diff options
Diffstat (limited to 'kernel/arch/sparc/lib/locks.S')
| -rw-r--r-- | kernel/arch/sparc/lib/locks.S | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/kernel/arch/sparc/lib/locks.S b/kernel/arch/sparc/lib/locks.S new file mode 100644 index 000000000..64f53f2b6 --- /dev/null +++ b/kernel/arch/sparc/lib/locks.S @@ -0,0 +1,92 @@ +/* + * 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 <asm/ptrace.h> +#include <asm/psr.h> +#include <asm/smp.h> +#include <asm/spinlock.h> + + .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_try_spin_on_wlock: + andcc %g2, 0xff, %g0 + be,a ___rw_read_try + ldstub [%g1 + 3], %g2 + xnorcc %g2, 0x0, %o0 /* if g2 is ~0, set o0 to 0 and bugger off */ + bne,a ___rw_read_enter_spin_on_wlock + ld [%g1], %g2 + retl + mov %g4, %o7 +___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_read_try +___rw_read_try: + orcc %g2, 0x0, %g0 + bne ___rw_read_try_spin_on_wlock + ld [%g1], %g2 + add %g2, 1, %g2 + st %g2, [%g1] + set 1, %o1 + 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 |