xref: /openbmc/linux/arch/arm/kernel/entry-common.S (revision 9b9eb8c0)
11da177e4SLinus Torvalds/*
21da177e4SLinus Torvalds *  linux/arch/arm/kernel/entry-common.S
31da177e4SLinus Torvalds *
41da177e4SLinus Torvalds *  Copyright (C) 2000 Russell King
51da177e4SLinus Torvalds *
61da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or modify
71da177e4SLinus Torvalds * it under the terms of the GNU General Public License version 2 as
81da177e4SLinus Torvalds * published by the Free Software Foundation.
91da177e4SLinus Torvalds */
101da177e4SLinus Torvalds#include <linux/config.h>
111da177e4SLinus Torvalds
121da177e4SLinus Torvalds#include <asm/unistd.h>
131da177e4SLinus Torvalds
141da177e4SLinus Torvalds#include "entry-header.S"
151da177e4SLinus Torvalds
161da177e4SLinus Torvalds
171da177e4SLinus Torvalds	.align	5
181da177e4SLinus Torvalds/*
191da177e4SLinus Torvalds * This is the fast syscall return path.  We do as little as
201da177e4SLinus Torvalds * possible here, and this includes saving r0 back into the SVC
211da177e4SLinus Torvalds * stack.
221da177e4SLinus Torvalds */
231da177e4SLinus Torvaldsret_fast_syscall:
241ec42c0cSRussell King	disable_irq				@ disable interrupts
251da177e4SLinus Torvalds	ldr	r1, [tsk, #TI_FLAGS]
261da177e4SLinus Torvalds	tst	r1, #_TIF_WORK_MASK
271da177e4SLinus Torvalds	bne	fast_work_pending
28f4dc9a4cSRussell King
29f4dc9a4cSRussell King	@ fast_restore_user_regs
30f4dc9a4cSRussell King	ldr	r1, [sp, #S_OFF + S_PSR]	@ get calling cpsr
31f4dc9a4cSRussell King	ldr	lr, [sp, #S_OFF + S_PC]!	@ get pc
32f4dc9a4cSRussell King	msr	spsr_cxsf, r1			@ save in spsr_svc
33f4dc9a4cSRussell King	ldmdb	sp, {r1 - lr}^			@ get calling r1 - lr
34f4dc9a4cSRussell King	mov	r0, r0
35f4dc9a4cSRussell King	add	sp, sp, #S_FRAME_SIZE - S_PC
36f4dc9a4cSRussell King	movs	pc, lr				@ return & move spsr_svc into cpsr
371da177e4SLinus Torvalds
381da177e4SLinus Torvalds/*
391da177e4SLinus Torvalds * Ok, we need to do extra processing, enter the slow path.
401da177e4SLinus Torvalds */
411da177e4SLinus Torvaldsfast_work_pending:
421da177e4SLinus Torvalds	str	r0, [sp, #S_R0+S_OFF]!		@ returned r0
431da177e4SLinus Torvaldswork_pending:
441da177e4SLinus Torvalds	tst	r1, #_TIF_NEED_RESCHED
451da177e4SLinus Torvalds	bne	work_resched
461da177e4SLinus Torvalds	tst	r1, #_TIF_NOTIFY_RESUME | _TIF_SIGPENDING
471da177e4SLinus Torvalds	beq	no_work_pending
481da177e4SLinus Torvalds	mov	r0, sp				@ 'regs'
491da177e4SLinus Torvalds	mov	r2, why				@ 'syscall'
501da177e4SLinus Torvalds	bl	do_notify_resume
511ec42c0cSRussell King	disable_irq				@ disable interrupts
521da177e4SLinus Torvalds	b	no_work_pending
531da177e4SLinus Torvalds
541da177e4SLinus Torvaldswork_resched:
551da177e4SLinus Torvalds	bl	schedule
561da177e4SLinus Torvalds/*
571da177e4SLinus Torvalds * "slow" syscall return path.  "why" tells us if this was a real syscall.
