armv7: add miscellaneous utility macros

add utility macros for:
 * bit field operations
 * log2n functions

Signed-off-by: Aneesh V <aneesh@ti.com>

1 files changed, 80 insertions, 0 deletions

diff --git a/arch/arm/include/asm/utils.h b/arch/arm/include/asm/utils.h
new file mode 100644
index 00000000000..d581539be57
--- /dev/null
+++ b/arch/arm/include/asm/utils.h
@@ -0,0 +1,80 @@
+/*
+ * (C) Copyright 2010
+ * Texas Instruments, <www.ti.com>
+ *
+ * Aneesh V <aneesh@ti.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#ifndef	_UTILS_H_
+#define	_UTILS_H_
+
+/* extract a bit field from a bit vector */
+#define get_bit_field(nr, start, mask)\
+	(((nr) & (mask)) >> (start))
+
+/* Set a field in a bit vector */
+#define set_bit_field(nr, start, mask, val)\
+	do { \
+		(nr) = ((nr) & ~(mask)) | (((val) << (start)) & (mask));\
+	} while (0);
+
+/*
+ * Utility macro for read-modify-write of a hardware register
+ *	addr - address of the register
+ *	shift - starting bit position of the field to be modified
+ *	msk - mask for the field
+ *	val - value to be shifted masked and written to the field
+ */
+#define modify_reg_32(addr, shift, msk, val) \
+	do {\
+		writel(((readl(addr) & ~(msk))|(((val) << (shift)) & (msk))),\
+		       (addr));\
+	} while (0);
+
+static inline s32 log_2_n_round_up(u32 n)
+{
+	s32 log2n = -1;
+	u32 temp = n;
+
+	while (temp) {
+		log2n++;
+		temp >>= 1;
+	}
+
+	if (n & (n - 1))
+		return log2n + 1; /* not power of 2 - round up */
+	else
+		return log2n; /* power of 2 */
+}
+
+static inline s32 log_2_n_round_down(u32 n)
+{
+	s32 log2n = -1;
+	u32 temp = n;
+
+	while (temp) {
+		log2n++;
+		temp >>= 1;
+	}
+
+	return log2n;
+}
+
+#endif /* _OMAP_COMMON_H_ */