/* rwsem.S: RW semaphore assembler. * * Written by David S. Miller (davem@redhat.com), 2001. * Derived from asm-i386/rwsem.h */ #include <asm/rwsem-const.h> .section .sched.text .globl __down_read __down_read: 1: lduw [%o0], %g1 add %g1, 1, %g7 cas [%o0], %g1, %g7 cmp %g1, %g7 bne,pn %icc, 1b add %g7, 1, %g7 cmp %g7, 0 membar #StoreLoad | #StoreStore bl,pn %icc, 3f nop 2: retl nop 3: save %sp, -192, %sp call rwsem_down_read_failed mov %i0, %o0 ret restore .size __down_read, .-__down_read .globl __down_read_trylock __down_read_trylock: 1: lduw [%o0], %g1 add %g1, 1, %g7 cmp %g7, 0 bl,pn %icc, 2f mov 0, %o1 cas [%o0], %g1, %g7 cmp %g1, %g7 bne,pn %icc, 1b mov 1, %o1 membar #StoreLoad | #StoreStore 2: retl mov %o1, %o0 .size __down_read_trylock, .-__down_read_trylock .globl __down_write __down_write: sethi %hi(RWSEM_ACTIVE_WRITE_BIAS), %g1 or %g1, %lo(RWSEM_ACTIVE_WRITE_BIAS), %g1 1: lduw [%o0], %g3 add %g3, %g1, %g7 cas [%o0], %g3, %g7 cmp %g3, %g7 bne,pn %icc, 1b cmp %g7, 0 membar #StoreLoad | #StoreStore bne,pn %icc, 3f nop 2: retl nop 3: save %sp, -192, %sp call rwsem_down_write_failed mov %i0, %o0 ret restore .size __down_write, .-__down_write .globl __down_write_trylock __down_write_trylock: sethi %hi(RWSEM_ACTIVE_WRITE_BIAS), %g1 or %g1, %lo(RWSEM_ACTIVE_WRITE_BIAS), %g1 1: lduw [%o0], %g3 cmp %g3, 0 bne,pn %icc, 2f mov 0, %o1 add %g3, %g1, %g7 cas [%o0], %g3, %g7 cmp %g3, %g7 bne,pn %icc, 1b mov 1, %o1 membar #StoreLoad | #StoreStore 2: retl mov %o1, %o0 .size __down_write_trylock, .-__down_write_trylock .globl __up_read __up_read: 1: lduw [%o0], %g1 sub %g1, 1, %g7 cas [%o0], %g1, %g7 cmp %g1, %g7 bne,pn %icc, 1b cmp %g7, 0 membar #StoreLoad | #StoreStore bl,pn %icc, 3f nop 2: retl nop 3: sethi %hi(RWSEM_ACTIVE_MASK), %g1 sub %g7, 1, %g7 or %g1, %lo(RWSEM_ACTIVE_MASK), %g1 andcc %g7, %g1, %g0 bne,pn %icc, 2b nop save %sp, -192, %sp call rwsem_wake mov %i0, %o0 ret restore .size __up_read, .-__up_read .globl __up_write __up_write: sethi %hi(RWSEM_ACTIVE_WRITE_BIAS), %g1 or %g1, %lo(RWSEM_ACTIVE_WRITE_BIAS), %g1 1: lduw [%o0], %g3 sub %g3, %g1, %g7 cas [%o0], %g3, %g7 cmp %g3, %g7 bne,pn %icc, 1b sub %g7, %g1, %g7 cmp %g7, 0 membar #StoreLoad | #StoreStore bl,pn %icc, 3f nop 2: retl nop 3: save %sp, -192, %sp call rwsem_wake mov %i0, %o0 ret restore .size __up_write, .-__up_write .globl __downgrade_write __downgrade_write: sethi %hi(RWSEM_WAITING_BIAS), %g1 or %g1, %lo(RWSEM_WAITING_BIAS), %g1 1: lduw [%o0], %g3 sub %g3, %g1, %g7 cas [%o0], %g3, %g7 cmp %g3, %g7 bne,pn %icc, 1b sub %g7, %g1, %g7 cmp %g7, 0 membar #StoreLoad | #StoreStore bl,pn %icc, 3f nop 2: retl nop 3: save %sp, -192, %sp call rwsem_downgrade_wake mov %i0, %o0 ret restore .size __downgrade_write, .-__downgrade_write