diff options
Diffstat (limited to 'include/drm/intel/reg_bits.h')
| -rw-r--r-- | include/drm/intel/reg_bits.h | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/include/drm/intel/reg_bits.h b/include/drm/intel/reg_bits.h new file mode 100644 index 000000000000..2a9066e1d808 --- /dev/null +++ b/include/drm/intel/reg_bits.h @@ -0,0 +1,139 @@ +/* SPDX-License-Identifier: MIT */ +/* Copyright © 2026 Intel Corporation */ + +#ifndef _REG_BITS_H_ +#define _REG_BITS_H_ + +#include <linux/bitfield.h> +#include <linux/bits.h> + +/* + * Wrappers over the generic fixed width BIT_U*() and GENMASK_U*() + * implementations, for compatibility reasons with previous implementation. + */ +#define REG_GENMASK(high, low) GENMASK_U32(high, low) +#define REG_GENMASK64(high, low) GENMASK_U64(high, low) +#define REG_GENMASK16(high, low) GENMASK_U16(high, low) +#define REG_GENMASK8(high, low) GENMASK_U8(high, low) + +#define REG_BIT(n) BIT_U32(n) +#define REG_BIT64(n) BIT_U64(n) +#define REG_BIT16(n) BIT_U16(n) +#define REG_BIT8(n) BIT_U8(n) + +/* + * Local integer constant expression version of is_power_of_2(). + */ +#define IS_POWER_OF_2(__x) ((__x) && (((__x) & ((__x) - 1)) == 0)) + +/** + * REG_FIELD_PREP8() - Prepare a u8 bitfield value + * @__mask: shifted mask defining the field's length and position + * @__val: value to put in the field + * + * Local copy of FIELD_PREP() to generate an integer constant expression, force + * u8 and for consistency with REG_FIELD_GET8(), REG_BIT8() and REG_GENMASK8(). + * + * @return: @__val masked and shifted into the field defined by @__mask. + */ +#define REG_FIELD_PREP8(__mask, __val) \ + ((u8)((((typeof(__mask))(__val) << __bf_shf(__mask)) & (__mask)) + \ + BUILD_BUG_ON_ZERO(!__is_constexpr(__mask)) + \ + BUILD_BUG_ON_ZERO((__mask) == 0 || (__mask) > U8_MAX) + \ + BUILD_BUG_ON_ZERO(!IS_POWER_OF_2((__mask) + (1ULL << __bf_shf(__mask)))) + \ + BUILD_BUG_ON_ZERO(__builtin_choose_expr(__is_constexpr(__val), (~((__mask) >> __bf_shf(__mask)) & (__val)), 0)))) + +/** + * REG_FIELD_PREP16() - Prepare a u16 bitfield value + * @__mask: shifted mask defining the field's length and position + * @__val: value to put in the field + * + * Local copy of FIELD_PREP16() to generate an integer constant + * expression, force u8 and for consistency with + * REG_FIELD_GET16(), REG_BIT16() and REG_GENMASK16(). + * + * @return: @__val masked and shifted into the field defined by @__mask. + */ +#define REG_FIELD_PREP16(__mask, __val) \ + ((u16)((((typeof(__mask))(__val) << __bf_shf(__mask)) & (__mask)) + \ + BUILD_BUG_ON_ZERO(!__is_constexpr(__mask)) + \ + BUILD_BUG_ON_ZERO((__mask) == 0 || (__mask) > U16_MAX) + \ + BUILD_BUG_ON_ZERO(!IS_POWER_OF_2((__mask) + (1ULL << __bf_shf(__mask)))) + \ + BUILD_BUG_ON_ZERO(__builtin_choose_expr(__is_constexpr(__val), (~((__mask) >> __bf_shf(__mask)) & (__val)), 0)))) + +/** + * REG_FIELD_PREP() - Prepare a u32 bitfield value + * @__mask: shifted mask defining the field's length and position + * @__val: value to put in the field + * + * Local copy of FIELD_PREP() to generate an integer constant expression, force + * u32 and for consistency with REG_FIELD_GET(), REG_BIT() and REG_GENMASK(). + * + * @return: @__val masked and shifted into the field defined by @__mask. + */ +#define REG_FIELD_PREP(__mask, __val) \ + ((u32)((((typeof(__mask))(__val) << __bf_shf(__mask)) & (__mask)) + \ + BUILD_BUG_ON_ZERO(!