xref: /openbmc/linux/arch/parisc/kernel/syscall.S (revision 0013a854)
11da177e4SLinus Torvalds/*
21da177e4SLinus Torvalds * Linux/PA-RISC Project (http://www.parisc-linux.org/)
31da177e4SLinus Torvalds *
41da177e4SLinus Torvalds * System call entry code Copyright (c) Matthew Wilcox 1999 <willy@bofh.ai>
51da177e4SLinus Torvalds * Licensed under the GNU GPL.
61da177e4SLinus Torvalds * thanks to Philipp Rumpf, Mike Shaver and various others
71da177e4SLinus Torvalds * sorry about the wall, puffin..
81da177e4SLinus Torvalds */
91da177e4SLinus Torvalds
100013a854SSam Ravnborg#include <asm/asm-offsets.h>
111da177e4SLinus Torvalds#include <asm/unistd.h>
121da177e4SLinus Torvalds#include <asm/errno.h>
131da177e4SLinus Torvalds#include <asm/psw.h>
141da177e4SLinus Torvalds#include <asm/thread_info.h>
151da177e4SLinus Torvalds
161da177e4SLinus Torvalds#include <asm/assembly.h>
171da177e4SLinus Torvalds#include <asm/processor.h>
181da177e4SLinus Torvalds
191da177e4SLinus Torvalds	/* We fill the empty parts of the gateway page with
201da177e4SLinus Torvalds 	 * something that will kill the kernel or a
211da177e4SLinus Torvalds 	 * userspace application.
221da177e4SLinus Torvalds	 */
231da177e4SLinus Torvalds#define KILL_INSN	break	0,0
241da177e4SLinus Torvalds
251da177e4SLinus Torvalds#include <linux/config.h> /* for CONFIG_SMP */
261da177e4SLinus Torvalds
271da177e4SLinus Torvalds#ifdef __LP64__
281da177e4SLinus Torvalds	.level          2.0w
291da177e4SLinus Torvalds#else
301da177e4SLinus Torvalds	.level		1.1
311da177e4SLinus Torvalds#endif
321da177e4SLinus Torvalds
331da177e4SLinus Torvalds#ifndef __LP64__
341da177e4SLinus Torvalds	.macro fixup_branch,lbl
351da177e4SLinus Torvalds	b	    \lbl
361da177e4SLinus Torvalds	.endm
371da177e4SLinus Torvalds#else
381da177e4SLinus Torvalds	.macro fixup_branch,lbl
391da177e4SLinus Torvalds	ldil	    L%\lbl, %r1
401da177e4SLinus Torvalds	ldo	    R%\lbl(%r1), %r1
411da177e4SLinus Torvalds	bv,n        %r0(%r1)
421da177e4SLinus Torvalds	.endm
431da177e4SLinus Torvalds#endif
441da177e4SLinus Torvalds
451da177e4SLinus Torvalds	.text
461da177e4SLinus Torvalds
471da177e4SLinus Torvalds	.import syscall_exit,code
481da177e4SLinus Torvalds	.import syscall_exit_rfi,code
491da177e4SLinus Torvalds	.export linux_gateway_page
501da177e4SLinus Torvalds
511da177e4SLinus Torvalds	/* Linux gateway page is aliased to virtual page 0 in the kernel
521da177e4SLinus Torvalds	 * address space. Since it is a gateway page it cannot be
531da177e4SLinus Torvalds	 * dereferenced, so null pointers will still fault. We start
541da177e4SLinus Torvalds	 * the actual entry point at 0x100. We put break instructions
551da177e4SLinus Torvalds	 * at the beginning of the page to trap null indirect function
561da177e4SLinus Torvalds	 * pointers.
571da177e4SLinus Torvalds	 */
581da177e4SLinus Torvalds
591da177e4SLinus Torvalds	.align 4096
601da177e4SLinus Torvaldslinux_gateway_page:
611da177e4SLinus Torvalds
621da177e4SLinus Torvalds        /* ADDRESS 0x00 to 0xb0 = 176 bytes / 4 bytes per insn = 44 insns */
631da177e4SLinus Torvalds	.rept 44
641da177e4SLinus Torvalds	KILL_INSN
651da177e4SLinus Torvalds	.endr
661da177e4SLinus Torvalds
671da177e4SLinus Torvalds	/* ADDRESS 0xb0 to 0xb4, lws uses 1 insns for entry */
681da177e4SLinus Torvalds	/* Light-weight-syscall entry must always be located at 0xb0 */
691da177e4SLinus Torvalds	/* WARNING: Keep this number updated with table size changes */
701da177e4SLinus Torvalds#define __NR_lws_entries (2)
711da177e4SLinus Torvalds
721da177e4SLinus Torvaldslws_entry:
731da177e4SLinus Torvalds	/* Unconditional branch to lws_start, located on the
741da177e4SLinus Torvalds	   same gateway page */
751da177e4SLinus Torvalds	b,n	lws_start
761da177e4SLinus Torvalds
771da177e4SLinus Torvalds	/* Fill from 0xb4 to 0xe0 */
781da177e4SLinus Torvalds	.rept 11
791da177e4SLinus Torvalds	KILL_INSN
801da177e4SLinus Torvalds	.endr
811da177e4SLinus Torvalds
821da177e4SLinus Torvalds	/* This function MUST be located at 0xe0 for glibc's threading
831da177e4SLinus Torvalds	mechanism to work. DO NOT MOVE THIS CODE EVER! */
841da177e4SLinus Torvaldsset_thread_pointer:
851da177e4SLinus Torvalds	gate	.+8, %r0		/* increase privilege */
861da177e4SLinus Torvalds	depi	3, 31, 2, %r31		/* Ensure we return into user mode. */
871da177e4SLinus Torvalds	be	0(%sr7,%r31)		/* return to user space */
881da177e4SLinus Torvalds	mtctl	%r26, %cr27		/* move arg0 to the control register */
891da177e4SLinus Torvalds
901da177e4SLinus Torvalds	/* Increase the chance of trapping if random jumps occur to this
911da177e4SLinus Torvalds	address, fill from 0xf0 to 0x100 */
921da177e4SLinus Torvalds	.rept 4
931da177e4SLinus Torvalds	KILL_INSN
941da177e4SLinus Torvalds	.endr
951da177e4SLinus Torvalds
961da177e4SLinus Torvalds/* This address must remain fixed at 0x100 for glibc's syscalls to work */
971da177e4SLinus Torvalds	.align 256
981da177e4SLinus Torvaldslinux_gateway_entry:
991da177e4SLinus Torvalds	gate	.+8, %r0			/* become privileged */
1001da177e4SLinus Torvalds	mtsp	%r0,%sr4			/* get kernel space into sr4 */
1011da177e4SLinus Torvalds	mtsp	%r0,%sr5			/* get kernel space into sr5 */
1021da177e4SLinus Torvalds	mtsp	%r0,%sr6			/* get kernel space into sr6 */
1031da177e4SLinus Torvalds	mfsp    %sr7,%r1                        /* save user sr7 */
1041da177e4SLinus Torvalds	mtsp    %r1,%sr3                        /* and store it in sr3 */
1051da177e4SLinus Torvalds
1061da177e4SLinus Torvalds#ifdef __LP64__
1071da177e4SLinus Torvalds	/* for now we can *always* set the W bit on entry to the syscall
1081da177e4SLinus Torvalds	 * since we don't support wide userland processes.  We could
1091da177e4SLinus Torvalds	 * also save the current SM other than in r0 and restore it on
1101da177e4SLinus Torvalds	 * exit from the syscall, and also use that value to know
1111da177e4SLinus Torvalds	 * whether to do narrow or wide syscalls. -PB
1121da177e4SLinus Torvalds	 */
1131da177e4SLinus Torvalds	ssm	PSW_SM_W, %r1
1141da177e4SLinus Torvalds	extrd,u	%r1,PSW_W_BIT,1,%r1
1151da177e4SLinus Torvalds	/* sp must be aligned on 4, so deposit the W bit setting into
1161da177e4SLinus Torvalds	 * the bottom of sp temporarily */
1171da177e4SLinus Torvalds	or,ev	%r1,%r30,%r30
1181da177e4SLinus Torvalds	b,n	1f
1191da177e4SLinus Torvalds	/* The top halves of argument registers must be cleared on syscall
1201da177e4SLinus Torvalds	 * entry from narrow executable.
