^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * arch/xtensa/lib/strnlen_user.S
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * This file is subject to the terms and conditions of the GNU General
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Public License. See the file "COPYING" in the main directory of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * this archive for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Returns strnlen, including trailing zero terminator.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Zero indicates error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * Copyright (C) 2002 Tensilica Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/linkage.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <asm/asmmacro.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <asm/core.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * size_t __strnlen_user(const char *s, size_t len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #ifdef __XTENSA_EB__
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) # define MASK0 0xff000000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) # define MASK1 0x00ff0000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) # define MASK2 0x0000ff00
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) # define MASK3 0x000000ff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) # define MASK0 0x000000ff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) # define MASK1 0x0000ff00
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) # define MASK2 0x00ff0000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) # define MASK3 0xff000000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) # Register use:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) # a2/ src
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) # a3/ len
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) # a4/ tmp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) # a5/ mask0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) # a6/ mask1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) # a7/ mask2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) # a8/ mask3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) # a9/ tmp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) # a10/ tmp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) .text
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) ENTRY(__strnlen_user)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) abi_entry_default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) # a2/ s, a3/ len
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) addi a4, a2, -4 # because we overincrement at the end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) # we compensate with load offsets of 4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) movi a5, MASK0 # mask for byte 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) movi a6, MASK1 # mask for byte 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) movi a7, MASK2 # mask for byte 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) movi a8, MASK3 # mask for byte 3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) bbsi.l a2, 0, .L1mod2 # if only 8-bit aligned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) bbsi.l a2, 1, .L2mod4 # if only 16-bit aligned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * String is word-aligned.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) .Laligned:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) srli a10, a3, 2 # number of loop iterations with 4B per loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) #if XCHAL_HAVE_LOOPS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) loopnez a10, .Ldone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) beqz a10, .Ldone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) slli a10, a10, 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) add a10, a10, a4 # a10 = end of last 4B chunk
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) #endif /* XCHAL_HAVE_LOOPS */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) .Loop:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) EX(10f) l32i a9, a4, 4 # get next word of string
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) addi a4, a4, 4 # advance string pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) bnone a9, a5, .Lz0 # if byte 0 is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) bnone a9, a6, .Lz1 # if byte 1 is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) bnone a9, a7, .Lz2 # if byte 2 is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) bnone a9, a8, .Lz3 # if byte 3 is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) #if !XCHAL_HAVE_LOOPS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) blt a4, a10, .Loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) .Ldone:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) EX(10f) l32i a9, a4, 4 # load 4 bytes for remaining checks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) bbci.l a3, 1, .L100
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) # check two more bytes (bytes 0, 1 of word)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) addi a4, a4, 2 # advance string pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) bnone a9, a5, .Lz0 # if byte 0 is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) bnone a9, a6, .Lz1 # if byte 1 is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) .L100:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) bbci.l a3, 0, .L101
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) # check one more byte (byte 2 of word)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) # Actually, we don't need to check. Zero or nonzero, we'll add one.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) # Do not add an extra one for the NULL terminator since we have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) # exhausted the original len parameter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) addi a4, a4, 1 # advance string pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) .L101:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) sub a2, a4, a2 # compute length
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) abi_ret_default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) # NOTE that in several places below, we point to the byte just after
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) # the zero byte in order to include the NULL terminator in the count.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) .Lz3: # byte 3 is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) addi a4, a4, 3 # point to zero byte
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) .Lz0: # byte 0 is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) addi a4, a4, 1 # point just beyond zero byte
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) sub a2, a4, a2 # subtract to get length
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) abi_ret_default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) .Lz1: # byte 1 is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) addi a4, a4, 1+1 # point just beyond zero byte
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) sub a2, a4, a2 # subtract to get length
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) abi_ret_default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) .Lz2: # byte 2 is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) addi a4, a4, 2+1 # point just beyond zero byte
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) sub a2, a4, a2 # subtract to get length
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) abi_ret_default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) .L1mod2: # address is odd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) EX(10f) l8ui a9, a4, 4 # get byte 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) addi a4, a4, 1 # advance string pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) beqz a9, .Lz3 # if byte 0 is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) bbci.l a4, 1, .Laligned # if string pointer is now word-aligned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) .L2mod4: # address is 2 mod 4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) addi a4, a4, 2 # advance ptr for aligned access
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) EX(10f) l32i a9, a4, 0 # get word with first two bytes of string
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) bnone a9, a7, .Lz2 # if byte 2 (of word, not string) is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) bany a9, a8, .Laligned # if byte 3 (of word, not string) is nonzero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) # byte 3 is zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) addi a4, a4, 3+1 # point just beyond zero byte
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) sub a2, a4, a2 # subtract to get length
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) abi_ret_default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) ENDPROC(__strnlen_user)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) .section .fixup, "ax"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) .align 4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 10:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) movi a2, 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) abi_ret_default
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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