From f7c34874f04a80d6c39a32f08da2529e59602d3c Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Thu, 20 Dec 2018 17:18:12 -0800 Subject: [PATCH] xtensa: add exclusive atomics support Implement atomic primitives using exclusive access opcodes available in the recent xtensa cores. Since l32ex/s32ex don't have any memory ordering guarantees don't define __smp_mb__before_atomic/__smp_mb__after_atomic to make them use memw. Signed-off-by: Max Filippov --- arch/xtensa/include/asm/atomic.h | 62 ++++++++++++++- arch/xtensa/include/asm/barrier.h | 4 + arch/xtensa/include/asm/bitops.h | 121 +++++++++++++++++++++++++++++- arch/xtensa/include/asm/cmpxchg.h | 36 ++++++++- arch/xtensa/include/asm/core.h | 4 + arch/xtensa/include/asm/futex.h | 43 ++++++++++- arch/xtensa/kernel/setup.c | 3 + 7 files changed, 267 insertions(+), 6 deletions(-) diff --git a/arch/xtensa/include/asm/atomic.h b/arch/xtensa/include/asm/atomic.h index 4e7311f58ae8..7b00d26f472e 100644 --- a/arch/xtensa/include/asm/atomic.h +++ b/arch/xtensa/include/asm/atomic.h @@ -56,7 +56,67 @@ */ #define atomic_set(v,i) WRITE_ONCE((v)->counter, (i)) -#if XCHAL_HAVE_S32C1I +#if XCHAL_HAVE_EXCLUSIVE +#define ATOMIC_OP(op) \ +static inline void atomic_##op(int i, atomic_t *v) \ +{ \ + unsigned long tmp; \ + int result; \ + \ + __asm__ __volatile__( \ + "1: l32ex %1, %3\n" \ + " " #op " %0, %1, %2\n" \ + " s32ex %0, %3\n" \ + " getex %0\n" \ + " beqz %0, 1b\n" \ + : "=&a" (result), "=&a" (tmp) \ + : "a" (i), "a" (v) \ + : "memory" \ + ); \ +} \ + +#define ATOMIC_OP_RETURN(op) \ +static inline int atomic_##op##_return(int i, atomic_t *v) \ +{ \ + unsigned long tmp; \ + int result; \ + \ + __asm__ __volatile__( \ + "1: l32ex %1, %3\n" \ + " " #op " %0, %1, %2\n" \ + " s32ex %0, %3\n" \ + " getex %0\n" \ + " beqz %0, 1b\n" \ + " " #op " %0, %1, %2\n" \ + : "=&a" (result), "=&a" (tmp) \ + : "a" (i), "a" (v) \ + : "memory" \ + ); \ + \ + return result; \ +} + +#define ATOMIC_FETCH_OP(op) \ +static inline int atomic_fetch_##op(int i, atomic_t *v) \ +{ \ + unsigned long tmp; \ + int result; \ + \ + __asm__ __volatile__( \ + "1: l32ex %1, %3\n" \ + " " #op " %0, %1, %2\n" \ + " s32ex %0, %3\n" \ + " getex %0\n" \ + " beqz %0, 1b\n" \ + : "=&a" (result), "=&a" (tmp) \ + : "a" (i), "a" (v) \ + : "memory" \ + ); \ + \ + return tmp; \ +} + +#elif XCHAL_HAVE_S32C1I #define ATOMIC_OP(op) \ static inline void atomic_##op(int i, atomic_t * v) \ { \ diff --git a/arch/xtensa/include/asm/barrier.h b/arch/xtensa/include/asm/barrier.h index 956596e4d437..d6f8d4ddc2bc 100644 --- a/arch/xtensa/include/asm/barrier.h +++ b/arch/xtensa/include/asm/barrier.h @@ -9,12 +9,16 @@ #ifndef _XTENSA_SYSTEM_H #define _XTENSA_SYSTEM_H +#include + #define mb() ({ __asm__ __volatile__("memw" : : : "memory"); }) #define rmb() barrier() #define wmb() mb() +#if XCHAL_HAVE_S32C1I #define __smp_mb__before_atomic() barrier() #define __smp_mb__after_atomic() barrier() +#endif #include diff --git a/arch/xtensa/include/asm/bitops.h b/arch/xtensa/include/asm/bitops.h index 345d28aead65..aeb15f4c755b 100644 --- a/arch/xtensa/include/asm/bitops.h +++ b/arch/xtensa/include/asm/bitops.h @@ -96,7 +96,126 @@ static inline unsigned long __fls(unsigned long word) #include -#if XCHAL_HAVE_S32C1I +#if XCHAL_HAVE_EXCLUSIVE + +static inline void set_bit(unsigned int