On some CPUs, it is more efficient to disable and enable interrupts in
the kernel rather than use ll/sc for atomic operations. But if we
were to set cpu_has_llsc to false, we would break the userspace futex
interface (in asm/futex.h).
We separate the two concepts, with a new predicate kernel_uses_llsc,
that lets us disable the kernel's use of ll/sc while still allowing
the futex code to use it.
Also there were a couple of cases in bitops.h where we were using
ll/sc unconditionally even if cpu_has_llsc were false. There are
several places in assembly code where the configure variable
CONFIG_CPU_HAS_LLSC is used instead of cpu_has_llsc, so we make
cpu_has_llsc true if CONFIG_CPU_HAS_LLSC is set, for consistency.
Signed-off-by: David Daney <ddaney@xxxxxxxxxxxxxxxxxx>
---
arch/mips/include/asm/atomic.h | 40 +++++++++++++++++-----------------
arch/mips/include/asm/bitops.h | 34 ++++++++++++++--------------
arch/mips/include/asm/cmpxchg.h | 4 +-
arch/mips/include/asm/cpu-features.h | 9 ++++++-
arch/mips/include/asm/local.h | 8 +++---
arch/mips/include/asm/system.h | 8 +++---
6 files changed, 55 insertions(+), 48 deletions(-)
diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h
index eb7f01c..dd75d67 100644
--- a/arch/mips/include/asm/atomic.h
+++ b/arch/mips/include/asm/atomic.h
@@ -49,7 +49,7 @@
*/
static __inline__ void atomic_add(int i, atomic_t * v)
{
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
int temp;
__asm__ __volatile__(
@@ -61,7 +61,7 @@ static __inline__ void atomic_add(int i, atomic_t * v)
" .set mips0 \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
int temp;
__asm__ __volatile__(
@@ -94,7 +94,7 @@ static __inline__ void atomic_add(int i, atomic_t * v)
*/
static __inline__ void atomic_sub(int i, atomic_t * v)
{
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
int temp;
__asm__ __volatile__(
@@ -106,7 +106,7 @@ static __inline__ void atomic_sub(int i, atomic_t * v)
" .set mips0 \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
int temp;
__asm__ __volatile__(
@@ -139,7 +139,7 @@ static __inline__ int atomic_add_return(int i, atomic_t * v)
smp_llsc_mb();
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
int temp;
__asm__ __volatile__(
@@ -153,7 +153,7 @@ static __inline__ int atomic_add_return(int i, atomic_t * v)
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
int temp;
__asm__ __volatile__(
@@ -191,7 +191,7 @@ static __inline__ int atomic_sub_return(int i, atomic_t * v)
smp_llsc_mb();
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
int temp;
__asm__ __volatile__(
@@ -205,7 +205,7 @@ static __inline__ int atomic_sub_return(int i, atomic_t * v)
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
int temp;
__asm__ __volatile__(
@@ -251,7 +251,7 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
smp_llsc_mb();
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
int temp;
__asm__ __volatile__(
@@ -269,7 +269,7 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
int temp;
__asm__ __volatile__(
@@ -428,7 +428,7 @@ static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
*/
static __inline__ void atomic64_add(long i, atomic64_t * v)
{
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
long temp;
__asm__ __volatile__(
@@ -440,7 +440,7 @@ static __inline__ void atomic64_add(long i, atomic64_t * v)
" .set mips0 \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
long temp;
__asm__ __volatile__(
@@ -473,7 +473,7 @@ static __inline__ void atomic64_add(long i, atomic64_t * v)
*/
static __inline__ void atomic64_sub(long i, atomic64_t * v)
{
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
long temp;
__asm__ __volatile__(
@@ -485,7 +485,7 @@ static __inline__ void atomic64_sub(long i, atomic64_t * v)
" .set mips0 \n"
: "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter));
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
long temp;
__asm__ __volatile__(
@@ -518,7 +518,7 @@ static __inline__ long atomic64_add_return(long i, atomic64_t * v)
smp_llsc_mb();
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
long temp;
__asm__ __volatile__(
@@ -532,7 +532,7 @@ static __inline__ long atomic64_add_return(long i, atomic64_t * v)
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
