xref: /openbmc/linux/arch/parisc/kernel/syscall.S (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
1/*
2 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
3 *
4 * System call entry code Copyright (c) Matthew Wilcox 1999 <willy@bofh.ai>
5 * Licensed under the GNU GPL.
6 * thanks to Philipp Rumpf, Mike Shaver and various others
7 * sorry about the wall, puffin..
8 */
9
10#include <asm/asm-offsets.h>
11#include <asm/unistd.h>
12#include <asm/errno.h>
13#include <asm/page.h>
14#include <asm/psw.h>
15#include <asm/thread_info.h>
16#include <asm/assembly.h>
17#include <asm/processor.h>
18
19#include <linux/linkage.h>
20
21	/* We fill the empty parts of the gateway page with
22 	 * something that will kill the kernel or a
23 	 * userspace application.
24	 */
25#define KILL_INSN	break	0,0
26
27	.level          LEVEL
28
29	.text
30
31	.import syscall_exit,code
32	.import syscall_exit_rfi,code
33
34	/* Linux gateway page is aliased to virtual page 0 in the kernel
35	 * address space. Since it is a gateway page it cannot be
36	 * dereferenced, so null pointers will still fault. We start
37	 * the actual entry point at 0x100. We put break instructions
38	 * at the beginning of the page to trap null indirect function
39	 * pointers.
40	 */
41
42	.align PAGE_SIZE
43ENTRY(linux_gateway_page)
44
45        /* ADDRESS 0x00 to 0xb0 = 176 bytes / 4 bytes per insn = 44 insns */
46	.rept 44
47	KILL_INSN
48	.endr
49
50	/* ADDRESS 0xb0 to 0xb4, lws uses 1 insns for entry */
51	/* Light-weight-syscall entry must always be located at 0xb0 */
52	/* WARNING: Keep this number updated with table size changes */
53#define __NR_lws_entries (2)
54
55lws_entry:
56	/* Unconditional branch to lws_start, located on the
57	   same gateway page */
58	b,n	lws_start
59
60	/* Fill from 0xb4 to 0xe0 */
61	.rept 11
62	KILL_INSN
63	.endr
64
65	/* This function MUST be located at 0xe0 for glibc's threading
66	mechanism to work. DO NOT MOVE THIS CODE EVER! */
67set_thread_pointer:
68	gate	.+8, %r0		/* increase privilege */
69	depi	3, 31, 2, %r31		/* Ensure we return into user mode. */
70	be	0(%sr7,%r31)		/* return to user space */
71	mtctl	%r26, %cr27		/* move arg0 to the control register */
72
73	/* Increase the chance of trapping if random jumps occur to this
74	address, fill from 0xf0 to 0x100 */
75	.rept 4
76	KILL_INSN
77	.endr
78
79/* This address must remain fixed at 0x100 for glibc's syscalls to work */
80	.align 256
81linux_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
89#ifdef CONFIG_64BIT
90	/* for now we can *always* set the W bit on entry to the syscall
91	 * since we don't support wide userland processes.  We could
92	 * also save the current SM other than in r0 and restore it on
93	 * exit from the syscall, and also use that value to know
94	 * whether to do narrow or wide syscalls. -PB
95	 */
96	ssm	PSW_SM_W, %r1
97	extrd,u	%r1,PSW_W_BIT,1,%r1
98	/* sp must be aligned on 4, so deposit the W bit setting into
99	 * the bottom of sp temporarily */
100	or,ev	%r1,%r30,%r30
101	b,n	1f
102	/* The top halves of argument registers must be cleared on syscall
103	 * entry from narrow executable.
104	 */
105	depdi	0, 31, 32, %r26
106	depdi	0, 31, 32, %r25
107	depdi	0, 31, 32, %r24
108	depdi	0, 31, 32, %r23
109	depdi	0, 31, 32, %r22
110	depdi	0, 31, 32, %r21
1111:
112#endif
113	mfctl   %cr30,%r1
114	xor     %r1,%r30,%r30                   /* ye olde xor trick */
115	xor     %r1,%r30,%r1
116	xor     %r1,%r30,%r30
117
118	ldo     THREAD_SZ_ALGN+FRAME_SIZE(%r30),%r30  /* set up kernel stack */
119
120	/* N.B.: It is critical that we don't set sr7 to 0 until r30
121	 *       contains a valid kernel stack pointer. It is also
122	 *       critical that we don't start using the kernel stack
123	 *       until after sr7 has been set to 0.
