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Diffstat (limited to 'arch/mips/include/asm/atomic.h')
-rw-r--r--arch/mips/include/asm/atomic.h367
1 files changed, 36 insertions, 331 deletions
diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h
index 0ab176bdb8e8..0269b3de8b51 100644
--- a/arch/mips/include/asm/atomic.h
+++ b/arch/mips/include/asm/atomic.h
@@ -22,6 +22,17 @@
#include <asm/cmpxchg.h>
#include <asm/war.h>
+/*
+ * Using a branch-likely instruction to check the result of an sc instruction
+ * works around a bug present in R10000 CPUs prior to revision 3.0 that could
+ * cause ll-sc sequences to execute non-atomically.
+ */
+#if R10000_LLSC_WAR
+# define __scbeqz "beqzl"
+#else
+# define __scbeqz "beqz"
+#endif
+
#define ATOMIC_INIT(i) { (i) }
/*
@@ -44,31 +55,18 @@
#define ATOMIC_OP(op, c_op, asm_op) \
static __inline__ void atomic_##op(int i, atomic_t * v) \
{ \
- if (kernel_uses_llsc && R10000_LLSC_WAR) { \
+ if (kernel_uses_llsc) { \
int temp; \
\
__asm__ __volatile__( \
- " .set arch=r4000 \n" \
+ " .set "MIPS_ISA_LEVEL" \n" \
"1: ll %0, %1 # atomic_" #op " \n" \
" " #asm_op " %0, %2 \n" \
" sc %0, %1 \n" \
- " beqzl %0, 1b \n" \
+ "\t" __scbeqz " %0, 1b \n" \
" .set mips0 \n" \
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
: "Ir" (i)); \
- } else if (kernel_uses_llsc) { \
- int temp; \
- \
- do { \
- __asm__ __volatile__( \
- " .set "MIPS_ISA_LEVEL" \n" \
- " ll %0, %1 # atomic_" #op "\n" \
- " " #asm_op " %0, %2 \n" \
- " sc %0, %1 \n" \
- " .set mips0 \n" \
- : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i)); \
- } while (unlikely(!temp)); \
} else { \
unsigned long flags; \
\
@@ -83,36 +81,20 @@ static __inline__ int atomic_##op##_return_relaxed(int i, atomic_t * v) \
{ \
int result; \
\
- if (kernel_uses_llsc && R10000_LLSC_WAR) { \
+ if (kernel_uses_llsc) { \
int temp; \
\
__asm__ __volatile__( \
- " .set arch=r4000 \n" \
+ " .set "MIPS_ISA_LEVEL" \n" \
"1: ll %1, %2 # atomic_" #op "_return \n" \
" " #asm_op " %0, %1, %3 \n" \
" sc %0, %2 \n" \
- " beqzl %0, 1b \n" \
+ "\t" __scbeqz " %0, 1b \n" \
" " #asm_op " %0, %1, %3 \n" \
" .set mips0 \n" \
: "=&r" (result), "=&r" (temp), \
"+" GCC_OFF_SMALL_ASM() (v->counter) \
: "Ir" (i)); \
- } else if (kernel_uses_llsc) { \
- int temp; \
- \
- do { \
- __asm__ __volatile__( \
- " .set "MIPS_ISA_LEVEL" \n" \
- " ll %1, %2 # atomic_" #op "_return \n" \
- " " #asm_op " %0, %1, %3 \n" \
- " sc %0, %2 \n" \
- " .set mips0 \n" \
- : "=&r" (result), "=&r" (temp), \
- "+" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i)); \
- } while (unlikely(!result)); \
- \
- result = temp; result c_op i; \
} else { \
unsigned long flags; \
\
@@ -131,36 +113,20 @@ static __inline__ int atomic_fetch_##op##_relaxed(int i, atomic_t * v) \
{ \
int result; \
\
- if (kernel_uses_llsc && R10000_LLSC_WAR) { \
+ if (kernel_uses_llsc) { \
int temp; \
\
__asm__ __volatile__( \
- " .set arch=r4000 \n" \
+ " .set "MIPS_ISA_LEVEL" \n" \
"1: ll %1, %2 # atomic_fetch_" #op " \n" \
" " #asm_op " %0, %1, %3 \n" \
" sc %0, %2 \n" \
- " beqzl %0, 1b \n" \
+ "\t" __scbeqz " %0, 1b \n" \
" move %0, %1 \n" \
" .set mips0 \n" \
: "=&r" (result), "=&r" (temp), \
"+" GCC_OFF_SMALL_ASM() (v->counter) \
: "Ir" (i)); \
- } else if (kernel_uses_llsc) { \
- int temp; \
- \
