| Message ID | 1384442387-18519-1-git-send-email-stefano.stabellini@eu.citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 14 Nov 2013, Stefano Stabellini wrote: > Remove !GENERIC_ATOMIC64 build dependency: > - rename atomic64_xchg to armv7_atomic64_xchg and define it even ifdef > GENERIC_ATOMIC64; > - call armv7_atomic64_xchg directly from xen/events.h. > > Remove !CPU_V6 build dependency: > - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef > CONFIG_CPU_V6; > - rename sync_cmpxchg to sync_cmpxchg16; > - implement sync_cmpxchg16 using __cmpxchg16. > > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > CC: arnd@arndb.de > CC: linux@arm.linux.org.uk FYI I forgot the x86 part of the patch, to rename sync_cmpxchg to sync_cmpxchg16. > arch/arm/Kconfig | 3 +- > arch/arm/include/asm/atomic.h | 47 +++++++++++++++------------ > arch/arm/include/asm/cmpxchg.h | 60 ++++++++++++++++++++++++------------ > arch/arm/include/asm/sync_bitops.h | 11 ++++++- > arch/arm/include/asm/xen/events.h | 2 +- > drivers/xen/grant-table.c | 6 ++-- > 6 files changed, 81 insertions(+), 48 deletions(-) > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 01f7013..3a888e1 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -1885,8 +1885,7 @@ config XEN_DOM0 > config XEN > bool "Xen guest support on ARM (EXPERIMENTAL)" > depends on ARM && AEABI && OF > - depends on CPU_V7 && !CPU_V6 > - depends on !GENERIC_ATOMIC64 > + depends on CPU_V7 > select ARM_PSCI > select SWIOTLB_XEN > help > diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h > index da1c77d..6d22634 100644 > --- a/arch/arm/include/asm/atomic.h > +++ b/arch/arm/include/asm/atomic.h > @@ -398,26 +398,7 @@ static inline u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old, u64 new) > return oldval; > } > > -static inline u64 atomic64_xchg(atomic64_t *ptr, u64 new) > -{ > - u64 result; > - unsigned long tmp; > - > - smp_mb(); > - > - __asm__ __volatile__("@ atomic64_xchg\n" > -"1: ldrexd %0, %H0, [%3]\n" > -" strexd %1, %4, %H4, [%3]\n" > -" teq %1, #0\n" > -" bne 1b" > - : "=&r" (result), "=&r" (tmp), "+Qo" (ptr->counter) > - : "r" (&ptr->counter), "r" (new) > - : "cc"); > - > - smp_mb(); > - > - return result; > -} > +#define armv7_atomic64_xchg atomic64_xchg > > static inline u64 atomic64_dec_if_positive(atomic64_t *v) > { > @@ -485,6 +466,30 @@ static inline int atomic64_add_unless(atomic64_t *v, u64 a, u64 u) > #define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0) > #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL) > > -#endif /* !CONFIG_GENERIC_ATOMIC64 */ > +#else /* !CONFIG_GENERIC_ATOMIC64 */ > +#include <asm-generic/atomic64.h> > +#endif > + > +static inline u64 armv7_atomic64_xchg(atomic64_t *ptr, u64 new) > +{ > + u64 result; > + unsigned long tmp; > + > + smp_mb(); > + > + __asm__ __volatile__("@ atomic64_xchg\n" > +"1: ldrexd %0, %H0, [%3]\n" > +" strexd %1, %4, %H4, [%3]\n" > +" teq %1, #0\n" > +" bne 1b" > + : "=&r" (result), "=&r" (tmp), "+Qo" (ptr->counter) > + : "r" (&ptr->counter), "r" (new) > + : "cc"); > + > + smp_mb(); > + > + return result; > +} > + > #endif > #endif > diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h > index 4f009c1..5b5eeb9 100644 > --- a/arch/arm/include/asm/cmpxchg.h > +++ b/arch/arm/include/asm/cmpxchg.h > @@ -133,6 +133,44 @@ extern void __bad_cmpxchg(volatile void *ptr, int size); > * cmpxchg only support 32-bits operands on ARMv6. > */ > > +static inline unsigned long __cmpxchg8(volatile void *ptr, unsigned long old, > + unsigned long new) > +{ > + unsigned long oldval, res; > + > + do { > + asm volatile("@ __cmpxchg1\n" > + " ldrexb %1, [%2]\n" > + " mov %0, #0\n" > + " teq %1, %3\n" > + " strexbeq %0, %4, [%2]\n" > + : "=&r" (res), "=&r" (oldval) > + : "r" (ptr), "Ir" (old), "r" (new) > + : "memory", "cc"); > + } while (res); > + > + return oldval; > +} > + > +static inline unsigned long __cmpxchg16(volatile void *ptr, unsigned long old, > + unsigned long new) > +{ > + unsigned long oldval, res; > + > + do { > + asm volatile("@ __cmpxchg1\n" > + " ldrexh %1, [%2]\n" > + " mov %0, #0\n" > + " teq %1, %3\n" > + " strexheq %0, %4, [%2]\n" > + : "=&r" (res), "=&r" (oldval) > + : "r" (ptr), "Ir" (old), "r" (new) > + : "memory", "cc"); > + } while (res); > + > + return oldval; > +} > + > static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, > unsigned long new, int size) > { > @@ -141,28 +179,10 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, > switch (size) { > #ifndef CONFIG_CPU_V6 /* min ARCH >= ARMv6K */ > case 1: > - do { > - asm volatile("@ __cmpxchg1\n" > - " ldrexb %1, [%2]\n" > - " mov %0, #0\n" > - " teq %1, %3\n" > - " strexbeq %0, %4, [%2]\n" > - : "=&r" (res), "=&r" (oldval) > - : "r" (ptr), "Ir" (old), "r" (new) > - : "memory", "cc"); > - } while (res); > + __cmpxchg8(ptr, old, new); > break; > case 2: > - do { > - asm volatile("@ __cmpxchg1\n" > - " ldrexh %1, [%2]\n" > - " mov %0, #0\n" > - " teq %1, %3\n" > - " strexheq %0, %4, [%2]\n" > - : "=&r" (res), "=&r" (oldval) > - : "r" (ptr), "Ir" (old), "r" (new) > - : "memory", "cc"); > - } while (res); > + __cmpxchg16(ptr, old, new); > break; > #endif > case 4: > diff --git a/arch/arm/include/asm/sync_bitops.h b/arch/arm/include/asm/sync_bitops.h > index 63479ee..02865ad 100644 > --- a/arch/arm/include/asm/sync_bitops.h > +++ b/arch/arm/include/asm/sync_bitops.h > @@ -21,7 +21,16 @@ > #define sync_test_and_clear_bit(nr, p) _test_and_clear_bit(nr, p) > #define sync_test_and_change_bit(nr, p) _test_and_change_bit(nr, p) > #define sync_test_bit(nr, addr) test_bit(nr, addr) > -#define sync_cmpxchg cmpxchg > > +static inline u16 sync_cmpxchg16(volatile void *ptr, u16 old, u16 new) > +{ > + unsigned long ret; > + > + smp_mb(); > + ret = __cmpxchg16(ptr, old, new); > + smp_mb(); > + > + return ret; > +} > > #endif > diff --git a/arch/arm/include/asm/xen/events.h b/arch/arm/include/asm/xen/events.h > index 8b1f37b..4269519 100644 > --- a/arch/arm/include/asm/xen/events.h > +++ b/arch/arm/include/asm/xen/events.h > @@ -16,7 +16,7 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) > return raw_irqs_disabled_flags(regs->ARM_cpsr); > } > > -#define xchg_xen_ulong(ptr, val) atomic64_xchg(container_of((ptr), \ > +#define xchg_xen_ulong(ptr, val) armv7_atomic64_xchg(container_of((ptr), \ > atomic64_t, \ > counter), (val)) > > diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c > index 62ccf54..bd37c14 100644 > --- a/drivers/xen/grant-table.c > +++ b/drivers/xen/grant-table.c > @@ -430,7 +430,7 @@ static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) > flags = nflags; > if (flags & (GTF_reading|GTF_writing)) > return 0; > - } while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags); > + } while ((nflags = sync_cmpxchg16(pflags, flags, 0)) != flags); > > return 1; > } > @@ -600,7 +600,7 @@ static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) > * reference and return failure (== 0). > */ > while (!((flags = *pflags) & GTF_transfer_committed)) { > - if (sync_cmpxchg(pflags, flags, 0) == flags) > + if (sync_cmpxchg16(pflags, flags, 0) == flags) > return 0; > cpu_relax(); > } > @@ -631,7 +631,7 @@ static unsigned long gnttab_end_foreign_transfer_ref_v2(grant_ref_t ref) > * reference and return failure (== 0). > */ > while (!((flags = *pflags) & GTF_transfer_committed)) { > - if (sync_cmpxchg(pflags, flags, 0) == flags) > + if (sync_cmpxchg16(pflags, flags, 0) == flags) > return 0; > cpu_relax(); > } > -- > 1.7.2.5 >