1211da177e4SLinus Torvalds	 */
1221da177e4SLinus Torvalds	depdi	0, 31, 32, %r26
1231da177e4SLinus Torvalds	depdi	0, 31, 32, %r25
1241da177e4SLinus Torvalds	depdi	0, 31, 32, %r24
1251da177e4SLinus Torvalds	depdi	0, 31, 32, %r23
1261da177e4SLinus Torvalds	depdi	0, 31, 32, %r22
1271da177e4SLinus Torvalds	depdi	0, 31, 32, %r21
1281da177e4SLinus Torvalds1:
1291da177e4SLinus Torvalds#endif
1301da177e4SLinus Torvalds	mfctl   %cr30,%r1
1311da177e4SLinus Torvalds	xor     %r1,%r30,%r30                   /* ye olde xor trick */
1321da177e4SLinus Torvalds	xor     %r1,%r30,%r1
1331da177e4SLinus Torvalds	xor     %r1,%r30,%r30
1341da177e4SLinus Torvalds
1351da177e4SLinus Torvalds	ldo     THREAD_SZ_ALGN+FRAME_SIZE(%r30),%r30  /* set up kernel stack */
1361da177e4SLinus Torvalds
1371da177e4SLinus Torvalds	/* N.B.: It is critical that we don't set sr7 to 0 until r30
1381da177e4SLinus Torvalds	 *       contains a valid kernel stack pointer. It is also
1391da177e4SLinus Torvalds	 *       critical that we don't start using the kernel stack
1401da177e4SLinus Torvalds	 *       until after sr7 has been set to 0.
1411da177e4SLinus Torvalds	 */
1421da177e4SLinus Torvalds
1431da177e4SLinus Torvalds	mtsp	%r0,%sr7			/* get kernel space into sr7 */
1441da177e4SLinus Torvalds	STREGM	%r1,FRAME_SIZE(%r30)		/* save r1 (usp) here for now */
1451da177e4SLinus Torvalds	mfctl	%cr30,%r1			/* get task ptr in %r1 */
1461da177e4SLinus Torvalds	LDREG	TI_TASK(%r1),%r1
1471da177e4SLinus Torvalds
1481da177e4SLinus Torvalds	/* Save some registers for sigcontext and potential task
1491da177e4SLinus Torvalds	   switch (see entry.S for the details of which ones are
1501da177e4SLinus Torvalds	   saved/restored).  TASK_PT_PSW is zeroed so we can see whether
1511da177e4SLinus Torvalds	   a process is on a syscall or not.  For an interrupt the real
1521da177e4SLinus Torvalds	   PSW value is stored.  This is needed for gdb and sys_ptrace. */
1531da177e4SLinus Torvalds	STREG	%r0,  TASK_PT_PSW(%r1)
1541da177e4SLinus Torvalds	STREG	%r2,  TASK_PT_GR2(%r1)		/* preserve rp */
1551da177e4SLinus Torvalds	STREG	%r19, TASK_PT_GR19(%r1)
1561da177e4SLinus Torvalds
1571da177e4SLinus Torvalds	LDREGM	-FRAME_SIZE(%r30), %r2		/* get users sp back */
1581da177e4SLinus Torvalds#ifdef __LP64__
1591da177e4SLinus Torvalds	extrd,u	%r2,63,1,%r19			/* W hidden in bottom bit */
1601da177e4SLinus Torvalds#if 0
1611da177e4SLinus Torvalds	xor	%r19,%r2,%r2			/* clear bottom bit */
1621da177e4SLinus Torvalds	depd,z	%r19,1,1,%r19
1631da177e4SLinus Torvalds	std	%r19,TASK_PT_PSW(%r1)
1641da177e4SLinus Torvalds#endif
1651da177e4SLinus Torvalds#endif
1661da177e4SLinus Torvalds	STREG	%r2,  TASK_PT_GR30(%r1)		/* ... and save it */
1671da177e4SLinus Torvalds
1681da177e4SLinus Torvalds	STREG	%r20, TASK_PT_GR20(%r1)
1691da177e4SLinus Torvalds	STREG	%r21, TASK_PT_GR21(%r1)
1701da177e4SLinus Torvalds	STREG	%r22, TASK_PT_GR22(%r1)
1711da177e4SLinus Torvalds	STREG	%r23, TASK_PT_GR23(%r1)		/* 4th argument */
1721da177e4SLinus Torvalds	STREG	%r24, TASK_PT_GR24(%r1)		/* 3rd argument */
1731da177e4SLinus Torvalds	STREG	%r25, TASK_PT_GR25(%r1)		/* 2nd argument */
1741da177e4SLinus Torvalds	STREG	%r26, TASK_PT_GR26(%r1)	 	/* 1st argument */
1751da177e4SLinus Torvalds	STREG	%r27, TASK_PT_GR27(%r1)		/* user dp */
1761da177e4SLinus Torvalds	STREG   %r28, TASK_PT_GR28(%r1)         /* return value 0 */
1771da177e4SLinus Torvalds	STREG   %r28, TASK_PT_ORIG_R28(%r1)     /* return value 0 (saved for signals) */
1781da177e4SLinus Torvalds	STREG	%r29, TASK_PT_GR29(%r1)		/* return value 1 */
1791da177e4SLinus Torvalds	STREG	%r31, TASK_PT_GR31(%r1)		/* preserve syscall return ptr */
1801da177e4SLinus Torvalds
1811da177e4SLinus Torvalds	ldo	TASK_PT_FR0(%r1), %r27		/* save fpregs from the kernel */
1821da177e4SLinus Torvalds	save_fp	%r27				/* or potential task switch  */
1831da177e4SLinus Torvalds
1841da177e4SLinus Torvalds	mfctl	%cr11, %r27			/* i.e. SAR */
1851da177e4SLinus Torvalds	STREG	%r27, TASK_PT_SAR(%r1)
1861da177e4SLinus Torvalds
1871da177e4SLinus Torvalds	loadgp
1881da177e4SLinus Torvalds
1891da177e4SLinus Torvalds#ifdef __LP64__
1901da177e4SLinus Torvalds	ldo	-16(%r30),%r29			/* Reference param save area */
1911da177e4SLinus Torvalds	copy	%r19,%r2			/* W bit back to r2 */