124	 */
125
126	mtsp	%r0,%sr7			/* get kernel space into sr7 */
127	STREGM	%r1,FRAME_SIZE(%r30)		/* save r1 (usp) here for now */
128	mfctl	%cr30,%r1			/* get task ptr in %r1 */
129	LDREG	TI_TASK(%r1),%r1
130
131	/* Save some registers for sigcontext and potential task
132	   switch (see entry.S for the details of which ones are
133	   saved/restored).  TASK_PT_PSW is zeroed so we can see whether
134	   a process is on a syscall or not.  For an interrupt the real
135	   PSW value is stored.  This is needed for gdb and sys_ptrace. */
136	STREG	%r0,  TASK_PT_PSW(%r1)
137	STREG	%r2,  TASK_PT_GR2(%r1)		/* preserve rp */
138	STREG	%r19, TASK_PT_GR19(%r1)
139
140	LDREGM	-FRAME_SIZE(%r30), %r2		/* get users sp back */
141#ifdef CONFIG_64BIT
142	extrd,u	%r2,63,1,%r19			/* W hidden in bottom bit */
143#if 0
144	xor	%r19,%r2,%r2			/* clear bottom bit */
145	depd,z	%r19,1,1,%r19
146	std	%r19,TASK_PT_PSW(%r1)
147#endif
148#endif
149	STREG	%r2,  TASK_PT_GR30(%r1)		/* ... and save it */
150
151	STREG	%r20, TASK_PT_GR20(%r1)		/* Syscall number */
152	STREG	%r21, TASK_PT_GR21(%r1)
153	STREG	%r22, TASK_PT_GR22(%r1)
154	STREG	%r23, TASK_PT_GR23(%r1)		/* 4th argument */
155	STREG	%r24, TASK_PT_GR24(%r1)		/* 3rd argument */
156	STREG	%r25, TASK_PT_GR25(%r1)		/* 2nd argument */
157	STREG	%r26, TASK_PT_GR26(%r1)	 	/* 1st argument */
158	STREG	%r27, TASK_PT_GR27(%r1)		/* user dp */
159	STREG   %r28, TASK_PT_GR28(%r1)         /* return value 0 */
160	STREG   %r28, TASK_PT_ORIG_R28(%r1)     /* return value 0 (saved for signals) */
161	STREG	%r29, TASK_PT_GR29(%r1)		/* return value 1 */
162	STREG	%r31, TASK_PT_GR31(%r1)		/* preserve syscall return ptr */
163
164	ldo	TASK_PT_FR0(%r1), %r27		/* save fpregs from the kernel */
165	save_fp	%r27				/* or potential task switch  */
166
167	mfctl	%cr11, %r27			/* i.e. SAR */
168	STREG	%r27, TASK_PT_SAR(%r1)
169
170	loadgp
171
172#ifdef CONFIG_64BIT
173	ldo	-16(%r30),%r29			/* Reference param save area */
174	copy	%r19,%r2			/* W bit back to r2 */
175#else
176	/* no need to save these on stack in wide mode because the first 8
177	 * args are passed in registers */
178	stw     %r22, -52(%r30)                 /* 5th argument */
179	stw     %r21, -56(%r30)                 /* 6th argument */
180#endif
181
182	/* Are we being ptraced? */
183	mfctl	%cr30, %r1
184	LDREG	TI_TASK(%r1),%r1
185	ldw	TASK_PTRACE(%r1), %r1
186	bb,<,n	%r1,31,.Ltracesys
187
188	/* Note!  We cannot use the syscall table that is mapped
189	nearby since the gateway page is mapped execute-only. */
190
191#ifdef CONFIG_64BIT
192	ldil	L%sys_call_table, %r1
193	or,=	%r2,%r2,%r2
194	addil	L%(sys_call_table64-sys_call_table), %r1
195	ldo	R%sys_call_table(%r1), %r19
196	or,=	%r2,%r2,%r2
197	ldo	R%sys_call_table64(%r1), %r19
198#else
199	ldil	L%sys_call_table, %r1
200	ldo     R%sys_call_table(%r1), %r19
201#endif
202	comiclr,>>	__NR_Linux_syscalls, %r20, %r0
203	b,n	.Lsyscall_nosys
204
205	LDREGX  %r20(%r19), %r19
206
207	/* If this is a sys_rt_sigreturn call, and the signal was received
208	 * when not in_syscall, then we want to return via syscall_exit_rfi,
209	 * not syscall_exit.  Signal no. in r20, in_syscall in r25 (see
210	 * trampoline code in signal.c).
