Messages in this thread Patch in this message | | | Date | Tue, 19 Jul 2011 12:59:51 +0100 | From | "Jan Beulich" <> | Subject | [PATCH 1/3, resend] x86: unify rwlock assembly implementation |
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Rather than having two functionally identical implementations for 32- and 64-bit configurations, extend the existing assembly abstractions enough to fold the two rwlock implementations into a shared one.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
--- arch/x86/include/asm/asm.h | 3 +- arch/x86/include/asm/frame.h | 11 +++++----- arch/x86/lib/Makefile | 6 +++-- arch/x86/lib/rwlock.S | 44 +++++++++++++++++++++++++++++++++++++++++++ arch/x86/lib/rwlock_64.S | 38 ------------------------------------- arch/x86/lib/semaphore_32.S | 44 ------------------------------------------- 6 files changed, 56 insertions(+), 90 deletions(-)
--- 3.0-rc7-x86-rw.orig/arch/x86/include/asm/asm.h +++ 3.0-rc7-x86-rw/arch/x86/include/asm/asm.h @@ -15,7 +15,8 @@ # define __ASM_SEL(a,b) __ASM_FORM(b) #endif -#define __ASM_SIZE(inst) __ASM_SEL(inst##l, inst##q) +#define __ASM_SIZE(inst, ...) __ASM_SEL(inst##l##__VA_ARGS__, \ + inst##q##__VA_ARGS__) #define __ASM_REG(reg) __ASM_SEL(e##reg, r##reg) #define _ASM_PTR __ASM_SEL(.long, .quad) --- 3.0-rc7-x86-rw.orig/arch/x86/include/asm/frame.h +++ 3.0-rc7-x86-rw/arch/x86/include/asm/frame.h @@ -1,5 +1,6 @@ #ifdef __ASSEMBLY__ +#include <asm/asm.h> #include <asm/dwarf2.h> /* The annotation hides the frame from the unwinder and makes it look @@ -7,13 +8,13 @@ frame pointer later */ #ifdef CONFIG_FRAME_POINTER .macro FRAME - pushl_cfi %ebp - CFI_REL_OFFSET ebp,0 - movl %esp,%ebp + __ASM_SIZE(push,_cfi) %__ASM_REG(bp) + CFI_REL_OFFSET __ASM_REG(bp), 0 + __ASM_SIZE(mov) %__ASM_REG(sp), %__ASM_REG(bp) .endm .macro ENDFRAME - popl_cfi %ebp - CFI_RESTORE ebp + __ASM_SIZE(pop,_cfi) %__ASM_REG(bp) + CFI_RESTORE __ASM_REG(bp) .endm #else .macro FRAME --- 3.0-rc7-x86-rw.orig/arch/x86/lib/Makefile +++ 3.0-rc7-x86-rw/arch/x86/lib/Makefile @@ -20,6 +20,7 @@ lib-y := delay.o lib-y += thunk_$(BITS).o lib-y += usercopy_$(BITS).o getuser.o putuser.o lib-y += memcpy_$(BITS).o +lib-$(CONFIG_SMP) += rwlock.o lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o obj-y += msr.o msr-reg.o msr-reg-export.o @@ -29,7 +30,8 @@ ifeq ($(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-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += semaphore_32.o + lib-y += string_32.o lib-y += cmpxchg.o ifneq ($(CONFIG_X86_CMPXCHG64),y) lib-y += cmpxchg8b_emu.o atomic64_386_32.o @@ -40,7 +42,7 @@ 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 lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem_64.o lib-y += cmpxchg16b_emu.o endif --- /dev/null +++ 3.0-rc7-x86-rw/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 + addl $RW_LOCK_BIAS, (%__lock_ptr) +1: rep; nop + cmpl $RW_LOCK_BIAS, (%__lock_ptr) + jne 1b + LOCK_PREFIX + subl $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 + incl (%__lock_ptr) +1: rep; nop + cmpl $1, (%__lock_ptr) + js 1b + LOCK_PREFIX + decl (%__lock_ptr) + js 0b + ENDFRAME + ret + CFI_ENDPROC +END(__read_lock_failed) --- 3.0-rc7-x86-rw.orig/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) --- 3.0-rc7-x86-rw.orig/arch/x86/lib/semaphore_32.S +++ 3.0-rc7-x86-rw/arch/x86/lib/semaphore_32.S @@ -14,8 +14,6 @@ */ #include <linux/linkage.h> -#include <asm/rwlock.h> -#include <asm/alternative-asm.h> #include <asm/frame.h> #include <asm/dwarf2.h> @@ -31,46 +29,6 @@ */ .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 @@ -120,5 +78,3 @@ ENTRY(call_rwsem_downgrade_wake) ret CFI_ENDPROC ENDPROC(call_rwsem_downgrade_wake) - -#endif
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