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 01f7013..3a888e1 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1885,8 +1885,7 @@ config XEN_DOM0 config XEN bool "Xen guest support on ARM (EXPERIMENTAL)" depends on ARM && AEABI && OF - depends on CPU_V7 && !CPU_V6 - depends on !GENERIC_ATOMIC64 + depends on CPU_V7 select ARM_PSCI select SWIOTLB_XEN help diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h index da1c77d..6d22634 100644 --- a/arch/arm/include/asm/atomic.h +++ b/arch/arm/include/asm/atomic.h @@ -398,26 +398,7 @@ static inline u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old, u64 new) return oldval; } -static inline u64 atomic64_xchg(atomic64_t *ptr, u64 new) -{ - u64 result; - unsigned long tmp; - - smp_mb(); - - __asm__ __volatile__("@ atomic64_xchg\n" -"1: ldrexd %0, %H0, [%3]\n" -" strexd %1, %4, %H4, [%3]\n" -" teq %1, #0\n" -" bne 1b" - : "=&r" (result), "=&r" (tmp), "+Qo" (ptr->counter) - : "r" (&ptr->counter), "r" (new) - : "cc"); - - smp_mb(); - - return result; -} +#define armv7_atomic64_xchg atomic64_xchg static inline u64 atomic64_dec_if_positive(atomic64_t *v) { @@ -485,6 +466,30 @@ static inline int atomic64_add_unless(atomic64_t *v, u64 a, u64 u) #define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0) #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL) -#endif /* !CONFIG_GENERIC_ATOMIC64 */ +#else /* !CONFIG_GENERIC_ATOMIC64 */ +#include <asm-generic/atomic64.h> +#endif + +static inline u64 armv7_atomic64_xchg(atomic64_t *ptr, u64 new) +{ + u64 result; + unsigned long tmp; + + smp_mb(); + + __asm__ __volatile__("@ atomic64_xchg\n" +"1: ldrexd %0, %H0, [%3]\n" +" strexd %1, %4, %H4, [%3]\n" +" teq %1, #0\n" +" bne 1b" + : "=&r" (result), "=&r" (tmp), "+Qo" (ptr->counter) + : "r" (&ptr->counter), "r" (new) + : "cc"); + + smp_mb(); + + return result; +} + #endif #endif diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h index 4f009c1..5b5eeb9 100644 --- a/arch/arm/include/asm/cmpxchg.h +++ b/arch/arm/include/asm/cmpxchg.h @@ -133,6 +133,44 @@ extern void __bad_cmpxchg(volatile void *ptr, int size); * cmpxchg only support 32-bits operands on ARMv6. */ +static inline unsigned long __cmpxchg8(volatile void *ptr, unsigned long old, + unsigned long new) +{ + unsigned long oldval, res; + + do { + asm volatile("@ __cmpxchg1\n" + " ldrexb %1, [%2]\n" + " mov %0, #0\n" + " teq %1, %3\n" + " strexbeq %0, %4, [%2]\n" + : "=&r" (res), "=&r" (oldval) + : "r" (ptr), "Ir" (old), "r" (new) + : "memory", "cc"); + } while (res); + + return oldval; +} + +static inline unsigned long __cmpxchg16(volatile void *ptr, unsigned long old, + unsigned long new) +{ + unsigned long oldval, res; + + do { + asm volatile("@ __cmpxchg1\n" + " ldrexh %1, [%2]\n" + " mov %0, #0\n" + " teq %1, %3\n" + " strexheq %0, %4, [%2]\n" + : "=&r" (res), "=&r" (oldval) + : "r" (ptr), "Ir" (old), "r" (new) + : "memory", "cc"); + } while (res); + + return oldval; +} + static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size) { @@ -141,28 +179,10 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, switch (size) { #ifndef CONFIG_CPU_V6 /* min ARCH >= ARMv6K */ case 1: - do { - asm volatile("@ __cmpxchg1\n" - " ldrexb %1, [%2]\n" - " mov %0, #0\n" - " teq %1, %3\n" - " strexbeq %0, %4, [%2]\n" - : "=&r" (res), "=&r" (oldval) - : "r" (ptr), "Ir" (old), "r" (new) - : "memory", "cc"); - } while (res); + __cmpxchg8(ptr, old, new); break; case 2: - do { - asm volatile("@ __cmpxchg1\n" - " ldrexh %1, [%2]\n" - " mov %0, #0\n" - " teq %1, %3\n" - " strexheq %0, %4, [%2]\n" - : "=&r" (res), "=&r" (oldval) - : "r" (ptr), "Ir" (old), "r" (new) - : "memory", "cc"); - } while (res); + __cmpxchg16(ptr, old, new); break; #endif case 4: diff --git a/arch/arm/include/asm/sync_bitops.h b/arch/arm/include/asm/sync_bitops.h index 63479ee..02865ad 100644 --- a/arch/arm/include/asm/sync_bitops.h +++ b/arch/arm/include/asm/sync_bitops.h @@ -21,7 +21,16 @@ #define sync_test_and_clear_bit(nr, p) _test_and_clear_bit(nr, p) #define sync_test_and_change_bit(nr, p) _test_and_change_bit(nr, p) #define sync_test_bit(nr, addr) test_bit(nr, addr) -#define sync_cmpxchg cmpxchg +static inline u16 sync_cmpxchg16(volatile void *ptr, u16 old, u16 new) +{ + unsigned long ret; + + smp_mb(); + ret = __cmpxchg16(ptr, old, new); + smp_mb(); + + return ret; +} #endif diff --git a/arch/arm/include/asm/xen/events.h b/arch/arm/include/asm/xen/events.h index 8b1f37b..4269519 100644 --- a/arch/arm/include/asm/xen/events.h +++ b/arch/arm/include/asm/xen/events.h @@ -16,7 +16,7 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) return raw_irqs_disabled_flags(regs->ARM_cpsr); } -#define xchg_xen_ulong(ptr, val) atomic64_xchg(container_of((ptr), \ +#define xchg_xen_ulong(ptr, val) armv7_atomic64_xchg(container_of((ptr), \ atomic64_t, \ counter), (val)) diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 62ccf54..bd37c14 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -430,7 +430,7 @@ static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly) flags = nflags; if (flags & (GTF_reading|GTF_writing)) return 0; - } while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags); + } while ((nflags = sync_cmpxchg16(pflags, flags, 0)) != flags); return 1; } @@ -600,7 +600,7 @@ static unsigned long gnttab_end_foreign_transfer_ref_v1(grant_ref_t ref) * reference and return failure (== 0). */ while (!((flags = *pflags) & GTF_transfer_committed)) { - if (sync_cmpxchg(pflags, flags, 0) == flags) + if (sync_cmpxchg16(pflags, flags, 0) == flags) return 0; cpu_relax(); } @@ -631,7 +631,7 @@ static unsigned long gnttab_end_foreign_transfer_ref_v2(grant_ref_t ref) * reference and return failure (== 0). */ while (!((flags = *pflags) & GTF_transfer_committed)) { - if (sync_cmpxchg(pflags, flags, 0) == flags) + if (sync_cmpxchg16(pflags, flags, 0) == flags) return 0; cpu_relax(); }
Remove !GENERIC_ATOMIC64 build dependency: - rename atomic64_xchg to armv7_atomic64_xchg and define it even ifdef GENERIC_ATOMIC64; - call armv7_atomic64_xchg directly from xen/events.h. Remove !CPU_V6 build dependency: - introduce __cmpxchg8 and __cmpxchg16, compiled even ifdef CONFIG_CPU_V6; - rename sync_cmpxchg to sync_cmpxchg16; - implement sync_cmpxchg16 using __cmpxchg16. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> CC: arnd@arndb.de CC: linux@arm.linux.org.uk --- arch/arm/Kconfig | 3 +- arch/arm/include/asm/atomic.h | 47 +++++++++++++++------------ arch/arm/include/asm/cmpxchg.h | 60 ++++++++++++++++++++++++------------ arch/arm/include/asm/sync_bitops.h | 11 ++++++- arch/arm/include/asm/xen/events.h | 2 +- drivers/xen/grant-table.c | 6 ++-- 6 files changed, 81 insertions(+), 48 deletions(-)