211	 */
212	ldi	__NR_rt_sigreturn,%r2
213	comb,=	%r2,%r20,.Lrt_sigreturn
214.Lin_syscall:
215	ldil	L%syscall_exit,%r2
216	be      0(%sr7,%r19)
217	ldo	R%syscall_exit(%r2),%r2
218.Lrt_sigreturn:
219	comib,<> 0,%r25,.Lin_syscall
220	ldil	L%syscall_exit_rfi,%r2
221	be      0(%sr7,%r19)
222	ldo	R%syscall_exit_rfi(%r2),%r2
223
224	/* Note!  Because we are not running where we were linked, any
225	calls to functions external to this file must be indirect.  To
226	be safe, we apply the opposite rule to functions within this
227	file, with local labels given to them to ensure correctness. */
228
229.Lsyscall_nosys:
230syscall_nosys:
231	ldil	L%syscall_exit,%r1
232	be	R%syscall_exit(%sr7,%r1)
233	ldo	-ENOSYS(%r0),%r28		   /* set errno */
234
235
236/* Warning! This trace code is a virtual duplicate of the code above so be
237 * sure to maintain both! */
238.Ltracesys:
239tracesys:
240	/* Need to save more registers so the debugger can see where we
241	 * are.  This saves only the lower 8 bits of PSW, so that the C
242	 * bit is still clear on syscalls, and the D bit is set if this
243	 * full register save path has been executed.  We check the D
244	 * bit on syscall_return_rfi to determine which registers to
245	 * restore.  An interrupt results in a full PSW saved with the
246	 * C bit set, a non-straced syscall entry results in C and D clear
247	 * in the saved PSW.
248	 */
249	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
250	LDREG	TI_TASK(%r1), %r1
251	ssm	0,%r2
252	STREG	%r2,TASK_PT_PSW(%r1)		/* Lower 8 bits only!! */
253	mfsp	%sr0,%r2
254	STREG	%r2,TASK_PT_SR0(%r1)
255	mfsp	%sr1,%r2
256	STREG	%r2,TASK_PT_SR1(%r1)
257	mfsp	%sr2,%r2
258	STREG	%r2,TASK_PT_SR2(%r1)
259	mfsp	%sr3,%r2
260	STREG	%r2,TASK_PT_SR3(%r1)
261	STREG	%r2,TASK_PT_SR4(%r1)
262	STREG	%r2,TASK_PT_SR5(%r1)
263	STREG	%r2,TASK_PT_SR6(%r1)
264	STREG	%r2,TASK_PT_SR7(%r1)
265	STREG	%r2,TASK_PT_IASQ0(%r1)
266	STREG	%r2,TASK_PT_IASQ1(%r1)
267	LDREG	TASK_PT_GR31(%r1),%r2
268	STREG	%r2,TASK_PT_IAOQ0(%r1)
269	ldo	4(%r2),%r2
270	STREG	%r2,TASK_PT_IAOQ1(%r1)
271	ldo	TASK_REGS(%r1),%r2
272	/* reg_save %r2 */
273	STREG	%r3,PT_GR3(%r2)
274	STREG	%r4,PT_GR4(%r2)
275	STREG	%r5,PT_GR5(%r2)
276	STREG	%r6,PT_GR6(%r2)
277	STREG	%r7,PT_GR7(%r2)
278	STREG	%r8,PT_GR8(%r2)
279	STREG	%r9,PT_GR9(%r2)
280	STREG	%r10,PT_GR10(%r2)
281	STREG	%r11,PT_GR11(%r2)
282	STREG	%r12,PT_GR12(%r2)
283	STREG	%r13,PT_GR13(%r2)
284	STREG	%r14,PT_GR14(%r2)
285	STREG	%r15,PT_GR15(%r2)
286	STREG	%r16,PT_GR16(%r2)
287	STREG	%r17,PT_GR17(%r2)
288	STREG	%r18,PT_GR18(%r2)
289	/* Finished saving things for the debugger */
290
291	ldil	L%syscall_trace,%r1
292	ldil	L%tracesys_next,%r2
293	be	R%syscall_trace(%sr7,%r1)
294	ldo	R%tracesys_next(%r2),%r2
295
296tracesys_next:
297	ldil	L%sys_call_table,%r1
298	ldo     R%sys_call_table(%r1), %r19
299
300	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
301	LDREG	TI_TASK(%r1), %r1
302	LDREG   TASK_PT_GR20(%r1), %r20
303	LDREG   TASK_PT_GR26(%r1), %r26		/* Restore the users args */
304	LDREG   TASK_PT_GR25(%r1), %r25
305	LDREG   TASK_PT_GR24(%r1), %r24
306	LDREG   TASK_PT_GR23(%r1), %r23
307#ifdef CONFIG_64BIT
308	LDREG   TASK_PT_GR22(%r1), %r22
309	LDREG   TASK_PT_GR21(%r1), %r21
310	ldo	-16(%r30),%r29			/* Reference param save area */
311#endif
312
313	comiclr,>>=	__NR_Linux_syscalls, %r20, %r0
314	b,n	.Lsyscall_nosys
315
316	LDREGX  %r20(%r19), %r19
317
318	/* If this is a sys_rt_sigreturn call, and the signal was received
319	 * when not in_syscall, then we want to return via syscall_exit_rfi,
320	 * not syscall_exit.  Signal no. in r20, in_syscall in r25 (see
321	 * trampoline code in signal.c).