581da177e4SLinus Torvalds */
591da177e4SLinus TorvaldsENTRY(ret_to_user)
601da177e4SLinus Torvaldsret_slow_syscall:
611ec42c0cSRussell King	disable_irq				@ disable interrupts
621da177e4SLinus Torvalds	ldr	r1, [tsk, #TI_FLAGS]
631da177e4SLinus Torvalds	tst	r1, #_TIF_WORK_MASK
641da177e4SLinus Torvalds	bne	work_pending
651da177e4SLinus Torvaldsno_work_pending:
66f4dc9a4cSRussell King	@ slow_restore_user_regs
67f4dc9a4cSRussell King	ldr	r1, [sp, #S_PSR]		@ get calling cpsr
68f4dc9a4cSRussell King	ldr	lr, [sp, #S_PC]!		@ get pc
69f4dc9a4cSRussell King	msr	spsr_cxsf, r1			@ save in spsr_svc
70f4dc9a4cSRussell King	ldmdb	sp, {r0 - lr}^			@ get calling r1 - lr
71f4dc9a4cSRussell King	mov	r0, r0
72f4dc9a4cSRussell King	add	sp, sp, #S_FRAME_SIZE - S_PC
73f4dc9a4cSRussell King	movs	pc, lr				@ return & move spsr_svc into cpsr
741da177e4SLinus Torvalds
751da177e4SLinus Torvalds/*
761da177e4SLinus Torvalds * This is how we return from a fork.
771da177e4SLinus Torvalds */
781da177e4SLinus TorvaldsENTRY(ret_from_fork)
791da177e4SLinus Torvalds	bl	schedule_tail
801da177e4SLinus Torvalds	get_thread_info tsk
811da177e4SLinus Torvalds	ldr	r1, [tsk, #TI_FLAGS]		@ check for syscall tracing
821da177e4SLinus Torvalds	mov	why, #1
831da177e4SLinus Torvalds	tst	r1, #_TIF_SYSCALL_TRACE		@ are we tracing syscalls?
841da177e4SLinus Torvalds	beq	ret_slow_syscall
851da177e4SLinus Torvalds	mov	r1, sp
861da177e4SLinus Torvalds	mov	r0, #1				@ trace exit [IP = 1]
871da177e4SLinus Torvalds	bl	syscall_trace
881da177e4SLinus Torvalds	b	ret_slow_syscall
891da177e4SLinus Torvalds
901da177e4SLinus Torvalds
911da177e4SLinus Torvalds#include "calls.S"
921da177e4SLinus Torvalds
931da177e4SLinus Torvalds/*=============================================================================
941da177e4SLinus Torvalds * SWI handler
951da177e4SLinus Torvalds *-----------------------------------------------------------------------------
961da177e4SLinus Torvalds */
971da177e4SLinus Torvalds
981da177e4SLinus Torvalds	/* If we're optimising for StrongARM the resulting code won't
991da177e4SLinus Torvalds	   run on an ARM7 and we can save a couple of instructions.
1001da177e4SLinus Torvalds								--pb */
1011da177e4SLinus Torvalds#ifdef CONFIG_CPU_ARM710
1021da177e4SLinus Torvalds	.macro	arm710_bug_check, instr, temp
1031da177e4SLinus Torvalds	and	\temp, \instr, #0x0f000000	@ check for SWI
1041da177e4SLinus Torvalds	teq	\temp, #0x0f000000
1051da177e4SLinus Torvalds	bne	.Larm700bug
1061da177e4SLinus Torvalds	.endm
1071da177e4SLinus Torvalds
1081da177e4SLinus Torvalds.Larm700bug:
1091da177e4SLinus Torvalds	ldr	r0, [sp, #S_PSR]		@ Get calling cpsr
1101da177e4SLinus Torvalds	sub	lr, lr, #4
1111da177e4SLinus Torvalds	str	lr, [r8]
1121da177e4SLinus Torvalds	msr	spsr_cxsf, r0
1131da177e4SLinus Torvalds	ldmia	sp, {r0 - lr}^			@ Get calling r0 - lr
1141da177e4SLinus Torvalds	mov	r0, r0
1151da177e4SLinus Torvalds	ldr	lr, [sp, #S_PC]			@ Get PC
1161da177e4SLinus Torvalds	add	sp, sp, #S_FRAME_SIZE
1171da177e4SLinus Torvalds	movs	pc, lr
1181da177e4SLinus Torvalds#else
1191da177e4SLinus Torvalds	.macro	arm710_bug_check, instr, temp
1201da177e4SLinus Torvalds	.endm
1211da177e4SLinus Torvalds#endif
1221da177e4SLinus Torvalds
1231da177e4SLinus Torvalds	.align	5
1241da177e4SLinus TorvaldsENTRY(vector_swi)
125f4dc9a4cSRussell King	sub	sp, sp, #S_FRAME_SIZE
126f4dc9a4cSRussell King	stmia	sp, {r0 - r12}			@ Calling r0 - r12
127f4dc9a4cSRussell King	add	r8, sp, #S_PC
128f4dc9a4cSRussell King	stmdb	r8, {sp, lr}^			@ Calling sp, lr
129f4dc9a4cSRussell King	mrs	r8, spsr			@ called from non-FIQ mode, so ok.
