| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* atomic.S: Move this stuff here for better ICACHE hit rates. |
| 2 | * |
| 3 | * Copyright (C) 1996 David S. Miller (davem@caipfs.rutgers.edu) |
| 4 | */ |
| 5 | |
| 6 | #include <linux/config.h> |
| 7 | #include <asm/ptrace.h> |
| 8 | #include <asm/psr.h> |
| 9 | |
| 10 | .text |
| 11 | .align 4 |
| 12 | |
| 13 | .globl __atomic_begin |
| 14 | __atomic_begin: |
| 15 | |
| 16 | #ifndef CONFIG_SMP |
| 17 | .globl ___xchg32_sun4c |
| 18 | ___xchg32_sun4c: |
| 19 | rd %psr, %g3 |
| 20 | andcc %g3, PSR_PIL, %g0 |
| 21 | bne 1f |
| 22 | nop |
| 23 | wr %g3, PSR_PIL, %psr |
| 24 | nop; nop; nop |
| 25 | 1: |
| 26 | andcc %g3, PSR_PIL, %g0 |
| 27 | ld [%g1], %g7 |
| 28 | bne 1f |
| 29 | st %g2, [%g1] |
| 30 | wr %g3, 0x0, %psr |
| 31 | nop; nop; nop |
| 32 | 1: |
| 33 | mov %g7, %g2 |
| 34 | jmpl %o7 + 8, %g0 |
| 35 | mov %g4, %o7 |
| 36 | |
| 37 | .globl ___xchg32_sun4md |
| 38 | ___xchg32_sun4md: |
| 39 | swap [%g1], %g2 |
| 40 | jmpl %o7 + 8, %g0 |
| 41 | mov %g4, %o7 |
| 42 | #endif |
| 43 | |
| 44 | /* Read asm-sparc/atomic.h carefully to understand how this works for SMP. |
| 45 | * Really, some things here for SMP are overly clever, go read the header. |
| 46 | */ |
| 47 | .globl ___atomic24_add |
| 48 | ___atomic24_add: |
| 49 | rd %psr, %g3 ! Keep the code small, old way was stupid |
| 50 | nop; nop; nop; ! Let the bits set |
| 51 | or %g3, PSR_PIL, %g7 ! Disable interrupts |
| 52 | wr %g7, 0x0, %psr ! Set %psr |
| 53 | nop; nop; nop; ! Let the bits set |
| 54 | #ifdef CONFIG_SMP |
| 55 | 1: ldstub [%g1 + 3], %g7 ! Spin on the byte lock for SMP. |
| 56 | orcc %g7, 0x0, %g0 ! Did we get it? |
| 57 | bne 1b ! Nope... |
| 58 | ld [%g1], %g7 ! Load locked atomic24_t |
| 59 | sra %g7, 8, %g7 ! Get signed 24-bit integer |
| 60 | add %g7, %g2, %g2 ! Add in argument |
| 61 | sll %g2, 8, %g7 ! Transpose back to atomic24_t |
| 62 | st %g7, [%g1] ! Clever: This releases the lock as well. |
| 63 | #else |
| 64 | ld [%g1], %g7 ! Load locked atomic24_t |
| 65 | add %g7, %g2, %g2 ! Add in argument |
| 66 | st %g2, [%g1] ! Store it back |
| 67 | #endif |
| 68 | wr %g3, 0x0, %psr ! Restore original PSR_PIL |
| 69 | nop; nop; nop; ! Let the bits set |
| 70 | jmpl %o7, %g0 ! NOTE: not + 8, see callers in atomic.h |
| 71 | mov %g4, %o7 ! Restore %o7 |
| 72 | |
| 73 | .globl ___atomic24_sub |
| 74 | ___atomic24_sub: |
| 75 | rd %psr, %g3 ! Keep the code small, old way was stupid |
| 76 | nop; nop; nop; ! Let the bits set |
| 77 | or %g3, PSR_PIL, %g7 ! Disable interrupts |
| 78 | wr %g7, 0x0, %psr ! Set %psr |
| 79 | nop; nop; nop; ! Let the bits set |
| 80 | #ifdef CONFIG_SMP |
| 81 | 1: ldstub [%g1 + 3], %g7 ! Spin on the byte lock for SMP. |
| 82 | orcc %g7, 0x0, %g0 ! Did we get it? |
| 83 | bne 1b ! Nope... |
| 84 | ld [%g1], %g7 ! Load locked atomic24_t |
| 85 | sra %g7, 8, %g7 ! Get signed 24-bit integer |
| 86 | sub %g7, %g2, %g2 ! Subtract argument |
| 87 | sll %g2, 8, %g7 ! Transpose back to atomic24_t |
| 88 | st %g7, [%g1] ! Clever: This releases the lock as well |
| 89 | #else |
| 90 | ld [%g1], %g7 ! Load locked atomic24_t |
| 91 | sub %g7, %g2, %g2 ! Subtract argument |
| 92 | st %g2, [%g1] ! Store it back |
| 93 | #endif |
| 94 | wr %g3, 0x0, %psr ! Restore original PSR_PIL |
| 95 | nop; nop; nop; ! Let the bits set |
| 96 | jmpl %o7, %g0 ! NOTE: not + 8, see callers in atomic.h |
| 97 | mov %g4, %o7 ! Restore %o7 |
| 98 | |
| 99 | .globl __atomic_end |
| 100 | __atomic_end: |