1 files changed, 260 insertions, 0 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
new file mode 100644
index 0000000..53a7e0d
--- /dev/null
+++ b/arch/arm/kernel/entry-common.S
@@ -0,0 +1,260 @@
+/*
+ *  linux/arch/arm/kernel/entry-common.S
+ *
+ *  Copyright (C) 2000 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/config.h>
+
+#include <asm/thread_info.h>
+#include <asm/ptrace.h>
+#include <asm/unistd.h>
+
+#include "entry-header.S"
+
+/* 
+ * We rely on the fact that R0 is at the bottom of the stack (due to
+ * slow/fast restore user regs).
+ */
+#if S_R0 != 0
+#error "Please fix"
+#endif
+
+	.align	5
+/*
+ * This is the fast syscall return path.  We do as little as
+ * possible here, and this includes saving r0 back into the SVC
+ * stack.
+ */
+ret_fast_syscall:
+	disable_irq r1				@ disable interrupts
+	ldr	r1, [tsk, #TI_FLAGS]
+	tst	r1, #_TIF_WORK_MASK
+	bne	fast_work_pending
+	fast_restore_user_regs
+
+/*
+ * Ok, we need to do extra processing, enter the slow path.
+ */
+fast_work_pending:
+	str	r0, [sp, #S_R0+S_OFF]!		@ returned r0
+work_pending:
+	tst	r1, #_TIF_NEED_RESCHED
+	bne	work_resched
+	tst	r1, #_TIF_NOTIFY_RESUME | _TIF_SIGPENDING
+	beq	no_work_pending
+	mov	r0, sp				@ 'regs'
+	mov	r2, why				@ 'syscall'
+	bl	do_notify_resume
+	disable_irq r1				@ disable interrupts
+	b	no_work_pending
+
+work_resched:
+	bl	schedule
+/*
+ * "slow" syscall return path.  "why" tells us if this was a real syscall.
+ */
+ENTRY(ret_to_user)
+ret_slow_syscall:
+	disable_irq r1				@ disable interrupts
+	ldr	r1, [tsk, #TI_FLAGS]
+	tst	r1, #_TIF_WORK_MASK
+	bne	work_pending
+no_work_pending:
+	slow_restore_user_regs
+
+/*
+ * This is how we return from a fork.
+ */
+ENTRY(ret_from_fork)
+	bl	schedule_tail
+	get_thread_info tsk
+	ldr	r1, [tsk, #TI_FLAGS]		@ check for syscall tracing
+	mov	why, #1
+	tst	r1, #_TIF_SYSCALL_TRACE		@ are we tracing syscalls?
+	beq	ret_slow_syscall
+	mov	r1, sp
+	mov	r0, #1				@ trace exit [IP = 1]
+	bl	syscall_trace
+	b	ret_slow_syscall
+	
+
+#include "calls.S"
+
+/*=============================================================================
+ * SWI handler
+ *-----------------------------------------------------------------------------
+ */
+
+	/* If we're optimising for StrongARM the resulting code won't 
+	   run on an ARM7 and we can save a couple of instructions.  
+								--pb */
+#ifdef CONFIG_CPU_ARM710
+	.macro	arm710_bug_check, instr, temp
+	and	\temp, \instr, #0x0f000000	@ check for SWI
+	teq	\temp, #0x0f000000
+	bne	.Larm700bug
+	.endm
+
+.Larm700bug:
+	ldr	r0, [sp, #S_PSR]		@ Get calling cpsr
+	sub	lr, lr, #4
+	str	lr, [r8]
+	msr	spsr_cxsf, r0
+	ldmia	sp, {r0 - lr}^			@ Get calling r0 - lr
+	mov	r0, r0
+	ldr	lr, [sp, #S_PC]			@ Get PC
+	add	sp, sp, #S_FRAME_SIZE
+	movs	pc, lr
+#else
+	.macro	arm710_bug_check, instr, temp
+	.endm
+#endif
+
+	.align	5
+ENTRY(vector_swi)
+	save_user_regs
+	zero_fp
+	get_scno
+	arm710_bug_check scno, ip
+
+#ifdef CONFIG_ALIGNMENT_TRAP
+	ldr	ip, __cr_alignment
+	ldr	ip, [ip]
+	mcr	p15, 0, ip, c1, c0		@ update control register
+#endif
+	enable_irq ip
+
+	str	r4, [sp, #-S_OFF]!		@ push fifth arg
+
+	get_thread_info tsk
+	ldr	ip, [tsk, #TI_FLAGS]		@ check for syscall tracing
+	bic	scno, scno, #0xff000000		@ mask off SWI op-code
+	eor	scno, scno, #OS_NUMBER << 20	@ check OS number
+	adr	tbl, sys_call_table		@ load syscall table pointer
+	tst	ip, #_TIF_SYSCALL_TRACE		@ are we tracing syscalls?
