diff options
Diffstat (limited to 'arch/avr32/lib/findbit.S')
| -rw-r--r-- | arch/avr32/lib/findbit.S | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/arch/avr32/lib/findbit.S b/arch/avr32/lib/findbit.S new file mode 100644 index 000000000000..2b4856f4bf7c --- /dev/null +++ b/arch/avr32/lib/findbit.S @@ -0,0 +1,154 @@ +/* + * Copyright (C) 2006 Atmel Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/linkage.h> + + .text + /* + * unsigned long find_first_zero_bit(const unsigned long *addr, + * unsigned long size) + */ +ENTRY(find_first_zero_bit) + cp.w r11, 0 + reteq r11 + mov r9, r11 +1: ld.w r8, r12[0] + com r8 + brne .L_found + sub r12, -4 + sub r9, 32 + brgt 1b + retal r11 + + /* + * unsigned long find_next_zero_bit(const unsigned long *addr, + * unsigned long size, + * unsigned long offset) + */ +ENTRY(find_next_zero_bit) + lsr r8, r10, 5 + sub r9, r11, r10 + retle r11 + + lsl r8, 2 + add r12, r8 + andl r10, 31, COH + breq 1f + + /* offset is not word-aligned. Handle the first (32 - r10) bits */ + ld.w r8, r12[0] + com r8 + sub r12, -4 + lsr r8, r8, r10 + brne .L_found + + /* r9 = r9 - (32 - r10) = r9 + r10 - 32 */ + add r9, r10 + sub r9, 32 + retle r11 + + /* Main loop. offset must be word-aligned */ +1: ld.w r8, r12[0] + com r8 + brne .L_found + sub r12, -4 + sub r9, 32 + brgt 1b + retal r11 + + /* Common return path for when a bit is actually found. */ +.L_found: + brev r8 + clz r10, r8 + rsub r9, r11 + add r10, r9 + + /* XXX: If we don't have to return exactly "size" when the bit + is not found, we may drop this "min" thing */ + min r12, r11, r10 + retal r12 + + /* + * unsigned long find_first_bit(const unsigned long *addr, + * unsigned long size) + */ +ENTRY(find_first_bit) + cp.w r11, 0 + reteq r11 + mov r9, r11 +1: ld.w r8, r12[0] + cp.w r8, 0 + brne .L_found + sub r12, -4 + sub r9, 32 + brgt 1b + retal r11 + + /* + * unsigned long find_next_bit(const unsigned long *addr, + * unsigned long size, + * unsigned long offset) + */ +ENTRY(find_next_bit) + lsr r8, r10, 5 + sub r9, r11, r10 + retle r11 + + lsl r8, 2 + add r12, r8 + andl r10, 31, COH + breq 1f + + /* offset is not word-aligned. Handle the first (32 - r10) bits */ + ld.w r8, r12[0] + sub r12, -4 + lsr r8, r8, r10 + brne .L_found + + /* r9 = r9 - (32 - r10) = r9 + r10 - 32 */ + add r9, r10 + sub r9, 32 + retle r11 + + /* Main loop. offset must be word-aligned */ +1: ld.w r8, r12[0] + cp.w r8, 0 + brne .L_found + sub r12, -4 + sub r9, 32 + brgt 1b + retal r11 + +ENTRY(generic_find_next_zero_le_bit) + lsr r8, r10, 5 + sub r9, r11, r10 + retle r11 + + lsl r8, 2 + add r12, r8 + andl r10, 31, COH + breq 1f + + /* offset is not word-aligned. Handle the first (32 - r10) bits */ + ldswp.w r8, r12[0] + sub r12, -4 + lsr r8, r8, r10 + brne .L_found + + /* r9 = r9 - (32 - r10) = r9 + r10 - 32 */ + add r9, r10 + sub r9, 32 + retle r11 + + /* Main loop. offset must be word-aligned */ +1: ldswp.w r8, r12[0] + cp.w r8, 0 + brne .L_found + sub r12, -4 + sub r9, 32 + brgt 1b + retal r11 |