */
1217
1218 /* Jump to the correct function */
1219 blr %r1, %r0
1220 /* Set %r28 as non-zero for now */
1221 ldo 1(%r0),%r28
1222
1223 /* 8-bit store */
12249: ldb 0(%r24), %r1
122510: stb %r1, 0(%r26)
1226 b lws_exit_noerror
1227 copy %r0, %r28
1228
1229 /* 16-bit store */
123011: ldh 0(%r24), %r1
123112: sth %r1, 0(%r26)
1232 b lws_exit_noerror
1233 copy %r0, %r28
1234
1235 /* 32-bit store */
123613: ldw 0(%r24), %r1
123714: stw %r1, 0(%r26)
1238 b lws_exit_noerror
1239 copy %r0, %r28
1240
1241 /* 64-bit store */
1242#ifdef CONFIG_64BIT
124315: ldd 0(%r24), %r1
124416: std %r1, 0(%r26)
1245#else
124615: flddx 0(%r24), %fr4
124716: fstdx %fr4, 0(%r26)
1248#endif
1249 b lws_exit_noerror
1250 copy %r0, %r28
1251
1252 /* A fault occurred on load or stbys,e store */
125330: b,n lws_fault
1254 ASM_EXCEPTIONTABLE_ENTRY(1b-linux_gateway_page, 30b-linux_gateway_page)
1255 ASM_EXCEPTIONTABLE_ENTRY(2b-linux_gateway_page, 30b-linux_gateway_page)
1256 ASM_EXCEPTIONTABLE_ENTRY(3b-linux_gateway_page, 30b-linux_gateway_page)
1257 ASM_EXCEPTIONTABLE_ENTRY(4b-linux_gateway_page, 30b-linux_gateway_page)
1258#ifndef CONFIG_64BIT
1259 ASM_EXCEPTIONTABLE_ENTRY(5b-linux_gateway_page, 30b-linux_gateway_page)
1260#endif
1261
1262 ASM_EXCEPTIONTABLE_ENTRY(6b-linux_gateway_page, 30b-linux_gateway_page)
1263 ASM_EXCEPTIONTABLE_ENTRY(7b-linux_gateway_page, 30b-linux_gateway_page)
1264
1265 /* A page fault occurred in critical region */
126631: b,n lws_pagefault
1267 ASM_EXCEPTIONTABLE_ENTRY(9b-linux_gateway_page, 31b-linux_gateway_page)
1268 ASM_EXCEPTIONTABLE_ENTRY(10b-linux_gateway_page, 31b-linux_gateway_page)
1269 ASM_EXCEPTIONTABLE_ENTRY(11b-linux_gateway_page, 31b-linux_gateway_page)
1270 ASM_EXCEPTIONTABLE_ENTRY(12b-linux_gateway_page, 31b-linux_gateway_page)
1271 ASM_EXCEPTIONTABLE_ENTRY(13b-linux_gateway_page, 31b-linux_gateway_page)
1272 ASM_EXCEPTIONTABLE_ENTRY(14b-linux_gateway_page, 31b-linux_gateway_page)
1273 ASM_EXCEPTIONTABLE_ENTRY(15b-linux_gateway_page, 31b-linux_gateway_page)
1274 ASM_EXCEPTIONTABLE_ENTRY(16b-linux_gateway_page, 31b-linux_gateway_page)
1275
1276 /* Make sure nothing else is placed on this page */
1277 .align PAGE_SIZE
1278END(linux_gateway_page)
1279ENTRY(end_linux_gateway_page)
1280
1281 /* Relocate symbols assuming linux_gateway_page is mapped
1282 to virtual address 0x0 */
1283
1284#define LWS_ENTRY(_name_) ASM_ULONG_INSN (lws_##_name_ - linux_gateway_page)
1285
1286 .section .rodata,"a"
1287
1288 .align 8
1289 /* Light-weight-syscall table */
1290 /* Start of lws table. */
1291ENTRY(lws_table)
1292 LWS_ENTRY(compare_and_swap32) /* 0 - ELF32 Atomic 32bit CAS */
1293 LWS_ENTRY(compare_and_swap64) /* 1 - ELF64 Atomic 32bit CAS */
1294 LWS_ENTRY(compare_and_swap_2) /* 2 - Atomic 64bit CAS */
1295 LWS_ENTRY(atomic_xchg) /* 3 - Atomic Exchange */
1296 LWS_ENTRY(atomic_store) /* 4 - Atomic Store */
1297END(lws_table)
1298 /* End of lws table */
1299
1300#ifdef CONFIG_64BIT
1301#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, compat)
1302#else
1303#define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)
1304#endif
1305#define __SYSCALL(nr, entry) ASM_ULONG_INSN entry
1306 .align 8
1307ENTRY(sys_call_table)
1308 .export sys_call_table,data
1309#include <asm/syscall_table_32.h> /* 32-bit syscalls */
1310END(sys_call_table)
1311
1312#ifdef CONFIG_64BIT
1313 .align 8
1314ENTRY(sys_call_table64)
1315#include <asm/syscall_table_64.h> /* 64-bit syscalls */
1316END(sys_call_table64)
1317#endif
1318
1319 /*
1320 All light-weight-syscall atomic operations
1321 will use this set of locks
1322
1323 NOTE: The lws_lock_start symbol must be
1324 at least 16-byte aligned for safe use
1325 with ldcw.
1326 */
1327 .section .data
1328 .align L1_CACHE_BYTES
1329ENTRY(lws_lock_start)
1330 /* lws locks */
1331 .rept 256
1332 /* Keep locks aligned at 16-bytes */
1333 .word 1
1334 .word 0
1335 .word 0
1336 .word 0
1337 .endr
1338END(lws_lock_start)
1339 .previous
1340
1341.end