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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm/lib/copy_page.S
parentInitial commit. (diff)
downloadlinux-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/copy_page.S')
-rw-r--r--arch/arm/lib/copy_page.S44
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/arm/lib/copy_page.S b/arch/arm/lib/copy_page.S
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+++ b/arch/arm/lib/copy_page.S
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * linux/arch/arm/lib/copypage.S
+ *
+ * Copyright (C) 1995-1999 Russell King
+ *
+ * ASM optimised string functions
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/asm-offsets.h>
+#include <asm/cache.h>
+
+#define COPY_COUNT (PAGE_SZ / (2 * L1_CACHE_BYTES) PLD( -1 ))
+
+ .text
+ .align 5
+/*
+ * StrongARM optimised copy_page routine
+ * now 1.78bytes/cycle, was 1.60 bytes/cycle (50MHz bus -> 89MB/s)
+ * Note that we probably achieve closer to the 100MB/s target with
+ * the core clock switching.
+ */
+ENTRY(copy_page)
+ stmfd sp!, {r4, lr} @ 2
+ PLD( pld [r1, #0] )
+ PLD( pld [r1, #L1_CACHE_BYTES] )
+ mov r2, #COPY_COUNT @ 1
+ ldmia r1!, {r3, r4, ip, lr} @ 4+1
+1: PLD( pld [r1, #2 * L1_CACHE_BYTES])
+ PLD( pld [r1, #3 * L1_CACHE_BYTES])
+2:
+ .rept (2 * L1_CACHE_BYTES / 16 - 1)
+ stmia r0!, {r3, r4, ip, lr} @ 4
+ ldmia r1!, {r3, r4, ip, lr} @ 4
+ .endr
+ subs r2, r2, #1 @ 1
+ stmia r0!, {r3, r4, ip, lr} @ 4
+ ldmiagt r1!, {r3, r4, ip, lr} @ 4
+ bgt 1b @ 1
+ PLD( ldmiaeq r1!, {r3, r4, ip, lr} )
+ PLD( beq 2b )
+ ldmfd sp!, {r4, pc} @ 3
+ENDPROC(copy_page)