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-rw-r--r--arch/arm/lib/io-readsb.S120
1 files changed, 120 insertions, 0 deletions
diff --git a/arch/arm/lib/io-readsb.S b/arch/arm/lib/io-readsb.S
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+++ b/arch/arm/lib/io-readsb.S
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * linux/arch/arm/lib/io-readsb.S
+ *
+ * Copyright (C) 1995-2000 Russell King
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+.Linsb_align: rsb ip, ip, #4
+ cmp ip, r2
+ movgt ip, r2
+ cmp ip, #2
+ ldrb r3, [r0]
+ strb r3, [r1], #1
+ ldrbge r3, [r0]
+ strbge r3, [r1], #1
+ ldrbgt r3, [r0]
+ strbgt r3, [r1], #1
+ subs r2, r2, ip
+ bne .Linsb_aligned
+
+ENTRY(__raw_readsb)
+ teq r2, #0 @ do we have to check for the zero len?
+ reteq lr
+ ands ip, r1, #3
+ bne .Linsb_align
+
+.Linsb_aligned: stmfd sp!, {r4 - r6, lr}
+
+ subs r2, r2, #16
+ bmi .Linsb_no_16
+
+.Linsb_16_lp: ldrb r3, [r0]
+ ldrb r4, [r0]
+ ldrb r5, [r0]
+ mov r3, r3, put_byte_0
+ ldrb r6, [r0]
+ orr r3, r3, r4, put_byte_1
+ ldrb r4, [r0]
+ orr r3, r3, r5, put_byte_2
+ ldrb r5, [r0]
+ orr r3, r3, r6, put_byte_3
+ ldrb r6, [r0]
+ mov r4, r4, put_byte_0
+ ldrb ip, [r0]
+ orr r4, r4, r5, put_byte_1
+ ldrb r5, [r0]
+ orr r4, r4, r6, put_byte_2
+ ldrb r6, [r0]
+ orr r4, r4, ip, put_byte_3
+ ldrb ip, [r0]
+ mov r5, r5, put_byte_0
+ ldrb lr, [r0]
+ orr r5, r5, r6, put_byte_1
+ ldrb r6, [r0]
+ orr r5, r5, ip, put_byte_2
+ ldrb ip, [r0]
+ orr r5, r5, lr, put_byte_3
+ ldrb lr, [r0]
+ mov r6, r6, put_byte_0
+ orr r6, r6, ip, put_byte_1
+ ldrb ip, [r0]
+ orr r6, r6, lr, put_byte_2
+ orr r6, r6, ip, put_byte_3
+ stmia r1!, {r3 - r6}
+
+ subs r2, r2, #16
+ bpl .Linsb_16_lp
+
+ tst r2, #15
+ ldmfdeq sp!, {r4 - r6, pc}
+
+.Linsb_no_16: tst r2, #8
+ beq .Linsb_no_8
+
+ ldrb r3, [r0]
+ ldrb r4, [r0]
+ ldrb r5, [r0]
+ mov r3, r3, put_byte_0
+ ldrb r6, [r0]
+ orr r3, r3, r4, put_byte_1
+ ldrb r4, [r0]
+ orr r3, r3, r5, put_byte_2
+ ldrb r5, [r0]
+ orr r3, r3, r6, put_byte_3
+ ldrb r6, [r0]
+ mov r4, r4, put_byte_0
+ ldrb ip, [r0]
+ orr r4, r4, r5, put_byte_1
+ orr r4, r4, r6, put_byte_2
+ orr r4, r4, ip, put_byte_3
+ stmia r1!, {r3, r4}
+
+.Linsb_no_8: tst r2, #4
+ beq .Linsb_no_4
+
+ ldrb r3, [r0]
+ ldrb r4, [r0]
+ ldrb r5, [r0]
+ ldrb r6, [r0]
+ mov r3, r3, put_byte_0
+ orr r3, r3, r4, put_byte_1
+ orr r3, r3, r5, put_byte_2
+ orr r3, r3, r6, put_byte_3
+ str r3, [r1], #4
+
+.Linsb_no_4: ands r2, r2, #3
+ ldmfdeq sp!, {r4 - r6, pc}
+
+ cmp r2, #2
+ ldrb r3, [r0]
+ strb r3, [r1], #1
+ ldrbge r3, [r0]
+ strbge r3, [r1], #1
+ ldrbgt r3, [r0]
+ strbgt r3, [r1]
+
+ ldmfd sp!, {r4 - r6, pc}
+ENDPROC(__raw_readsb)