Commit ecaf45ee authored by Andi Kleen's avatar Andi Kleen Committed by Andi Kleen
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[PATCH] i386: Redo semaphore and rwlock assembly helpers



- Move them to a pure assembly file. Previously they were in
a C file that only consisted of inline assembly. Doing it in pure
assembler is much nicer.
- Add a frame.i include with FRAME/ENDFRAME macros to easily
add frame pointers to assembly functions
- Add dwarf2 annotation to them so that the new dwarf2 unwinder
doesn't get stuck on them
- Random cleanups

Includes feedback from Jan Beulich and a UML build fix from Andrew
Morton.

Cc: jbeulich@novell.com
Cc: jdike@addtoit.com
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent 07c9819b
......@@ -4,7 +4,7 @@
extra-y := head.o init_task.o vmlinux.lds
obj-y := process.o semaphore.o signal.o entry.o traps.o irq.o \
obj-y := process.o signal.o entry.o traps.o irq.o \
ptrace.o time.o ioport.o ldt.o setup.o i8259.o sys_i386.o \
pci-dma.o i386_ksyms.o i387.o bootflag.o \
quirks.o i8237.o topology.o alternative.o i8253.o tsc.o
......
......@@ -4,6 +4,6 @@
lib-y = checksum.o delay.o usercopy.o getuser.o putuser.o memcpy.o strstr.o \
bitops.o
bitops.o semaphore.o
lib-$(CONFIG_X86_USE_3DNOW) += mmx.o
......@@ -12,7 +12,13 @@
*
* rw semaphores implemented November 1999 by Benjamin LaHaise <bcrl@kvack.org>
*/
#include <asm/semaphore.h>
#include <linux/config.h>
#include <linux/linkage.h>
#include <asm/rwlock.h>
#include <asm/alternative-asm.i>
#include <asm/frame.i>
#include <asm/dwarf2.h>
/*
* The semaphore operations have a special calling sequence that
......@@ -24,111 +30,125 @@
* registers (%eax, %edx and %ecx) except %eax whish is either a return
* value or just clobbered..
*/
asm(
".section .sched.text\n"
".align 4\n"
".globl __down_failed\n"
"__down_failed:\n\t"
#if defined(CONFIG_FRAME_POINTER)
"pushl %ebp\n\t"
"movl %esp,%ebp\n\t"
#endif
"pushl %edx\n\t"
"pushl %ecx\n\t"
"call __down\n\t"
"popl %ecx\n\t"
"popl %edx\n\t"
#if defined(CONFIG_FRAME_POINTER)
"movl %ebp,%esp\n\t"
"popl %ebp\n\t"
#endif
"ret"
);
.section .sched.text
ENTRY(__down_failed)
CFI_STARTPROC
FRAME
pushl %edx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET edx,0
pushl %ecx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET ecx,0
call __down
popl %ecx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE ecx
popl %edx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE edx
ENDFRAME
ret
CFI_ENDPROC
END(__down_failed)
asm(
".section .sched.text\n"
".align 4\n"
".globl __down_failed_interruptible\n"
"__down_failed_interruptible:\n\t"
#if defined(CONFIG_FRAME_POINTER)
"pushl %ebp\n\t"
"movl %esp,%ebp\n\t"
#endif
"pushl %edx\n\t"
"pushl %ecx\n\t"
"call __down_interruptible\n\t"
"popl %ecx\n\t"
"popl %edx\n\t"
#if defined(CONFIG_FRAME_POINTER)
"movl %ebp,%esp\n\t"
"popl %ebp\n\t"
#endif
"ret"
);
ENTRY(__down_failed_interruptible)
CFI_STARTPROC
FRAME
pushl %edx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET edx,0
pushl %ecx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET ecx,0
call __down_interruptible
popl %ecx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE ecx
popl %edx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE edx
ENDFRAME
ret
CFI_ENDPROC
END(__down_failed_interruptible)
asm(
".section .sched.text\n"
".align 4\n"