- do { \
- __asm__ __volatile__( \
- " .set "MIPS_ISA_LEVEL" \n" \
- " ll %1, %2 # atomic_fetch_" #op " \n" \
- " " #asm_op " %0, %1, %3 \n" \
- " sc %0, %2 \n" \
- " .set mips0 \n" \
- : "=&r" (result), "=&r" (temp), \
- "+" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i)); \
- } while (unlikely(!result)); \
- \
- result = temp; \
} else { \
unsigned long flags; \
\
@@ -218,38 +184,17 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
smp_mb__before_llsc();
- if (kernel_uses_llsc && R10000_LLSC_WAR) {
- int temp;
-
- __asm__ __volatile__(
- " .set arch=r4000 \n"
- "1: ll %1, %2 # atomic_sub_if_positive\n"
- " subu %0, %1, %3 \n"
- " bltz %0, 1f \n"
- " sc %0, %2 \n"
- " .set noreorder \n"
- " beqzl %0, 1b \n"
- " subu %0, %1, %3 \n"
- " .set reorder \n"
- "1: \n"
- " .set mips0 \n"
- : "=&r" (result), "=&r" (temp),
- "+" GCC_OFF_SMALL_ASM() (v->counter)
- : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter)
- : "memory");
- } else if (kernel_uses_llsc) {
+ if (kernel_uses_llsc) {
int temp;
__asm__ __volatile__(
" .set "MIPS_ISA_LEVEL" \n"
"1: ll %1, %2 # atomic_sub_if_positive\n"
" subu %0, %1, %3 \n"
+ " move %1, %0 \n"
" bltz %0, 1f \n"
- " sc %0, %2 \n"
- " .set noreorder \n"
- " beqz %0, 1b \n"
- " subu %0, %1, %3 \n"
- " .set reorder \n"
+ " sc %1, %2 \n"
+ "\t" __scbeqz " %1, 1b \n"
"1: \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp),
@@ -274,97 +219,12 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
-/**
- * __atomic_add_unless - add unless the number is a given value
- * @v: pointer of type atomic_t
- * @a: the amount to add to v...
- * @u: ...unless v is equal to u.
- *
- * Atomically adds @a to @v, so long as it was not @u.
- * Returns the old value of @v.
- */
-static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
-{
- int c, old;
- c = atomic_read(v);
- for (;;) {
- if (unlikely(c == (u)))
- break;
- old = atomic_cmpxchg((v), c, c + (a));
- if (likely(old == c))
- break;
- c = old;
- }
- return c;
-}
-
-#define atomic_dec_return(v) atomic_sub_return(1, (v))
-#define atomic_inc_return(v) atomic_add_return(1, (v))
-
-/*
- * atomic_sub_and_test - subtract value from variable and test result
- * @i: integer value to subtract
- * @v: pointer of type atomic_t
- *
- * Atomically subtracts @i from @v and returns
- * true if the result is zero, or false for all
- * other cases.
- */
-#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
-
-/*
- * atomic_inc_and_test - increment and test
- * @v: pointer of type atomic_t
- *
- * Atomically increments @v by 1
- * and returns true if the result is zero, or false for all
- * other cases.
- */
-#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
-
-/*
- * atomic_dec_and_test - decrement by 1 and test
- * @v: pointer of type atomic_t
- *
- * Atomically decrements @v by 1 and
- * returns true if the result is 0, or false for all other
- * cases.
- */
-#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
-
/*
* 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)
-/*
- * atomic_inc - increment atomic variable
- * @v: pointer of type atomic_t
- *
- * Atomically increments @v by 1.
- */
-#define atomic_inc(v) atomic_add(1, (v))
-
-/*
- * atomic_dec - decrement and test
- * @v: pointer of type atomic_t
- *
- * Atomically decrements @v by 1.
