leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

x86, bitops: remove use of "sbb" to return CF

Browse Source 
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 <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1465414726-197858-2-git-send-email-hpa@linux.intel.com
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
This commit is contained in:
H. Peter Anvin 2016-06-08 12:38:37 -07:00 committed by H. Peter Anvin
parent f5967101e9
commit 2823d4da5d
5 changed files with 31 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
arch/x86/include/asm/bitops.h
View File

@ -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) 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" asm("bts %2,%1\n\t"
"sbb %0,%0" "setc %0"
: "=r" (oldbit), ADDR : "=qm" (oldbit), ADDR
: "Ir" (nr)); : "Ir" (nr));
return oldbit; 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) 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" asm volatile("btr %2,%1\n\t"
"sbb %0,%0" "setc %0"
: "=r" (oldbit), ADDR : "=qm" (oldbit), ADDR
: "Ir" (nr)); : "Ir" (nr));
return oldbit; 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! */ /* WARNING: non atomic and it can be reordered! */
static __always_inline int __test_and_change_bit(long nr, volatile unsigned long *addr) 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" asm volatile("btc %2,%1\n\t"
"sbb %0,%0" "setc %0"
: "=r" (oldbit), ADDR : "=qm" (oldbit), ADDR
: "Ir" (nr) : "memory"); : "Ir" (nr) : "memory");
return oldbit; 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) 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" asm volatile("bt %2,%1\n\t"
"sbb %0,%0" "setc %0"
: "=r" (oldbit) : "=qm" (oldbit)
: "m" (*(unsigned long *)addr), "Ir" (nr)); : "m" (*(unsigned long *)addr), "Ir" (nr));
return oldbit; return oldbit;

12
arch/x86/include/asm/percpu.h
View File

@ -510,9 +510,9 @@ do { \
/* This is not atomic against other CPUs -- CPU preemption needs to be off */ /* This is not atomic against other CPUs -- CPU preemption needs to be off */
#define x86_test_and_clear_bit_percpu(bit, var) \ #define x86_test_and_clear_bit_percpu(bit, var) \
({ \ ({ \
int old__; \ unsigned char old__; \
asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0" \ asm volatile("btr %2,"__percpu_arg(1)"\n\tsetc %0" \
: "=r" (old__), "+m" (var) \ : "=qm" (old__), "+m" (var) \
: "dIr" (bit)); \ : "dIr" (bit)); \
old__; \ 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, static inline int x86_this_cpu_variable_test_bit(int nr,
const unsigned long __percpu *addr) const unsigned long __percpu *addr)
{ {
int oldbit; unsigned char oldbit;
asm volatile("bt "__percpu_arg(2)",%1\n\t" asm volatile("bt "__percpu_arg(2)",%1\n\t"
"sbb %0,%0" "setc %0"
: "=r" (oldbit) : "=qm" (oldbit)
: "m" (*(unsigned long *)addr), "Ir" (nr)); : "m" (*(unsigned long *)addr), "Ir" (nr));
return oldbit; return oldbit;

6
arch/x86/include/asm/signal.h
View File

@ -81,9 +81,9 @@ static inline int __const_sigismember(sigset_t *set, int _sig)
static inline int __gen_sigismember(sigset_t *set, int _sig) static inline int __gen_sigismember(sigset_t *set, int _sig)
{ {
int ret; unsigned char ret;
asm("btl %2,%1\n\tsbbl %0,%0" asm("btl %2,%1\n\tsetc %0"
: "=r"(ret) : "m"(*set), "Ir"(_sig-1) : "cc"); : "=qm"(ret) : "m"(*set), "Ir"(_sig-1) : "cc");
return ret; return ret;
} }

18
arch/x86/include/asm/sync_bitops.h
View File

@ -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) 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" asm volatile("lock; bts %2,%1\n\tsetc %0"
: "=r" (oldbit), "+m" (ADDR) : "=qm" (oldbit), "+m" (ADDR)
: "Ir" (nr) : "memory"); : "Ir" (nr) : "memory");
return oldbit; 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) 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" asm volatile("lock; btr %2,%1\n\tsetc %0"
: "=r" (oldbit), "+m" (ADDR) : "=qm" (oldbit), "+m" (ADDR)
: "Ir" (nr) : "memory"); : "Ir" (nr) : "memory");
return oldbit; 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) 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" asm volatile("lock; btc %2,%1\n\tsetc %0"
: "=r" (oldbit), "+m" (ADDR) : "=qm" (oldbit), "+m" (ADDR)
: "Ir" (nr) : "memory"); : "Ir" (nr) : "memory");
return oldbit; return oldbit;
} }

5
arch/x86/kernel/vm86_32.c
View File

@ -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) static inline int is_revectored(int nr, struct revectored_struct *bitmap)
{ {
__asm__ __volatile__("btl %2,%1\n\tsbbl %0,%0" return test_bit(nr, bitmap->__map);
:"=r" (nr)
:"m" (*bitmap), "r" (nr));
return nr;
} }
#define val_byte(val, n) (((__u8 *)&val)[n]) #define val_byte(val, n) (((__u8 *)&val)[n])