Author: jhibbits Date: Mon Jan 30 02:15:54 2017 New Revision: 312973 URL: https://svnweb.freebsd.org/changeset/base/312973
Log: Add atomic_fcmpset_*() inlines for powerpc Summary: atomic_fcmpset_*() is analogous to atomic_cmpset(), but saves off the read value from the target memory location into the 'old' pointer in the case of failure. Requested by: mjg Differential Revision: https://reviews.freebsd.org/D9325 Modified: head/sys/powerpc/include/atomic.h Modified: head/sys/powerpc/include/atomic.h ============================================================================== --- head/sys/powerpc/include/atomic.h Mon Jan 30 01:11:30 2017 (r312972) +++ head/sys/powerpc/include/atomic.h Mon Jan 30 02:15:54 2017 (r312973) @@ -674,6 +674,129 @@ atomic_cmpset_rel_long(volatile u_long * #define atomic_cmpset_rel_ptr atomic_cmpset_rel_int #endif +/* + * Atomically compare the value stored at *p with *cmpval and if the + * two values are equal, update the value of *p with newval. Returns + * zero if the compare failed and sets *cmpval to the read value from *p, + * nonzero otherwise. + */ +static __inline int +atomic_fcmpset_int(volatile u_int *p, u_int *cmpval, u_int newval) +{ + int ret; + +#ifdef __GNUCLIKE_ASM + __asm __volatile ( + "1:\tlwarx %0, 0, %3\n\t" /* load old value */ + "cmplw %4, %0\n\t" /* compare */ + "bne 2f\n\t" /* exit if not equal */ + "stwcx. %5, 0, %3\n\t" /* attempt to store */ + "bne- 1b\n\t" /* spin if failed */ + "li %0, 1\n\t" /* success - retval = 1 */ + "b 3f\n\t" /* we've succeeded */ + "2:\n\t" + "stwcx. %0, 0, %3\n\t" /* clear reservation (74xx) */ + "stwx %0, 0, %7\n\t" + "li %0, 0\n\t" /* failure - retval = 0 */ + "3:\n\t" + : "=&r" (ret), "=m" (*p), "=m" (*cmpval) + : "r" (p), "r" (*cmpval), "r" (newval), "m" (*p), "r"(cmpval) + : "cr0", "memory"); +#endif + + return (ret); +} +static __inline int +atomic_fcmpset_long(volatile u_long *p, u_long *cmpval, u_long newval) +{ + int ret; + +#ifdef __GNUCLIKE_ASM + __asm __volatile ( + #ifdef __powerpc64__ + "1:\tldarx %0, 0, %3\n\t" /* load old value */ + "cmpld %4, %0\n\t" /* compare */ + "bne 2f\n\t" /* exit if not equal */ + "stdcx. %5, 0, %3\n\t" /* attempt to store */ + #else + "1:\tlwarx %0, 0, %3\n\t" /* load old value */ + "cmplw %4, %0\n\t" /* compare */ + "bne 2f\n\t" /* exit if not equal */ + "stwcx. %5, 0, %3\n\t" /* attempt to store */ + #endif + "bne- 1b\n\t" /* spin if failed */ + "li %0, 1\n\t" /* success - retval = 1 */ + "b 3f\n\t" /* we've succeeded */ + "2:\n\t" + #ifdef __powerpc64__ + "stdcx. %0, 0, %3\n\t" /* clear reservation (74xx) */ + "stdx %0, 0, %7\n\t" + #else + "stwcx. %0, 0, %3\n\t" /* clear reservation (74xx) */ + "stwx %0, 0, %7\n\t" + #endif + "li %0, 0\n\t" /* failure - retval = 0 */ + "3:\n\t" + : "=&r" (ret), "=m" (*p), "=m" (*cmpval) + : "r" (p), "r" (*cmpval), "r" (newval), "m" (*p), "r"(cmpval) + : "cr0", "memory"); +#endif + + return (ret); +} + +static __inline int +atomic_fcmpset_acq_int(volatile u_int *p, u_int *cmpval, u_int newval) +{ + int retval; + + retval = atomic_fcmpset_int(p, cmpval, newval); + __ATOMIC_ACQ(); + return (retval); +} + +static __inline int +atomic_fcmpset_rel_int(volatile u_int *p, u_int *cmpval, u_int newval) +{ + __ATOMIC_REL(); + return (atomic_fcmpset_int(p, cmpval, newval)); +} + +static __inline int +atomic_fcmpset_acq_long(volatile u_long *p, u_long *cmpval, u_long newval) +{ + u_long retval; + + retval = atomic_fcmpset_long(p, cmpval, newval); + __ATOMIC_ACQ(); + return (retval); +} + +static __inline int +atomic_fcmpset_rel_long(volatile u_long *p, u_long *cmpval, u_long newval) +{ + __ATOMIC_REL(); + return (atomic_fcmpset_long(p, cmpval, newval)); +} + +#define atomic_fcmpset_32 atomic_fcmpset_int +#define atomic_fcmpset_acq_32 atomic_fcmpset_acq_int +#define atomic_fcmpset_rel_32 atomic_fcmpset_rel_int + +#ifdef __powerpc64__ +#define atomic_fcmpset_64 atomic_fcmpset_long +#define atomic_fcmpset_acq_64 atomic_fcmpset_acq_long +#define atomic_fcmpset_rel_64 atomic_fcmpset_rel_long + +#define atomic_fcmpset_ptr atomic_fcmpset_long +#define atomic_fcmpset_acq_ptr atomic_fcmpset_acq_long +#define atomic_fcmpset_rel_ptr atomic_fcmpset_rel_long +#else +#define atomic_fcmpset_ptr atomic_fcmpset_int +#define atomic_fcmpset_acq_ptr atomic_fcmpset_acq_int +#define atomic_fcmpset_rel_ptr atomic_fcmpset_rel_int +#endif + static __inline u_int atomic_fetchadd_int(volatile u_int *p, u_int v) { _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
