[x86] Unify semaphore_32.S and rwlock_64.S
From: Christoph Lameter
Date: Tue Jan 19 2010 - 17:22:26 EST
From: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
Subject: [x86] Unify semaphore_32.S and rwlock_64.S
Both implement semaphore handling and the code for __read_lock_failed()
and __write_lock_failed() look eearily similar aside from the use of
different registers.
Create a new arch/x86/lib/semaphore.S out of the two files.
This is also a good preparatory patch for getting the rwsem XADD stuff
to work on x86_64.
x86_64 gains the FRAME/ENDFRAME handling that i386 has (not sure what the
point is of having that there).
Signed-off-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/lib/Makefile | 5 -
arch/x86/lib/rwlock_64.S | 38 -----------
arch/x86/lib/semaphore.S | 146 ++++++++++++++++++++++++++++++++++++++++++++
arch/x86/lib/semaphore_32.S | 136 ----------------------------------------
4 files changed, 149 insertions(+), 176 deletions(-)
Index: linux-2.6/arch/x86/lib/Makefile
===================================================================
--- linux-2.6.orig/arch/x86/lib/Makefile 2010-01-19 14:35:40.000000000 -0600
+++ linux-2.6/arch/x86/lib/Makefile 2010-01-19 14:36:29.000000000 -0600
@@ -21,6 +21,7 @@ lib-y += thunk_$(BITS).o
lib-y += usercopy_$(BITS).o getuser.o putuser.o
lib-y += memcpy_$(BITS).o
lib-$(CONFIG_KPROBES) += insn.o inat.o
+lib-y += semaphore.o
obj-y += msr.o msr-reg.o msr-reg-export.o
@@ -28,7 +29,7 @@ ifeq ($(CONFIG_X86_32),y)
obj-y += atomic64_32.o
lib-y += checksum_32.o
lib-y += strstr_32.o
- lib-y += semaphore_32.o string_32.o
+ lib-y += string_32.o
ifneq ($(CONFIG_X86_CMPXCHG64),y)
lib-y += cmpxchg8b_emu.o
endif
@@ -38,5 +39,5 @@ else
lib-y += csum-partial_64.o csum-copy_64.o csum-wrappers_64.o
lib-y += thunk_64.o clear_page_64.o copy_page_64.o
lib-y += memmove_64.o memset_64.o
- lib-y += copy_user_64.o rwlock_64.o copy_user_nocache_64.o
+ lib-y += copy_user_64.o copy_user_nocache_64.o
endif
Index: linux-2.6/arch/x86/lib/rwlock_64.S
===================================================================
--- linux-2.6.orig/arch/x86/lib/rwlock_64.S 2010-01-19 14:35:40.000000000 -0600
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,38 +0,0 @@
-/* Slow paths of read/write spinlocks. */
-
-#include <linux/linkage.h>
-#include <asm/rwlock.h>
-#include <asm/alternative-asm.h>
-#include <asm/dwarf2.h>
-
-/* rdi: pointer to rwlock_t */
-ENTRY(__write_lock_failed)
- CFI_STARTPROC
- LOCK_PREFIX
- addl $RW_LOCK_BIAS,(%rdi)
-1: rep
- nop
- cmpl $RW_LOCK_BIAS,(%rdi)
- jne 1b
- LOCK_PREFIX
- subl $RW_LOCK_BIAS,(%rdi)
- jnz __write_lock_failed
- ret
- CFI_ENDPROC
-END(__write_lock_failed)
-
-/* rdi: pointer to rwlock_t */
-ENTRY(__read_lock_failed)
- CFI_STARTPROC
- LOCK_PREFIX
- incl (%rdi)
-1: rep
- nop
- cmpl $1,(%rdi)
- js 1b
- LOCK_PREFIX
- decl (%rdi)
- js __read_lock_failed
- ret
- CFI_ENDPROC
-END(__read_lock_failed)
Index: linux-2.6/arch/x86/lib/semaphore.S
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6/arch/x86/lib/semaphore.S 2010-01-19 14:43:40.000000000 -0600
@@ -0,0 +1,146 @@
+/*
+ * i386/x86_64 semaphore implementation.