322	 */
323	ldi	__NR_rt_sigreturn,%r2
324	comb,=	%r2,%r20,.Ltrace_rt_sigreturn
325.Ltrace_in_syscall:
326	ldil	L%tracesys_exit,%r2
327	be      0(%sr7,%r19)
328	ldo	R%tracesys_exit(%r2),%r2
329
330	/* Do *not* call this function on the gateway page, because it
331	makes a direct call to syscall_trace. */
332
333tracesys_exit:
334	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
335	LDREG	TI_TASK(%r1), %r1
336#ifdef CONFIG_64BIT
337	ldo	-16(%r30),%r29			/* Reference param save area */
338#endif
339	bl	syscall_trace, %r2
340	STREG   %r28,TASK_PT_GR28(%r1)          /* save return value now */
341	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
342	LDREG	TI_TASK(%r1), %r1
343	LDREG   TASK_PT_GR28(%r1), %r28		/* Restore return val. */
344
345	ldil	L%syscall_exit,%r1
346	be,n	R%syscall_exit(%sr7,%r1)
347
348.Ltrace_rt_sigreturn:
349	comib,<> 0,%r25,.Ltrace_in_syscall
350	ldil	L%tracesys_sigexit,%r2
351	be      0(%sr7,%r19)
352	ldo	R%tracesys_sigexit(%r2),%r2
353
354tracesys_sigexit:
355	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
356	LDREG	0(%r1), %r1
357#ifdef CONFIG_64BIT
358	ldo	-16(%r30),%r29			/* Reference param save area */
359#endif
360	bl	syscall_trace, %r2
361	nop
362
363	ldil	L%syscall_exit_rfi,%r1
364	be,n	R%syscall_exit_rfi(%sr7,%r1)
365
366
367	/*********************************************************
368		Light-weight-syscall code
369
370		r20 - lws number
371		r26,r25,r24,r23,r22 - Input registers
372		r28 - Function return register
373		r21 - Error code.
374
375		Scracth: Any of the above that aren't being
376		currently used, including r1.
377
378		Return pointer: r31 (Not usable)
379
380		Error codes returned by entry path:
381
382		ENOSYS - r20 was an invalid LWS number.
383
384	*********************************************************/
385lws_start:
386	/* Gate and ensure we return to userspace */
387	gate	.+8, %r0
388	depi	3, 31, 2, %r31	/* Ensure we return to userspace */
389
390#ifdef CONFIG_64BIT
391	/* FIXME: If we are a 64-bit kernel just
392	 *        turn this on unconditionally.