1921da177e4SLinus Torvalds#else
1931da177e4SLinus Torvalds	/* no need to save these on stack in wide mode because the first 8
1941da177e4SLinus Torvalds	 * args are passed in registers */
1951da177e4SLinus Torvalds	stw     %r22, -52(%r30)                 /* 5th argument */
1961da177e4SLinus Torvalds	stw     %r21, -56(%r30)                 /* 6th argument */
1971da177e4SLinus Torvalds#endif
1981da177e4SLinus Torvalds
1991da177e4SLinus Torvalds	/* Are we being ptraced? */
2001da177e4SLinus Torvalds	mfctl	%cr30, %r1
2011da177e4SLinus Torvalds	LDREG	TI_TASK(%r1),%r1
2021da177e4SLinus Torvalds	LDREG	TASK_PTRACE(%r1), %r1
2031da177e4SLinus Torvalds	bb,<,n	%r1,31,.Ltracesys
2041da177e4SLinus Torvalds
2051da177e4SLinus Torvalds	/* Note!  We cannot use the syscall table that is mapped
2061da177e4SLinus Torvalds	nearby since the gateway page is mapped execute-only. */
2071da177e4SLinus Torvalds
2081da177e4SLinus Torvalds#ifdef __LP64__
2091da177e4SLinus Torvalds	ldil	L%sys_call_table, %r1
2101da177e4SLinus Torvalds	or,=	%r2,%r2,%r2
2111da177e4SLinus Torvalds	addil	L%(sys_call_table64-sys_call_table), %r1
2121da177e4SLinus Torvalds	ldo	R%sys_call_table(%r1), %r19
2131da177e4SLinus Torvalds	or,=	%r2,%r2,%r2
2141da177e4SLinus Torvalds	ldo	R%sys_call_table64(%r1), %r19
2151da177e4SLinus Torvalds#else
2161da177e4SLinus Torvalds	ldil	L%sys_call_table, %r1
2171da177e4SLinus Torvalds	ldo     R%sys_call_table(%r1), %r19
2181da177e4SLinus Torvalds#endif
2191da177e4SLinus Torvalds	comiclr,>>=	__NR_Linux_syscalls, %r20, %r0
2201da177e4SLinus Torvalds	b,n	.Lsyscall_nosys
2211da177e4SLinus Torvalds
2221da177e4SLinus Torvalds	LDREGX  %r20(%r19), %r19
2231da177e4SLinus Torvalds
2241da177e4SLinus Torvalds	/* If this is a sys_rt_sigreturn call, and the signal was received
2251da177e4SLinus Torvalds	 * when not in_syscall, then we want to return via syscall_exit_rfi,
2261da177e4SLinus Torvalds	 * not syscall_exit.  Signal no. in r20, in_syscall in r25 (see
2271da177e4SLinus Torvalds	 * trampoline code in signal.c).
2281da177e4SLinus Torvalds	 */
2291da177e4SLinus Torvalds	ldi	__NR_rt_sigreturn,%r2
2301da177e4SLinus Torvalds	comb,=	%r2,%r20,.Lrt_sigreturn
2311da177e4SLinus Torvalds.Lin_syscall:
2321da177e4SLinus Torvalds	ldil	L%syscall_exit,%r2
2331da177e4SLinus Torvalds	be      0(%sr7,%r19)
2341da177e4SLinus Torvalds	ldo	R%syscall_exit(%r2),%r2
2351da177e4SLinus Torvalds.Lrt_sigreturn:
2361da177e4SLinus Torvalds	comib,<> 0,%r25,.Lin_syscall
2371da177e4SLinus Torvalds	ldil	L%syscall_exit_rfi,%r2
2381da177e4SLinus Torvalds	be      0(%sr7,%r19)
2391da177e4SLinus Torvalds	ldo	R%syscall_exit_rfi(%r2),%r2
2401da177e4SLinus Torvalds
2411da177e4SLinus Torvalds	/* Note!  Because we are not running where we were linked, any
2421da177e4SLinus Torvalds	calls to functions external to this file must be indirect.  To
2431da177e4SLinus Torvalds	be safe, we apply the opposite rule to functions within this
2441da177e4SLinus Torvalds	file, with local labels given to them to ensure correctness. */
2451da177e4SLinus Torvalds
2461da177e4SLinus Torvalds.Lsyscall_nosys:
2471da177e4SLinus Torvaldssyscall_nosys:
2481da177e4SLinus Torvalds	ldil	L%syscall_exit,%r1
2491da177e4SLinus Torvalds	be	R%syscall_exit(%sr7,%r1)
2501da177e4SLinus Torvalds	ldo	-ENOSYS(%r0),%r28		   /* set errno */
2511da177e4SLinus Torvalds
2521da177e4SLinus Torvalds
2531da177e4SLinus Torvalds/* Warning! This trace code is a virtual duplicate of the code above so be
2541da177e4SLinus Torvalds * sure to maintain both! */
2551da177e4SLinus Torvalds.Ltracesys:
2561da177e4SLinus Torvaldstracesys:
2571da177e4SLinus Torvalds	/* Need to save more registers so the debugger can see where we
2581da177e4SLinus Torvalds	 * are.  This saves only the lower 8 bits of PSW, so that the C
2591da177e4SLinus Torvalds	 * bit is still clear on syscalls, and the D bit is set if this
2601da177e4SLinus Torvalds	 * full register save path has been executed.  We check the D
2611da177e4SLinus Torvalds	 * bit on syscall_return_rfi to determine which registers to
2621da177e4SLinus Torvalds	 * restore.  An interrupt results in a full PSW saved with the
2631da177e4SLinus Torvalds	 * C bit set, a non-straced syscall entry results in C and D clear
2641da177e4SLinus Torvalds	 * in the saved PSW.
