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authorLinus Torvalds <torvalds@linux-foundation.org>2011-07-23 02:02:24 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-23 02:02:24 +0200
commiteb47418dc56baaca33d270a868d8ddaa81150952 (patch)
tree16c0b09bacf3f6c25e5786afcfa741fa2a550ae5 /arch/x86/lib
parentMerge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kerne... (diff)
parentx86: Fix write lock scalability 64-bit issue (diff)
downloadlinux-eb47418dc56baaca33d270a868d8ddaa81150952.tar.xz
linux-eb47418dc56baaca33d270a868d8ddaa81150952.zip
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: Fix write lock scalability 64-bit issue x86: Unify rwsem assembly implementation x86: Unify rwlock assembly implementation x86, asm: Fix binutils 2.16 issue with __USER32_CS x86, asm: Cleanup thunk_64.S x86, asm: Flip RESTORE_ARGS arguments logic x86, asm: Flip SAVE_ARGS arguments logic x86, asm: Thin down SAVE/RESTORE_* asm macros
Diffstat (limited to 'arch/x86/lib')
-rw-r--r--arch/x86/lib/Makefile7
-rw-r--r--arch/x86/lib/rwlock.S44
-rw-r--r--arch/x86/lib/rwlock_64.S38
-rw-r--r--arch/x86/lib/rwsem.S (renamed from arch/x86/lib/rwsem_64.S)75
-rw-r--r--arch/x86/lib/semaphore_32.S124
-rw-r--r--arch/x86/lib/thunk_64.S45
6 files changed, 125 insertions, 208 deletions
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index 6ba477342b8e..b00f6785da74 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -20,6 +20,8 @@ lib-y := delay.o
lib-y += thunk_$(BITS).o
lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o
lib-y += memcpy_$(BITS).o
+lib-$(CONFIG_SMP) += rwlock.o
+lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o
obj-y += msr.o msr-reg.o msr-reg-export.o
@@ -29,7 +31,7 @@ ifeq ($(CONFIG_X86_32),y)
lib-y += atomic64_cx8_32.o
lib-y += checksum_32.o
lib-y += strstr_32.o
- lib-y += semaphore_32.o string_32.o
+ lib-y += string_32.o
lib-y += cmpxchg.o
ifneq ($(CONFIG_X86_CMPXCHG64),y)
lib-y += cmpxchg8b_emu.o atomic64_386_32.o
@@ -40,7 +42,6 @@ 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-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem_64.o
+ lib-y += copy_user_64.o copy_user_nocache_64.o
lib-y += cmpxchg16b_emu.o
endif
diff --git a/arch/x86/lib/rwlock.S b/arch/x86/lib/rwlock.S
new file mode 100644
index 000000000000..1cad22139c88
--- /dev/null
+++ b/arch/x86/lib/rwlock.S
@@ -0,0 +1,44 @@
+/* Slow paths of read/write spinlocks. */
+
+#include <linux/linkage.h>
+#include <asm/alternative-asm.h>
+#include <asm/frame.h>
+#include <asm/rwlock.h>
+
+#ifdef CONFIG_X86_32
+# define __lock_ptr eax
+#else
+# define __lock_ptr rdi
+#endif
+
+ENTRY(__write_lock_failed)
+ CFI_STARTPROC
+ FRAME
+0: LOCK_PREFIX
+ WRITE_LOCK_ADD($RW_LOCK_BIAS) (%__lock_ptr)
+1: rep; nop
+ cmpl $WRITE_LOCK_CMP, (%__lock_ptr)
+ jne 1b
+ LOCK_PREFIX
+ WRITE_LOCK_SUB($RW_LOCK_BIAS) (%__lock_ptr)
+ jnz 0b
+ ENDFRAME
+ ret
+ CFI_ENDPROC
+END(__write_lock_failed)
+
+ENTRY(__read_lock_failed)
+ CFI_STARTPROC
+ FRAME
+0: LOCK_PREFIX
+ READ_LOCK_SIZE(inc) (%__lock_ptr)
+1: rep; nop
+ READ_LOCK_SIZE(cmp) $1, (%__lock_ptr)
+ js 1b
+ LOCK_PREFIX
+ READ_LOCK_SIZE(dec) (%__lock_ptr)
+ js 0b
+ ENDFRAME
+ ret
+ CFI_ENDPROC
+END(__read_lock_failed)
diff --git a/arch/x86/lib/rwlock_64.S b/arch/x86/lib/rwlock_64.S
deleted file mode 100644
index 05ea55f71405..000000000000
--- a/arch/x86/lib/rwlock_64.S
+++ /dev/null
@@ -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)
diff --git a/arch/x86/lib/rwsem_64.S b/arch/x86/lib/rwsem.S
index 67743977398b..5dff5f042468 100644
--- a/arch/x86/lib/rwsem_64.S
+++ b/arch/x86/lib/rwsem.S
@@ -1,4 +1,51 @@
/*
+ * x86 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@kvack.org>
+ */
+
+#include <linux/linkage.h>
+#include <asm/alternative-asm.h>
+#include <asm/dwarf2.h>
+
+#define __ASM_HALF_REG(reg) __ASM_SEL(reg, e##reg)
+#define __ASM_HALF_SIZE(inst) __ASM_SEL(inst##w, inst##l)
+
+#ifdef CONFIG_X86_32
+
+/*
+ * 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..
