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author | 2023-10-10 14:33:42 +0000 | |
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committer | 2023-10-10 14:33:42 +0000 | |
commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/u-boot/arch/arm/lib/memset.S | |
parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/u-boot/arch/arm/lib/memset.S')
-rw-r--r-- | roms/u-boot/arch/arm/lib/memset.S | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/roms/u-boot/arch/arm/lib/memset.S b/roms/u-boot/arch/arm/lib/memset.S new file mode 100644 index 000000000..2277d1202 --- /dev/null +++ b/roms/u-boot/arch/arm/lib/memset.S @@ -0,0 +1,125 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * linux/arch/arm/lib/memset.S + * + * Copyright (C) 1995-2000 Russell King + * + * ASM optimised string functions + */ +#include <linux/linkage.h> +#include <asm/assembler.h> + + .text + .align 5 + + .syntax unified +#if CONFIG_IS_ENABLED(SYS_THUMB_BUILD) && !defined(MEMSET_NO_THUMB_BUILD) + .thumb + .thumb_func +#endif +ENTRY(memset) + ands r3, r0, #3 @ 1 unaligned? + mov ip, r0 @ preserve r0 as return value + bne 6f @ 1 +/* + * we know that the pointer in ip is aligned to a word boundary. + */ +1: orr r1, r1, r1, lsl #8 + orr r1, r1, r1, lsl #16 + mov r3, r1 + cmp r2, #16 + blt 4f + +#if ! CALGN(1)+0 + +/* + * We need 2 extra registers for this loop - use r8 and the LR + */ + stmfd sp!, {r8, lr} + mov r8, r1 + mov lr, r1 + +2: subs r2, r2, #64 + stmiage ip!, {r1, r3, r8, lr} @ 64 bytes at a time. + stmiage ip!, {r1, r3, r8, lr} + stmiage ip!, {r1, r3, r8, lr} + stmiage ip!, {r1, r3, r8, lr} + bgt 2b + ldmfdeq sp!, {r8, pc} @ Now <64 bytes to go. +/* + * No need to correct the count; we're only testing bits from now on + */ + tst r2, #32 + stmiane ip!, {r1, r3, r8, lr} + stmiane ip!, {r1, r3, r8, lr} + tst r2, #16 + stmiane ip!, {r1, r3, r8, lr} + ldmfd sp!, {r8, lr} + +#else + +/* + * This version aligns the destination pointer in order to write + * whole cache lines at once. + */ + + stmfd sp!, {r4-r8, lr} + mov r4, r1 + mov r5, r1 + mov r6, r1 + mov r7, r1 + mov r8, r1 + mov lr, r1 + + cmp r2, #96 + tstgt ip, #31 + ble 3f + + and r8, ip, #31 + rsb r8, r8, #32 + sub r2, r2, r8 + movs r8, r8, lsl #(32 - 4) + stmiacs ip!, {r4, r5, r6, r7} + stmiami ip!, {r4, r5} + tst r8, #(1 << 30) + mov r8, r1 + strne r1, [ip], #4 + +3: subs r2, r2, #64 + stmiage ip!, {r1, r3-r8, lr} + stmiage ip!, {r1, r3-r8, lr} + bgt 3b + ldmfdeq sp!, {r4-r8, pc} + + tst r2, #32 + stmiane ip!, {r1, r3-r8, lr} + tst r2, #16 + stmiane ip!, {r4-r7} + ldmfd sp!, {r4-r8, lr} + +#endif + +4: tst r2, #8 + stmiane ip!, {r1, r3} + tst r2, #4 + strne r1, [ip], #4 +/* + * When we get here, we've got less than 4 bytes to zero. We + * may have an unaligned pointer as well. + */ +5: tst r2, #2 + strbne r1, [ip], #1 + strbne r1, [ip], #1 + tst r2, #1 + strbne r1, [ip], #1 + ret lr + +6: subs r2, r2, #4 @ 1 do we have enough + blt 5b @ 1 bytes to align with? + cmp r3, #2 @ 1 + strblt r1, [ip], #1 @ 1 + strble r1, [ip], #1 @ 1 + strb r1, [ip], #1 @ 1 + add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3)) + b 1b +ENDPROC(memset) |