long temp;
__asm__ __volatile__(
@@ -570,7 +570,7 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
smp_llsc_mb();
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
long temp;
__asm__ __volatile__(
@@ -584,7 +584,7 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
long temp;
__asm__ __volatile__(
@@ -630,7 +630,7 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
smp_llsc_mb();
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
long temp;
__asm__ __volatile__(
@@ -648,7 +648,7 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
: "=&r" (result), "=&r" (temp), "=m" (v->counter)
: "Ir" (i), "m" (v->counter)
: "memory");
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
long temp;
__asm__ __volatile__(
diff --git a/arch/mips/include/asm/bitops.h b/arch/mips/include/asm/bitops.h
index b1e9e97..84a3838 100644
--- a/arch/mips/include/asm/bitops.h
+++ b/arch/mips/include/asm/bitops.h
@@ -61,7 +61,7 @@ static inline void set_bit(unsigned long nr, volatile unsigned long *addr)
unsigned short bit = nr & SZLONG_MASK;
unsigned long temp;
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
__asm__ __volatile__(
" .set mips3 \n"
"1: " __LL "%0, %1 # set_bit \n"
@@ -72,7 +72,7 @@ static inline void set_bit(unsigned long nr, volatile unsigned long *addr)
: "=&r" (temp), "=m" (*m)
: "ir" (1UL << bit), "m" (*m));
#ifdef CONFIG_CPU_MIPSR2
- } else if (__builtin_constant_p(bit)) {
+ } else if (kernel_uses_llsc && __builtin_constant_p(bit)) {
__asm__ __volatile__(
"1: " __LL "%0, %1 # set_bit \n"
" " __INS "%0, %4, %2, 1 \n"
@@ -84,7 +84,7 @@ static inline void set_bit(unsigned long nr, volatile unsigned long *addr)
: "=&r" (temp), "=m" (*m)
: "ir" (bit), "m" (*m), "r" (~0));
#endif /* CONFIG_CPU_MIPSR2 */
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
__asm__ __volatile__(
" .set mips3 \n"
"1: " __LL "%0, %1 # set_bit \n"
@@ -126,7 +126,7 @@ static inline void clear_bit(unsigned long nr, volatile unsigned long *addr)
unsigned short bit = nr & SZLONG_MASK;
unsigned long temp;
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
__asm__ __volatile__(
" .set mips3 \n"
"1: " __LL "%0, %1 # clear_bit \n"
@@ -137,7 +137,7 @@ static inline void clear_bit(unsigned long nr, volatile unsigned long *addr)
: "=&r" (temp), "=m" (*m)
: "ir" (~(1UL << bit)), "m" (*m));
#ifdef CONFIG_CPU_MIPSR2
- } else if (__builtin_constant_p(bit)) {
+ } else if (kernel_uses_llsc && __builtin_constant_p(bit)) {
__asm__ __volatile__(
"1: " __LL "%0, %1 # clear_bit \n"
" " __INS "%0, $0, %2, 1 \n"
@@ -149,7 +149,7 @@ static inline void clear_bit(unsigned long nr, volatile unsigned long *addr)
: "=&r" (temp), "=m" (*m)
: "ir" (bit), "m" (*m));
#endif /* CONFIG_CPU_MIPSR2 */
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
__asm__ __volatile__(
" .set mips3 \n"
"1: " __LL "%0, %1 # clear_bit \n"
@@ -202,7 +202,7 @@ static inline void change_bit(unsigned long nr, volatile unsigned long *addr)
{
unsigned short bit = nr & SZLONG_MASK;
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
@@ -215,7 +215,7 @@ static inline void change_bit(unsigned long nr, volatile unsigned long *addr)
" .set mips0 \n"
: "=&r" (temp), "=m" (*m)
: "ir" (1UL << bit), "m" (*m));
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
@@ -260,7 +260,7 @@ static inline int test_and_set_bit(unsigned long nr,
smp_llsc_mb();
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
@@ -275,7 +275,7 @@ static inline int test_and_set_bit(unsigned long nr,
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "r" (1UL << bit), "m" (*m)
: "memory");
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
@@ -328,7 +328,7 @@ static inline int test_and_set_bit_lock(unsigned long nr,
unsigned short bit = nr & SZLONG_MASK;
unsigned long res;
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
@@ -343,7 +343,7 @@ static inline int test_and_set_bit_lock(unsigned long nr,
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "r" (1UL << bit), "m" (*m)
: "memory");
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
@@ -397,7 +397,7 @@ static inline int test_and_clear_bit(unsigned long nr,
smp_llsc_mb();
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
@@ -414,7 +414,7 @@ static inline int test_and_clear_bit(unsigned long nr,
