From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 arch/avr32/lib/findbit.S | 185 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 185 insertions(+)
 create mode 100644 arch/avr32/lib/findbit.S

(limited to 'arch/avr32/lib/findbit.S')

diff --git a/arch/avr32/lib/findbit.S b/arch/avr32/lib/findbit.S
new file mode 100644
index 000000000..b93586460
--- /dev/null
+++ b/arch/avr32/lib/findbit.S
@@ -0,0 +1,185 @@
+/*
+ * 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(find_next_bit_le)
+	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
+
+ENTRY(find_next_zero_bit_le)
+	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
+	com	r8
+	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]
+	com	r8
+	brne	.L_found
+	sub	r12, -4
+	sub	r9, 32
+	brgt	1b
+	retal	r11
-- 
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