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+/* 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, "ax"
+
+ .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
+ 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
+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
+ 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
+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
+ 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
+ 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
+ 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