393	 */
394	ssm	PSW_SM_W, %r1
395	extrd,u	%r1,PSW_W_BIT,1,%r1
396	/* sp must be aligned on 4, so deposit the W bit setting into
397	 * the bottom of sp temporarily */
398	or,ev	%r1,%r30,%r30
399
400	/* Clip LWS number to a 32-bit value always */
401	depdi	0, 31, 32, %r20
402#endif
403
404        /* Is the lws entry number valid? */
405	comiclr,>>=	__NR_lws_entries, %r20, %r0
406	b,n	lws_exit_nosys
407
408	/* WARNING: Trashing sr2 and sr3 */
409	mfsp	%sr7,%r1			/* get userspace into sr3 */
410	mtsp	%r1,%sr3
411	mtsp	%r0,%sr2			/* get kernel space into sr2 */
412
413	/* Load table start */
414	ldil	L%lws_table, %r1
415	ldo	R%lws_table(%r1), %r28	/* Scratch use of r28 */
416	LDREGX	%r20(%sr2,r28), %r21	/* Scratch use of r21 */
417
418	/* Jump to lws, lws table pointers already relocated */
419	be,n	0(%sr2,%r21)
420
421lws_exit_nosys:
422	ldo	-ENOSYS(%r0),%r21		   /* set errno */
423	/* Fall through: Return to userspace */
424
425lws_exit:
426#ifdef CONFIG_64BIT
427	/* decide whether to reset the wide mode bit
428	 *
429	 * For a syscall, the W bit is stored in the lowest bit
430	 * of sp.  Extract it and reset W if it is zero */
431	extrd,u,*<>	%r30,63,1,%r1
432	rsm	PSW_SM_W, %r0
433	/* now reset the lowest bit of sp if it was set */
434	xor	%r30,%r1,%r30
435#endif
436	be,n	0(%sr3, %r31)
437
438
439
440	/***************************************************
441		Implementing CAS as an atomic operation:
442
443		%r26 - Address to examine
444		%r25 - Old value to check (old)
445		%r24 - New value to set (new)
446		%r28 - Return prev through this register.
447		%r21 - Kernel error code
448
449		If debugging is DISabled:
450
451		%r21 has the following meanings:
452
453		EAGAIN - CAS is busy, ldcw failed, try again.
454		EFAULT - Read or write failed.
455
456		If debugging is enabled:
457
458		EDEADLOCK - CAS called recursively.
459		EAGAIN && r28 == 1 - CAS is busy. Lock contended.
460		EAGAIN && r28 == 2 - CAS is busy. ldcw failed.
461		EFAULT - Read or write failed.
462
463		Scratch: r20, r28, r1
464
465	****************************************************/
466
467	/* Do not enable LWS debugging */
468#define ENABLE_LWS_DEBUG 0
469
470	/* ELF64 Process entry path */
471lws_compare_and_swap64:
472#ifdef CONFIG_64BIT
473	b,n	lws_compare_and_swap
474#else
475	/* If we are not a 64-bit kernel, then we don't
476	 * implement having 64-bit input registers
477	 */
478	b,n	lws_exit_nosys
479#endif
480
481	/* ELF32 Process entry path */
482lws_compare_and_swap32:
483#ifdef CONFIG_64BIT
484	/* Clip all the input registers */
485	depdi	0, 31, 32, %r26
486	depdi	0, 31, 32, %r25
487	depdi	0, 31, 32, %r24
488#endif
489
490lws_compare_and_swap:
491#ifdef CONFIG_SMP
492	/* Load start of lock table */
493	ldil	L%lws_lock_start, %r20
494	ldo	R%lws_lock_start(%r20), %r28
495
496	/* Extract four bits from r26 and hash lock (Bits 4-7) */
497	extru  %r26, 27, 4, %r20
498
499	/* Find lock to use, the hash is either one of 0 to
500	   15, multiplied by 16 (keep it 16-byte aligned)
501	   and add to the lock table offset. */
502	shlw	%r20, 4, %r20
503	add	%r20, %r28, %r20
504
505# if ENABLE_LWS_DEBUG
506	/*
507		DEBUG, check for deadlock!
508		If the thread register values are the same
509		then we were the one that locked it last and
510		this is a recurisve call that will deadlock.
