^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /* SPDX-License-Identifier: GPL-2.0-only */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * linux/arch/arm/lib/findbit.S
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 1995-2000 Russell King
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * 16th March 2001 - John Ripley <jripley@sonicblue.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Fixed so that "size" is an exclusive not an inclusive quantity.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * All users of these functions expect exclusive sizes, and may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * also call with zero size.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * Reworked by rmk.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/linkage.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <asm/assembler.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) .text
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * Purpose : Find a 'zero' bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * Prototype: int find_first_zero_bit(void *addr, unsigned int maxbit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) ENTRY(_find_first_zero_bit_le)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) teq r1, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) beq 3f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) mov r2, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) ARM( ldrb r3, [r0, r2, lsr #3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) THUMB( lsr r3, r2, #3 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) THUMB( ldrb r3, [r0, r3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) eors r3, r3, #0xff @ invert bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) bne .L_found @ any now set - found zero bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) add r2, r2, #8 @ next bit pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 2: cmp r2, r1 @ any more?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) blo 1b
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 3: mov r0, r1 @ no free bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) ret lr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) ENDPROC(_find_first_zero_bit_le)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) * Purpose : Find next 'zero' bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) ENTRY(_find_next_zero_bit_le)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) teq r1, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) beq 3b
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) ands ip, r2, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) beq 1b @ If new byte, goto old routine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) ARM( ldrb r3, [r0, r2, lsr #3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) THUMB( lsr r3, r2, #3 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) THUMB( ldrb r3, [r0, r3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) eor r3, r3, #0xff @ now looking for a 1 bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) movs r3, r3, lsr ip @ shift off unused bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) bne .L_found
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) orr r2, r2, #7 @ if zero, then no bits here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) add r2, r2, #1 @ align bit pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) b 2b @ loop for next bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) ENDPROC(_find_next_zero_bit_le)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * Purpose : Find a 'one' bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * Prototype: int find_first_bit(const unsigned long *addr, unsigned int maxbit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) ENTRY(_find_first_bit_le)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) teq r1, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) beq 3f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) mov r2, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) ARM( ldrb r3, [r0, r2, lsr #3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) THUMB( lsr r3, r2, #3 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) THUMB( ldrb r3, [r0, r3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) movs r3, r3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) bne .L_found @ any now set - found zero bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) add r2, r2, #8 @ next bit pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) 2: cmp r2, r1 @ any more?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) blo 1b
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) 3: mov r0, r1 @ no free bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) ret lr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) ENDPROC(_find_first_bit_le)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) * Purpose : Find next 'one' bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) ENTRY(_find_next_bit_le)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) teq r1, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) beq 3b
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) ands ip, r2, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) beq 1b @ If new byte, goto old routine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) ARM( ldrb r3, [r0, r2, lsr #3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) THUMB( lsr r3, r2, #3 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) THUMB( ldrb r3, [r0, r3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) movs r3, r3, lsr ip @ shift off unused bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) bne .L_found
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) orr r2, r2, #7 @ if zero, then no bits here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) add r2, r2, #1 @ align bit pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) b 2b @ loop for next bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) ENDPROC(_find_next_bit_le)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) #ifdef __ARMEB__
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) ENTRY(_find_first_zero_bit_be)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) teq r1, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) beq 3f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) mov r2, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 1: eor r3, r2, #0x18 @ big endian byte ordering
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) ARM( ldrb r3, [r0, r3, lsr #3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) THUMB( lsr r3, #3 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) THUMB( ldrb r3, [r0, r3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) eors r3, r3, #0xff @ invert bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) bne .L_found @ any now set - found zero bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) add r2, r2, #8 @ next bit pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 2: cmp r2, r1 @ any more?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) blo 1b
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 3: mov r0, r1 @ no free bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) ret lr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) ENDPROC(_find_first_zero_bit_be)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) ENTRY(_find_next_zero_bit_be)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) teq r1, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) beq 3b
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) ands ip, r2, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) beq 1b @ If new byte, goto old routine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) eor r3, r2, #0x18 @ big endian byte ordering
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) ARM( ldrb r3, [r0, r3, lsr #3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) THUMB( lsr r3, #3 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) THUMB( ldrb r3, [r0, r3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) eor r3, r3, #0xff @ now looking for a 1 bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) movs r3, r3, lsr ip @ shift off unused bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) bne .L_found
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) orr r2, r2, #7 @ if zero, then no bits here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) add r2, r2, #1 @ align bit pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) b 2b @ loop for next bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) ENDPROC(_find_next_zero_bit_be)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) ENTRY(_find_first_bit_be)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) teq r1, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) beq 3f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) mov r2, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 1: eor r3, r2, #0x18 @ big endian byte ordering
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) ARM( ldrb r3, [r0, r3, lsr #3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) THUMB( lsr r3, #3 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) THUMB( ldrb r3, [r0, r3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) movs r3, r3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) bne .L_found @ any now set - found zero bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) add r2, r2, #8 @ next bit pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 2: cmp r2, r1 @ any more?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) blo 1b
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 3: mov r0, r1 @ no free bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) ret lr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) ENDPROC(_find_first_bit_be)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) ENTRY(_find_next_bit_be)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) teq r1, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) beq 3b
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) ands ip, r2, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) beq 1b @ If new byte, goto old routine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) eor r3, r2, #0x18 @ big endian byte ordering
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) ARM( ldrb r3, [r0, r3, lsr #3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) THUMB( lsr r3, #3 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) THUMB( ldrb r3, [r0, r3] )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) movs r3, r3, lsr ip @ shift off unused bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) bne .L_found
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) orr r2, r2, #7 @ if zero, then no bits here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) add r2, r2, #1 @ align bit pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) b 2b @ loop for next bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) ENDPROC(_find_next_bit_be)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) * One or more bits in the LSB of r3 are assumed to be set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) .L_found:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) #if __LINUX_ARM_ARCH__ >= 5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) rsb r0, r3, #0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) and r3, r3, r0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) clz r3, r3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) rsb r3, r3, #31
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) add r0, r2, r3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) tst r3, #0x0f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) addeq r2, r2, #4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) movne r3, r3, lsl #4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) tst r3, #0x30
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) addeq r2, r2, #2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) movne r3, r3, lsl #2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) tst r3, #0x40
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) addeq r2, r2, #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) mov r0, r2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) cmp r1, r0 @ Clamp to maxbit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) movlo r0, r1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) ret lr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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