130f4dc9a4cSRussell King	str	lr, [sp, #S_PC]			@ Save calling PC
131f4dc9a4cSRussell King	str	r8, [sp, #S_PSR]		@ Save CPSR
132f4dc9a4cSRussell King	str	r0, [sp, #S_OLD_R0]		@ Save OLD_R0
1331da177e4SLinus Torvalds	zero_fp
134e0f9f4a6SRussell King
135e0f9f4a6SRussell King	/*
136e0f9f4a6SRussell King	 * Get the system call number.
137e0f9f4a6SRussell King	 */
138e0f9f4a6SRussell King#ifdef CONFIG_ARM_THUMB
139e0f9f4a6SRussell King	tst	r8, #PSR_T_BIT			@ this is SPSR from save_user_regs
140e0f9f4a6SRussell King	addne	scno, r7, #__NR_SYSCALL_BASE	@ put OS number in
141e0f9f4a6SRussell King	ldreq	scno, [lr, #-4]
142e0f9f4a6SRussell King#else
143e0f9f4a6SRussell King	ldr	scno, [lr, #-4]			@ get SWI instruction
144e0f9f4a6SRussell King#endif
1451da177e4SLinus Torvalds	arm710_bug_check scno, ip
1461da177e4SLinus Torvalds
1471da177e4SLinus Torvalds#ifdef CONFIG_ALIGNMENT_TRAP
1481da177e4SLinus Torvalds	ldr	ip, __cr_alignment
1491da177e4SLinus Torvalds	ldr	ip, [ip]
1501da177e4SLinus Torvalds	mcr	p15, 0, ip, c1, c0		@ update control register
1511da177e4SLinus Torvalds#endif
1521ec42c0cSRussell King	enable_irq
1531da177e4SLinus Torvalds
1541da177e4SLinus Torvalds	str	r4, [sp, #-S_OFF]!		@ push fifth arg
1551da177e4SLinus Torvalds
1561da177e4SLinus Torvalds	get_thread_info tsk
1571da177e4SLinus Torvalds	ldr	ip, [tsk, #TI_FLAGS]		@ check for syscall tracing
1581da177e4SLinus Torvalds	bic	scno, scno, #0xff000000		@ mask off SWI op-code
159e0f9f4a6SRussell King	eor	scno, scno, #__NR_SYSCALL_BASE	@ check OS number
1601da177e4SLinus Torvalds	adr	tbl, sys_call_table		@ load syscall table pointer
1611da177e4SLinus Torvalds	tst	ip, #_TIF_SYSCALL_TRACE		@ are we tracing syscalls?
1621da177e4SLinus Torvalds	bne	__sys_trace
1631da177e4SLinus Torvalds
1641da177e4SLinus Torvalds	adr	lr, ret_fast_syscall		@ return address
1651da177e4SLinus Torvalds	cmp	scno, #NR_syscalls		@ check upper syscall limit
1661da177e4SLinus Torvalds	ldrcc	pc, [tbl, scno, lsl #2]		@ call sys_* routine
1671da177e4SLinus Torvalds
1681da177e4SLinus Torvalds	add	r1, sp, #S_OFF
1691da177e4SLinus Torvalds2:	mov	why, #0				@ no longer a real syscall
170e0f9f4a6SRussell King	cmp	scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
171e0f9f4a6SRussell King	eor	r0, scno, #__NR_SYSCALL_BASE	@ put OS number back
1721da177e4SLinus Torvalds	bcs	arm_syscall
1731da177e4SLinus Torvalds	b	sys_ni_syscall			@ not private func
1741da177e4SLinus Torvalds
1751da177e4SLinus Torvalds	/*
1761da177e4SLinus Torvalds	 * This is the really slow path.  We're going to be doing
1771da177e4SLinus Torvalds	 * context switches, and waiting for our parent to respond.
