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/arm26/lib/memzero.S | 80 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 arch/arm26/lib/memzero.S (limited to 'arch/arm26/lib/memzero.S') diff --git a/arch/arm26/lib/memzero.S b/arch/arm26/lib/memzero.S new file mode 100644 index 000000000000..cc5bf6860061 --- /dev/null +++ b/arch/arm26/lib/memzero.S @@ -0,0 +1,80 @@ +/* + * linux/arch/arm26/lib/memzero.S + * + * Copyright (C) 1995-2000 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 + .align 5 + .word 0 +/* + * Align the pointer in r0. r3 contains the number of bytes that we are + * mis-aligned by, and r1 is the number of bytes. If r1 < 4, then we + * don't bother; we use byte stores instead. + */ +1: subs r1, r1, #4 @ 1 do we have enough + blt 5f @ 1 bytes to align with? + cmp r3, #2 @ 1 + strltb r2, [r0], #1 @ 1 + strleb r2, [r0], #1 @ 1 + strb r2, [r0], #1 @ 1 + add r1, r1, r3 @ 1 (r1 = r1 - (4 - r3)) +/* + * The pointer is now aligned and the length is adjusted. Try doing the + * memzero again. + */ + +ENTRY(__memzero) + mov r2, #0 @ 1 + ands r3, r0, #3 @ 1 unaligned? + bne 1b @ 1 +/* + * r3 = 0, and we know that the pointer in r0 is aligned to a word boundary. + */ + cmp r1, #16 @ 1 we can skip this chunk if we + blt 4f @ 1 have < 16 bytes +/* + * We need an extra register for this loop - save the return address and + * use the LR + */ + str lr, [sp, #-4]! @ 1 + mov ip, r2 @ 1 + mov lr, r2 @ 1 + +3: subs r1, r1, #64 @ 1 write 32 bytes out per loop + stmgeia r0!, {r2, r3, ip, lr} @ 4 + stmgeia r0!, {r2, r3, ip, lr} @ 4 + stmgeia r0!, {r2, r3, ip, lr} @ 4 + stmgeia r0!, {r2, r3, ip, lr} @ 4 + bgt 3b @ 1 + LOADREGS(eqfd, sp!, {pc}) @ 1/2 quick exit +/* + * No need to correct the count; we're only testing bits from now on + */ + tst r1, #32 @ 1 + stmneia r0!, {r2, r3, ip, lr} @ 4 + stmneia r0!, {r2, r3, ip, lr} @ 4 + tst r1, #16 @ 1 16 bytes or more? + stmneia r0!, {r2, r3, ip, lr} @ 4 + ldr lr, [sp], #4 @ 1 + +4: tst r1, #8 @ 1 8 bytes or more? + stmneia r0!, {r2, r3} @ 2 + tst r1, #4 @ 1 4 bytes or more? + strne r2, [r0], #4 @ 1 +/* + * When we get here, we've got less than 4 bytes to zero. We + * may have an unaligned pointer as well. + */ +5: tst r1, #2 @ 1 2 bytes or more? + strneb r2, [r0], #1 @ 1 + strneb r2, [r0], #1 @ 1 + tst r1, #1 @ 1 a byte left over + strneb r2, [r0], #1 @ 1 + RETINSTR(mov,pc,lr) @ 1 -- cgit v1.2.2