511		We *must* giveup this call and fail.
512	*/
513	ldw	4(%sr2,%r20), %r28			/* Load thread register */
514	/* WARNING: If cr27 cycles to the same value we have problems */
515	mfctl	%cr27, %r21				/* Get current thread register */
516	cmpb,<>,n	%r21, %r28, cas_lock		/* Called recursive? */
517	b	lws_exit				/* Return error! */
518	ldo	-EDEADLOCK(%r0), %r21
519cas_lock:
520	cmpb,=,n	%r0, %r28, cas_nocontend	/* Is nobody using it? */
521	ldo	1(%r0), %r28				/* 1st case */
522	b	lws_exit				/* Contended... */
523	ldo	-EAGAIN(%r0), %r21			/* Spin in userspace */
524cas_nocontend:
525# endif
526/* ENABLE_LWS_DEBUG */
527
528	LDCW	0(%sr2,%r20), %r28			/* Try to acquire the lock */
529	cmpb,<>,n	%r0, %r28, cas_action		/* Did we get it? */
530cas_wouldblock:
531	ldo	2(%r0), %r28				/* 2nd case */
532	b	lws_exit				/* Contended... */
533	ldo	-EAGAIN(%r0), %r21			/* Spin in userspace */
534#endif
535/* CONFIG_SMP */
536
537	/*
538		prev = *addr;
539		if ( prev == old )
540		  *addr = new;
541		return prev;
542	*/
543
544	/* NOTES:
545		This all works becuse intr_do_signal
546		and schedule both check the return iasq
547		and see that we are on the kernel page
548		so this process is never scheduled off
549		or is ever sent any signal of any sort,
550		thus it is wholly atomic from usrspaces
551		perspective
552	*/
553cas_action:
554#if defined CONFIG_SMP && ENABLE_LWS_DEBUG
555	/* DEBUG */
556	mfctl	%cr27, %r1
557	stw	%r1, 4(%sr2,%r20)
558#endif
559	/* The load and store could fail */
5601:	ldw	0(%sr3,%r26), %r28
561	sub,<>	%r28, %r25, %r0
5622:	stw	%r24, 0(%sr3,%r26)
563#ifdef CONFIG_SMP
564	/* Free lock */
565	stw	%r20, 0(%sr2,%r20)
566# if ENABLE_LWS_DEBUG
567	/* Clear thread register indicator */
568	stw	%r0, 4(%sr2,%r20)
569# endif
570#endif
571	/* Return to userspace, set no error */
572	b	lws_exit
573	copy	%r0, %r21
574
5753:
576	/* Error occured on load or store */
577#ifdef CONFIG_SMP
578	/* Free lock */
579	stw	%r20, 0(%sr2,%r20)
580# if ENABLE_LWS_DEBUG
581	stw	%r0, 4(%sr2,%r20)
582# endif
583#endif
584	b	lws_exit
585	ldo	-EFAULT(%r0),%r21	/* set errno */
586	nop
587	nop
588	nop
589	nop
590
591	/* Two exception table entries, one for the load,
592	   the other for the store. Either return -EFAULT.
593	   Each of the entries must be relocated. */
594	.section __ex_table,"aw"
595	ASM_ULONG_INSN (1b - linux_gateway_page), (3b - linux_gateway_page)
596	ASM_ULONG_INSN (2b - linux_gateway_page), (3b - linux_gateway_page)
597	.previous
598
599
600	/* Make sure nothing else is placed on this page */
601	.align PAGE_SIZE
602END(linux_gateway_page)
603ENTRY(end_linux_gateway_page)
604
605	/* Relocate symbols assuming linux_gateway_page is mapped
606	   to virtual address 0x0 */
607
608#define LWS_ENTRY(_name_) ASM_ULONG_INSN (lws_##_name_ - linux_gateway_page)
609
610	.section .rodata,"a"
611
612	.align PAGE_SIZE
613	/* Light-weight-syscall table */
614	/* Start of lws table. */
615ENTRY(lws_table)
616	LWS_ENTRY(compare_and_swap32)	/* 0 - ELF32 Atomic compare and swap */
617	LWS_ENTRY(compare_and_swap64)	/* 1 - ELF64 Atomic compare and swap */
618END(lws_table)
619	/* End of lws table */
620
621	.align PAGE_SIZE
622ENTRY(sys_call_table)
623#include "syscall_table.S"
624END(sys_call_table)
625
626#ifdef CONFIG_64BIT
627	.align PAGE_SIZE
628ENTRY(sys_call_table64)
629#define SYSCALL_TABLE_64BIT
630#include "syscall_table.S"
631END(sys_call_table64)
632#endif
633
634#ifdef CONFIG_SMP
635	/*
636		All light-weight-syscall atomic operations
637		will use this set of locks
638	*/
639	.section .data
640	.align	PAGE_SIZE
641ENTRY(lws_lock_start)
642	/* lws locks */
643	.align 16
644	.rept 16
645	/* Keep locks aligned at 16-bytes */
646	.word 1
647	.word 0
648	.word 0
649	.word 0
650	.endr
651END(lws_lock_start)
652	.previous
653#endif
654/* CONFIG_SMP for lws_lock_start */
655
656.end
657
658
659