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| author | Eric Chan <ericchancf@google.com> | 2024-02-17 13:13:02 +0000 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-03-19 18:52:23 -0700 |
| commit | b3c8064ccc447be45a3bdc2c4a9ea0491f011920 (patch) | |
| tree | 1b3c8d45dbac207efd5bde0a529fe1a41410539b | |
| parent | 89f4fd7b1ab7733d9d817e7123c58996ca38ae98 (diff) | |
| download | linux-b3c8064ccc447be45a3bdc2c4a9ea0491f011920.tar.gz linux-b3c8064ccc447be45a3bdc2c4a9ea0491f011920.tar.bz2 linux-b3c8064ccc447be45a3bdc2c4a9ea0491f011920.zip | |
riscv/barrier: Define RISCV_FULL_BARRIER
Introduce RISCV_FULL_BARRIER and use in arch_atomic* function.
like RISCV_ACQUIRE_BARRIER and RISCV_RELEASE_BARRIER, the fence
instruction can be eliminated When SMP is not enabled.
Signed-off-by: Eric Chan <ericchancf@google.com>
Reviewed-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20240217131302.3668481-1-ericchancf@google.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| -rw-r--r-- | arch/riscv/include/asm/atomic.h | 16 | ||||
| -rw-r--r-- | arch/riscv/include/asm/cmpxchg.h | 4 | ||||
| -rw-r--r-- | arch/riscv/include/asm/fence.h | 2 |
3 files changed, 12 insertions, 10 deletions
diff --git a/arch/riscv/include/asm/atomic.h b/arch/riscv/include/asm/atomic.h index f5dfef6c2153..31e6e2e7cc18 100644 --- a/arch/riscv/include/asm/atomic.h +++ b/arch/riscv/include/asm/atomic.h @@ -207,7 +207,7 @@ static __always_inline int arch_atomic_fetch_add_unless(atomic_t *v, int a, int " add %[rc], %[p], %[a]\n" " sc.w.rl %[rc], %[rc], %[c]\n" " bnez %[rc], 0b\n" - " fence rw, rw\n" + RISCV_FULL_BARRIER "1:\n" : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) : [a]"r" (a), [u]"r" (u) @@ -228,7 +228,7 @@ static __always_inline s64 arch_atomic64_fetch_add_unless(atomic64_t *v, s64 a, " add %[rc], %[p], %[a]\n" " sc.d.rl %[rc], %[rc], %[c]\n" " bnez %[rc], 0b\n" - " fence rw, rw\n" + RISCV_FULL_BARRIER "1:\n" : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) : [a]"r" (a), [u]"r" (u) @@ -248,7 +248,7 @@ static __always_inline bool arch_atomic_inc_unless_negative(atomic_t *v) " addi %[rc], %[p], 1\n" " sc.w.rl %[rc], %[rc], %[c]\n" " bnez %[rc], 0b\n" - " fence rw, rw\n" + RISCV_FULL_BARRIER "1:\n" : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) : @@ -268,7 +268,7 @@ static __always_inline bool arch_atomic_dec_unless_positive(atomic_t *v) " addi %[rc], %[p], -1\n" " sc.w.rl %[rc], %[rc], %[c]\n" " bnez %[rc], 0b\n" - " fence rw, rw\n" + RISCV_FULL_BARRIER "1:\n" : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) : @@ -288,7 +288,7 @@ static __always_inline int arch_atomic_dec_if_positive(atomic_t *v) " bltz %[rc], 1f\n" " sc.w.rl %[rc], %[rc], %[c]\n" " bnez %[rc], 0b\n" - " fence rw, rw\n" + RISCV_FULL_BARRIER "1:\n" : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) : @@ -310,7 +310,7 @@ static __always_inline bool arch_atomic64_inc_unless_negative(atomic64_t *v) " addi %[rc], %[p], 1\n" " sc.d.rl %[rc], %[rc], %[c]\n" " bnez %[rc], 0b\n" - " fence rw, rw\n" + RISCV_FULL_BARRIER "1:\n" : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) : @@ -331,7 +331,7 @@ static __always_inline bool arch_atomic64_dec_unless_positive(atomic64_t *v) " addi %[rc], %[p], -1\n" " sc.d.rl %[rc], %[rc], %[c]\n" " bnez %[rc], 0b\n" - " fence rw, rw\n" + RISCV_FULL_BARRIER "1:\n" : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) : @@ -352,7 +352,7 @@ static __always_inline s64 arch_atomic64_dec_if_positive(atomic64_t *v) " bltz %[rc], 1f\n" " sc.d.rl %[rc], %[rc], %[c]\n" " bnez %[rc], 0b\n" - " fence rw, rw\n" + RISCV_FULL_BARRIER "1:\n" : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter) : diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h index 2f4726d3cfcc..a608e4d1a0a4 100644 --- a/arch/riscv/include/asm/cmpxchg.h +++ b/arch/riscv/include/asm/cmpxchg.h @@ -313,7 +313,7 @@ " bne %0, %z3, 1f\n" \ " sc.w.rl %1, %z4, %2\n" \ " bnez %1, 0b\n" \ - " fence rw, rw\n" \ + RISCV_FULL_BARRIER \ "1:\n" \ : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \ : "rJ" ((long)__old), "rJ" (__new) \ @@ -325,7 +325,7 @@ " bne %0, %z3, 1f\n" \ " sc.d.rl %1, %z4, %2\n" \ " bnez %1, 0b\n" \ - " fence rw, rw\n" \ + RISCV_FULL_BARRIER \ "1:\n" \ : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \ : "rJ" (__old), "rJ" (__new) \ diff --git a/arch/riscv/include/asm/fence.h b/arch/riscv/include/asm/fence.h index 2b443a3a487f..6c26c44dfcd6 100644 --- a/arch/riscv/include/asm/fence.h +++ b/arch/riscv/include/asm/fence.h @@ -4,9 +4,11 @@ #ifdef CONFIG_SMP #define RISCV_ACQUIRE_BARRIER "\tfence r , rw\n" #define RISCV_RELEASE_BARRIER "\tfence rw, w\n" +#define RISCV_FULL_BARRIER "\tfence rw, rw\n" #else #define RISCV_ACQUIRE_BARRIER #define RISCV_RELEASE_BARRIER +#define RISCV_FULL_BARRIER #endif #endif /* _ASM_RISCV_FENCE_H */ |