bit, volatile unsigned long *p) +{ + unsigned long tmp; + unsigned long mask = 1UL << (bit & 31); + + p += bit >> 5; + + __asm__ __volatile__( + "1: l32ex %0, %2\n" + " or %0, %0, %1\n" + " s32ex %0, %2\n" + " getex %0\n" + " beqz %0, 1b\n" + : "=&a" (tmp) + : "a" (mask), "a" (p) + : "memory"); +} + +static inline void clear_bit(unsigned int bit, volatile unsigned long *p) +{ + unsigned long tmp; + unsigned long mask = 1UL << (bit & 31); + + p += bit >> 5; + + __asm__ __volatile__( + "1: l32ex %0, %2\n" + " and %0, %0, %1\n" + " s32ex %0, %2\n" + " getex %0\n" + " beqz %0, 1b\n" + : "=&a" (tmp) + : "a" (~mask), "a" (p) + : "memory"); +} + +static inline void change_bit(unsigned int bit, volatile unsigned long *p) +{ + unsigned long tmp; + unsigned long mask = 1UL << (bit & 31); + + p += bit >> 5; + + __asm__ __volatile__( + "1: l32ex %0, %2\n" + " xor %0, %0, %1\n" + " s32ex %0, %2\n" + " getex %0\n" + " beqz %0, 1b\n" + : "=&a" (tmp) + : "a" (~mask), "a" (p) + : "memory"); +} + +static inline int +test_and_set_bit(unsigned int bit, volatile unsigned long *p) +{ + unsigned long tmp, value; + unsigned long mask = 1UL << (bit & 31); + + p += bit >> 5; + + __asm__ __volatile__( + "1: l32ex %1, %3\n" + " or %0, %1, %2\n" + " s32ex %0, %3\n" + " getex %0\n" + " beqz %0, 1b\n" + : "=&a" (tmp), "=&a" (value) + : "a" (mask), "a" (p) + : "memory"); + + return value & mask; +} + +static inline int +test_and_clear_bit(unsigned int bit, volatile unsigned long *p) +{ + unsigned long tmp, value; + unsigned long mask = 1UL << (bit & 31); + + p += bit >> 5; + + __asm__ __volatile__( + "1: l32ex %1, %3\n" + " and %0, %1, %2\n" + " s32ex %0, %3\n" + " getex %0\n" + " beqz %0, 1b\n" + : "=&a" (tmp), "=&a" (value) + : "a" (~mask), "a" (p) + : "memory"); + + return value & mask; +} + +static inline int +test_and_change_bit(unsigned int bit, volatile unsigned long *p) +{ + unsigned long tmp, value; + unsigned long mask = 1UL << (bit & 31); + + p += bit >> 5; + + __asm__ __volatile__( + "1: l32ex %1, %3\n" + " xor %0, %1, %2\n" + " s32ex %0, %3\n" + " getex %0\n" + " beqz %0, 1b\n" + : "=&a" (tmp), "=&a" (value) + : "a" (mask), "a" (p) + : "memory"); + + return value & mask; +} + +#elif XCHAL_HAVE_S32C1I static inline void set_bit(unsigned int bit, volatile unsigned long *p) { diff --git a/arch/xtensa/include/asm/cmpxchg.h b/arch/xtensa/include/asm/cmpxchg.h index 22a10c715c1f..7ccc5cbf441b 100644 --- a/arch/xtensa/include/asm/cmpxchg.h +++ b/arch/xtensa/include/asm/cmpxchg.h @@ -23,7 +23,24 @@ static inline unsigned long __cmpxchg_u32(volatile int *p, int old, int new) { -#if XCHAL_HAVE_S32C1I +#if XCHAL_HAVE_EXCLUSIVE + unsigned long tmp, result; + + __asm__ __volatile__( + "1: l32ex %0, %3\n" + " bne %0, %4, 2f\n" + " mov %1, %2\n" + " s32ex %1, %3\n" + " getex %1\n" + " beqz %1, 1b\n" + "2:\n" + : "=&a" (result), "=&a" (tmp) + : "a" (new), "a" (p), "a" (old) + : "memory" + ); + + return result; +#elif XCHAL_HAVE_S32C1I __asm__ __volatile__( " wsr %2, scompare1\n" " s32c1i %0, %1, 0\n" @@ -108,7 +125,22 @@ static inline unsigned long __cmpxchg_local(volatile void *ptr, static inline unsigned long xchg_u32(volatile int * m, unsigned long val) { -#if XCHAL_HAVE_S32C1I +#if XCHAL_HAVE_EXCLUSIVE + unsigned long tmp, result; + + __asm__ __volatile__( + "1: l32ex %0, %3\n" + " mov %1, %2\n" + " s32ex %1, %3\n" + " getex %1\n" + " beqz %1, 1b\n" + : "=&a" (result), "=&a" (tmp) + : "a" (val), "a" (m) + : "memory" + ); + + return result; +#elif XCHAL_HAVE_S32C1I unsigned long tmp, result; __asm__ __volatile__( "1: l32i %1, %2, 0\n" diff --git a/arch/xtensa/include/asm/core.h b/arch/xtensa/include/asm/core.h index b1f57519df49..ee02e164b673 100644 --- a/arch/xtensa/include/asm/core.h +++ b/arch/xtensa/include/asm/core.h @@ -6,6 +6,10 @@ #include +#ifndef XCHAL_HAVE_EXCLUSIVE +#define XCHAL_HAVE_EXCLUSIVE 0 +#endif + #ifndef XCHAL_SPANNING_WAY #define XCHAL_SPANNING_WAY 0 #endif diff --git a/arch/xtensa/include/asm/futex.h b/arch/xtensa/include/asm/futex.h index a67f801aa303..9538b0f7953c 100644 --- a/arch/xtensa/include/asm/futex.h +++ b/arch/xtensa/include/asm/futex.h @@ -19,6 +19,31 @@ #include #include +#if XCHAL_HAVE_EXCLUSIVE +#define __futex_atomic_op(insn, ret, old, uaddr, arg) \ + __asm__ __volatile( \ + "1: l32ex %[oldval], %[addr]\n" \ + insn "\n" \ + "2: s32ex %[newval], %[addr]\n" \ + " getex %[newval]\n" \ + " beqz %[newval], 1b\n" \ + " movi %[newval], 0\n" \ + "3:\n" \ + " .section .fixup,\"ax\"\n" \ + " .align 4\n" \ + " .literal_position\n" \ + "5: movi %[oldval], 3b\n" \ + " movi %[newval], %[fault]\n" \ + " jx %[oldval]\n" \ + " .previous\n" \ + " .section __ex_table,\"a\"\n" \ + " .long 1b, 5b, 2b, 5b\n" \ + " .previous\n" \ + : [oldval] "=&r" (old), [newval] "=&r" (ret) \ + : [addr] "r" (uaddr), [oparg] "r" (arg), \ + [fault] "I" (-EFAULT) \ + : "memory") +#elif XCHAL_HAVE_S32C1I #define __futex_atomic_op(insn, ret, old, uaddr, arg) \ __asm__ __volatile( \ "1: l32i %[oldval], %[addr], 0\n" \ @@ -42,11 +67,12 @@ : [addr] "r" (uaddr), [oparg] "r" (arg), \ [fault] "I" (-EFAULT) \ : "memory") +#endif static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr) { -#if XCHAL_HAVE_S32C1I +#if XCHAL_HAVE_S32C1I || XCHAL_HAVE_EXCLUSIVE int oldval = 0, ret; pagefault_disable(); @@ -91,7 +117,7 @@ static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval) { -#if XCHAL_HAVE_S32C1I +#if XCHAL_HAVE_S32C1I || XCHAL_HAVE_EXCLUSIVE unsigned long tmp; int ret = 0; @@ -100,9 +126,19 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, __asm__ __volatile__ ( " # futex_atomic_cmpxchg_inatomic\n" +#if XCHAL_HAVE_EXCLUSIVE + "1: l32ex %[tmp], %[addr]\n" + " s32i %[tmp], %[uval], 0\n" + " bne %[tmp], %[oldval], 2f\n" + " mov %[tmp], %[newval]\n" + "3: s32ex %[tmp], %[addr]\n" + " getex %[tmp]\n" + " beqz %[tmp], 1b\n" +#elif XCHAL_HAVE_S32C1I " wsr %[oldval], scompare1\n" "1: s32c1i %[newval], %[addr], 0\n" " s32i %[newval], %[uval], 0\n" +#endif "2:\n" " .section .fixup,\"ax\"\n" " .align 4\n" @@ -113,6 +149,9 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, " .previous\n" " .section __ex_table,\"a\"\n" " .long 1b, 4b\n" +#if XCHAL_HAVE_EXCLUSIVE + " .long 3b, 4b\n" +#endif " .previous\n" : [ret] "+r" (ret), [newval] "+r" (newval), [tmp] "=&r" (tmp) : [addr] "r" (uaddr), [oldval] "r" (oldval), [uval] "r" (uval), diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c index 4ec6fbb696bf..c0ec24349421 100644 --- a/arch/xtensa/kernel/setup.c +++ b/arch/xtensa/kernel/setup.c @@ -650,6 +650,9 @@ c_show(struct seq_file *f, void *slot) #endif #if XCHAL_HAVE_S32C1I "s32c1i " +#endif +#if XCHAL_HAVE_EXCLUSIVE + "exclusive " #endif "\n");