[PATCH v2 10/36] MIPS: atomic: Handle !kernel_uses_llsc first

From: Paul Burton
Date: Tue Oct 01 2019 - 17:53:28 EST


Handle the !kernel_uses_llsc path first in our ATOMIC_OP(),
ATOMIC_OP_RETURN() & ATOMIC_FETCH_OP() macros & return from within the
block. This allows us to de-indent the kernel_uses_llsc path by one
level which will be useful when making further changes.

Signed-off-by: Paul Burton <paul.burton@xxxxxxxx>
---

Changes in v2: None

arch/mips/include/asm/atomic.h | 99 +++++++++++++++++-----------------
1 file changed, 49 insertions(+), 50 deletions(-)

diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h
index 2d2a8a74c51b..ace2ea005588 100644
--- a/arch/mips/include/asm/atomic.h
+++ b/arch/mips/include/asm/atomic.h
@@ -45,51 +45,36 @@
#define ATOMIC_OP(op, c_op, asm_op) \
static __inline__ void atomic_##op(int i, atomic_t * v) \
{ \
- if (kernel_uses_llsc) { \
- int temp; \
+ int temp; \
\
- loongson_llsc_mb(); \
- __asm__ __volatile__( \
- " .set push \n" \
- " .set "MIPS_ISA_LEVEL" \n" \
- "1: ll %0, %1 # atomic_" #op " \n" \
- " " #asm_op " %0, %2 \n" \
- " sc %0, %1 \n" \
- "\t" __SC_BEQZ "%0, 1b \n" \
- " .set pop \n" \
- : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i) : __LLSC_CLOBBER); \
- } else { \
+ if (!kernel_uses_llsc) { \
unsigned long flags; \
\
raw_local_irq_save(flags); \
v->counter c_op i; \
raw_local_irq_restore(flags); \
+ return; \
} \
+ \
+ loongson_llsc_mb(); \
+ __asm__ __volatile__( \
+ " .set push \n" \
+ " .set " MIPS_ISA_LEVEL " \n" \
+ "1: ll %0, %1 # atomic_" #op " \n" \
+ " " #asm_op " %0, %2 \n" \
+ " sc %0, %1 \n" \
+ "\t" __SC_BEQZ "%0, 1b \n" \
+ " .set pop \n" \
+ : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
+ : "Ir" (i) : __LLSC_CLOBBER); \
}

#define ATOMIC_OP_RETURN(op, c_op, asm_op) \
static __inline__ int atomic_##op##_return_relaxed(int i, atomic_t * v) \
{ \
- int result; \
- \
- if (kernel_uses_llsc) { \
- int temp; \
+ int temp, result; \
\
- loongson_llsc_mb(); \
- __asm__ __volatile__( \
- " .set push \n" \
- " .set "MIPS_ISA_LEVEL" \n" \
- "1: ll %1, %2 # atomic_" #op "_return \n" \
- " " #asm_op " %0, %1, %3 \n" \
- " sc %0, %2 \n" \
- "\t" __SC_BEQZ "%0, 1b \n" \
- " " #asm_op " %0, %1, %3 \n" \
- " .set pop \n" \
- : "=&r" (result), "=&r" (temp), \
- "+" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i) : __LLSC_CLOBBER); \
- } else { \
+ if (!kernel_uses_llsc) { \
unsigned long flags; \
\
raw_local_irq_save(flags); \
@@ -97,41 +82,55 @@ static __inline__ int atomic_##op##_return_relaxed(int i, atomic_t * v) \
result c_op i; \
v->counter = result; \
raw_local_irq_restore(flags); \
+ return result; \
} \
\
+ loongson_llsc_mb(); \
+ __asm__ __volatile__( \
+ " .set push \n" \
+ " .set " MIPS_ISA_LEVEL " \n" \
+ "1: ll %1, %2 # atomic_" #op "_return \n" \
+ " " #asm_op " %0, %1, %3 \n" \
+ " sc %0, %2 \n" \
+ "\t" __SC_BEQZ "%0, 1b \n" \
+ " " #asm_op " %0, %1, %3 \n" \
+ " .set pop \n" \
+ : "=&r" (result), "=&r" (temp), \
+ "+" GCC_OFF_SMALL_ASM() (v->counter) \
+ : "Ir" (i) : __LLSC_CLOBBER); \
+ \
return result; \
}

#define ATOMIC_FETCH_OP(op, c_op, asm_op) \
static __inline__ int atomic_fetch_##op##_relaxed(int i, atomic_t * v) \
{ \
- int result; \
+ int temp, result; \
\
- if (kernel_uses_llsc) { \
- int temp; \
- \
- loongson_llsc_mb(); \
- __asm__ __volatile__( \
- " .set push \n" \
- " .set "MIPS_ISA_LEVEL" \n" \
- "1: ll %1, %2 # atomic_fetch_" #op " \n" \
- " " #asm_op " %0, %1, %3 \n" \
- " sc %0, %2 \n" \
- "\t" __SC_BEQZ "%0, 1b \n" \
- " .set pop \n" \
- " move %0, %1 \n" \
- : "=&r" (result), "=&r" (temp), \
- "+" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i) : __LLSC_CLOBBER); \
- } else { \
+ if (!kernel_uses_llsc) { \
unsigned long flags; \
\
raw_local_irq_save(flags); \
result = v->counter; \
v->counter c_op i; \
raw_local_irq_restore(flags); \
+ return result; \
} \
\
+ loongson_llsc_mb(); \
+ __asm__ __volatile__( \
+ " .set push \n" \
+ " .set "MIPS_ISA_LEVEL" \n" \
+ "1: ll %1, %2 # atomic_fetch_" #op " \n" \
+ " " #asm_op " %0, %1, %3 \n" \
+ " sc %0, %2 \n" \
+ "\t" __SC_BEQZ "%0, 1b \n" \
+ " .set pop \n" \
+ " move %0, %1 \n" \
+ : "=&r" (result), "=&r" (temp), \
+ "+" GCC_OFF_SMALL_ASM() (v->counter) \
+ : "Ir" (i) : __LLSC_CLOBBER); \
+ \
return result; \
}

--
2.23.0