+ */
+
+#define save_common_regs \
+ pushl_cfi %ecx; CFI_REL_OFFSET ecx, 0
+
+#define restore_common_regs \
+ popl_cfi %ecx; CFI_RESTORE ecx
+
+ /* Avoid uglifying the argument copying x86-64 needs to do. */
+ .macro movq src, dst
+ .endm
+
+#else
+
+/*
* x86-64 rwsem wrappers
*
* This interfaces the inline asm code to the slow-path
@@ -16,12 +63,6 @@
* but %rdi, %rsi, %rcx, %r8-r11 always need saving.
*/
-#include <linux/linkage.h>
-#include <asm/rwlock.h>
-#include <asm/alternative-asm.h>
-#include <asm/frame.h>
-#include <asm/dwarf2.h>
-
#define save_common_regs \
pushq_cfi %rdi; CFI_REL_OFFSET rdi, 0; \
pushq_cfi %rsi; CFI_REL_OFFSET rsi, 0; \
@@ -40,16 +81,18 @@
popq_cfi %rsi; CFI_RESTORE rsi; \
popq_cfi %rdi; CFI_RESTORE rdi
+#endif
+
/* Fix up special calling conventions */
ENTRY(call_rwsem_down_read_failed)
CFI_STARTPROC
save_common_regs
- pushq_cfi %rdx
- CFI_REL_OFFSET rdx, 0
+ __ASM_SIZE(push,_cfi) %__ASM_REG(dx)
+ CFI_REL_OFFSET __ASM_REG(dx), 0
movq %rax,%rdi
call rwsem_down_read_failed
- popq_cfi %rdx
- CFI_RESTORE rdx
+ __ASM_SIZE(pop,_cfi) %__ASM_REG(dx)
+ CFI_RESTORE __ASM_REG(dx)
restore_common_regs
ret
CFI_ENDPROC
@@ -67,7 +110,8 @@ ENDPROC(call_rwsem_down_write_failed)
ENTRY(call_rwsem_wake)
CFI_STARTPROC
- decl %edx /* do nothing if still outstanding active readers */
+ /* do nothing if still outstanding active readers */
+ __ASM_HALF_SIZE(dec) %__ASM_HALF_REG(dx)
jnz 1f
save_common_regs
movq %rax,%rdi
@@ -77,16 +121,15 @@ ENTRY(call_rwsem_wake)
CFI_ENDPROC
ENDPROC(call_rwsem_wake)
-/* Fix up special calling conventions */
ENTRY(call_rwsem_downgrade_wake)
CFI_STARTPROC
save_common_regs
- pushq_cfi %rdx
- CFI_REL_OFFSET rdx, 0
+ __ASM_SIZE(push,_cfi) %__ASM_REG(dx)
+ CFI_REL_OFFSET __ASM_REG(dx), 0
movq %rax,%rdi
call rwsem_downgrade_wake
- popq_cfi %rdx
- CFI_RESTORE rdx
+ __ASM_SIZE(pop,_cfi) %__ASM_REG(dx)
+ CFI_RESTORE __ASM_REG(dx)
restore_common_regs
ret
CFI_ENDPROC
diff --git a/arch/x86/lib/semaphore_32.S b/arch/x86/lib/semaphore_32.S
deleted file mode 100644
index 06691daa4108..000000000000
--- a/arch/x86/lib/semaphore_32.S
+++ /dev/null
@@ -1,124 +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@kvack.org>
- */
-
-#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
- 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
- pushl_cfi %ecx
- CFI_REL_OFFSET ecx,0
- pushl_cfi %edx
- CFI_REL_OFFSET edx,0
- call rwsem_down_read_failed
- popl_cfi %edx
- popl_cfi %ecx
- ret
- CFI_ENDPROC
