From: Ralf Baechle Date: Fri, 29 Oct 2010 18:08:24 +0000 (+0100) Subject: MIPS: Get rid of branches to .subsections. X-Git-Tag: upstream/snapshot3+hdmi~12580^2~45 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7837314d141c661c70bc13c5050694413ecfe14a;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git MIPS: Get rid of branches to .subsections. It was a nice optimization - on paper at least. In practice it results in branches that may exceed the maximum legal range for a branch. We can fight that problem with -ffunction-sections but -ffunction-sections again is incompatible with -pg used by the function tracer. By rewriting the loop around all simple LL/SC blocks to C we reduce the amount of inline assembler and at the same time allow GCC to often fill the branch delay slots with something sensible or whatever else clever optimization it may have up in its sleeve. With this optimization gone we also no longer need -ffunction-sections, so drop it. This optimization was originally introduced in 2.6.21, commit 5999eca25c1fd4b9b9aca7833b04d10fe4bc877d (linux-mips.org) rsp. f65e4fa8e0c6022ad58dc88d1b11b12589ed7f9f (kernel.org). Original fix for the issues which caused me to pull this optimization by Paul Gortmaker . Signed-off-by: Ralf Baechle --- diff --git a/arch/mips/Makefile b/arch/mips/Makefile index f4a4b66..1a81240 100644 --- a/arch/mips/Makefile +++ b/arch/mips/Makefile @@ -48,9 +48,6 @@ ifneq ($(SUBARCH),$(ARCH)) endif endif -ifndef CONFIG_FUNCTION_TRACER -cflags-y := -ffunction-sections -endif ifdef CONFIG_FUNCTION_GRAPH_TRACER ifndef KBUILD_MCOUNT_RA_ADDRESS ifeq ($(call cc-option-yn,-mmcount-ra-address), y) diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h index 47d87da..4a02fe8 100644 --- a/arch/mips/include/asm/atomic.h +++ b/arch/mips/include/asm/atomic.h @@ -64,18 +64,16 @@ static __inline__ void atomic_add(int i, atomic_t * v) } else if (kernel_uses_llsc) { int temp; - __asm__ __volatile__( - " .set mips3 \n" - "1: ll %0, %1 # atomic_add \n" - " addu %0, %2 \n" - " sc %0, %1 \n" - " beqz %0, 2f \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - " .set mips0 \n" - : "=&r" (temp), "=m" (v->counter) - : "Ir" (i), "m" (v->counter)); + do { + __asm__ __volatile__( + " .set mips3 \n" + " ll %0, %1 # atomic_add \n" + " addu %0, %2 \n" + " sc %0, %1 \n" + " .set mips0 \n" + : "=&r" (temp), "=m" (v->counter) + : "Ir" (i), "m" (v->counter)); + } while (unlikely(!temp)); } else { unsigned long flags; @@ -109,18 +107,16 @@ static __inline__ void atomic_sub(int i, atomic_t * v) } else if (kernel_uses_llsc) { int temp; - __asm__ __volatile__( - " .set mips3 \n" - "1: ll %0, %1 # atomic_sub \n" - " subu %0, %2 \n" - " sc %0, %1 \n" - " beqz %0, 2f \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - " .set mips0 \n" - : "=&r" (temp), "=m" (v->counter) - : "Ir" (i), "m" (v->counter)); + do { + __asm__ __volatile__( + " .set mips3 \n" + " ll %0, %1 # atomic_sub \n" + " subu %0, %2 \n" + " sc %0, %1 \n" + " .set mips0 \n" + : "=&r" (temp), "=m" (v->counter) + : "Ir" (i), "m" (v->counter)); + } while (unlikely(!temp)); } else { unsigned long flags; @@ -156,20 +152,19 @@ static __inline__ int atomic_add_return(int i, atomic_t * v) } else if (kernel_uses_llsc) { int temp; - __asm__ __volatile__( - " .set mips3 \n" - "1: ll %1, %2 # atomic_add_return \n" - " addu %0, %1, %3 \n" - " sc %0, %2 \n" - " beqz %0, 2f \n" - " addu %0, %1, %3 \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - " .set mips0 \n" - : "=&r" (result), "=&r" (temp), "=m" (v->counter) - : "Ir" (i), "m" (v->counter) - : "memory"); + do { + __asm__ __volatile__( + " .set mips3 \n" + " ll %1, %2 # atomic_add_return \n" + " addu %0, %1, %3 \n" + " sc %0, %2 \n" + " .set mips0 \n" + : "=&r" (result), "=&r" (temp), "=m" (v->counter) + : "Ir" (i), "m" (v->counter) + : "memory"); + } while (unlikely(!result)); + + result = temp + i; } else { unsigned long flags; @@ -205,23 +200,24 @@ static __inline__ int atomic_sub_return(int i, atomic_t * v) : "=&r" (result), "=&r" (temp), "=m" (v->counter) : "Ir" (i), "m" (v->counter) : "memory"); + + result = temp - i; } else if (kernel_uses_llsc) { int temp; - __asm__ __volatile__( - " .set mips3 \n" - "1: ll %1, %2 # atomic_sub_return \n" - " subu %0, %1, %3 \n" - " sc %0, %2 \n" - " beqz %0, 2f \n" - " subu %0, %1, %3 \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - " .set mips0 \n" - : "=&r" (result), "=&r" (temp), "=m" (v->counter) - : "Ir" (i), "m" (v->counter) - : "memory"); + do { + __asm__ __volatile__( + " .set mips3 \n" + " ll %1, %2 # atomic_sub_return \n" + " subu %0, %1, %3 \n" + " sc %0, %2 \n" + " .set mips0 \n" + : "=&r" (result), "=&r" (temp), "=m" (v->counter) + : "Ir" (i), "m" (v->counter) + : "memory"); + } while (unlikely(!result)); + + result = temp - i; } else { unsigned long flags; @@ -279,12 +275,9 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v) " bltz %0, 1f \n" " sc %0, %2 \n" " .set noreorder \n" - " beqz %0, 2f \n" + " beqz %0, 1b \n" " subu %0, %1, %3 \n" " .set reorder \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" "1: \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), "=m" (v->counter) @@ -443,18 +436,16 @@ static __inline__ void atomic64_add(long i, atomic64_t * v) } else if (kernel_uses_llsc) { long temp; - __asm__ __volatile__( - " .set mips3 \n" - "1: lld %0, %1 # atomic64_add \n" - " daddu %0, %2 \n" - " scd %0, %1 \n" - " beqz %0, 2f \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - " .set mips0 \n" - : "=&r" (temp), "=m" (v->counter) - : "Ir" (i), "m" (v->counter)); + do { + __asm__ __volatile__( + " .set mips3 \n" + " lld %0, %1 # atomic64_add \n" + " daddu %0, %2 \n" + " scd %0, %1 \n" + " .set mips0 \n" + : "=&r" (temp), "=m" (v->counter) + : "Ir" (i), "m" (v->counter)); + } while (unlikely(!temp)); } else { unsigned long flags; @@ -488,18 +479,16 @@ static __inline__ void atomic64_sub(long i, atomic64_t * v) } else if (kernel_uses_llsc) { long temp; - __asm__ __volatile__( - " .set mips3 \n" - "1: lld %0, %1 # atomic64_sub \n" - " dsubu %0, %2 \n" - " scd %0, %1 \n" - " beqz %0, 2f \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - " .set mips0 \n" - : "=&r" (temp), "=m" (v->counter) - : "Ir" (i), "m" (v->counter)); + do { + __asm__ __volatile__( + " .set mips3 \n" + " lld %0, %1 # atomic64_sub \n" + " dsubu %0, %2 \n" + " scd %0, %1 \n" + " .set mips0 \n" + : "=&r" (temp), "=m" (v->counter) + : "Ir" (i), "m" (v->counter)); + } while (unlikely(!temp)); } else { unsigned long flags; @@ -535,20 +524,19 @@ static __inline__ long atomic64_add_return(long i, atomic64_t * v) } else