2651da177e4SLinus Torvalds	 */
2661da177e4SLinus Torvalds	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
2671da177e4SLinus Torvalds	LDREG	TI_TASK(%r1), %r1
2681da177e4SLinus Torvalds	ssm	0,%r2
2691da177e4SLinus Torvalds	STREG	%r2,TASK_PT_PSW(%r1)		/* Lower 8 bits only!! */
2701da177e4SLinus Torvalds	mfsp	%sr0,%r2
2711da177e4SLinus Torvalds	STREG	%r2,TASK_PT_SR0(%r1)
2721da177e4SLinus Torvalds	mfsp	%sr1,%r2
2731da177e4SLinus Torvalds	STREG	%r2,TASK_PT_SR1(%r1)
2741da177e4SLinus Torvalds	mfsp	%sr2,%r2
2751da177e4SLinus Torvalds	STREG	%r2,TASK_PT_SR2(%r1)
2761da177e4SLinus Torvalds	mfsp	%sr3,%r2
2771da177e4SLinus Torvalds	STREG	%r2,TASK_PT_SR3(%r1)
2781da177e4SLinus Torvalds	STREG	%r2,TASK_PT_SR4(%r1)
2791da177e4SLinus Torvalds	STREG	%r2,TASK_PT_SR5(%r1)
2801da177e4SLinus Torvalds	STREG	%r2,TASK_PT_SR6(%r1)
2811da177e4SLinus Torvalds	STREG	%r2,TASK_PT_SR7(%r1)
2821da177e4SLinus Torvalds	STREG	%r2,TASK_PT_IASQ0(%r1)
2831da177e4SLinus Torvalds	STREG	%r2,TASK_PT_IASQ1(%r1)
2841da177e4SLinus Torvalds	LDREG	TASK_PT_GR31(%r1),%r2
2851da177e4SLinus Torvalds	STREG	%r2,TASK_PT_IAOQ0(%r1)
2861da177e4SLinus Torvalds	ldo	4(%r2),%r2
2871da177e4SLinus Torvalds	STREG	%r2,TASK_PT_IAOQ1(%r1)
2881da177e4SLinus Torvalds	ldo	TASK_REGS(%r1),%r2
2891da177e4SLinus Torvalds	/* reg_save %r2 */
2901da177e4SLinus Torvalds	STREG	%r3,PT_GR3(%r2)
2911da177e4SLinus Torvalds	STREG	%r4,PT_GR4(%r2)
2921da177e4SLinus Torvalds	STREG	%r5,PT_GR5(%r2)
2931da177e4SLinus Torvalds	STREG	%r6,PT_GR6(%r2)
2941da177e4SLinus Torvalds	STREG	%r7,PT_GR7(%r2)
2951da177e4SLinus Torvalds	STREG	%r8,PT_GR8(%r2)
2961da177e4SLinus Torvalds	STREG	%r9,PT_GR9(%r2)
2971da177e4SLinus Torvalds	STREG	%r10,PT_GR10(%r2)
2981da177e4SLinus Torvalds	STREG	%r11,PT_GR11(%r2)
2991da177e4SLinus Torvalds	STREG	%r12,PT_GR12(%r2)
3001da177e4SLinus Torvalds	STREG	%r13,PT_GR13(%r2)
3011da177e4SLinus Torvalds	STREG	%r14,PT_GR14(%r2)
3021da177e4SLinus Torvalds	STREG	%r15,PT_GR15(%r2)
3031da177e4SLinus Torvalds	STREG	%r16,PT_GR16(%r2)
3041da177e4SLinus Torvalds	STREG	%r17,PT_GR17(%r2)
3051da177e4SLinus Torvalds	STREG	%r18,PT_GR18(%r2)
3061da177e4SLinus Torvalds	/* Finished saving things for the debugger */
3071da177e4SLinus Torvalds
3081da177e4SLinus Torvalds	ldil	L%syscall_trace,%r1
3091da177e4SLinus Torvalds	ldil	L%tracesys_next,%r2
3101da177e4SLinus Torvalds	be	R%syscall_trace(%sr7,%r1)
3111da177e4SLinus Torvalds	ldo	R%tracesys_next(%r2),%r2
3121da177e4SLinus Torvalds
3131da177e4SLinus Torvaldstracesys_next:
3141da177e4SLinus Torvalds	ldil	L%sys_call_table,%r1
3151da177e4SLinus Torvalds	ldo     R%sys_call_table(%r1), %r19
3161da177e4SLinus Torvalds
3171da177e4SLinus Torvalds	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
3181da177e4SLinus Torvalds	LDREG	TI_TASK(%r1), %r1
3191da177e4SLinus Torvalds	LDREG   TASK_PT_GR20(%r1), %r20
3201da177e4SLinus Torvalds	LDREG   TASK_PT_GR26(%r1), %r26		/* Restore the users args */
3211da177e4SLinus Torvalds	LDREG   TASK_PT_GR25(%r1), %r25
3221da177e4SLinus Torvalds	LDREG   TASK_PT_GR24(%r1), %r24
3231da177e4SLinus Torvalds	LDREG   TASK_PT_GR23(%r1), %r23
3241da177e4SLinus Torvalds#ifdef __LP64__
3251da177e4SLinus Torvalds	LDREG   TASK_PT_GR22(%r1), %r22
3261da177e4SLinus Torvalds	LDREG   TASK_PT_GR21(%r1), %r21
3271da177e4SLinus Torvalds	ldo	-16(%r30),%r29			/* Reference param save area */
3281da177e4SLinus Torvalds#endif
3291da177e4SLinus Torvalds
3301da177e4SLinus Torvalds	comiclr,>>=	__NR_Linux_syscalls, %r20, %r0
3311da177e4SLinus Torvalds	b,n	.Lsyscall_nosys
3321da177e4SLinus Torvalds
3331da177e4SLinus Torvalds	LDREGX  %r20(%r19), %r19
3341da177e4SLinus Torvalds
3351da177e4SLinus Torvalds	/* If this is a sys_rt_sigreturn call, and the signal was received
3361da177e4SLinus Torvalds	 * when not in_syscall, then we want to return via syscall_exit_rfi,
3371da177e4SLinus Torvalds	 * not syscall_exit.  Signal no. in r20, in_syscall in r25 (see
3381da177e4SLinus Torvalds	 * trampoline code in signal.c).
3391da177e4SLinus Torvalds	 */
3401da177e4SLinus Torvalds	ldi	__NR_rt_sigreturn,%r2
3411da177e4SLinus Torvalds	comb,=	%r2,%r20,.Ltrace_rt_sigreturn
3421da177e4SLinus Torvalds.Ltrace_in_syscall:
3431da177e4SLinus Torvalds	ldil	L%tracesys_exit,%r2
3441da177e4SLinus Torvalds	be      0(%sr7,%r19)
3451da177e4SLinus Torvalds	ldo	R%tracesys_exit(%r2),%r2
3461da177e4SLinus Torvalds
3471da177e4SLinus Torvalds	/* Do *not* call this function on the gateway page, because it
3481da177e4SLinus Torvalds	makes a direct call to syscall_trace. */
3491da177e4SLinus Torvalds
3501da177e4SLinus Torvaldstracesys_exit:
3511da177e4SLinus Torvalds	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
3521da177e4SLinus Torvalds	LDREG	TI_TASK(%r1), %r1
3531da177e4SLinus Torvalds#ifdef __LP64__
3541da177e4SLinus Torvalds	ldo	-16(%r30),%r29			/* Reference param save area */
3551da177e4SLinus Torvalds#endif
3561da177e4SLinus Torvalds	bl	syscall_trace, %r2
3571da177e4SLinus Torvalds	STREG   %r28,TASK_PT_GR28(%r1)          /* save return value now */
3581da177e4SLinus Torvalds	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
3591da177e4SLinus Torvalds	LDREG	TI_TASK(%r1), %r1
3601da177e4SLinus Torvalds	LDREG   TASK_PT_GR28(%r1), %r28		/* Restore return val. */
3611da177e4SLinus Torvalds
3621da177e4SLinus Torvalds	ldil	L%syscall_exit,%r1
3631da177e4SLinus Torvalds	be,n	R%syscall_exit(%sr7,%r1)
3641da177e4SLinus Torvalds
3651da177e4SLinus Torvalds.Ltrace_rt_sigreturn:
3661da177e4SLinus Torvalds	comib,<> 0,%r25,.Ltrace_in_syscall
3671da177e4SLinus Torvalds	ldil	L%tracesys_sigexit,%r2
3681da177e4SLinus Torvalds	be      0(%sr7,%r19)
3691da177e4SLinus Torvalds	ldo	R%tracesys_sigexit(%r2),%r2
3701da177e4SLinus Torvalds
3711da177e4SLinus Torvaldstracesys_sigexit:
3721da177e4SLinus Torvalds	ldo     -THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1      /* get task ptr */
3731da177e4SLinus Torvalds	LDREG	0(%r1), %r1
3741da177e4SLinus Torvalds#ifdef __LP64__
3751da177e4SLinus Torvalds	ldo	-16(%r30),%r29			/* Reference param save area */
3761da177e4SLinus Torvalds#endif
3771da177e4SLinus Torvalds	bl	syscall_trace, %r2
3781da177e4SLinus Torvalds	nop
3791da177e4SLinus Torvalds
3801da177e4SLinus Torvalds	ldil	L%syscall_exit_rfi,%r1
3811da177e4SLinus Torvalds	be,n	R%syscall_exit_rfi(%sr7,%r1)
3821da177e4SLinus Torvalds
3831da177e4SLinus Torvalds
3841da177e4SLinus Torvalds	/*********************************************************
3851da177e4SLinus Torvalds		Light-weight-syscall code
3861da177e4SLinus Torvalds
3871da177e4SLinus Torvalds		r20 - lws number
3881da177e4SLinus Torvalds		r26,r25,r24,r23,r22 - Input registers
3891da177e4SLinus Torvalds		r28 - Function return register
3901da177e4SLinus Torvalds		r21 - Error code.
3911da177e4SLinus Torvalds
3921da177e4SLinus Torvalds		Scracth: Any of the above that aren't being
3931da177e4SLinus Torvalds		currently used, including r1.
3941da177e4SLinus Torvalds
3951da177e4SLinus Torvalds		Return pointer: r31 (Not usable)
3961da177e4SLinus Torvalds
3971da177e4SLinus Torvalds		Error codes returned by entry path:
3981da177e4SLinus Torvalds
3991da177e4SLinus Torvalds		ENOSYS - r20 was an invalid LWS number.
4001da177e4SLinus Torvalds
4011da177e4SLinus Torvalds	*********************************************************/
4021da177e4SLinus Torvaldslws_start:
4031da177e4SLinus Torvalds	/* Gate and ensure we return to userspace */
4041da177e4SLinus Torvalds	gate	.+8, %r0
4051da177e4SLinus Torvalds	depi	3, 31, 2, %r31	/* Ensure we return to userspace */
4061da177e4SLinus Torvalds
4071da177e4SLinus Torvalds#ifdef __LP64__
4081da177e4SLinus Torvalds	/* FIXME: If we are a 64-bit kernel just
4091da177e4SLinus Torvalds	 *        turn this on unconditionally.
