From a738669464a1e0d8e7b20f631120192f9cf7cfbd Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 19 Jul 2011 13:00:19 +0100 Subject: [PATCH] x86: Unify rwsem assembly implementation Rather than having two functionally identical implementations for 32- and 64-bit configurations, use the previously extended assembly abstractions to fold the rwsem two 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/4E258DF3020000780004E3ED@nat28.tlf.novell.com Signed-off-by: Ingo Molnar --- arch/um/sys-i386/Makefile | 2 +- arch/um/sys-x86_64/Makefile | 2 +- arch/x86/lib/Makefile | 3 +- arch/x86/lib/{rwsem_64.S => rwsem.S} | 75 ++++++++++++++++++++------ arch/x86/lib/semaphore_32.S | 80 ---------------------------- 5 files changed, 62 insertions(+), 100 deletions(-) rename arch/x86/lib/{rwsem_64.S => rwsem.S} (55%) delete mode 100644 arch/x86/lib/semaphore_32.S diff --git a/arch/um/sys-i386/Makefile b/arch/um/sys-i386/Makefile index b1da91c1b200..15587ed9a361 100644 --- a/arch/um/sys-i386/Makefile +++ b/arch/um/sys-i386/Makefile @@ -8,7 +8,7 @@ obj-y = bug.o bugs.o checksum.o delay.o fault.o ksyms.o ldt.o ptrace.o \ obj-$(CONFIG_BINFMT_ELF) += elfcore.o -subarch-obj-y = lib/semaphore_32.o lib/string_32.o +subarch-obj-y = lib/rwsem.o lib/string_32.o subarch-obj-$(CONFIG_HIGHMEM) += mm/highmem_32.o subarch-obj-$(CONFIG_MODULES) += kernel/module.o diff --git a/arch/um/sys-x86_64/Makefile b/arch/um/sys-x86_64/Makefile index c1ea9eb04466..61fc99a42e10 100644 --- a/arch/um/sys-x86_64/Makefile +++ b/arch/um/sys-x86_64/Makefile @@ -9,7 +9,7 @@ obj-y = bug.o bugs.o delay.o fault.o ldt.o mem.o ptrace.o ptrace_user.o \ sysrq.o ksyms.o tls.o subarch-obj-y = lib/csum-partial_64.o lib/memcpy_64.o lib/thunk_64.o \ - lib/rwsem_64.o + lib/rwsem.o subarch-obj-$(CONFIG_MODULES) += kernel/module.o ldt-y = ../sys-i386/ldt.o diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index d3ed1203cdd7..5d46ddcb69c5 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -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_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 @@ -30,7 +31,6 @@ ifeq ($(CONFIG_X86_32),y) lib-y += atomic64_cx8_32.o lib-y += checksum_32.o lib-y += strstr_32.o - lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += semaphore_32.o lib-y += string_32.o lib-y += cmpxchg.o ifneq ($(CONFIG_X86_CMPXCHG64),y) @@ -43,6 +43,5 @@ else lib-y += thunk_64.o clear_page_64.o copy_page_64.o lib-y += memmove_64.o memset_64.o lib-y += copy_user_64.o copy_user_nocache_64.o - lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem_64.o lib-y += cmpxchg16b_emu.o endif diff --git a/arch/x86/lib/rwsem_64.S b/arch/x86/lib/rwsem.S similarity index 55% rename from arch/x86/lib/rwsem_64.S rename to arch/x86/lib/rwsem.S index 67743977398b..5dff5f042468 100644 --- a/arch/x86/lib/rwsem_64.S +++ b/arch/x86/lib/rwsem.S @@ -1,3 +1,50 @@ +/* + * 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 + */ + +#include +#include +#include + +#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 * @@ -16,12 +63,6 @@ * but %rdi, %rsi, %rcx, %r8-r11 always need saving. */ -#include -#include -#include -#include -#include - #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 65b591d778b1..000000000000 --- a/arch/x86/lib/semaphore_32.S +++ /dev/null @@ -1,80 +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 - */ - -#include -#include -#include - -/* - * 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" - -/* 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) -- 2.20.1