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