4101da177e4SLinus Torvalds	 */
4111da177e4SLinus Torvalds	ssm	PSW_SM_W, %r1
4121da177e4SLinus Torvalds	extrd,u	%r1,PSW_W_BIT,1,%r1
4131da177e4SLinus Torvalds	/* sp must be aligned on 4, so deposit the W bit setting into
4141da177e4SLinus Torvalds	 * the bottom of sp temporarily */
4151da177e4SLinus Torvalds	or,ev	%r1,%r30,%r30
4161da177e4SLinus Torvalds
4171da177e4SLinus Torvalds	/* Clip LWS number to a 32-bit value always */
4181da177e4SLinus Torvalds	depdi	0, 31, 32, %r20
4191da177e4SLinus Torvalds#endif
4201da177e4SLinus Torvalds
4211da177e4SLinus Torvalds        /* Is the lws entry number valid? */
4221da177e4SLinus Torvalds	comiclr,>>=	__NR_lws_entries, %r20, %r0
4231da177e4SLinus Torvalds	b,n	lws_exit_nosys
4241da177e4SLinus Torvalds
4251da177e4SLinus Torvalds	/* WARNING: Trashing sr2 and sr3 */
4261da177e4SLinus Torvalds	mfsp	%sr7,%r1			/* get userspace into sr3 */
4271da177e4SLinus Torvalds	mtsp	%r1,%sr3
4281da177e4SLinus Torvalds	mtsp	%r0,%sr2			/* get kernel space into sr2 */
4291da177e4SLinus Torvalds
4301da177e4SLinus Torvalds	/* Load table start */
4311da177e4SLinus Torvalds	ldil	L%lws_table, %r1
4321da177e4SLinus Torvalds	ldo	R%lws_table(%r1), %r28	/* Scratch use of r28 */
4331da177e4SLinus Torvalds	LDREGX	%r20(%sr2,r28), %r21	/* Scratch use of r21 */
4341da177e4SLinus Torvalds
4351da177e4SLinus Torvalds	/* Jump to lws, lws table pointers already relocated */
4361da177e4SLinus Torvalds	be,n	0(%sr2,%r21)
4371da177e4SLinus Torvalds
4381da177e4SLinus Torvaldslws_exit_nosys:
4391da177e4SLinus Torvalds	ldo	-ENOSYS(%r0),%r21		   /* set errno */
4401da177e4SLinus Torvalds	/* Fall through: Return to userspace */
4411da177e4SLinus Torvalds
4421da177e4SLinus Torvaldslws_exit:
4431da177e4SLinus Torvalds#ifdef __LP64__
4441da177e4SLinus Torvalds	/* decide whether to reset the wide mode bit
4451da177e4SLinus Torvalds	 *
4461da177e4SLinus Torvalds	 * For a syscall, the W bit is stored in the lowest bit
4471da177e4SLinus Torvalds	 * of sp.  Extract it and reset W if it is zero */
4481da177e4SLinus Torvalds	extrd,u,*<>	%r30,63,1,%r1
4491da177e4SLinus Torvalds	rsm	PSW_SM_W, %r0
4501da177e4SLinus Torvalds	/* now reset the lowest bit of sp if it was set */
4511da177e4SLinus Torvalds	xor	%r30,%r1,%r30
4521da177e4SLinus Torvalds#endif
4531da177e4SLinus Torvalds	be,n	0(%sr3, %r31)
4541da177e4SLinus Torvalds
4551da177e4SLinus Torvalds
4561da177e4SLinus Torvalds
4571da177e4SLinus Torvalds	/***************************************************
4581da177e4SLinus Torvalds		Implementing CAS as an atomic operation:
4591da177e4SLinus Torvalds
4601da177e4SLinus Torvalds		%r26 - Address to examine
4611da177e4SLinus Torvalds		%r25 - Old value to check (old)
4621da177e4SLinus Torvalds		%r24 - New value to set (new)
4631da177e4SLinus Torvalds		%r28 - Return prev through this register.
4641da177e4SLinus Torvalds		%r21 - Kernel error code
4651da177e4SLinus Torvalds
4661da177e4SLinus Torvalds		If debugging is DISabled:
4671da177e4SLinus Torvalds
4681da177e4SLinus Torvalds		%r21 has the following meanings:
4691da177e4SLinus Torvalds
4701da177e4SLinus Torvalds		EAGAIN - CAS is busy, ldcw failed, try again.
4711da177e4SLinus Torvalds		EFAULT - Read or write failed.
4721da177e4SLinus Torvalds
4731da177e4SLinus Torvalds		If debugging is enabled:
4741da177e4SLinus Torvalds
4751da177e4SLinus Torvalds		EDEADLOCK - CAS called recursively.
4761da177e4SLinus Torvalds		EAGAIN && r28 == 1 - CAS is busy. Lock contended.
4771da177e4SLinus Torvalds		EAGAIN && r28 == 2 - CAS is busy. ldcw failed.
4781da177e4SLinus Torvalds		EFAULT - Read or write failed.
4791da177e4SLinus Torvalds
4801da177e4SLinus Torvalds		Scratch: r20, r28, r1
4811da177e4SLinus Torvalds
4821da177e4SLinus Torvalds	****************************************************/
4831da177e4SLinus Torvalds
4841da177e4SLinus Torvalds	/* Do not enable LWS debugging */
4851da177e4SLinus Torvalds#define ENABLE_LWS_DEBUG 0
4861da177e4SLinus Torvalds
4871da177e4SLinus Torvalds	/* ELF64 Process entry path */
4881da177e4SLinus Torvaldslws_compare_and_swap64:
4891da177e4SLinus Torvalds#ifdef __LP64__
4901da177e4SLinus Torvalds	b,n	lws_compare_and_swap
4911da177e4SLinus Torvalds#else
4921da177e4SLinus Torvalds	/* If we are not a 64-bit kernel, then we don't
4931da177e4SLinus Torvalds	 * implement having 64-bit input registers
4941da177e4SLinus Torvalds	 */
4951da177e4SLinus Torvalds	b,n	lws_exit_nosys
4961da177e4SLinus Torvalds#endif
4971da177e4SLinus Torvalds
4981da177e4SLinus Torvalds	/* ELF32 Process entry path */
4991da177e4SLinus Torvaldslws_compare_and_swap32:
5001da177e4SLinus Torvalds#ifdef __LP64__
5011da177e4SLinus Torvalds	/* Clip all the input registers */
5021da177e4SLinus Torvalds	depdi	0, 31, 32, %r26
5031da177e4SLinus Torvalds	depdi	0, 31, 32, %r25
5041da177e4SLinus Torvalds	depdi	0, 31, 32, %r24
5051da177e4SLinus Torvalds#endif
5061da177e4SLinus Torvalds
5071da177e4SLinus Torvaldslws_compare_and_swap:
5081da177e4SLinus Torvalds#ifdef CONFIG_SMP
5091da177e4SLinus Torvalds	/* Load start of lock table */
5101da177e4SLinus Torvalds	ldil	L%lws_lock_start, %r20
5111da177e4SLinus Torvalds	ldo	R%lws_lock_start(%r20), %r28
5121da177e4SLinus Torvalds
5131da177e4SLinus Torvalds	/* Extract four bits from r26 and hash lock (Bits 4-7) */
5141da177e4SLinus Torvalds	extru  %r26, 27, 4, %r20
5151da177e4SLinus Torvalds
5161da177e4SLinus Torvalds	/* Find lock to use, the hash is either one of 0 to
5171da177e4SLinus Torvalds	   15, multiplied by 16 (keep it 16-byte aligned)
5181da177e4SLinus Torvalds	   and add to the lock table offset. */
5191da177e4SLinus Torvalds	shlw	%r20, 4, %r20
5201da177e4SLinus Torvalds	add	%r20, %r28, %r20
5211da177e4SLinus Torvalds
5221da177e4SLinus Torvalds# ifdef ENABLE_LWS_DEBUG
5231da177e4SLinus Torvalds	/*
5241da177e4SLinus Torvalds		DEBUG, check for deadlock!
5251da177e4SLinus Torvalds		If the thread register values are the same
5261da177e4SLinus Torvalds		then we were the one that locked it last and
5271da177e4SLinus Torvalds		this is a recurisve call that will deadlock.
5281da177e4SLinus Torvalds		We *must* giveup this call and fail.
5291da177e4SLinus Torvalds	*/
5301da177e4SLinus Torvalds	ldw	4(%sr2,%r20), %r28			/* Load thread register */
5311da177e4SLinus Torvalds	mfctl	%cr27, %r21				/* Get current thread register */
5321da177e4SLinus Torvalds	cmpb,<>,n	%r21, %r28, cas_lock		/* Called recursive? */
5331da177e4SLinus Torvalds	b	lws_exit				/* Return error! */
5341da177e4SLinus Torvalds	ldo	-EDEADLOCK(%r0), %r21
5351da177e4SLinus Torvaldscas_lock:
5361da177e4SLinus Torvalds	cmpb,=,n	%r0, %r28, cas_nocontend	/* Is nobody using it? */
5371da177e4SLinus Torvalds	ldo	1(%r0), %r28				/* 1st case */
5381da177e4SLinus Torvalds	b	lws_exit				/* Contended... */
5391da177e4SLinus Torvalds	ldo	-EAGAIN(%r0), %r21			/* Spin in userspace */
5401da177e4SLinus Torvaldscas_nocontend:
5411da177e4SLinus Torvalds# endif
5421da177e4SLinus Torvalds/* ENABLE_LWS_DEBUG */
5431da177e4SLinus Torvalds
5441da177e4SLinus Torvalds	ldcw	0(%sr2,%r20), %r28			/* Try to acquire the lock */
5451da177e4SLinus Torvalds	cmpb,<>,n	%r0, %r28, cas_action		/* Did we get it? */
5461da177e4SLinus Torvaldscas_wouldblock:
5471da177e4SLinus Torvalds	ldo	2(%r0), %r28				/* 2nd case */
5481da177e4SLinus Torvalds	b	lws_exit				/* Contended... */
5491da177e4SLinus Torvalds	ldo	-EAGAIN(%r0), %r21			/* Spin in userspace */
5501da177e4SLinus Torvalds#endif
5511da177e4SLinus Torvalds/* CONFIG_SMP */
5521da177e4SLinus Torvalds
5531da177e4SLinus Torvalds	/*
5541da177e4SLinus Torvalds		prev = *addr;
5551da177e4SLinus Torvalds		if ( prev == old )
5561da177e4SLinus Torvalds		  *addr = new;
5571da177e4SLinus Torvalds		return prev;
5581da177e4SLinus Torvalds	*/
5591da177e4SLinus Torvalds
5601da177e4SLinus Torvalds	/* NOTES:
5611da177e4SLinus Torvalds		This all works becuse intr_do_signal
5621da177e4SLinus Torvalds		and schedule both check the return iasq
5631da177e4SLinus Torvalds		and see that we are on the kernel page
5641da177e4SLinus Torvalds		so this process is never scheduled off
5651da177e4SLinus Torvalds		or is ever sent any signal of any sort,
5661da177e4SLinus Torvalds		thus it is wholly atomic from usrspaces
5671da177e4SLinus Torvalds		perspective
5681da177e4SLinus Torvalds	*/
5691da177e4SLinus Torvaldscas_action:
5701da177e4SLinus Torvalds#if defined CONFIG_SMP && defined ENABLE_LWS_DEBUG
5711da177e4SLinus Torvalds	/* DEBUG */
5721da177e4SLinus Torvalds	mfctl	%cr27, %r1
5731da177e4SLinus Torvalds	stw	%r1, 4(%sr2,%r20)
5741da177e4SLinus Torvalds#endif
5751da177e4SLinus Torvalds	/* The load and store could fail */
5761da177e4SLinus Torvalds1:	ldw	0(%sr3,%r26), %r28
5771da177e4SLinus Torvalds	sub,<>	%r28, %r25, %r0
5781da177e4SLinus Torvalds2:	stw	%r24, 0(%sr3,%r26)
5791da177e4SLinus Torvalds#ifdef CONFIG_SMP
5801da177e4SLinus Torvalds	/* Free lock */
5811da177e4SLinus Torvalds	stw	%r20, 0(%sr2,%r20)
5821da177e4SLinus Torvalds# ifdef ENABLE_LWS_DEBUG
5831da177e4SLinus Torvalds	/* Clear thread register indicator */
5841da177e4SLinus Torvalds	stw	%r0, 4(%sr2,%r20)
5851da177e4SLinus Torvalds# endif
5861da177e4SLinus Torvalds#endif
5871da177e4SLinus Torvalds	/* Return to userspace, set no error */
5881da177e4SLinus Torvalds	b	lws_exit
5891da177e4SLinus Torvalds	copy	%r0, %r21
5901da177e4SLinus Torvalds
5911da177e4SLinus Torvalds3:
5921da177e4SLinus Torvalds	/* Error occured on load or store */
5931da177e4SLinus Torvalds#ifdef CONFIG_SMP
5941da177e4SLinus Torvalds	/* Free lock */
5951da177e4SLinus Torvalds	stw	%r20, 0(%sr2,%r20)
5961da177e4SLinus Torvalds# ifdef ENABLE_LWS_DEBUG
5971da177e4SLinus Torvalds	stw	%r0, 4(%sr2,%r20)
5981da177e4SLinus Torvalds# endif
5991da177e4SLinus Torvalds#endif
6001da177e4SLinus Torvalds	b	lws_exit
6011da177e4SLinus Torvalds	ldo	-EFAULT(%r0),%r21	/* set errno */
6021da177e4SLinus Torvalds	nop
6031da177e4SLinus Torvalds	nop
6041da177e4SLinus Torvalds	nop
6051da177e4SLinus Torvalds	nop
6061da177e4SLinus Torvalds
6071da177e4SLinus Torvalds	/* Two exception table entries, one for the load,
6081da177e4SLinus Torvalds	   the other for the store. Either return -EFAULT.