1781da177e4SLinus Torvalds	 */
1791da177e4SLinus Torvalds__sys_trace:
1801da177e4SLinus Torvalds	add	r1, sp, #S_OFF
1811da177e4SLinus Torvalds	mov	r0, #0				@ trace entry [IP = 0]
1821da177e4SLinus Torvalds	bl	syscall_trace
1831da177e4SLinus Torvalds
1841da177e4SLinus Torvalds	adr	lr, __sys_trace_return		@ return address
1851da177e4SLinus Torvalds	add	r1, sp, #S_R0 + S_OFF		@ pointer to regs
1861da177e4SLinus Torvalds	cmp	scno, #NR_syscalls		@ check upper syscall limit
1871da177e4SLinus Torvalds	ldmccia	r1, {r0 - r3}			@ have to reload r0 - r3
1881da177e4SLinus Torvalds	ldrcc	pc, [tbl, scno, lsl #2]		@ call sys_* routine
1891da177e4SLinus Torvalds	b	2b
1901da177e4SLinus Torvalds
1911da177e4SLinus Torvalds__sys_trace_return:
1921da177e4SLinus Torvalds	str	r0, [sp, #S_R0 + S_OFF]!	@ save returned r0
1931da177e4SLinus Torvalds	mov	r1, sp
1941da177e4SLinus Torvalds	mov	r0, #1				@ trace exit [IP = 1]
1951da177e4SLinus Torvalds	bl	syscall_trace
1961da177e4SLinus Torvalds	b	ret_slow_syscall
1971da177e4SLinus Torvalds
1981da177e4SLinus Torvalds	.align	5
1991da177e4SLinus Torvalds#ifdef CONFIG_ALIGNMENT_TRAP
2001da177e4SLinus Torvalds	.type	__cr_alignment, #object
2011da177e4SLinus Torvalds__cr_alignment:
2021da177e4SLinus Torvalds	.word	cr_alignment
2031da177e4SLinus Torvalds#endif
2041da177e4SLinus Torvalds
2051da177e4SLinus Torvalds	.type	sys_call_table, #object
2061da177e4SLinus TorvaldsENTRY(sys_call_table)
2071da177e4SLinus Torvalds#include "calls.S"
2081da177e4SLinus Torvalds
2091da177e4SLinus Torvalds/*============================================================================
2101da177e4SLinus Torvalds * Special system call wrappers
2111da177e4SLinus Torvalds */
2121da177e4SLinus Torvalds@ r0 = syscall number
2131da177e4SLinus Torvalds@ r5 = syscall table
2141da177e4SLinus Torvalds		.type	sys_syscall, #function
2151da177e4SLinus Torvaldssys_syscall:
216e0f9f4a6SRussell King		eor	scno, r0, #__NR_SYSCALL_BASE
2171da177e4SLinus Torvalds		cmp	scno, #__NR_syscall - __NR_SYSCALL_BASE
2181da177e4SLinus Torvalds		cmpne	scno, #NR_syscalls	@ check range
2191da177e4SLinus Torvalds		stmloia	sp, {r5, r6}		@ shuffle args
2201da177e4SLinus Torvalds		movlo	r0, r1
2211da177e4SLinus Torvalds		movlo	r1, r2
2221da177e4SLinus Torvalds		movlo	r2, r3
2231da177e4SLinus Torvalds		movlo	r3, r4
2241da177e4SLinus Torvalds		ldrlo	pc, [tbl, scno, lsl #2]
2251da177e4SLinus Torvalds		b	sys_ni_syscall
2261da177e4SLinus Torvalds
2271da177e4SLinus Torvaldssys_fork_wrapper:
2281da177e4SLinus Torvalds		add	r0, sp, #S_OFF
2291da177e4SLinus Torvalds		b	sys_fork
2301da177e4SLinus Torvalds
2311da177e4SLinus Torvaldssys_vfork_wrapper:
