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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm/lib/csumpartial.S | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/lib/csumpartial.S')
-rw-r--r-- | arch/arm/lib/csumpartial.S | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/arm/lib/csumpartial.S b/arch/arm/lib/csumpartial.S new file mode 100644 index 000000000..87c9471be --- /dev/null +++ b/arch/arm/lib/csumpartial.S @@ -0,0 +1,139 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/arch/arm/lib/csumpartial.S + * + * Copyright (C) 1995-1998 Russell King + */ +#include <linux/linkage.h> +#include <asm/assembler.h> + + .text + +/* + * Function: __u32 csum_partial(const char *src, int len, __u32 sum) + * Params : r0 = buffer, r1 = len, r2 = checksum + * Returns : r0 = new checksum + */ + +buf .req r0 +len .req r1 +sum .req r2 +td0 .req r3 +td1 .req r4 @ save before use +td2 .req r5 @ save before use +td3 .req lr + +.Lzero: mov r0, sum + add sp, sp, #4 + ldr pc, [sp], #4 + + /* + * Handle 0 to 7 bytes, with any alignment of source and + * destination pointers. Note that when we get here, C = 0 + */ +.Lless8: teq len, #0 @ check for zero count + beq .Lzero + + /* we must have at least one byte. */ + tst buf, #1 @ odd address? + movne sum, sum, ror #8 + ldrbne td0, [buf], #1 + subne len, len, #1 + adcsne sum, sum, td0, put_byte_1 + +.Lless4: tst len, #6 + beq .Lless8_byte + + /* we are now half-word aligned */ + +.Lless8_wordlp: +#if __LINUX_ARM_ARCH__ >= 4 + ldrh td0, [buf], #2 + sub len, len, #2 +#else + ldrb td0, [buf], #1 + ldrb td3, [buf], #1 + sub len, len, #2 +#ifndef __ARMEB__ + orr td0, td0, td3, lsl #8 +#else + orr td0, td3, td0, lsl #8 +#endif +#endif + adcs sum, sum, td0 + tst len, #6 + bne .Lless8_wordlp + +.Lless8_byte: tst len, #1 @ odd number of bytes + ldrbne td0, [buf], #1 @ include last byte + adcsne sum, sum, td0, put_byte_0 @ update checksum + +.Ldone: adc r0, sum, #0 @ collect up the last carry + ldr td0, [sp], #4 + tst td0, #1 @ check buffer alignment + movne r0, r0, ror #8 @ rotate checksum by 8 bits + ldr pc, [sp], #4 @ return + +.Lnot_aligned: tst buf, #1 @ odd address + ldrbne td0, [buf], #1 @ make even + subne len, len, #1 + adcsne sum, sum, td0, put_byte_1 @ update checksum + + tst buf, #2 @ 32-bit aligned? +#if __LINUX_ARM_ARCH__ >= 4 + ldrhne td0, [buf], #2 @ make 32-bit aligned + subne len, len, #2 +#else + ldrbne td0, [buf], #1 + ldrbne ip, [buf], #1 + subne len, len, #2 +#ifndef __ARMEB__ + orrne td0, td0, ip, lsl #8 +#else + orrne td0, ip, td0, lsl #8 +#endif +#endif + adcsne sum, sum, td0 @ update checksum + ret lr + +ENTRY(csum_partial) + stmfd sp!, {buf, lr} + cmp len, #8 @ Ensure that we have at least + blo .Lless8 @ 8 bytes to copy. + + tst buf, #1 + movne sum, sum, ror #8 + + adds sum, sum, #0 @ C = 0 + tst buf, #3 @ Test destination alignment + blne .Lnot_aligned @ align destination, return here + +1: bics ip, len, #31 + beq 3f + + stmfd sp!, {r4 - r5} +2: ldmia buf!, {td0, td1, td2, td3} + adcs sum, sum, td0 + adcs sum, sum, td1 + adcs sum, sum, td2 + adcs sum, sum, td3 + ldmia buf!, {td0, td1, td2, td3} + adcs sum, sum, td0 + adcs sum, sum, td1 + adcs sum, sum, td2 + adcs sum, sum, td3 + sub ip, ip, #32 + teq ip, #0 + bne 2b + ldmfd sp!, {r4 - r5} + +3: tst len, #0x1c @ should not change C + beq .Lless4 + +4: ldr td0, [buf], #4 + sub len, len, #4 + adcs sum, sum, td0 + tst len, #0x1c + bne 4b + b .Lless4 +ENDPROC(csum_partial) |