From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- arch/arm/lib/csumpartial.S | 137 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 137 insertions(+) create mode 100644 arch/arm/lib/csumpartial.S (limited to 'arch/arm/lib/csumpartial.S') diff --git a/arch/arm/lib/csumpartial.S b/arch/arm/lib/csumpartial.S new file mode 100644 index 00000000000..cb5e3708f11 --- /dev/null +++ b/arch/arm/lib/csumpartial.S @@ -0,0 +1,137 @@ +/* + * linux/arch/arm/lib/csumpartial.S + * + * Copyright (C) 1995-1998 Russell King + * + * 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 +#include + + .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 + +.zero: 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 + */ +.less8: teq len, #0 @ check for zero count + beq .zero + + /* we must have at least one byte. */ + tst buf, #1 @ odd address? + ldrneb td0, [buf], #1 + subne len, len, #1 + adcnes sum, sum, td0, put_byte_1 + +.less4: tst len, #6 + beq .less8_byte + + /* we are now half-word aligned */ + +.less8_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 .less8_wordlp + +.less8_byte: tst len, #1 @ odd number of bytes + ldrneb td0, [buf], #1 @ include last byte + adcnes sum, sum, td0, put_byte_0 @ update checksum + +.done: 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 + +.not_aligned: tst buf, #1 @ odd address + ldrneb td0, [buf], #1 @ make even + subne len, len, #1 + adcnes sum, sum, td0, put_byte_1 @ update checksum + + tst buf, #2 @ 32-bit aligned? +#if __LINUX_ARM_ARCH__ >= 4 + ldrneh td0, [buf], #2 @ make 32-bit aligned + subne len, len, #2 +#else + ldrneb td0, [buf], #1 + ldrneb ip, [buf], #1 + subne len, len, #2 +#ifndef __ARMEB__ + orrne td0, td0, ip, lsl #8 +#else + orrne td0, ip, td0, lsl #8 +#endif +#endif + adcnes sum, sum, td0 @ update checksum + mov pc, lr + +ENTRY(csum_partial) + stmfd sp!, {buf, lr} + cmp len, #8 @ Ensure that we have at least + blo .less8 @ 8 bytes to copy. + + adds sum, sum, #0 @ C = 0 + tst buf, #3 @ Test destination alignment + blne .not_aligned @ aligh 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 .less4 + +4: ldr td0, [buf], #4 + sub len, len, #4 + adcs sum, sum, td0 + tst len, #0x1c + bne 4b + b .less4 -- cgit v1.2.3