__is_constexpr(__mask)) + \ + BUILD_BUG_ON_ZERO((__mask) == 0 || (__mask) > U32_MAX) + \ + BUILD_BUG_ON_ZERO(!IS_POWER_OF_2((__mask) + (1ULL << __bf_shf(__mask)))) + \ + BUILD_BUG_ON_ZERO(__builtin_choose_expr(__is_constexpr(__val), (~((__mask) >> __bf_shf(__mask)) & (__val)), 0)))) + +/** + * REG_FIELD_GET8() - Extract a u8 bitfield value + * @__mask: shifted mask defining the field's length and position + * @__val: value to extract the bitfield value from + * + * Local wrapper for FIELD_GET() to force u8 and for consistency with + * REG_FIELD_PREP(), REG_BIT() and REG_GENMASK(). + * + * @return: Masked and shifted value of the field defined by @__mask in @__val. + */ +#define REG_FIELD_GET8(__mask, __val) ((u8)FIELD_GET(__mask, __val)) + +/** + * REG_FIELD_GET() - Extract a u32 bitfield value + * @__mask: shifted mask defining the field's length and position + * @__val: value to extract the bitfield value from + * + * Local wrapper for FIELD_GET() to force u32 and for consistency with + * REG_FIELD_PREP(), REG_BIT() and REG_GENMASK(). + * + * @return: Masked and shifted value of the field defined by @__mask in @__val. + */ +#define REG_FIELD_GET(__mask, __val) ((u32)FIELD_GET(__mask, __val)) + +/** + * REG_FIELD_GET64() - Extract a u64 bitfield value + * @__mask: shifted mask defining the field's length and position + * @__val: value to extract the bitfield value from + * + * Local wrapper for FIELD_GET() to force u64 and for consistency with + * REG_GENMASK64(). + * + * @return: Masked and shifted value of the field defined by @__mask in @__val. + */ +#define REG_FIELD_GET64(__mask, __val) ((u64)FIELD_GET(__mask, __val)) + +/** + * REG_FIELD_MAX() - produce the maximum value representable by a field + * @__mask: shifted mask defining the field's length and position + * + * Local wrapper for FIELD_MAX() to return the maximum bit value that can + * be held in the field specified by @_mask, cast to u32 for consistency + * with other macros. + */ +#define REG_FIELD_MAX(__mask) ((u32)FIELD_MAX(__mask)) + +#define REG_MASKED_FIELD(mask, value) \ + (BUILD_BUG_ON_ZERO(__builtin_choose_expr(__builtin_constant_p(mask), (mask) & 0xffff0000, 0)) + \ + BUILD_BUG_ON_ZERO(__builtin_choose_expr(__builtin_constant_p(value), (value) & 0xffff0000, 0)) + \ + BUILD_BUG_ON_ZERO(__builtin_choose_expr(__builtin_constant_p(mask) && __builtin_constant_p(value), (value) & ~(mask), 0)) + \ + ((mask) << 16 | (value))) + +#define REG_MASKED_FIELD_ENABLE(a) \ + (__builtin_choose_expr(__builtin_constant_p(a), REG_MASKED_FIELD((a), (a)), ({ typeof(a) _a = (a); REG_MASKED_FIELD(_a, _a); }))) + +#define REG_MASKED_FIELD_DISABLE(a) \ + (REG_MASKED_FIELD((a), 0)) + +#endif |