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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm/lib/csumpartialcopygeneric.S | |
download | kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 |
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!
Diffstat (limited to 'arch/arm/lib/csumpartialcopygeneric.S')
-rw-r--r-- | arch/arm/lib/csumpartialcopygeneric.S | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/arch/arm/lib/csumpartialcopygeneric.S b/arch/arm/lib/csumpartialcopygeneric.S new file mode 100644 index 0000000..d3a2f46 --- /dev/null +++ b/arch/arm/lib/csumpartialcopygeneric.S @@ -0,0 +1,331 @@ +/* + * linux/arch/arm/lib/csumpartialcopygeneric.S + * + * Copyright (C) 1995-2001 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. + */ + +/* + * unsigned int + * csum_partial_copy_xxx(const char *src, char *dst, int len, int sum, ) + * r0 = src, r1 = dst, r2 = len, r3 = sum + * Returns : r0 = checksum + * + * Note that 'tst' and 'teq' preserve the carry flag. + */ + +src .req r0 +dst .req r1 +len .req r2 +sum .req r3 + +.zero: mov r0, sum + load_regs ea + + /* + * Align an unaligned destination pointer. We know that + * we have >= 8 bytes here, so we don't need to check + * the length. Note that the source pointer hasn't been + * aligned yet. + */ +.dst_unaligned: tst dst, #1 + beq .dst_16bit + + load1b ip + sub len, len, #1 + adcs sum, sum, ip, put_byte_1 @ update checksum + strb ip, [dst], #1 + tst dst, #2 + moveq pc, lr @ dst is now 32bit aligned + +.dst_16bit: load2b r8, ip + sub len, len, #2 + adcs sum, sum, r8, put_byte_0 + strb r8, [dst], #1 + adcs sum, sum, ip, put_byte_1 + strb ip, [dst], #1 + mov pc, lr @ dst is now 32bit aligned + + /* + * 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 dst, #1 @ dst 16-bit aligned + beq .less8_aligned + + /* Align dst */ + load1b ip + sub len, len, #1 + adcs sum, sum, ip, put_byte_1 @ update checksum + strb ip, [dst], #1 + tst len, #6 + beq .less8_byteonly + +1: load2b r8, ip + sub len, len, #2 + adcs sum, sum, r8, put_byte_0 + strb r8, [dst], #1 + adcs sum, sum, ip, put_byte_1 + strb ip, [dst], #1 +.less8_aligned: tst len, #6 + bne 1b +.less8_byteonly: + tst len, #1 + beq .done + load1b r8 + adcs sum, sum, r8, put_byte_0 @ update checksum + strb r8, [dst], #1 + b .done + +FN_ENTRY + mov ip, sp + save_regs + sub fp, ip, #4 + + cmp len, #8 @ Ensure that we have at least + blo .less8 @ 8 bytes to copy. + + adds sum, sum, #0 @ C = 0 + tst dst, #3 @ Test destination alignment + blne .dst_unaligned @ align destination, return here + + /* + * Ok, the dst pointer is now 32bit aligned, and we know + * that we must have more than 4 bytes to copy. Note + * that C contains the carry from the dst alignment above. + */ + + tst src, #3 @ Test source alignment + bne .src_not_aligned + + /* Routine for src & dst aligned */ + + bics ip, len, #15 + beq 2f + +1: load4l r4, r5, r6, r7 + stmia dst!, {r4, r5, r6, r7} + adcs sum, sum, r4 + adcs sum, sum, r5 + adcs sum, sum, r6 + adcs sum, sum, r7 + sub ip, ip, #16 + teq ip, #0 + bne 1b + +2: ands ip, len, #12 + beq 4f + tst ip, #8 + beq 3f + load2l r4, r5 + stmia dst!, {r4, r5} + adcs sum, sum, r4 + adcs sum, sum, r5 + tst ip, #4 + beq 4f + +3: load1l r4 + str r4, [dst], #4 + adcs sum, sum, r4 + +4: ands len, len, #3 + beq .done + load1l r4 + tst len, #2 + mov r5, r4, get_byte_0 + beq .exit + adcs sum, sum, r4, push #16 + strb r5, [dst], #1 + mov r5, r4, get_byte_1 + strb r5, [dst], #1 + mov r5, r4, get_byte_2 +.exit: tst len, #1 + strneb r5, [dst], #1 + andne r5, r5, #255 + adcnes sum, sum, r5, put_byte_0 + + /* + * If the dst pointer was not 16-bit aligned, we + * need to rotate the checksum here to get around + * the inefficient byte manipulations in the + * architecture independent code. + */ +.done: adc r0, sum, #0 + ldr sum, [sp, #0] @ dst + tst sum, #1 + movne r0, r0, ror #8 + load_regs ea + +.src_not_aligned: + adc sum, sum, #0 @ include C from dst alignment + and ip, src, #3 + bic src, src, #3 + load1l r5 + cmp ip, #2 + beq .src2_aligned + bhi .src3_aligned + mov r4, r5, pull #8 @ C = 0 + bics ip, len, #15 + beq 2f +1: load4l r5, r6, r7, r8 + orr r4, r4, r5, push #24 + mov r5, r5, pull #8 + orr r5, r5, r6, push #24 + mov r6, r6, pull #8 + orr r6, r6, r7, push #24 + mov r7, r7, pull #8 + orr r7, r7, r8, push #24 + stmia dst!, {r4, r5, r6, r7} + adcs sum, sum, r4 + adcs sum, sum, r5 + adcs sum, sum, r6 + adcs sum, sum, r7 + mov r4, r8, pull #8 + sub ip, ip, #16 + teq ip, #0 + bne 1b +2: ands ip, len, #12 + beq 4f + tst ip, #8 + beq 3f + load2l r5, r6 + orr r4, r4, r5, push #24 + mov r5, r5, pull #8 + orr r5, r5, r6, push #24 + stmia dst!, {r4, r5} + adcs sum, sum, r4 + adcs sum, sum, r5 + mov r4, r6, pull #8 + tst ip, #4 + beq 4f +3: load1l r5 + orr r4, r4, r5, push #24 + str r4, [dst], #4 + adcs sum, sum, r4 + mov r4, r5, pull #8 +4: ands len, len, #3 + beq .done + mov r5, r4, get_byte_0 + tst len, #2 + beq .exit + adcs sum, sum, r4, push #16 + strb r5, [dst], #1 + mov r5, r4, get_byte_1 + strb r5, [dst], #1 + mov r5, r4, get_byte_2 + b .exit + +.src2_aligned: mov r4, r5, pull #16 + adds sum, sum, #0 + bics ip, len, #15 + beq 2f +1: load4l r5, r6, r7, r8 + orr r4, r4, r5, push #16 + mov r5, r5, pull #16 + orr r5, r5, r6, push #16 + mov r6, r6, pull #16 + orr r6, r6, r7, push #16 + mov r7, r7, pull #16 + orr r7, r7, r8, push #16 + stmia dst!, {r4, r5, r6, r7} + adcs sum, sum, r4 + adcs sum, sum, r5 + adcs sum, sum, r6 + adcs sum, sum, r7 + mov r4, r8, pull #16 + sub ip, ip, #16 + teq ip, #0 + bne 1b +2: ands ip, len, #12 + beq 4f + tst ip, #8 + beq 3f + load2l r5, r6 + orr r4, r4, r5, push #16 + mov r5, r5, pull #16 + orr r5, r5, r6, push #16 + stmia dst!, {r4, r5} + adcs sum, sum, r4 + adcs sum, sum, r5 + mov r4, r6, pull #16 + tst ip, #4 + beq 4f +3: load1l r5 + orr r4, r4, r5, push #16 + str r4, [dst], #4 + adcs sum, sum, r4 + mov r4, r5, pull #16 +4: ands len, len, #3 + beq .done + mov r5, r4, get_byte_0 + tst len, #2 + beq .exit + adcs sum, sum, r4 + strb r5, [dst], #1 + mov r5, r4, get_byte_1 + strb r5, [dst], #1 + tst len, #1 + beq .done + load1b r5 + b .exit + +.src3_aligned: mov r4, r5, pull #24 + adds sum, sum, #0 + bics ip, len, #15 + beq 2f +1: load4l r5, r6, r7, r8 + orr r4, r4, r5, push #8 + mov r5, r5, pull #24 + orr r5, r5, r6, push #8 + mov r6, r6, pull #24 + orr r6, r6, r7, push #8 + mov r7, r7, pull #24 + orr r7, r7, r8, push #8 + stmia dst!, {r4, r5, r6, r7} + adcs sum, sum, r4 + adcs sum, sum, r5 + adcs sum, sum, r6 + adcs sum, sum, r7 + mov r4, r8, pull #24 + sub ip, ip, #16 + teq ip, #0 + bne 1b +2: ands ip, len, #12 + beq 4f + tst ip, #8 + beq 3f + load2l r5, r6 + orr r4, r4, r5, push #8 + mov r5, r5, pull #24 + orr r5, r5, r6, push #8 + stmia dst!, {r4, r5} + adcs sum, sum, r4 + adcs sum, sum, r5 + mov r4, r6, pull #24 + tst ip, #4 + beq 4f +3: load1l r5 + orr r4, r4, r5, push #8 + str r4, [dst], #4 + adcs sum, sum, r4 + mov r4, r5, pull #24 +4: ands len, len, #3 + beq .done + mov r5, r4, get_byte_0 + tst len, #2 + beq .exit + strb r5, [dst], #1 + adcs sum, sum, r4 + load1l r4 + mov r5, r4, get_byte_0 + strb r5, [dst], #1 + adcs sum, sum, r4, push #24 + mov r5, r4, get_byte_1 + b .exit |