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authorMax Filippov <jcmvbkbc@gmail.com>2018-12-20 17:18:12 -0800
committerMax Filippov <jcmvbkbc@gmail.com>2019-05-07 10:36:31 -0700
commitf7c34874f04a80d6c39a32f08da2529e59602d3c (patch)
treea225ab153205701d24bee7423fc950a9009cb533 /arch
parentd065fcf12c21348cbc125460f75332f467518fb1 (diff)
downloadlinux-f7c34874f04a80d6c39a32f08da2529e59602d3c.tar.bz2
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 <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/xtensa/include/asm/atomic.h62
-rw-r--r--arch/xtensa/include/asm/barrier.h4
-rw-r--r--arch/xtensa/include/asm/bitops.h121
-rw-r--r--arch/xtensa/include/asm/cmpxchg.h36
-rw-r--r--arch/xtensa/include/asm/core.h4
-rw-r--r--arch/xtensa/include/asm/futex.h43
-rw-r--r--arch/xtensa/kernel/setup.c3
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 <asm/core.h>
+
#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 <asm-generic/barrier.h>
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 <asm-generic/bitops/fls64.h>
-#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 <variant/core.h>
+#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 <linux/uaccess.h>
#include <linux/errno.h>
+#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
@@ -651,6 +651,9 @@ c_show(struct seq_file *f, void *slot)
#if XCHAL_HAVE_S32C1I
"s32c1i "
#endif
+#if XCHAL_HAVE_EXCLUSIVE
+ "exclusive "
+#endif
"\n");
/* Registers. */