From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423851AbcFHTi5 (ORCPT ); Wed, 8 Jun 2016 15:38:57 -0400 Received: from mga01.intel.com ([192.55.52.88]:46767 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161980AbcFHTi4 (ORCPT ); Wed, 8 Jun 2016 15:38:56 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,440,1459839600"; d="scan'208";a="998050605" From: "H. Peter Anvin" To: Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Linux Kernel Mailing List Cc: Andy Lutomirski , Borislav Petkov Subject: [PATCH v2 01/10] x86, bitops: remove use of "sbb" to return CF Date: Wed, 8 Jun 2016 12:38:37 -0700 Message-Id: <1465414726-197858-2-git-send-email-hpa@linux.intel.com> X-Mailer: git-send-email 2.7.3.0.11.gd79db92 In-Reply-To: <1465414726-197858-1-git-send-email-hpa@linux.intel.com> References: <1465414726-197858-1-git-send-email-hpa@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "H. Peter Anvin" Use SETC instead of SBB to return the value of CF from assembly. Using SETcc enables uniformity with other flags-returning pieces of assembly code. Signed-off-by: H. Peter Anvin Reviewed-by: Andy Lutomirski Reviewed-by: Borislav Petkov Acked-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/bitops.h | 24 ++++++++++++------------ arch/x86/include/asm/percpu.h | 12 ++++++------ arch/x86/include/asm/signal.h | 6 +++--- arch/x86/include/asm/sync_bitops.h | 18 +++++++++--------- arch/x86/kernel/vm86_32.c | 5 +---- 5 files changed, 31 insertions(+), 34 deletions(-) diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h index 7766d1c..b2b797d 100644 --- a/arch/x86/include/asm/bitops.h +++ b/arch/x86/include/asm/bitops.h @@ -230,11 +230,11 @@ test_and_set_bit_lock(long nr, volatile unsigned long *addr) */ static __always_inline int __test_and_set_bit(long nr, volatile unsigned long *addr) { - int oldbit; + unsigned char oldbit; asm("bts %2,%1\n\t" - "sbb %0,%0" - : "=r" (oldbit), ADDR + "setc %0" + : "=qm" (oldbit), ADDR : "Ir" (nr)); return oldbit; } @@ -270,11 +270,11 @@ static __always_inline int test_and_clear_bit(long nr, volatile unsigned long *a */ static __always_inline int __test_and_clear_bit(long nr, volatile unsigned long *addr) { - int oldbit; + unsigned char oldbit; asm volatile("btr %2,%1\n\t" - "sbb %0,%0" - : "=r" (oldbit), ADDR + "setc %0" + : "=qm" (oldbit), ADDR : "Ir" (nr)); return oldbit; } @@ -282,11 +282,11 @@ static __always_inline int __test_and_clear_bit(long nr, volatile unsigned long /* WARNING: non atomic and it can be reordered! */ static __always_inline int __test_and_change_bit(long nr, volatile unsigned long *addr) { - int oldbit; + unsigned char oldbit; asm volatile("btc %2,%1\n\t" - "sbb %0,%0" - : "=r" (oldbit), ADDR + "setc %0" + : "=qm" (oldbit), ADDR : "Ir" (nr) : "memory"); return oldbit; @@ -313,11 +313,11 @@ static __always_inline int constant_test_bit(long nr, const volatile unsigned lo static __always_inline int variable_test_bit(long nr, volatile const unsigned long *addr) { - int oldbit; + unsigned char oldbit; asm volatile("bt %2,%1\n\t" - "sbb %0,%0" - : "=r" (oldbit) + "setc %0" + : "=qm" (oldbit) : "m" (*(unsigned long *)addr), "Ir" (nr)); return oldbit; diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index e0ba66c..65039e9 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -510,9 +510,9 @@ do { \ /* This is not atomic against other CPUs -- CPU preemption needs to be off */ #define x86_test_and_clear_bit_percpu(bit, var) \ ({ \ - int old__; \ - asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0" \ - : "=r" (old__), "+m" (var) \ + unsigned char old__; \ + asm volatile("btr %2,"__percpu_arg(1)"\n\tsetc %0" \ + : "=qm" (old__), "+m" (var) \ : "dIr" (bit)); \ old__; \ }) @@ -532,11 +532,11 @@ static __always_inline int x86_this_cpu_constant_test_bit(unsigned int nr, static inline int x86_this_cpu_variable_test_bit(int nr, const unsigned long __percpu *addr) { - int oldbit; + unsigned char oldbit; asm volatile("bt "__percpu_arg(2)",%1\n\t" - "sbb %0,%0" - : "=r" (oldbit) + "setc %0" + : "=qm" (oldbit) : "m" (*(unsigned long *)addr), "Ir" (nr)); return oldbit; diff --git a/arch/x86/include/asm/signal.h b/arch/x86/include/asm/signal.h index 2138c9a..dd1e7d6 100644 --- a/arch/x86/include/asm/signal.h +++ b/arch/x86/include/asm/signal.h @@ -81,9 +81,9 @@ static inline int __const_sigismember(sigset_t *set, int _sig) static inline int __gen_sigismember(sigset_t *set, int _sig) { - int ret; - asm("btl %2,%1\n\tsbbl %0,%0" - : "=r"(ret) : "m"(*set), "Ir"(_sig-1) : "cc"); + unsigned char ret; + asm("btl %2,%1\n\tsetc %0" + : "=qm"(ret) : "m"(*set), "Ir"(_sig-1) : "cc"); return ret; } diff --git a/arch/x86/include/asm/sync_bitops.h b/arch/x86/include/asm/sync_bitops.h index f28a24b..cbf8847 100644 --- a/arch/x86/include/asm/sync_bitops.h +++ b/arch/x86/include/asm/sync_bitops.h @@ -79,10 +79,10 @@ static inline void sync_change_bit(long nr, volatile unsigned long *addr) */ static inline int sync_test_and_set_bit(long nr, volatile unsigned long *addr) { - int oldbit; + unsigned char oldbit; - asm volatile("lock; bts %2,%1\n\tsbbl %0,%0" - : "=r" (oldbit), "+m" (ADDR) + asm volatile("lock; bts %2,%1\n\tsetc %0" + : "=qm" (oldbit), "+m" (ADDR) : "Ir" (nr) : "memory"); return oldbit; } @@ -97,10 +97,10 @@ static inline int sync_test_and_set_bit(long nr, volatile unsigned long *addr) */ static inline int sync_test_and_clear_bit(long nr, volatile unsigned long *addr) { - int oldbit; + unsigned char oldbit; - asm volatile("lock; btr %2,%1\n\tsbbl %0,%0" - : "=r" (oldbit), "+m" (ADDR) + asm volatile("lock; btr %2,%1\n\tsetc %0" + : "=qm" (oldbit), "+m" (ADDR) : "Ir" (nr) : "memory"); return oldbit; } @@ -115,10 +115,10 @@ static inline int sync_test_and_clear_bit(long nr, volatile unsigned long *addr) */ static inline int sync_test_and_change_bit(long nr, volatile unsigned long *addr) { - int oldbit; + unsigned char oldbit; - asm volatile("lock; btc %2,%1\n\tsbbl %0,%0" - : "=r" (oldbit), "+m" (ADDR) + asm volatile("lock; btc %2,%1\n\tsetc %0" + : "=qm" (oldbit), "+m" (ADDR) : "Ir" (nr) : "memory"); return oldbit; } diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c index 3dce1ca..01f30e5 100644 --- a/arch/x86/kernel/vm86_32.c +++ b/arch/x86/kernel/vm86_32.c @@ -440,10 +440,7 @@ static inline unsigned long get_vflags(struct kernel_vm86_regs *regs) static inline int is_revectored(int nr, struct revectored_struct *bitmap) { - __asm__ __volatile__("btl %2,%1\n\tsbbl %0,%0" - :"=r" (nr) - :"m" (*bitmap), "r" (nr)); - return nr; + return test_bit(nr, bitmap->__map); } #define val_byte(val, n) (((__u8 *)&val)[n]) -- 2.7.3.0.11.gd79db92