: "r" (1UL << bit), "m" (*m)
: "memory");
#ifdef CONFIG_CPU_MIPSR2
- } else if (__builtin_constant_p(nr)) {
+ } else if (kernel_uses_llsc && __builtin_constant_p(nr)) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
@@ -431,7 +431,7 @@ static inline int test_and_clear_bit(unsigned long nr,
: "ir" (bit), "m" (*m)
: "memory");
#endif
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
@@ -487,7 +487,7 @@ static inline int test_and_change_bit(unsigned long nr,
smp_llsc_mb();
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
@@ -502,7 +502,7 @@ static inline int test_and_change_bit(unsigned long nr,
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "r" (1UL << bit), "m" (*m)
: "memory");
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
diff --git a/arch/mips/include/asm/cmpxchg.h b/arch/mips/include/asm/cmpxchg.h
index 4a812c3..815a438 100644
--- a/arch/mips/include/asm/cmpxchg.h
+++ b/arch/mips/include/asm/cmpxchg.h
@@ -16,7 +16,7 @@
({ \
__typeof(*(m)) __ret; \
\
- if (cpu_has_llsc && R10000_LLSC_WAR) { \
+ if (kernel_uses_llsc && R10000_LLSC_WAR) { \
__asm__ __volatile__( \
" .set push \n" \
" .set noat \n" \
@@ -33,7 +33,7 @@
: "=&r" (__ret), "=R" (*m) \
: "R" (*m), "Jr" (old), "Jr" (new) \
: "memory"); \
- } else if (cpu_has_llsc) { \
+ } else if (kernel_uses_llsc) { \
__asm__ __volatile__( \
" .set push \n" \
" .set noat \n" \
diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 8ab1d12..e581cc0 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -78,7 +78,14 @@
#define cpu_has_ejtag (cpu_data[0].options & MIPS_CPU_EJTAG)
#endif
#ifndef cpu_has_llsc
-#define cpu_has_llsc (cpu_data[0].options & MIPS_CPU_LLSC)
+# ifdef CONFIG_CPU_HAS_LLSC
+# define cpu_has_llsc 1
+# else
+# define cpu_has_llsc (cpu_data[0].options & MIPS_CPU_LLSC)
+# endif
+#endif
+#ifndef kernel_uses_llsc
+#define kernel_uses_llsc cpu_has_llsc
#endif
#ifndef cpu_has_mips16
#define cpu_has_mips16 (cpu_data[0].ases & MIPS_ASE_MIPS16)
diff --git a/arch/mips/include/asm/local.h b/arch/mips/include/asm/local.h
index f96fd59..361f4f1 100644
--- a/arch/mips/include/asm/local.h
+++ b/arch/mips/include/asm/local.h
@@ -29,7 +29,7 @@ static __inline__ long local_add_return(long i, local_t * l)
{
unsigned long result;
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
unsigned long temp;
__asm__ __volatile__(
@@ -43,7 +43,7 @@ static __inline__ long local_add_return(long i, local_t * l)
: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
: "Ir" (i), "m" (l->a.counter)
: "memory");
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
unsigned long temp;
__asm__ __volatile__(
@@ -74,7 +74,7 @@ static __inline__ long local_sub_return(long i, local_t * l)
{
unsigned long result;
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
unsigned long temp;
__asm__ __volatile__(
@@ -88,7 +88,7 @@ static __inline__ long local_sub_return(long i, local_t * l)
: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
: "Ir" (i), "m" (l->a.counter)
: "memory");
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
unsigned long temp;
__asm__ __volatile__(
diff --git a/arch/mips/include/asm/system.h b/arch/mips/include/asm/system.h
index cd30f83..5e6287f 100644
--- a/arch/mips/include/asm/system.h
+++ b/arch/mips/include/asm/system.h
@@ -84,7 +84,7 @@ static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
{
__u32 retval;
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
unsigned long dummy;
__asm__ __volatile__(
@@ -99,7 +99,7 @@ static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
: "=&r" (retval), "=m" (*m), "=&r" (dummy)
: "R" (*m), "Jr" (val)
: "memory");
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
unsigned long dummy;
__asm__ __volatile__(
@@ -136,7 +136,7 @@ static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
{
__u64 retval;
- if (cpu_has_llsc && R10000_LLSC_WAR) {
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
unsigned long dummy;
__asm__ __volatile__(
@@ -149,7 +149,7 @@ static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
: "=&r" (retval), "=m" (*m), "=&r" (dummy)
: "R" (*m), "Jr" (val)
: "memory");
- } else if (cpu_has_llsc) {
+ } else if (kernel_uses_llsc) {
unsigned long dummy;
__asm__ __volatile__(
--
1.6.0.6