+ *
+ * (C) Copyright 1999 Linus Torvalds
+ *
+ * Portions Copyright 1999 Red Hat, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * rw semaphores implemented November 1999 by Benjamin LaHaise <bcrl@xxxxxxxxx>
+ * 32 and 64 bit versions merged Jan 2010 by Christoph Lameter
+ */
+
+#include <linux/linkage.h>
+#include <asm/rwlock.h>
+#include <asm/alternative-asm.h>
+#include <asm/frame.h>
+#include <asm/dwarf2.h>
+
+#ifdef CONFIG_64BIT
+#define SEMPOINTER %rdi
+#else
+#define SEMPOINTER %eax
+#endif
+
+/*
+ * The semaphore operations have a special calling sequence that
+ * allow us to do a simpler in-line version of them. These routines
+ * need to convert that sequence back into the C sequence when
+ * there is contention on the semaphore.
+ *
+ * The register SEMPOINTER contains the semaphore pointer on entry. Save the
+ * C-clobbered registers except SEMPOINTER which is either a return value or
+ * just clobbered..
+ */
+ .section .sched.text, "ax"
+
+/*
+ * rw spinlock fallbacks
+ */
+#if defined(CONFIG_SMP) || defined(CONFIG_64BIT)
+ENTRY(__write_lock_failed)
+#ifdef CONFIG_64BIT
+ CFI_STARTPROC
+#else
+ CFI_STARTPROC simple
+#endif
+ FRAME
+2: LOCK_PREFIX
+ addl $ RW_LOCK_BIAS,(SEMPOINTER)
+1: rep; nop
+ cmpl $ RW_LOCK_BIAS,(SEMPOINTER)
+ jne 1b
+ LOCK_PREFIX
+ subl $ RW_LOCK_BIAS,(SEMPOINTER)
+ jnz 2b
+ ENDFRAME
+ ret
+ CFI_ENDPROC
+ENDPROC(__write_lock_failed)
+
+ENTRY(__read_lock_failed)
+ CFI_STARTPROC
+ FRAME
+2: LOCK_PREFIX
+ incl (SEMPOINTER)
+1: rep; nop
+ cmpl $1,(SEMPOINTER)
+ js 1b
+ LOCK_PREFIX
+ decl (SEMPOINTER)
+ js 2b
+ ENDFRAME
+ ret
+ CFI_ENDPROC
+ENDPROC(__read_lock_failed)
+#endif
+
+#ifdef CONFIG_RWSEM_XCHGADD_ALGORITHM
+
+/* Fix up special calling conventions */
+ENTRY(call_rwsem_down_read_failed)
+ CFI_STARTPROC
+ push %ecx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ecx,0
+ push %edx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET edx,0
+ call rwsem_down_read_failed
+ pop %edx
+ CFI_ADJUST_CFA_OFFSET -4
+ pop %ecx
+ CFI_ADJUST_CFA_OFFSET -4
+ ret
+ CFI_ENDPROC
+ ENDPROC(call_rwsem_down_read_failed)
+
+ENTRY(call_rwsem_down_write_failed)
+ CFI_STARTPROC
+ push %ecx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ecx,0
+ calll rwsem_down_write_failed
+ pop %ecx
+ CFI_ADJUST_CFA_OFFSET -4
+ ret
+ CFI_ENDPROC
+ ENDPROC(call_rwsem_down_write_failed)
+
+ENTRY(call_rwsem_wake)
+ CFI_STARTPROC
+ decw %dx /* do nothing if still outstanding active readers */
+ jnz 1f
+ push %ecx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ecx,0
+ call rwsem_wake
+ pop %ecx
+ CFI_ADJUST_CFA_OFFSET -4
+1: ret
+ CFI_ENDPROC
+ ENDPROC(call_rwsem_wake)
+
+/* Fix up special calling conventions */
+ENTRY(call_rwsem_downgrade_wake)
+ CFI_STARTPROC
+ push %ecx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ecx,0
+ push %edx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET edx,0
+ call rwsem_downgrade_wake
+ pop %edx
+ CFI_ADJUST_CFA_OFFSET -4
+ pop %ecx
+ CFI_ADJUST_CFA_OFFSET -4
+ ret
+ CFI_ENDPROC
+ ENDPROC(call_rwsem_downgrade_wake)
+
+#endif
Index: linux-2.6/arch/x86/lib/semaphore_32.S
===================================================================
--- linux-2.6.orig/arch/x86/lib/semaphore_32.S 2010-01-19 14:35:40.000000000 -0600
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,136 +0,0 @@
-/*
- * i386 semaphore implementation.