- */
-#define atomic_dec(v) atomic_sub(1, (v))
-
-/*
- * atomic_add_negative - add and test if negative
- * @v: pointer of type atomic_t
- * @i: integer value to add
- *
- * Atomically adds @i to @v and returns true
- * if the result is negative, or false when
- * result is greater than or equal to zero.
- */
-#define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0)
-
#ifdef CONFIG_64BIT
#define ATOMIC64_INIT(i) { (i) }
@@ -386,31 +246,18 @@ static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
#define ATOMIC64_OP(op, c_op, asm_op) \
static __inline__ void atomic64_##op(long i, atomic64_t * v) \
{ \
- if (kernel_uses_llsc && R10000_LLSC_WAR) { \
+ if (kernel_uses_llsc) { \
long temp; \
\
__asm__ __volatile__( \
- " .set arch=r4000 \n" \
+ " .set "MIPS_ISA_LEVEL" \n" \
"1: lld %0, %1 # atomic64_" #op " \n" \
" " #asm_op " %0, %2 \n" \
" scd %0, %1 \n" \
- " beqzl %0, 1b \n" \
+ "\t" __scbeqz " %0, 1b \n" \
" .set mips0 \n" \
: "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
: "Ir" (i)); \
- } else if (kernel_uses_llsc) { \
- long temp; \
- \
- do { \
- __asm__ __volatile__( \
- " .set "MIPS_ISA_LEVEL" \n" \
- " lld %0, %1 # atomic64_" #op "\n" \
- " " #asm_op " %0, %2 \n" \
- " scd %0, %1 \n" \
- " .set mips0 \n" \
- : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i)); \
- } while (unlikely(!temp)); \
} else { \
unsigned long flags; \
\
@@ -425,37 +272,20 @@ static __inline__ long atomic64_##op##_return_relaxed(long i, atomic64_t * v) \
{ \
long result; \
\
- if (kernel_uses_llsc && R10000_LLSC_WAR) { \
+ if (kernel_uses_llsc) { \
long temp; \
\
__asm__ __volatile__( \
- " .set arch=r4000 \n" \
+ " .set "MIPS_ISA_LEVEL" \n" \
"1: lld %1, %2 # atomic64_" #op "_return\n" \
" " #asm_op " %0, %1, %3 \n" \
" scd %0, %2 \n" \
- " beqzl %0, 1b \n" \
+ "\t" __scbeqz " %0, 1b \n" \
" " #asm_op " %0, %1, %3 \n" \
" .set mips0 \n" \
: "=&r" (result), "=&r" (temp), \
"+" GCC_OFF_SMALL_ASM() (v->counter) \
: "Ir" (i)); \
- } else if (kernel_uses_llsc) { \
- long temp; \
- \
- do { \
- __asm__ __volatile__( \
- " .set "MIPS_ISA_LEVEL" \n" \
- " lld %1, %2 # atomic64_" #op "_return\n" \
- " " #asm_op " %0, %1, %3 \n" \
- " scd %0, %2 \n" \
- " .set mips0 \n" \
- : "=&r" (result), "=&r" (temp), \
- "=" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) \
- : "memory"); \
- } while (unlikely(!result)); \
- \
- result = temp; result c_op i; \
} else { \
unsigned long flags; \
\
@@ -478,33 +308,16 @@ static __inline__ long atomic64_fetch_##op##_relaxed(long i, atomic64_t * v) \
long temp; \
\
__asm__ __volatile__( \
- " .set arch=r4000 \n" \
+ " .set "MIPS_ISA_LEVEL" \n" \
"1: lld %1, %2 # atomic64_fetch_" #op "\n" \
" " #asm_op " %0, %1, %3 \n" \
" scd %0, %2 \n" \
- " beqzl %0, 1b \n" \
+ "\t" __scbeqz " %0, 1b \n" \
" move %0, %1 \n" \
" .set mips0 \n" \
: "=&r" (result), "=&r" (temp), \
"+" GCC_OFF_SMALL_ASM() (v->counter) \
: "Ir" (i)); \
- } else if (kernel_uses_llsc) { \
- long temp; \
- \
- do { \
- __asm__ __volatile__( \
- " .set "MIPS_ISA_LEVEL" \n" \
- " lld %1, %2 # atomic64_fetch_" #op "\n" \
- " " #asm_op " %0, %1, %3 \n" \
- " scd %0, %2 \n" \
- " .set mips0 \n" \
- : "=&r" (result), "=&r" (temp), \
- "=" GCC_OFF_SMALL_ASM() (v->counter) \
- : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) \
- : "memory"); \
- } while (unlikely(!result)); \
- \
- result = temp; \
} else { \
unsigned long flags; \
\
