| /* 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: |