".globl __down_failed_trylock\n"
"__down_failed_trylock:\n\t"
#if defined(CONFIG_FRAME_POINTER)
"pushl %ebp\n\t"
"movl %esp,%ebp\n\t"
#endif
"pushl %edx\n\t"
"pushl %ecx\n\t"
"call __down_trylock\n\t"
"popl %ecx\n\t"
"popl %edx\n\t"
#if defined(CONFIG_FRAME_POINTER)
"movl %ebp,%esp\n\t"
"popl %ebp\n\t"
#endif
"ret"
);
ENTRY(__down_failed_trylock)
CFI_STARTPROC
FRAME
pushl %edx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET edx,0
pushl %ecx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET ecx,0
call __down_trylock
popl %ecx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE ecx
popl %edx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE edx
ENDFRAME
ret
CFI_ENDPROC
END(__down_failed_trylock)
asm(
".section .sched.text\n"
".align 4\n"
".globl __up_wakeup\n"
"__up_wakeup:\n\t"
"pushl %edx\n\t"
"pushl %ecx\n\t"
"call __up\n\t"
"popl %ecx\n\t"
"popl %edx\n\t"
"ret"
);
ENTRY(__up_wakeup)
CFI_STARTPROC
FRAME
pushl %edx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET edx,0
pushl %ecx
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET ecx,0
call __up
popl %ecx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE ecx
popl %edx
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE edx
ENDFRAME
ret
CFI_ENDPROC
END(__up_wakeup)
/*
* rw spinlock fallbacks
*/
#if defined(CONFIG_SMP)
asm(
".section .sched.text\n"
".align 4\n"
".globl __write_lock_failed\n"
"__write_lock_failed:\n\t"
LOCK_PREFIX "addl $" RW_LOCK_BIAS_STR ",(%eax)\n"
"1: rep; nop\n\t"
"cmpl $" RW_LOCK_BIAS_STR ",(%eax)\n\t"
"jne 1b\n\t"
LOCK_PREFIX "subl $" RW_LOCK_BIAS_STR ",(%eax)\n\t"
"jnz __write_lock_failed\n\t"
"ret"
);
#ifdef CONFIG_SMP
ENTRY(__write_lock_failed)
CFI_STARTPROC simple
FRAME
2: LOCK_PREFIX
addl $ RW_LOCK_BIAS,(%eax)
1: rep; nop
cmpl $ RW_LOCK_BIAS,(%eax)
jne 1b
LOCK_PREFIX
subl $ RW_LOCK_BIAS,(%eax)
jnz 2b
ENDFRAME
ret
CFI_ENDPROC
END(__write_lock_failed)
ENTRY(__read_lock_failed)
CFI_STARTPROC
FRAME
2: LOCK_PREFIX
incl (%eax)
1: rep; nop
cmpl $1,(%eax)
js 1b
LOCK_PREFIX
decl (%eax)
js 2b
ENDFRAME
ret
CFI_ENDPROC
END(__read_lock_failed)
asm(
".section .sched.text\n"
".align 4\n"
".globl __read_lock_failed\n"
"__read_lock_failed:\n\t"
LOCK_PREFIX "incl (%eax)\n"
"1: rep; nop\n\t"
"cmpl $1,(%eax)\n\t"
"js 1b\n\t"
LOCK_PREFIX "decl (%eax)\n\t"
"js __read_lock_failed\n\t"
"ret"
);
#endif
......@@ -4,7 +4,7 @@ obj-y = bugs.o checksum.o delay.o fault.o ksyms.o ldt.o ptrace.o \
obj-$(CONFIG_MODE_SKAS) += stub.o stub_segv.o
subarch-obj-y = lib/bitops.o kernel/semaphore.o
subarch-obj-y = lib/bitops.o lib/semaphore.o
subarch-obj-$(CONFIG_HIGHMEM) += mm/highmem.o
subarch-obj-$(CONFIG_MODULES) += kernel/module.o
......
#include <linux/config.h>
#include <asm/dwarf2.h>
/* The annotation hides the frame from the unwinder and makes it look
like a ordinary ebp save/restore. This avoids some special cases for
frame pointer later */
#ifdef CONFIG_FRAME_POINTER
.macro FRAME
pushl %ebp
CFI_ADJUST_CFA_OFFSET 4
CFI_REL_OFFSET ebp,0
movl %esp,%ebp
.endm
.macro ENDFRAME
popl %ebp
CFI_ADJUST_CFA_OFFSET -4
CFI_RESTORE ebp
.endm
#else
.macro FRAME
.endm
.macro ENDFRAME
.endm
#endif
#ifndef __UM_ALTERNATIVE_ASM_I
#define __UM_ALTERNATIVE_ASM_I
#include "asm/arch/alternative-asm.i"
#endif
#ifndef __UM_FRAME_I
#define __UM_FRAME_I
#include "asm/arch/frame.i"
#endif
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