@@ -563,38 +376,17 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
smp_mb__before_llsc();
- if (kernel_uses_llsc && R10000_LLSC_WAR) {
- long temp;
-
- __asm__ __volatile__(
- " .set arch=r4000 \n"
- "1: lld %1, %2 # atomic64_sub_if_positive\n"
- " dsubu %0, %1, %3 \n"
- " bltz %0, 1f \n"
- " scd %0, %2 \n"
- " .set noreorder \n"
- " beqzl %0, 1b \n"
- " dsubu %0, %1, %3 \n"
- " .set reorder \n"
- "1: \n"
- " .set mips0 \n"
- : "=&r" (result), "=&r" (temp),
- "=" GCC_OFF_SMALL_ASM() (v->counter)
- : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter)
- : "memory");
- } else if (kernel_uses_llsc) {
+ if (kernel_uses_llsc) {
long temp;
__asm__ __volatile__(
" .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 %0, %2 \n"
- " .set noreorder \n"
- " beqz %0, 1b \n"
- " dsubu %0, %1, %3 \n"
- " .set reorder \n"
+ " scd %1, %2 \n"
+ "\t" __scbeqz " %1, 1b \n"
"1: \n"
" .set mips0 \n"
: "=&r" (result), "=&r" (temp),
@@ -620,99 +412,12 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
#define atomic64_xchg(v, new) (xchg(&((v)->counter), (new)))
-/**
- * atomic64_add_unless - add unless the number is a given value
- * @v: pointer of type atomic64_t
- * @a: the amount to add to v...
- * @u: ...unless v is equal to u.
- *
- * Atomically adds @a to @v, so long as it was not @u.
- * Returns true iff @v was not @u.
- */
-static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
-{
- long c, old;
- c = atomic64_read(v);
- for (;;) {
- if (unlikely(c == (u)))
- break;
- old = atomic64_cmpxchg((v), c, c + (a));
- if (likely(old == c))
- break;
- c = old;
- }
- return c != (u);
-}
-
-#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
-
-#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
-#define atomic64_inc_return(v) atomic64_add_return(1, (v))
-
-/*
- * atomic64_sub_and_test - subtract value from variable and test result
- * @i: integer value to subtract
- * @v: pointer of type atomic64_t
- *
- * Atomically subtracts @i from @v and returns
- * true if the result is zero, or false for all
- * other cases.
- */
-#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
-
-/*
- * atomic64_inc_and_test - increment and test
- * @v: pointer of type atomic64_t
- *
- * Atomically increments @v by 1
- * and returns true if the result is zero, or false for all
- * other cases.
- */
-#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
-
-/*
- * atomic64_dec_and_test - decrement by 1 and test
- * @v: pointer of type atomic64_t
- *
- * Atomically decrements @v by 1 and
- * returns true if the result is 0, or false for all other
- * cases.
- */
-#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
-
/*
* 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)
-/*
- * atomic64_inc - increment atomic variable
- * @v: pointer of type atomic64_t
- *
- * Atomically increments @v by 1.
- */
-#define atomic64_inc(v) atomic64_add(1, (v))
-
-/*
- * atomic64_dec - decrement and test
- * @v: pointer of type atomic64_t
- *
- * Atomically decrements @v by 1.
- */
-#define atomic64_dec(v) atomic64_sub(1, (v))
-
-/*
- * atomic64_add_negative - add and test if negative
- * @v: pointer of type atomic64_t
- * @i: integer value to add
- *
- * Atomically adds @i to @v and returns true
- * if the result is negative, or false when
- * result is greater than or equal to zero.
- */
-#define atomic64_add_negative(i, v) (atomic64_add_return(i, (v)) < 0)
-
#endif /* CONFIG_64BIT */
#endif /* _ASM_ATOMIC_H */