if (kernel_uses_llsc) { long temp; - __asm__ __volatile__( - " .set mips3 \n" - "1: lld %1, %2 # atomic64_add_return \n" - " daddu %0, %1, %3 \n" - " scd %0, %2 \n" - " beqz %0, 2f \n" - " daddu %0, %1, %3 \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - " .set mips0 \n" - : "=&r" (result), "=&r" (temp), "=m" (v->counter) - : "Ir" (i), "m" (v->counter) - : "memory"); + do { + __asm__ __volatile__( + " .set mips3 \n" + " lld %1, %2 # atomic64_add_return \n" + " daddu %0, %1, %3 \n" + " scd %0, %2 \n" + " .set mips0 \n" + : "=&r" (result), "=&r" (temp), "=m" (v->counter) + : "Ir" (i), "m" (v->counter) + : "memory"); + } while (unlikely(!result)); + + result = temp + i; } else { unsigned long flags; @@ -587,20 +575,19 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t * v) } else if (kernel_uses_llsc) { long temp; - __asm__ __volatile__( - " .set mips3 \n" - "1: lld %1, %2 # atomic64_sub_return \n" - " dsubu %0, %1, %3 \n" - " scd %0, %2 \n" - " beqz %0, 2f \n" - " dsubu %0, %1, %3 \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - " .set mips0 \n" - : "=&r" (result), "=&r" (temp), "=m" (v->counter) - : "Ir" (i), "m" (v->counter) - : "memory"); + do { + __asm__ __volatile__( + " .set mips3 \n" + " lld %1, %2 # atomic64_sub_return \n" + " dsubu %0, %1, %3 \n" + " scd %0, %2 \n" + " .set mips0 \n" + : "=&r" (result), "=&r" (temp), "=m" (v->counter) + : "Ir" (i), "m" (v->counter) + : "memory"); + } while (unlikely(!result)); + + result = temp - i; } else { unsigned long flags; @@ -658,12 +645,9 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v) " bltz %0, 1f \n" " scd %0, %2 \n" " .set noreorder \n" - " beqz %0, 2f \n" + " beqz %0, 1b \n" " dsubu %0, %1, %3 \n" " .set reorder \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" "1: \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), "=m" (v->counter) diff --git a/arch/mips/include/asm/bitops.h b/arch/mips/include/asm/bitops.h index b0ce7ca..50b4ef2 100644 --- a/arch/mips/include/asm/bitops.h +++ b/arch/mips/include/asm/bitops.h @@ -73,30 +73,26 @@ static inline void set_bit(unsigned long nr, volatile unsigned long *addr) : "ir" (1UL << bit), "m" (*m)); #ifdef CONFIG_CPU_MIPSR2 } else if (kernel_uses_llsc && __builtin_constant_p(bit)) { - __asm__ __volatile__( - "1: " __LL "%0, %1 # set_bit \n" - " " __INS "%0, %4, %2, 1 \n" - " " __SC "%0, %1 \n" - " beqz %0, 2f \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - : "=&r" (temp), "=m" (*m) - : "ir" (bit), "m" (*m), "r" (~0)); + do { + __asm__ __volatile__( + " " __LL "%0, %1 # set_bit \n" + " " __INS "%0, %3, %2, 1 \n" + " " __SC "%0, %1 \n" + : "=&r" (temp), "+m" (*m) + : "ir" (bit), "r" (~0)); + } while (unlikely(!temp)); #endif /* CONFIG_CPU_MIPSR2 */ } else if (kernel_uses_llsc) { - __asm__ __volatile__( - " .set mips3 \n" - "1: " __LL "%0, %1 # set_bit \n" - " or %0, %2 \n" - " " __SC "%0, %1 \n" - " beqz %0, 2f \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - " .set mips0 \n" - : "=&r" (temp), "=m" (*m) - : "ir" (1UL << bit), "m" (*m)); + do { + __asm__ __volatile__( + " .set mips3 \n" + " " __LL "%0, %1 # set_bit \n" + " or %0, %2 \n" + " " __SC "%0, %1 \n" + " .set mips0 \n" + : "=&r" (temp), "+m" (*m) + : "ir" (1UL << bit)); + } while (unlikely(!temp)); } else { volatile unsigned long *a = addr; unsigned long mask; @@ -134,34 +130,30 @@ static inline void clear_bit(unsigned long nr, volatile unsigned long *addr) " " __SC "%0, %1 \n" " beqzl %0, 1b \n" " .set mips0 \n" - : "=&r" (temp), "=m" (*m) - : "ir" (~(1UL << bit)), "m" (*m)); + : "=&r" (temp), "+m" (*m) + : "ir" (~(1UL << bit))); #ifdef CONFIG_CPU_MIPSR2 } else if (kernel_uses_llsc && __builtin_constant_p(bit)) { - __asm__ __volatile__( - "1: " __LL "%0, %1 # clear_bit \n" - " " __INS "%0, $0, %2, 1 \n" - " " __SC "%0, %1 \n" - " beqz %0, 2f \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - : "=&r" (temp), "=m" (*m) - : "ir" (bit), "m" (*m)); + do { + __asm__ __volatile__( + " " __LL "%0, %1 # clear_bit \n" + " " __INS "%0, $0, %2, 1 \n" + " " __SC "%0, %1 \n" + : "=&r" (temp), "+m" (*m) + : "ir" (bit)); + } while (unlikely(!temp)); #endif /* CONFIG_CPU_MIPSR2 */ } else if (kernel_uses_llsc) { - __asm__ __volatile__( - " .set mips3 \n" - "1: " __LL "%0, %1 # clear_bit \n" - " and %0, %2 \n" - " " __SC "%0, %1 \n" - " beqz %0, 2f \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - " .set mips0 \n" - : "=&r" (temp), "=m" (*m) - : "ir" (~(1UL << bit)), "m" (*m)); + do { + __asm__ __volatile__( + " .set mips3 \n" + " " __LL "%0, %1 # clear_bit \n" + " and %0, %2 \n" + " " __SC "%0, %1 \n" + " .set mips0 \n" + : "=&r" (temp), "+m" (*m) + : "ir" (~(1UL << bit))); + } while (unlikely(!temp)); } else { volatile unsigned long *a = addr; unsigned long mask; @@ -213,24 +205,22 @@ static inline void change_bit(unsigned long nr, volatile unsigned long *addr) " " __SC "%0, %1 \n" " beqzl %0, 1b \n" " .set mips0 \n" - : "=&r" (temp), "=m" (*m) - : "ir" (1UL << bit), "m" (*m)); + : "=&r" (temp), "+m" (*m) + : "ir" (1UL << bit)); } else if (kernel_uses_llsc) { unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG); unsigned long temp; - __asm__ __volatile__( - " .set mips3 \n" - "1: " __LL "%0, %1 # change_bit \n" - " xor %0, %2 \n" - " " __SC "%0, %1 \n" - " beqz %0, 2f \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - " .set mips0 \n" - : "=&r" (temp), "=m" (*m) - : "ir" (1UL << bit), "m" (*m)); + do { + __asm__ __volatile__( + " .set mips3 \n" + " " __LL "%0, %1 # change_bit \n" + " xor %0, %2 \n" + " " __SC "%0, %1 \n" + " .set mips0 \n" + : "=&r" (temp), "+m" (*m) + : "ir" (1UL << bit)); + } while (unlikely(!temp)); } else { volatile unsigned long *a = addr; unsigned long mask; @@ -272,30 +262,26 @@ static inline int test_and_set_bit(unsigned long nr, " beqzl %2, 1b \n" " and %2, %0, %3 \n" " .set mips0 \n" - : "=&r" (temp), "=m" (*m), "=&r" (res) - : "r" (1UL << bit), "m" (*m) + : "=&r" (temp), "+m" (*m), "=&r" (res) + : "r" (1UL << bit) : "memory"); } else if (kernel_uses_llsc) { unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG); unsigned long temp; - __asm__ __volatile__( - " .set push \n" - " .set noreorder \n" - " .set mips3 \n" - "1: " __LL "%0, %1 # test_and_set_bit \n" - " or %2, %0, %3 \n" - " " __SC "%2, %1 \n" - " beqz %2, 2f \n" - " and %2, %0, %3 \n" - " .subsection 2 \n" - "2: b 1b \n" - " nop \n" - " .previous \n" - " .set pop \n" - : "=&r" (temp), "=m" (*m), "=&r" (res) - : "r" (1UL << bit), "m" (*m) - : "memory"); + do { + __asm__ __volatile__( + " .set mips3 \n" + " " __LL "%0, %1 # test_and_set_bit \n" + " or %2, %0, %3 \n" + " " __SC "%2, %1 \n" + " .set mips0 \n" + : "=&r" (temp), "+m" (*m), "=&r" (res) + : "r" (1UL << bit) + : "memory"); + } while (unlikely(!res)); + + res = temp & (1UL << bit); } else { volatile unsigned long *a = addr; unsigned long mask; @@ -340,30 +326,26 @@ static inline int test_and_set_bit_lock(unsigned long nr, " beqzl %2, 1b \n" " and %2, %0, %3 \n" " .set mips0 \n" - : "=&r" (temp), "=m" (*m), "=&r" (res) - : "r" (1UL << bit), "m" (*m) + : "=&r" (temp), "+m" (*m), "=&r" (res) + : "r" (1UL << bit) : "memory"); } else if (kernel_uses_llsc) { unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG); unsigned long temp; - __asm__ __volatile__( - " .set push \n" - " .set noreorder \n" - " .set mips3 \n" - "1: " __LL "%0, %1 # test_and_set_bit \n" - " or %2, %0, %3 \n" - " " __SC "%2, %1 \n" - " beqz %2, 2f \n" - " and %2, %0, %3 \n" - " .subsection 2 \n" - "2: b 1b \n" - " nop \n" - " .previous \n" - " .set pop \n" - : "=&r" (temp), "=m" (*m), "=&r" (res) - : "r" (1UL << bit), "m" (*m) - : "memory"); + do { + __asm__ __volatile__( + " .set mips3 \n" + " " __LL "%0, %1 # test_and_set_bit \n" + " or %2, %0, %3 \n" + " " __SC "%2, %1 \n" + " .set mips0 \n" + : "=&r" (temp), "+m" (*m), "=&r" (res) + : "r" (1UL << bit) + : "memory"); + } while (unlikely(!res)); + + res = temp & (1UL << bit); } else { volatile unsigned long *a = addr; unsigned long mask; @@ -410,49 +392,43 @@ static inline int test_and_clear_bit(unsigned long nr, " beqzl %2, 1b \n" " and %2, %0, %3 \n" " .set mips0 \n" - : "=&r" (temp), "=m" (*m), "=&r" (res) - : "r" (1UL << bit), "m" (*m) + : "=&r" (temp), "+m" (*m), "=&r" (res) + : "r" (1UL << bit) : "memory"); #ifdef CONFIG_CPU_MIPSR2 } else if (kernel_uses_llsc && __builtin_constant_p(nr)) { unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG); unsigned long temp; - __asm__ __volatile__( - "1: " __LL "%0, %1 # test_and_clear_bit \n" - " " __EXT "%2, %0, %3, 1 \n" - " " __INS "%0, $0, %3, 1 \n" - " " __SC "%0, %1 \n" - " beqz %0, 2f \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - : "=&r" (temp), "=m" (*m), "=&r" (res) - : "ir" (bit), "m" (*m) - : "memory"); + do { + __asm__ __volatile__( + " " __LL "%0, %1 # test_and_clear_bit \n" + " " __EXT "%2, %0, %3, 1 \n" + " " __INS "%0, $0, %3, 1 \n" + " " __SC "%0, %1 \n" + : "=&r" (temp), "+m" (*m), "=&r" (res) + : "ir" (bit) + : "memory"); + } while (unlikely(!temp)); #endif } else if (kernel_uses_llsc) { unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG); unsigned long temp; - __asm__ __volatile__( - " .set push \n" - " .set noreorder \n" - " .set mips3 \n" - "1: " __LL "%0, %1 # test_and_clear_bit \n" - " or %2, %0, %3 \n" - " xor %2, %3 \n" - " " __SC "%2, %1 \n" - " beqz %2, 2f \n" - " and %2, %0, %3 \n" - " .subsection 2 \n" - "2: b 1b \n" - " nop \n" - " .previous \n" - " .set pop \n" - : "=&r" (temp), "=m" (*m), "=&r" (res) - : "r" (1UL << bit), "m" (*m) - : "memory"); + do { + __asm__ __volatile__( + " .set mips3 \n" + " " __LL "%0, %1 # test_and_clear_bit \n" + " or %2, %0, %3 \n" + " xor %2, %3 \n" + " " __SC "%2, %1 \n" + " .set mips0 \n" + : "=&r" (temp), "+m" (*m), "=&r" (res) + : "r" (1UL << bit) + : "memory"); + } while (unlikely(!res)); + + res = temp & (1UL << bit); } else { volatile unsigned long *a = addr; unsigned long mask; @@ -499,30 +475,26 @@ static