/* $Id: locks.S,v 1.16 2000/02/26 11:02:47 anton Exp $ * locks.S: SMP low-level lock primitives on Sparc. * * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) * Copyright (C) 1998 Anton Blanchard (anton@progsoc.uts.edu.au) * Copyright (C) 1998 Jakub Jelinek (jj@ultra.linux.cz) */ #include #include #include #include .text .align 4 /* Read/writer locks, as usual this is overly clever to make it * as fast as possible. */ /* caches... */ ___rw_read_enter_spin_on_wlock: orcc %g2, 0x0, %g0 be,a ___rw_read_enter ldstub [%g1 + 3], %g2 b ___rw_read_enter_spin_on_wlock ldub [%g1 + 3], %g2 ___rw_read_exit_spin_on_wlock: orcc %g2, 0x0, %g0 be,a ___rw_read_exit ldstub [%g1 + 3], %g2 b ___rw_read_exit_spin_on_wlock ldub [%g1 + 3], %g2 ___rw_write_enter_spin_on_wlock: orcc %g2, 0x0, %g0 be,a ___rw_write_enter ldstub [%g1 + 3], %g2 b ___rw_write_enter_spin_on_wlock ld [%g1], %g2 .globl ___rw_read_enter ___rw_read_enter: orcc %g2, 0x0, %g0 bne,a ___rw_read_enter_spin_on_wlock ldub [%g1 + 3], %g2 ld [%g1], %g2 add %g2, 1, %g2 st %g2, [%g1] retl mov %g4, %o7 .globl ___rw_read_exit ___rw_read_exit: orcc %g2, 0x0, %g0 bne,a ___rw_read_exit_spin_on_wlock ldub [%g1 + 3], %g2 ld [%g1], %g2 sub %g2, 0x1ff, %g2 st %g2, [%g1] retl mov %g4, %o7 .globl ___rw_write_enter ___rw_write_enter: orcc %g2, 0x0, %g0 bne ___rw_write_enter_spin_on_wlock ld [%g1], %g2 andncc %g2, 0xff, %g0 bne,a ___rw_write_enter_spin_on_wlock stb %g0, [%g1 + 3] retl mov %g4, %o7