- ENDPROC(call_rwsem_down_read_failed)
-
-ENTRY(call_rwsem_down_write_failed)
- CFI_STARTPROC
- pushl_cfi %ecx
- CFI_REL_OFFSET ecx,0
- calll rwsem_down_write_failed
- popl_cfi %ecx
- 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
- pushl_cfi %ecx
- CFI_REL_OFFSET ecx,0
- call rwsem_wake
- popl_cfi %ecx
-1: ret
- CFI_ENDPROC
- ENDPROC(call_rwsem_wake)
-
-/* Fix up special calling conventions */
-ENTRY(call_rwsem_downgrade_wake)
- CFI_STARTPROC
- pushl_cfi %ecx
- CFI_REL_OFFSET ecx,0
- pushl_cfi %edx
- CFI_REL_OFFSET edx,0
- call rwsem_downgrade_wake
- popl_cfi %edx
- popl_cfi %ecx
- ret
- CFI_ENDPROC
- ENDPROC(call_rwsem_downgrade_wake)
-
-#endif
diff --git a/arch/x86/lib/thunk_64.S b/arch/x86/lib/thunk_64.S
index 782b082c9ff7..a63efd6bb6a5 100644
--- a/arch/x86/lib/thunk_64.S
+++ b/arch/x86/lib/thunk_64.S
@@ -5,50 +5,41 @@
* Added trace_hardirqs callers - Copyright 2007 Steven Rostedt, Red Hat, Inc.
* Subject to the GNU public license, v.2. No warranty of any kind.
*/
+#include <linux/linkage.h>
+#include <asm/dwarf2.h>
+#include <asm/calling.h>
- #include <linux/linkage.h>
- #include <asm/dwarf2.h>
- #include <asm/calling.h>
- #include <asm/rwlock.h>
-
- /* rdi: arg1 ... normal C conventions. rax is saved/restored. */
- .macro thunk name,func
- .globl \name
-\name:
- CFI_STARTPROC
- SAVE_ARGS
- call \func
- jmp restore
- CFI_ENDPROC
- .endm
-
-#ifdef CONFIG_TRACE_IRQFLAGS
- /* put return address in rdi (arg1) */
- .macro thunk_ra name,func
+ /* rdi: arg1 ... normal C conventions. rax is saved/restored. */
+ .macro THUNK name, func, put_ret_addr_in_rdi=0
.globl \name
\name:
CFI_STARTPROC
+
+ /* this one pushes 9 elems, the next one would be %rIP */
SAVE_ARGS
- /* SAVE_ARGS pushs 9 elements */
- /* the next element would be the rip */
- movq 9*8(%rsp), %rdi
+
+ .if \put_ret_addr_in_rdi
+ movq_cfi_restore 9*8, rdi
+ .endif
+
call \func
jmp restore
CFI_ENDPROC
.endm
- thunk_ra trace_hardirqs_on_thunk,trace_hardirqs_on_caller
- thunk_ra trace_hardirqs_off_thunk,trace_hardirqs_off_caller
+#ifdef CONFIG_TRACE_IRQFLAGS
+ THUNK trace_hardirqs_on_thunk,trace_hardirqs_on_caller,1
+ THUNK trace_hardirqs_off_thunk,trace_hardirqs_off_caller,1
#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
- thunk lockdep_sys_exit_thunk,lockdep_sys_exit
+ THUNK lockdep_sys_exit_thunk,lockdep_sys_exit
#endif
-
+
/* SAVE_ARGS below is used only for the .cfi directives it contains. */
CFI_STARTPROC
SAVE_ARGS
restore:
RESTORE_ARGS
- ret
+ ret
CFI_ENDPROC