+	bne	__sys_trace
+
+	adr	lr, ret_fast_syscall		@ return address
+	cmp	scno, #NR_syscalls		@ check upper syscall limit
+	ldrcc	pc, [tbl, scno, lsl #2]		@ call sys_* routine
+
+	add	r1, sp, #S_OFF
+2:	mov	why, #0				@ no longer a real syscall
+	cmp	scno, #ARMSWI_OFFSET
+	eor	r0, scno, #OS_NUMBER << 20	@ put OS number back
+	bcs	arm_syscall	
+	b	sys_ni_syscall			@ not private func
+
+	/*
+	 * This is the really slow path.  We're going to be doing
+	 * context switches, and waiting for our parent to respond.
+	 */
+__sys_trace:
+	add	r1, sp, #S_OFF
+	mov	r0, #0				@ trace entry [IP = 0]
+	bl	syscall_trace
+
+	adr	lr, __sys_trace_return		@ return address
+	add	r1, sp, #S_R0 + S_OFF		@ pointer to regs
+	cmp	scno, #NR_syscalls		@ check upper syscall limit
+	ldmccia	r1, {r0 - r3}			@ have to reload r0 - r3
+	ldrcc	pc, [tbl, scno, lsl #2]		@ call sys_* routine
+	b	2b
+
+__sys_trace_return:
+	str	r0, [sp, #S_R0 + S_OFF]!	@ save returned r0
+	mov	r1, sp
+	mov	r0, #1				@ trace exit [IP = 1]
+	bl	syscall_trace
+	b	ret_slow_syscall
+
+	.align	5
+#ifdef CONFIG_ALIGNMENT_TRAP
+	.type	__cr_alignment, #object
+__cr_alignment:
+	.word	cr_alignment
+#endif
+
+	.type	sys_call_table, #object
+ENTRY(sys_call_table)
+#include "calls.S"
+
+/*============================================================================
+ * Special system call wrappers
+ */
+@ r0 = syscall number
+@ r5 = syscall table
+		.type	sys_syscall, #function
+sys_syscall:
+		eor	scno, r0, #OS_NUMBER << 20
+		cmp	scno, #__NR_syscall - __NR_SYSCALL_BASE
+		cmpne	scno, #NR_syscalls	@ check range
+		stmloia	sp, {r5, r6}		@ shuffle args
+		movlo	r0, r1
+		movlo	r1, r2
+		movlo	r2, r3
+		movlo	r3, r4
+		ldrlo	pc, [tbl, scno, lsl #2]
+		b	sys_ni_syscall
+
+sys_fork_wrapper:
+		add	r0, sp, #S_OFF
+		b	sys_fork
+
+sys_vfork_wrapper:
+		add	r0, sp, #S_OFF
+		b	sys_vfork
+
+sys_execve_wrapper:
+		add	r3, sp, #S_OFF
+		b	sys_execve
+
+sys_clone_wrapper:
+		add	ip, sp, #S_OFF
+		str	ip, [sp, #4]
+		b	sys_clone
+
+sys_sigsuspend_wrapper:
+		add	r3, sp, #S_OFF
+		b	sys_sigsuspend
+
+sys_rt_sigsuspend_wrapper:
+		add	r2, sp, #S_OFF
+		b	sys_rt_sigsuspend
+
+sys_sigreturn_wrapper:
+		add	r0, sp, #S_OFF
+		b	sys_sigreturn
+
+sys_rt_sigreturn_wrapper:
+		add	r0, sp, #S_OFF
+		b	sys_rt_sigreturn
+
+sys_sigaltstack_wrapper:
+		ldr	r2, [sp, #S_OFF + S_SP]
+		b	do_sigaltstack
+
+sys_futex_wrapper:
+		str	r5, [sp, #4]		@ push sixth arg
+		b	sys_futex
+
+/*
+ * Note: off_4k (r5) is always units of 4K.  If we can't do the requested
+ * offset, we return EINVAL.
+ */
+sys_mmap2:
+#if PAGE_SHIFT > 12
+		tst	r5, #PGOFF_MASK
+		moveq	r5, r5, lsr #PAGE_SHIFT - 12
+		streq	r5, [sp, #4]
+		beq	do_mmap2
+		mov	r0, #-EINVAL
+		RETINSTR(mov,pc, lr)
+#else
+		str	r5, [sp, #4]
+		b	do_mmap2
+#endif