6091da177e4SLinus Torvalds	   Each of the entries must be relocated. */
6101da177e4SLinus Torvalds	.section __ex_table,"aw"
6111da177e4SLinus Torvalds#ifdef __LP64__
6121da177e4SLinus Torvalds	/* Pad the address calculation */
6131da177e4SLinus Torvalds	.word	0,(2b - linux_gateway_page)
6141da177e4SLinus Torvalds	.word	0,(3b - linux_gateway_page)
6151da177e4SLinus Torvalds#else
6161da177e4SLinus Torvalds	.word	(2b - linux_gateway_page)
6171da177e4SLinus Torvalds	.word	(3b - linux_gateway_page)
6181da177e4SLinus Torvalds#endif
6191da177e4SLinus Torvalds	.previous
6201da177e4SLinus Torvalds
6211da177e4SLinus Torvalds	.section __ex_table,"aw"
6221da177e4SLinus Torvalds#ifdef __LP64__
6231da177e4SLinus Torvalds	/* Pad the address calculation */
6241da177e4SLinus Torvalds	.word	0,(1b - linux_gateway_page)
6251da177e4SLinus Torvalds	.word	0,(3b - linux_gateway_page)
6261da177e4SLinus Torvalds#else
6271da177e4SLinus Torvalds	.word	(1b - linux_gateway_page)
6281da177e4SLinus Torvalds	.word	(3b - linux_gateway_page)
6291da177e4SLinus Torvalds#endif
6301da177e4SLinus Torvalds	.previous
6311da177e4SLinus Torvalds
6321da177e4SLinus Torvaldsend_compare_and_swap:
6331da177e4SLinus Torvalds
6341da177e4SLinus Torvalds	/* Make sure nothing else is placed on this page */
6351da177e4SLinus Torvalds	.align 4096
6361da177e4SLinus Torvalds	.export end_linux_gateway_page
6371da177e4SLinus Torvaldsend_linux_gateway_page:
6381da177e4SLinus Torvalds
6391da177e4SLinus Torvalds	/* Relocate symbols assuming linux_gateway_page is mapped
6401da177e4SLinus Torvalds	   to virtual address 0x0 */
6411da177e4SLinus Torvalds#ifdef __LP64__
6421da177e4SLinus Torvalds	/* FIXME: The code will always be on the gateay page
6431da177e4SLinus Torvalds		  and thus it will be on the first 4k, the
6441da177e4SLinus Torvalds		  assembler seems to think that the final
6451da177e4SLinus Torvalds		  subtraction result is only a word in
6461da177e4SLinus Torvalds		  length, so we pad the value.
6471da177e4SLinus Torvalds	*/
6481da177e4SLinus Torvalds#define LWS_ENTRY(_name_) .word 0,(lws_##_name_ - linux_gateway_page)
6491da177e4SLinus Torvalds#else
6501da177e4SLinus Torvalds#define LWS_ENTRY(_name_) .word  (lws_##_name_ - linux_gateway_page)
6511da177e4SLinus Torvalds#endif
6521da177e4SLinus Torvalds
6531da177e4SLinus Torvalds	.align 4096
6541da177e4SLinus Torvalds	/* Light-weight-syscall table */
6551da177e4SLinus Torvalds	/* Start of lws table. */
6561da177e4SLinus Torvalds	.export lws_table
6571da177e4SLinus Torvalds.Llws_table:
6581da177e4SLinus Torvaldslws_table:
6591da177e4SLinus Torvalds	LWS_ENTRY(compare_and_swap32)	/* 0 - ELF32 Atomic compare and swap */
6601da177e4SLinus Torvalds	LWS_ENTRY(compare_and_swap64)	/* 1 - ELF64 Atomic compare and swap */
6611da177e4SLinus Torvalds	/* End of lws table */
6621da177e4SLinus Torvalds
6631da177e4SLinus Torvalds	.align 4096
6641da177e4SLinus Torvalds	.export sys_call_table
6651da177e4SLinus Torvalds.Lsys_call_table:
6661da177e4SLinus Torvaldssys_call_table:
6671da177e4SLinus Torvalds#include "syscall_table.S"
6681da177e4SLinus Torvalds
6691da177e4SLinus Torvalds#ifdef __LP64__
6701da177e4SLinus Torvalds	.align 4096
6711da177e4SLinus Torvalds	.export sys_call_table64
6721da177e4SLinus Torvalds.Lsys_call_table64:
6731da177e4SLinus Torvaldssys_call_table64:
6741da177e4SLinus Torvalds#define SYSCALL_TABLE_64BIT
6751da177e4SLinus Torvalds#include "syscall_table.S"
6761da177e4SLinus Torvalds#endif
6771da177e4SLinus Torvalds
6781da177e4SLinus Torvalds#ifdef CONFIG_SMP
6791da177e4SLinus Torvalds	/*
6801da177e4SLinus Torvalds		All light-weight-syscall atomic operations
6811da177e4SLinus Torvalds		will use this set of locks
6821da177e4SLinus Torvalds	*/
6831da177e4SLinus Torvalds	.section .data
6841da177e4SLinus Torvalds	.align 4096
6851da177e4SLinus Torvalds	.export lws_lock_start
6861da177e4SLinus Torvalds.Llws_lock_start:
6871da177e4SLinus Torvaldslws_lock_start:
6881da177e4SLinus Torvalds	/* lws locks */
6891da177e4SLinus Torvalds	.align 16
6901da177e4SLinus Torvalds	.rept 16
6911da177e4SLinus Torvalds	/* Keep locks aligned at 16-bytes */
6921da177e4SLinus Torvalds	.word 1
6931da177e4SLinus Torvalds	.word 0
6941da177e4SLinus Torvalds	.word 0
6951da177e4SLinus Torvalds	.word 0
6961da177e4SLinus Torvalds	.endr
6971da177e4SLinus Torvalds	.previous
6981da177e4SLinus Torvalds#endif
6991da177e4SLinus Torvalds/* CONFIG_SMP for lws_lock_start */
7001da177e4SLinus Torvalds
7011da177e4SLinus Torvalds.end
7021da177e4SLinus Torvalds
7031da177e4SLinus Torvalds
704