- *
- * (C) Copyright 1999 Linus Torvalds
- *
- * Portions Copyright 1999 Red Hat, Inc.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
- * rw semaphores implemented November 1999 by Benjamin LaHaise <bcrl@xxxxxxxxx>
- */
-
-#include <linux/linkage.h>
-#include <asm/rwlock.h>
-#include <asm/alternative-asm.h>
-#include <asm/frame.h>
-#include <asm/dwarf2.h>
-
-/*
- * The semaphore operations have a special calling sequence that
- * allow us to do a simpler in-line version of them. These routines
- * need to convert that sequence back into the C sequence when
- * there is contention on the semaphore.
- *
- * %eax contains the semaphore pointer on entry. Save the C-clobbered
- * registers (%eax, %edx and %ecx) except %eax whish is either a return
- * value or just clobbered..
- */
- .section .sched.text, "ax"
-
-/*
- * rw spinlock fallbacks
- */
-#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
- ENDPROC(__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
- ENDPROC(__read_lock_failed)
-
-#endif
-
-#ifdef CONFIG_RWSEM_XCHGADD_ALGORITHM
-
-/* Fix up special calling conventions */
-ENTRY(call_rwsem_down_read_failed)
- CFI_STARTPROC
- push %ecx
- CFI_ADJUST_CFA_OFFSET 4
- CFI_REL_OFFSET ecx,0
- push %edx
- CFI_ADJUST_CFA_OFFSET 4
- CFI_REL_OFFSET edx,0
- call rwsem_down_read_failed
- pop %edx
- CFI_ADJUST_CFA_OFFSET -4
- pop %ecx
- CFI_ADJUST_CFA_OFFSET -4
- ret
- CFI_ENDPROC
- ENDPROC(call_rwsem_down_read_failed)
-
-ENTRY(call_rwsem_down_write_failed)
- CFI_STARTPROC
- push %ecx
- CFI_ADJUST_CFA_OFFSET 4
- CFI_REL_OFFSET ecx,0
- calll rwsem_down_write_failed
- pop %ecx
- CFI_ADJUST_CFA_OFFSET -4
- ret
- CFI_ENDPROC
- ENDPROC(call_rwsem_down_write_failed)
-
-ENTRY(call_rwsem_wake)
- CFI_STARTPROC
- decw %dx /* do nothing if still outstanding active readers */
- jnz 1f
- push %ecx
- CFI_ADJUST_CFA_OFFSET 4
- CFI_REL_OFFSET ecx,0
- call rwsem_wake
- pop %ecx
- CFI_ADJUST_CFA_OFFSET -4
-1: ret
- CFI_ENDPROC
- ENDPROC(call_rwsem_wake)
-
-/* Fix up special calling conventions */
-ENTRY(call_rwsem_downgrade_wake)
- CFI_STARTPROC
- push %ecx
- CFI_ADJUST_CFA_OFFSET 4
- CFI_REL_OFFSET ecx,0
- push %edx
- CFI_ADJUST_CFA_OFFSET 4
- CFI_REL_OFFSET edx,0
- call rwsem_downgrade_wake
- pop %edx
- CFI_ADJUST_CFA_OFFSET -4
- pop %ecx
- CFI_ADJUST_CFA_OFFSET -4
- ret
- CFI_ENDPROC
- ENDPROC(call_rwsem_downgrade_wake)
-
-#endif
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/