Subversion Repositories or1k

/* bitops.S: Low level assembler bit operations.
 *
 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
 */

#include <linux/config.h>
#include <asm/cprefix.h>
#include <asm/ptrace.h>
#include <asm/psr.h>

        .text
        .align  4

        .globl  __bitops_begin
__bitops_begin:

        /* Take bits in %g2 and set them in word at %g1,
         * return whether bits were set in original value
         * in %g2.  %g4 holds value to restore into %o7
         * in delay slot of jmpl return, %g3 + %g5 + %g7 can be
         * used as temporaries and thus is considered clobbered
         * by all callers.
         */
        .globl  ___set_bit
___set_bit:
        rd      %psr, %g3
        nop; nop; nop;
        or      %g3, PSR_PIL, %g5
        wr      %g5, 0x0, %psr
        nop; nop; nop
#ifdef CONFIG_SMP
        set     C_LABEL(bitops_spinlock), %g5
2:      ldstub  [%g5], %g7              ! Spin on the byte lock for SMP.
        orcc    %g7, 0x0, %g0           ! Did we get it?
        bne     2b                      ! Nope...
#endif
         ld     [%g1], %g7
        or      %g7, %g2, %g5
        and     %g7, %g2, %g2
#ifdef CONFIG_SMP
        st      %g5, [%g1]
        set     C_LABEL(bitops_spinlock), %g5
        stb     %g0, [%g5]
#else
        st      %g5, [%g1]
#endif
        wr      %g3, 0x0, %psr
        nop; nop; nop
        jmpl    %o7, %g0
         mov    %g4, %o7

        /* Same as above, but clears the bits from %g2 instead. */
        .globl  ___clear_bit
___clear_bit:
        rd      %psr, %g3
        nop; nop; nop
        or      %g3, PSR_PIL, %g5
        wr      %g5, 0x0, %psr
        nop; nop; nop
#ifdef CONFIG_SMP
        set     C_LABEL(bitops_spinlock), %g5
2:      ldstub  [%g5], %g7              ! Spin on the byte lock for SMP.
        orcc    %g7, 0x0, %g0           ! Did we get it?
        bne     2b                      ! Nope...
#endif
         ld     [%g1], %g7
        andn    %g7, %g2, %g5
        and     %g7, %g2, %g2
#ifdef CONFIG_SMP
        st      %g5, [%g1]
        set     C_LABEL(bitops_spinlock), %g5
        stb     %g0, [%g5]
#else
        st      %g5, [%g1]
#endif
        wr      %g3, 0x0, %psr
        nop; nop; nop
        jmpl    %o7, %g0
         mov    %g4, %o7

        /* Same thing again, but this time toggles the bits from %g2. */
        .globl  ___change_bit
___change_bit:
        rd      %psr, %g3
        nop; nop; nop
        or      %g3, PSR_PIL, %g5
        wr      %g5, 0x0, %psr
        nop; nop; nop
#ifdef CONFIG_SMP
        set     C_LABEL(bitops_spinlock), %g5
2:      ldstub  [%g5], %g7              ! Spin on the byte lock for SMP.
        orcc    %g7, 0x0, %g0           ! Did we get it?
        bne     2b                      ! Nope...
#endif
         ld     [%g1], %g7
        xor     %g7, %g2, %g5
        and     %g7, %g2, %g2
#ifdef CONFIG_SMP
        st      %g5, [%g1]
        set     C_LABEL(bitops_spinlock), %g5
        stb     %g0, [%g5]
#else
        st      %g5, [%g1]
#endif
        wr      %g3, 0x0, %psr
        nop; nop; nop
        jmpl    %o7, %g0
         mov    %g4, %o7

        .globl  __bitops_end
__bitops_end: