diff options
| author | GuanXuetao <gxt@mprc.pku.edu.cn> | 2011-01-15 05:23:09 -0500 |
|---|---|---|
| committer | GuanXuetao <gxt@mprc.pku.edu.cn> | 2011-03-16 21:19:13 -0400 |
| commit | 96cf5185a95e0b304596fe19edcf8dfcd5c10699 (patch) | |
| tree | aebdf44fdfa8841577171df18cb1b0745b54d64e /arch/unicore32/lib/findbit.S | |
| parent | 77c93b2f2388b974253af4149aa025b4751f92ad (diff) | |
unicore32 additional architecture files: low-level lib: misc
This patch implements the rest low-level libraries.
Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/unicore32/lib/findbit.S')
| -rw-r--r-- | arch/unicore32/lib/findbit.S | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/unicore32/lib/findbit.S b/arch/unicore32/lib/findbit.S new file mode 100644 index 000000000000..c360ce905d8b --- /dev/null +++ b/arch/unicore32/lib/findbit.S | |||
| @@ -0,0 +1,98 @@ | |||
| 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 | */ | ||
| 20 | __uc32_find_first_zero_bit: | ||
| 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 | ||
| 32 | |||
| 33 | /* | ||
| 34 | * Purpose : Find next 'zero' bit | ||
| 35 | * Prototype: int find_next_zero_bit | ||
| 36 | * (void *addr, unsigned int maxbit, int offset) | ||
| 37 | */ | ||
| 38 | ENTRY(__uc32_find_next_zero_bit) | ||
| 39 | cxor.a r1, #0 | ||
| 40 | beq 3b | ||
| 41 | and.a ip, r2, #7 | ||
| 42 | beq 1b @ If new byte, goto old routine | ||
| 43 | ldb r3, [r0+], r2 >> #3 | ||
| 44 | xor r3, r3, #0xff @ now looking for a 1 bit | ||
| 45 | mov.a r3, r3 >> ip @ shift off unused bits | ||
| 46 | bne .L_found | ||
| 47 | or r2, r2, #7 @ if zero, then no bits here | ||
| 48 | add r2, r2, #1 @ align bit pointer | ||
| 49 | b 2b @ loop for next bit | ||
| 50 | ENDPROC(__uc32_find_next_zero_bit) | ||
| 51 | |||
| 52 | /* | ||
| 53 | * Purpose : Find a 'one' bit | ||
| 54 | * Prototype: int find_first_bit | ||
| 55 | * (const unsigned long *addr, unsigned int maxbit); | ||
| 56 | */ | ||
| 57 | __uc32_find_first_bit: | ||
| 58 | cxor.a r1, #0 | ||
| 59 | beq 3f | ||
| 60 | mov r2, #0 | ||
| 61 | 1: ldb r3, [r0+], r2 >> #3 | ||
| 62 | mov.a r3, r3 | ||
| 63 | bne .L_found @ any now set - found zero bit | ||
| 64 | add r2, r2, #8 @ next bit pointer | ||
| 65 | 2: csub.a r2, r1 @ any more? | ||
| 66 | bub 1b | ||
| 67 | 3: mov r0, r1 @ no free bits | ||
| 68 | mov pc, lr | ||
| 69 | |||
| 70 | /* | ||
| 71 | * Purpose : Find next 'one' bit | ||
| 72 | * Prototype: int find_next_zero_bit | ||
| 73 | * (void *addr, unsigned int maxbit, int offset) | ||
| 74 | */ | ||
| 75 | ENTRY(__uc32_find_next_bit) | ||
| 76 | cxor.a r1, #0 | ||
| 77 | beq 3b | ||
| 78 | and.a ip, r2, #7 | ||
| 79 | beq 1b @ If new byte, goto old routine | ||
| 80 | ldb r3, [r0+], r2 >> #3 | ||
| 81 | mov.a r3, r3 >> ip @ shift off unused bits | ||
| 82 | bne .L_found | ||
| 83 | or r2, r2, #7 @ if zero, then no bits here | ||
| 84 | add r2, r2, #1 @ align bit pointer | ||
| 85 | b 2b @ loop for next bit | ||
| 86 | ENDPROC(__uc32_find_next_bit) | ||
| 87 | |||
| 88 | /* | ||
| 89 | * One or more bits in the LSB of r3 are assumed to be set. | ||
| 90 | */ | ||
| 91 | .L_found: | ||
| 92 | rsub r1, r3, #0 | ||
| 93 | and r3, r3, r1 | ||
| 94 | cntlz r3, r3 | ||
| 95 | rsub r3, r3, #31 | ||
| 96 | add r0, r2, r3 | ||
| 97 | mov pc, lr | ||
| 98 | |||