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-rw-r--r--arch/avr32/lib/findbit.S154
1 files changed, 154 insertions, 0 deletions
diff --git a/arch/avr32/lib/findbit.S b/arch/avr32/lib/findbit.S
new file mode 100644
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+++ b/arch/avr32/lib/findbit.S
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+/*
+ * Copyright (C) 2006 Atmel Corporation
+ *
+ * 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 <linux/linkage.h>
+
+ .text
+ /*
+ * unsigned long find_first_zero_bit(const unsigned long *addr,
+ * unsigned long size)
+ */
+ENTRY(find_first_zero_bit)
+ cp.w r11, 0
+ reteq r11
+ mov r9, r11
+1: ld.w r8, r12[0]
+ com r8
+ brne .L_found
+ sub r12, -4
+ sub r9, 32
+ brgt 1b
+ retal r11
+
+ /*
+ * unsigned long find_next_zero_bit(const unsigned long *addr,
+ * unsigned long size,
+ * unsigned long offset)
+ */
+ENTRY(find_next_zero_bit)
+ lsr r8, r10, 5
+ sub r9, r11, r10
+ retle r11
+
+ lsl r8, 2
+ add r12, r8
+ andl r10, 31, COH
+ breq 1f
+
+ /* offset is not word-aligned. Handle the first (32 - r10) bits */
+ ld.w r8, r12[0]
+ com r8
+ sub r12, -4
+ lsr r8, r8, r10
+ brne .L_found
+
+ /* r9 = r9 - (32 - r10) = r9 + r10 - 32 */
+ add r9, r10
+ sub r9, 32
+ retle r11
+
+ /* Main loop. offset must be word-aligned */
+1: ld.w r8, r12[0]
+ com r8
+ brne .L_found
+ sub r12, -4
+ sub r9, 32
+ brgt 1b
+ retal r11
+
+ /* Common return path for when a bit is actually found. */
+.L_found:
+ brev r8
+ clz r10, r8
+ rsub r9, r11
+ add r10, r9
+
+ /* XXX: If we don't have to return exactly "size" when the bit
+ is not found, we may drop this "min" thing */
+ min r12, r11, r10
+ retal r12
+
+ /*
+ * unsigned long find_first_bit(const unsigned long *addr,
+ * unsigned long size)
+ */
+ENTRY(find_first_bit)
+ cp.w r11, 0
+ reteq r11
+ mov r9, r11
+1: ld.w r8, r12[0]
+ cp.w r8, 0
+ brne .L_found
+ sub r12, -4
+ sub r9, 32
+ brgt 1b
+ retal r11
+
+ /*
+ * unsigned long find_next_bit(const unsigned long *addr,
+ * unsigned long size,
+ * unsigned long offset)
+ */
+ENTRY(find_next_bit)
+ lsr r8, r10, 5
+ sub r9, r11, r10
+ retle r11
+
+ lsl r8, 2
+ add r12, r8
+ andl r10, 31, COH
+ breq 1f
+
+ /* offset is not word-aligned. Handle the first (32 - r10) bits */
+ ld.w r8, r12[0]
+ sub r12, -4
+ lsr r8, r8, r10
+ brne .L_found
+
+ /* r9 = r9 - (32 - r10) = r9 + r10 - 32 */
+ add r9, r10
+ sub r9, 32
+ retle r11
+
+ /* Main loop. offset must be word-aligned */
+1: ld.w r8, r12[0]
+ cp.w r8, 0
+ brne .L_found
+ sub r12, -4
+ sub r9, 32
+ brgt 1b
+ retal r11
+
+ENTRY(generic_find_next_zero_le_bit)
+ lsr r8, r10, 5
+ sub r9, r11, r10
+ retle r11
+
+ lsl r8, 2
+ add r12, r8
+ andl r10, 31, COH
+ breq 1f
+
+ /* offset is not word-aligned. Handle the first (32 - r10) bits */
+ ldswp.w r8, r12[0]
+ sub r12, -4
+ lsr r8, r8, r10
+ brne .L_found
+
+ /* r9 = r9 - (32 - r10) = r9 + r10 - 32 */
+ add r9, r10
+ sub r9, 32
+ retle r11
+
+ /* Main loop. offset must be word-aligned */
+1: ldswp.w r8, r12[0]
+ cp.w r8, 0
+ brne .L_found
+ sub r12, -4
+ sub r9, 32
+ brgt 1b
+ retal r11
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