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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm/kernel/entry-common.S
downloadconfigs-2.6.12-rc2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/arm/kernel/entry-common.S')
-rw-r--r--arch/arm/kernel/entry-common.S260
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 00000000000..53a7e0dea44
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+++ 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