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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

arch/i386/kernel/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -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

arch/i386/lib/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -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

arch/i386/kernel/semaphore.c→arch/i386/lib/semaphore.S

+154 −0
Original line number Diff line number Diff line
@@ -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

arch/um/sys-i386/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -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/asm-i386/frame.i

0 → 100644
+24 −0
Original line number Diff line number Diff line 
#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