projects / mirror_ubuntu-artful-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 96cf5185 G |
1 | /* |
| 2 | * linux/arch/unicore32/lib/findbit.S | |
| 3 | * | |
| 4 | * Code specific to PKUnity SoC and UniCore ISA | |
| 5 | * | |
| 6 | * Copyright (C) 2001-2010 GUAN Xue-tao | |
| 7 | * | |
| 8 | * This program is free software; you can redistribute it and/or modify | |
| 9 | * it under the terms of the GNU General Public License version 2 as | |
| 10 | * published by the Free Software Foundation. | |
| 11 | */ | |
| 12 | #include <linux/linkage.h> | |
| 13 | #include <asm/assembler.h> | |
| 14 | .text | |
| 15 | ||
| 16 | /* | |
| 17 | * Purpose : Find a 'zero' bit | |
| 18 | * Prototype: int find_first_zero_bit(void *addr, unsigned int maxbit); | |
| 19 | */ | |
| e13b91c1 | 20 | ENTRY(find_first_zero_bit) |
| 96cf5185 G |
21 | cxor.a r1, #0 |
| 22 | beq 3f | |
| 23 | mov r2, #0 | |
| 24 | 1: ldb r3, [r0+], r2 >> #3 | |
| 25 | xor.a r3, r3, #0xff @ invert bits | |
| 26 | bne .L_found @ any now set - found zero bit | |
| 27 | add r2, r2, #8 @ next bit pointer | |
| 28 | 2: csub.a r2, r1 @ any more? | |
| 29 | bub 1b | |
| 30 | 3: mov r0, r1 @ no free bits | |
| 31 | mov pc, lr | |
| e13b91c1 | 32 | ENDPROC(find_first_zero_bit) |
| 96cf5185 G |
33 | |
| 34 | /* | |
| 35 | * Purpose : Find next 'zero' bit | |
| 36 | * Prototype: int find_next_zero_bit | |
| 37 | * (void *addr, unsigned int maxbit, int offset) | |
| 38 | */ | |
| e13b91c1 | 39 | ENTRY(find_next_zero_bit) |
| 96cf5185 G |
40 | cxor.a r1, #0 |
| 41 | beq 3b | |
| 42 | and.a ip, r2, #7 | |
| 43 | beq 1b @ If new byte, goto old routine | |
| 44 | ldb r3, [r0+], r2 >> #3 | |
| 45 | xor r3, r3, #0xff @ now looking for a 1 bit | |
| 46 | mov.a r3, r3 >> ip @ shift off unused bits | |
| 47 | bne .L_found | |
| 48 | or r2, r2, #7 @ if zero, then no bits here | |
| 49 | add r2, r2, #1 @ align bit pointer | |
| 50 | b 2b @ loop for next bit | |
| e13b91c1 | 51 | ENDPROC(find_next_zero_bit) |
| 96cf5185 G |
52 | |
| 53 | /* | |
| 54 | * Purpose : Find a 'one' bit | |
| 55 | * Prototype: int find_first_bit | |
| 56 | * (const unsigned long *addr, unsigned int maxbit); | |
| 57 | */ | |
| e13b91c1 | 58 | ENTRY(find_first_bit) |
| 96cf5185 G |
59 | cxor.a r1, #0 |
| 60 | beq 3f | |
| 61 | mov r2, #0 | |
| 62 | 1: ldb r3, [r0+], r2 >> #3 | |
| 63 | mov.a r3, r3 | |
| 64 | bne .L_found @ any now set - found zero bit | |
| 65 | add r2, r2, #8 @ next bit pointer | |
| 66 | 2: csub.a r2, r1 @ any more? | |
| 67 | bub 1b | |
| 68 | 3: mov r0, r1 @ no free bits | |
| 69 | mov pc, lr | |
| e13b91c1 | 70 | ENDPROC(find_first_bit) |
| 96cf5185 G |
71 | |
| 72 | /* | |
| 73 | * Purpose : Find next 'one' bit | |
| 74 | * Prototype: int find_next_zero_bit | |
| 75 | * (void *addr, unsigned int maxbit, int offset) | |
| 76 | */ | |
| e13b91c1 | 77 | ENTRY(find_next_bit) |
| 96cf5185 G |
78 | cxor.a r1, #0 |
| 79 | beq 3b | |
| 80 | and.a ip, r2, #7 | |
| 81 | beq 1b @ If new byte, goto old routine | |
| 82 | ldb r3, [r0+], r2 >> #3 | |
| 83 | mov.a r3, r3 >> ip @ shift off unused bits | |
| 84 | bne .L_found | |
| 85 | or r2, r2, #7 @ if zero, then no bits here | |
| 86 | add r2, r2, #1 @ align bit pointer | |
| 87 | b 2b @ loop for next bit | |
| e13b91c1 | 88 | ENDPROC(find_next_bit) |
| 96cf5185 G |
89 | |
| 90 | /* | |
| 91 | * One or more bits in the LSB of r3 are assumed to be set. | |
| 92 | */ | |
| 93 | .L_found: | |
| 94 | rsub r1, r3, #0 | |
| 95 | and r3, r3, r1 | |
| 96 | cntlz r3, r3 | |
| 97 | rsub r3, r3, #31 | |
| 98 | add r0, r2, r3 | |
| 99 | mov pc, lr | |
| 100 |