From 4625cd637919edfb562e0d62abf94f52e9321335 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 19 Jul 2011 12:59:51 +0100 Subject: x86: Unify rwlock assembly implementation 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 Cc: Linus Torvalds Cc: Andrew Morton Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/4E258DD7020000780004E3EA@nat28.tlf.novell.com Signed-off-by: Ingo Molnar --- 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 -------------------------------------------- 4 files changed, 48 insertions(+), 84 deletions(-) create mode 100644 arch/x86/lib/rwlock.S delete mode 100644 arch/x86/lib/rwlock_64.S (limited to 'arch/x86/lib') diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index f2479f19ddde..d3ed1203cdd7 100644 --- a/arch/x86/lib/Makefile +++ b/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 diff --git a/arch/x86/lib/rwlock.S b/arch/x86/lib/rwlock.S new file mode 100644 index 000000000000..fca17829caa8 --- /dev/null +++ b/arch/x86/lib/rwlock.S @@ -0,0 +1,44 @@ +/* Slow paths of read/write spinlocks. */ + +#include +#include +#include +#include + +#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) 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 -#include -#include -#include - -/* 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/semaphore_32.S b/arch/x86/lib/semaphore_32.S index 06691daa4108..65b591d778b1 100644 --- a/arch/x86/lib/semaphore_32.S +++ b/arch/x86/lib/semaphore_32.S @@ -14,8 +14,6 @@ */ #include -#include -#include #include #include @@ -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 -- cgit v1.2.3-59-g8ed1b