inline int test_and_change_bit(unsigned long nr, " beqzl %2, 1b \n" " and %2, %0, %3 \n" " .set mips0 \n" - : "=&r" (temp), "=m" (*m), "=&r" (res) - : "r" (1UL << bit), "m" (*m) + : "=&r" (temp), "+m" (*m), "=&r" (res) + : "r" (1UL << bit) : "memory"); } else if (kernel_uses_llsc) { unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG); unsigned long temp; - __asm__ __volatile__( - " .set push \n" - " .set noreorder \n" - " .set mips3 \n" - "1: " __LL "%0, %1 # test_and_change_bit \n" - " xor %2, %0, %3 \n" - " " __SC "\t%2, %1 \n" - " beqz %2, 2f \n" - " and %2, %0, %3 \n" - " .subsection 2 \n" - "2: b 1b \n" - " nop \n" - " .previous \n" - " .set pop \n" - : "=&r" (temp), "=m" (*m), "=&r" (res) - : "r" (1UL << bit), "m" (*m) - : "memory"); + do { + __asm__ __volatile__( + " .set mips3 \n" + " " __LL "%0, %1 # test_and_change_bit \n" + " xor %2, %0, %3 \n" + " " __SC "\t%2, %1 \n" + " .set mips0 \n" + : "=&r" (temp), "+m" (*m), "=&r" (res) + : "r" (1UL << bit) + : "memory"); + } while (unlikely(!res)); + + res = temp & (1UL << bit); } else { volatile unsigned long *a = addr; unsigned long mask; diff --git a/arch/mips/include/asm/cmpxchg.h b/arch/mips/include/asm/cmpxchg.h index 2d28017..d8d1c28 100644 --- a/arch/mips/include/asm/cmpxchg.h +++ b/arch/mips/include/asm/cmpxchg.h @@ -44,12 +44,9 @@ " move $1, %z4 \n" \ " .set mips3 \n" \ " " st " $1, %1 \n" \ - " beqz $1, 3f \n" \ - "2: \n" \ - " .subsection 2 \n" \ - "3: b 1b \n" \ - " .previous \n" \ + " beqz $1, 1b \n" \ " .set pop \n" \ + "2: \n" \ : "=&r" (__ret), "=R" (*m) \ : "R" (*m), "Jr" (old), "Jr" (new) \ : "memory"); \ diff --git a/arch/mips/include/asm/system.h b/arch/mips/include/asm/system.h index bb937cc..6018c80 100644 --- a/arch/mips/include/asm/system.h +++ b/arch/mips/include/asm/system.h @@ -115,21 +115,19 @@ static inline unsigned long __xchg_u32(volatile int * m, unsigned int val) } else if (kernel_uses_llsc) { unsigned long dummy; - __asm__ __volatile__( - " .set mips3 \n" - "1: ll %0, %3 # xchg_u32 \n" - " .set mips0 \n" - " move %2, %z4 \n" - " .set mips3 \n" - " sc %2, %1 \n" - " beqz %2, 2f \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - " .set mips0 \n" - : "=&r" (retval), "=m" (*m), "=&r" (dummy) - : "R" (*m), "Jr" (val) - : "memory"); + do { + __asm__ __volatile__( + " .set mips3 \n" + " ll %0, %3 # xchg_u32 \n" + " .set mips0 \n" + " move %2, %z4 \n" + " .set mips3 \n" + " sc %2, %1 \n" + " .set mips0 \n" + : "=&r" (retval), "=m" (*m), "=&r" (dummy) + : "R" (*m), "Jr" (val) + : "memory"); + } while (unlikely(!dummy)); } else { unsigned long flags; @@ -167,19 +165,17 @@ static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val) } else if (kernel_uses_llsc) { unsigned long dummy; - __asm__ __volatile__( - " .set mips3 \n" - "1: lld %0, %3 # xchg_u64 \n" - " move %2, %z4 \n" - " scd %2, %1 \n" - " beqz %2, 2f \n" - " .subsection 2 \n" - "2: b 1b \n" - " .previous \n" - " .set mips0 \n" - : "=&r" (retval), "=m" (*m), "=&r" (dummy) - : "R" (*m), "Jr" (val) - : "memory"); + do { + __asm__ __volatile__( + " .set mips3 \n" + " lld %0, %3 # xchg_u64 \n" + " move %2, %z4 \n" + " scd %2, %1 \n" + " .set mips0 \n" + : "=&r" (retval), "=m" (*m), "=&r" (dummy) + : "R" (*m), "Jr" (val) + : "memory"); + } while (unlikely(!dummy)); } else { unsigned long flags;