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author | Yang Zhang <yang.z.zhang@intel.com> | 2015-08-28 09:58:54 +0800 |
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committer | Yang Zhang <yang.z.zhang@intel.com> | 2015-09-01 12:44:00 +0800 |
commit | e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch) | |
tree | 66b09f592c55df2878107a468a91d21506104d3f /qemu/roms/u-boot/include/bitfield.h | |
parent | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff) |
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/roms/u-boot/include/bitfield.h')
-rw-r--r-- | qemu/roms/u-boot/include/bitfield.h | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/qemu/roms/u-boot/include/bitfield.h b/qemu/roms/u-boot/include/bitfield.h new file mode 100644 index 000000000..ec4815c8e --- /dev/null +++ b/qemu/roms/u-boot/include/bitfield.h @@ -0,0 +1,58 @@ +/* + * Copyright 2013 Broadcom Corporation. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +/* + * Bitfield operations + * + * These are generic bitfield operations which allow manipulation of variable + * width bitfields within a word. One use of this would be to use data tables + * to determine how to reprogram fields within R/W hardware registers. + * + * Example: + * + * old_reg_val + * +--------+----+---+--+-----+----------+ + * | | | | | old | | + * +--------+----+---+--+-----+----------+ + * + * new_reg_val + * +--------+----+---+--+-----+----------+ + * | | | | | new | | + * +--------+----+---+--+-----+----------+ + * + * mask = bitfield_mask(10, 5); + * old = bitfield_extract(old_reg_val, 10, 5); + * new_reg_val = bitfield_replace(old_reg_val, 10, 5, new); + * + * The numbers 10 and 5 could for example come from data + * tables which describe all bitfields in all registers. + */ + +#include <linux/types.h> + +/* Produces a mask of set bits covering a range of a uint value */ +static inline uint bitfield_mask(uint shift, uint width) +{ + return ((1 << width) - 1) << shift; +} + +/* Extract the value of a bitfield found within a given register value */ +static inline uint bitfield_extract(uint reg_val, uint shift, uint width) +{ + return (reg_val & bitfield_mask(shift, width)) >> shift; +} + +/* + * Replace the value of a bitfield found within a given register value + * Returns the newly modified uint value with the replaced field. + */ +static inline uint bitfield_replace(uint reg_val, uint shift, uint width, + uint bitfield_val) +{ + uint mask = bitfield_mask(shift, width); + + return (reg_val & ~mask) | (bitfield_val << shift); +} |