2321da177e4SLinus Torvalds		add	r0, sp, #S_OFF
2331da177e4SLinus Torvalds		b	sys_vfork
2341da177e4SLinus Torvalds
2351da177e4SLinus Torvaldssys_execve_wrapper:
2361da177e4SLinus Torvalds		add	r3, sp, #S_OFF
2371da177e4SLinus Torvalds		b	sys_execve
2381da177e4SLinus Torvalds
2391da177e4SLinus Torvaldssys_clone_wrapper:
2401da177e4SLinus Torvalds		add	ip, sp, #S_OFF
2411da177e4SLinus Torvalds		str	ip, [sp, #4]
2421da177e4SLinus Torvalds		b	sys_clone
2431da177e4SLinus Torvalds
2441da177e4SLinus Torvaldssys_sigsuspend_wrapper:
2451da177e4SLinus Torvalds		add	r3, sp, #S_OFF
2461da177e4SLinus Torvalds		b	sys_sigsuspend
2471da177e4SLinus Torvalds
2481da177e4SLinus Torvaldssys_rt_sigsuspend_wrapper:
2491da177e4SLinus Torvalds		add	r2, sp, #S_OFF
2501da177e4SLinus Torvalds		b	sys_rt_sigsuspend
2511da177e4SLinus Torvalds
2521da177e4SLinus Torvaldssys_sigreturn_wrapper:
2531da177e4SLinus Torvalds		add	r0, sp, #S_OFF
2541da177e4SLinus Torvalds		b	sys_sigreturn
2551da177e4SLinus Torvalds
2561da177e4SLinus Torvaldssys_rt_sigreturn_wrapper:
2571da177e4SLinus Torvalds		add	r0, sp, #S_OFF
2581da177e4SLinus Torvalds		b	sys_rt_sigreturn
2591da177e4SLinus Torvalds
2601da177e4SLinus Torvaldssys_sigaltstack_wrapper:
2611da177e4SLinus Torvalds		ldr	r2, [sp, #S_OFF + S_SP]
2621da177e4SLinus Torvalds		b	do_sigaltstack
2631da177e4SLinus Torvalds
2641da177e4SLinus Torvaldssys_futex_wrapper:
2651da177e4SLinus Torvalds		str	r5, [sp, #4]		@ push sixth arg
2661da177e4SLinus Torvalds		b	sys_futex
2671da177e4SLinus Torvalds
26868d9102fSNicolas Pitresys_arm_fadvise64_64_wrapper:
26968d9102fSNicolas Pitre		str	r5, [sp, #4]		@ push r5 to stack
27068d9102fSNicolas Pitre		b	sys_arm_fadvise64_64
27168d9102fSNicolas Pitre
2729b9eb8c0SRussell Kingsys_mbind_wrapper:
2739b9eb8c0SRussell King		str	r5, [sp, #4]
2749b9eb8c0SRussell King		b	sys_mbind
2759b9eb8c0SRussell King
2761da177e4SLinus Torvalds/*
2771da177e4SLinus Torvalds * Note: off_4k (r5) is always units of 4K.  If we can't do the requested
2781da177e4SLinus Torvalds * offset, we return EINVAL.
2791da177e4SLinus Torvalds */
2801da177e4SLinus Torvaldssys_mmap2:
2811da177e4SLinus Torvalds#if PAGE_SHIFT > 12
2821da177e4SLinus Torvalds		tst	r5, #PGOFF_MASK
2831da177e4SLinus Torvalds		moveq	r5, r5, lsr #PAGE_SHIFT - 12
2841da177e4SLinus Torvalds		streq	r5, [sp, #4]
2851da177e4SLinus Torvalds		beq	do_mmap2
2861da177e4SLinus Torvalds		mov	r0, #-EINVAL
2871da177e4SLinus Torvalds		RETINSTR(mov,pc, lr)
2881da177e4SLinus Torvalds#else
2891da177e4SLinus Torvalds		str	r5, [sp, #4]
2901da177e4SLinus Torvalds		b	do_mmap2
2911da177e4SLinus Torvalds#endif
292