From 40e784b4d4bc31dee5f1db6a20287777d3aaa4dc Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Tue, 1 Oct 2019 21:53:23 +0000 Subject: [PATCH] MIPS: atomic: Unify 32b & 64b sub_if_positive Unify the definitions of atomic_sub_if_positive() & atomic64_sub_if_positive() using a macro like we do for most other atomic functions. This allows us to share the implementation ensuring consistency between the two. Notably this provides the appropriate loongson3_war barriers in the atomic64_sub_if_positive() case which were previously missing. The code is rearranged a little to handle the !kernel_uses_llsc case first in order to de-indent the LL/SC case & allow us not to go over 80 characters per line. Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org Cc: Huacai Chen Cc: Jiaxun Yang Cc: linux-kernel@vger.kernel.org --- arch/mips/include/asm/atomic.h | 164 +++++++++++++++-------------------------- 1 file changed, 58 insertions(+), 106 deletions(-) diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h index 24443ef29337..96ef50fa2817 100644 --- a/arch/mips/include/asm/atomic.h +++ b/arch/mips/include/asm/atomic.h @@ -192,65 +192,71 @@ ATOMIC_OPS(atomic64, xor, s64, ^=, xor, lld, scd) * Atomically test @v and subtract @i if @v is greater or equal than @i. * The function returns the old value of @v minus @i. */ -static __inline__ int atomic_sub_if_positive(int i, atomic_t * v) -{ - int result; - - smp_mb__before_atomic(); - - if (kernel_uses_llsc) { - int temp; - - __asm__ __volatile__( - " .set push \n" - " .set "MIPS_ISA_LEVEL" \n" - " " __SYNC(full, loongson3_war) " \n" - "1: ll %1, %2 # atomic_sub_if_positive\n" - " .set pop \n" - " subu %0, %1, %3 \n" - " move %1, %0 \n" - " bltz %0, 2f \n" - " .set push \n" - " .set "MIPS_ISA_LEVEL" \n" - " sc %1, %2 \n" - "\t" __SC_BEQZ "%1, 1b \n" - "2: " __SYNC(full, loongson3_war) " \n" - " .set pop \n" - : "=&r" (result), "=&r" (temp), - "+" GCC_OFF_SMALL_ASM() (v->counter) - : "Ir" (i) : __LLSC_CLOBBER); - } else { - unsigned long flags; +#define ATOMIC_SIP_OP(pfx, type, op, ll, sc) \ +static __inline__ int pfx##_sub_if_positive(type i, pfx##_t * v) \ +{ \ + type temp, result; \ + \ + smp_mb__before_atomic(); \ + \ + if (!kernel_uses_llsc) { \ + unsigned long flags; \ + \ + raw_local_irq_save(flags); \ + result = v->counter; \ + result -= i; \ + if (result >= 0) \ + v->counter = result; \ + raw_local_irq_restore(flags); \ + smp_mb__after_atomic(); \ + return result; \ + } \ + \ + __asm__ __volatile__( \ + " .set push \n" \ + " .set " MIPS_ISA_LEVEL " \n" \ + " " __SYNC(full, loongson3_war) " \n" \ + "1: " #ll " %1, %2 # atomic_sub_if_positive\n" \ + " .set pop \n" \ + " " #op " %0, %1, %3 \n" \ + " move %1, %0 \n" \ + " bltz %0, 2f \n" \ + " .set push \n" \ + " .set " MIPS_ISA_LEVEL " \n" \ + " " #sc " %1, %2 \n" \ + " " __SC_BEQZ "%1, 1b \n" \ + "2: " __SYNC(full, loongson3_war) " \n" \ + " .set pop \n" \ + : "=&r" (result), "=&r" (temp), \ + "+" GCC_OFF_SMALL_ASM() (v->counter) \ + : "Ir" (i) \ + : __LLSC_CLOBBER); \ + \ + /* \ + * In the Loongson3 workaround case we already have a \ + * completion barrier at 2: above, which is needed due to the \ + * bltz that can branch to code outside of the LL/SC loop. As \ + * such, we don't need to emit another barrier here. \ + */ \ + if (!__SYNC_loongson3_war) \ + smp_mb__after_atomic(); \ + \ + return result; \ +} - raw_local_irq_save(flags); - result = v->counter; - result -= i; - if (result >= 0) - v->counter = result; - raw_local_irq_restore(flags); - } +ATOMIC_SIP_OP(atomic, int, subu, ll, sc) +#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v) - /* - * In the Loongson3 workaround case we already have a completion - * barrier at 2: above, which is needed due to the bltz that can branch - * to code outside of the LL/SC loop. As such, we don't need to emit - * another barrier here. - */ - if (!__SYNC_loongson3_war) - smp_mb__after_atomic(); +#ifdef CONFIG_64BIT +ATOMIC_SIP_OP(atomic64, s64, dsubu, lld, scd) +#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v) +#endif - return result; -} +#undef ATOMIC_SIP_OP #define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n))) #define atomic_xchg(v, new) (xchg(&((v)->counter), (new))) -/* - * atomic_dec_if_positive - decrement by 1 if old value positive - * @v: pointer of type atomic_t - */ -#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v) - #ifdef CONFIG_64BIT #define ATOMIC64_INIT(i) { (i) } @@ -269,64 +275,10 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v) */ #define atomic64_set(v, i) WRITE_ONCE((v)->counter, (i)) -/* - * atomic64_sub_if_positive - conditionally subtract integer from atomic - * variable - * @i: integer value to subtract - * @v: pointer of type atomic64_t - * - * Atomically test @v and subtract @i if @v is greater or equal than @i. - * The function returns the old value of @v minus @i. - */ -static __inline__ s64 atomic64_sub_if_positive(s64 i, atomic64_t * v) -{ - s64 result; - - smp_mb__before_llsc(); - - if (kernel_uses_llsc) { - s64 temp; - - __asm__ __volatile__( - " .set push \n" - " .set "MIPS_ISA_LEVEL" \n" - "1: lld %1, %2 # atomic64_sub_if_positive\n" - " dsubu %0, %1, %3 \n" - " move %1, %0 \n" - " bltz %0, 1f \n" - " scd %1, %2 \n" - "\t" __SC_BEQZ "%1, 1b \n" - "1: \n" - " .set pop \n" - : "=&r" (result), "=&r" (temp), - "+" GCC_OFF_SMALL_ASM() (v->counter) - : "Ir" (i)); - } else { - unsigned long flags; - - raw_local_irq_save(flags); - result = v->counter; - result -= i; - if (result >= 0) - v->counter = result; - raw_local_irq_restore(flags); - } - - smp_llsc_mb(); - - return result; -} - #define atomic64_cmpxchg(v, o, n) \ ((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n))) #define atomic64_xchg(v, new) (xchg(&((v)->counter), (new))) -/* - * atomic64_dec_if_positive - decrement by 1 if old value positive - * @v: pointer of type atomic64_t - */ -#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v) - #endif /* CONFIG_64BIT */ #endif /* _ASM_ATOMIC_H */ -- 2.11.0