xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

atomics/treewide: Make test ops optional

Browse Source 
Some of the atomics return the result of a test applied after the atomic
operation, and almost all architectures implement these as trivial
wrappers around the underlying atomic. Specifically:

 * <atomic>_inc_and_test(v)    is (<atomic>_inc_return(v)    == 0)
 * <atomic>_dec_and_test(v)    is (<atomic>_dec_return(v)    == 0)
 * <atomic>_sub_and_test(i, v) is (<atomic>_sub_return(i, v) == 0)
 * <atomic>_add_negative(i, v) is (<atomic>_add_return(i, v)  < 0)

Rather than have these definitions duplicated in all architectures, with
minor inconsistencies in formatting and documentation, let's make these
operations optional, with default fallbacks as above. Implementations
must now provide a preprocessor symbol.

The instrumented atomics are updated accordingly.

Both x86 and m68k have custom implementations, which are left as-is,
given preprocessor symbols to avoid being overridden.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-16-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Mark Rutland
2018-06-21 13:13:18 +01:00
committed by Ingo Molnar
parent 356701329f
commit 18cc1814d4
24 changed files with 160 additions and 410 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
arch/x86/include/asm/atomic.h
View File

@@ -80,6 +80,7 @@ static __always_inline void arch_atomic_sub(int i, atomic_t *v)
* true if the result is zero, or false for all
* other cases.
*/
#define arch_atomic_sub_and_test arch_atomic_sub_and_test
static __always_inline bool arch_atomic_sub_and_test(int i, atomic_t *v)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, "er", i, "%0", e);
@@ -117,6 +118,7 @@ static __always_inline void arch_atomic_dec(atomic_t *v)
* returns true if the result is 0, or false for all other
* cases.
*/
#define arch_atomic_dec_and_test arch_atomic_dec_and_test
static __always_inline bool arch_atomic_dec_and_test(atomic_t *v)
{
GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, "%0", e);
@@ -130,6 +132,7 @@ static __always_inline bool arch_atomic_dec_and_test(atomic_t *v)
* and returns true if the result is zero, or false for all
* other cases.
*/
#define arch_atomic_inc_and_test arch_atomic_inc_and_test
static __always_inline bool arch_atomic_inc_and_test(atomic_t *v)
{
GEN_UNARY_RMWcc(LOCK_PREFIX "incl", v->counter, "%0", e);
@@ -144,6 +147,7 @@ static __always_inline bool arch_atomic_inc_and_test(atomic_t *v)
* if the result is negative, or false when
* result is greater than or equal to zero.
*/
#define arch_atomic_add_negative arch_atomic_add_negative
static __always_inline bool arch_atomic_add_negative(int i, atomic_t *v)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, "er", i, "%0", s);