1 /* SPDX-License-Identifier: MIT */ 2 /* 3 * Copyright © 2022 Intel Corporation 4 */ 5 6 #ifndef __I915_REG_DEFS__ 7 #define __I915_REG_DEFS__ 8 9 #include <linux/bitfield.h> 10 #include <linux/bits.h> 11 12 /** 13 * REG_BIT() - Prepare a u32 bit value 14 * @__n: 0-based bit number 15 * 16 * Local wrapper for BIT() to force u32, with compile time checks. 17 * 18 * @return: Value with bit @__n set. 19 */ 20 #define REG_BIT(__n) \ 21 ((u32)(BIT(__n) + \ 22 BUILD_BUG_ON_ZERO(__is_constexpr(__n) && \ 23 ((__n) < 0 || (__n) > 31)))) 24 25 /** 26 * REG_GENMASK() - Prepare a continuous u32 bitmask 27 * @__high: 0-based high bit 28 * @__low: 0-based low bit 29 * 30 * Local wrapper for GENMASK() to force u32, with compile time checks. 31 * 32 * @return: Continuous bitmask from @__high to @__low, inclusive. 33 */ 34 #define REG_GENMASK(__high, __low) \ 35 ((u32)(GENMASK(__high, __low) + \ 36 BUILD_BUG_ON_ZERO(__is_constexpr(__high) && \ 37 __is_constexpr(__low) && \ 38 ((__low) < 0 || (__high) > 31 || (__low) > (__high))))) 39 40 /** 41 * REG_GENMASK64() - Prepare a continuous u64 bitmask 42 * @__high: 0-based high bit 43 * @__low: 0-based low bit 44 * 45 * Local wrapper for GENMASK_ULL() to force u64, with compile time checks. 46 * 47 * @return: Continuous bitmask from @__high to @__low, inclusive. 48 */ 49 #define REG_GENMASK64(__high, __low) \ 50 ((u64)(GENMASK_ULL(__high, __low) + \ 51 BUILD_BUG_ON_ZERO(__is_constexpr(__high) && \ 52 __is_constexpr(__low) && \ 53 ((__low) < 0 || (__high) > 63 || (__low) > (__high))))) 54 55 /* 56 * Local integer constant expression version of is_power_of_2(). 57 */ 58 #define IS_POWER_OF_2(__x) ((__x) && (((__x) & ((__x) - 1)) == 0)) 59 60 /** 61 * REG_FIELD_PREP() - Prepare a u32 bitfield value 62 * @__mask: shifted mask defining the field's length and position 63 * @__val: value to put in the field 64 * 65 * Local copy of FIELD_PREP() to generate an integer constant expression, force 66 * u32 and for consistency with REG_FIELD_GET(), REG_BIT() and REG_GENMASK(). 67 * 68 * @return: @__val masked and shifted into the field defined by @__mask. 69 */ 70 #define REG_FIELD_PREP(__mask, __val) \ 71 ((u32)((((typeof(__mask))(__val) << __bf_shf(__mask)) & (__mask)) + \ 72 BUILD_BUG_ON_ZERO(!__is_constexpr(__mask)) + \ 73 BUILD_BUG_ON_ZERO((__mask) == 0 || (__mask) > U32_MAX) + \ 74 BUILD_BUG_ON_ZERO(!IS_POWER_OF_2((__mask) + (1ULL << __bf_shf(__mask)))) + \ 75 BUILD_BUG_ON_ZERO(__builtin_choose_expr(__is_constexpr(__val), (~((__mask) >> __bf_shf(__mask)) & (__val)), 0)))) 76 77 /** 78 * REG_FIELD_GET() - Extract a u32 bitfield value 79 * @__mask: shifted mask defining the field's length and position 80 * @__val: value to extract the bitfield value from 81 * 82 * Local wrapper for FIELD_GET() to force u32 and for consistency with 83 * REG_FIELD_PREP(), REG_BIT() and REG_GENMASK(). 84 * 85 * @return: Masked and shifted value of the field defined by @__mask in @__val. 86 */ 87 #define REG_FIELD_GET(__mask, __val) ((u32)FIELD_GET(__mask, __val)) 88 89 /** 90 * REG_FIELD_GET64() - Extract a u64 bitfield value 91 * @__mask: shifted mask defining the field's length and position 92 * @__val: value to extract the bitfield value from 93 * 94 * Local wrapper for FIELD_GET() to force u64 and for consistency with 95 * REG_GENMASK64(). 96 * 97 * @return: Masked and shifted value of the field defined by @__mask in @__val. 98 */ 99 #define REG_FIELD_GET64(__mask, __val) ((u64)FIELD_GET(__mask, __val)) 100 101 #define __MASKED_FIELD(mask, value) ((mask) << 16 | (value)) 102 #define _MASKED_FIELD(mask, value) ({ \ 103 if (__builtin_constant_p(mask)) \ 104 BUILD_BUG_ON_MSG(((mask) & 0xffff0000), "Incorrect mask"); \ 105 if (__builtin_constant_p(value)) \ 106 BUILD_BUG_ON_MSG((value) & 0xffff0000, "Incorrect value"); \ 107 if (__builtin_constant_p(mask) && __builtin_constant_p(value)) \ 108 BUILD_BUG_ON_MSG((value) & ~(mask), \ 109 "Incorrect value for mask"); \ 110 __MASKED_FIELD(mask, value); }) 111 #define _MASKED_BIT_ENABLE(a) ({ typeof(a) _a = (a); _MASKED_FIELD(_a, _a); }) 112 #define _MASKED_BIT_DISABLE(a) (_MASKED_FIELD((a), 0)) 113 114 /* 115 * Given the first two numbers __a and __b of arbitrarily many evenly spaced 116 * numbers, pick the 0-based __index'th value. 117 * 118 * Always prefer this over _PICK() if the numbers are evenly spaced. 119 */ 120 #define _PICK_EVEN(__index, __a, __b) ((__a) + (__index) * ((__b) - (__a))) 121 122 /* 123 * Given the arbitrary numbers in varargs, pick the 0-based __index'th number. 124 * 125 * Always prefer _PICK_EVEN() over this if the numbers are evenly spaced. 126 */ 127 #define _PICK(__index, ...) (((const u32 []){ __VA_ARGS__ })[__index]) 128 129 typedef struct { 130 u32 reg; 131 } i915_reg_t; 132 133 #define _MMIO(r) ((const i915_reg_t){ .reg = (r) }) 134 135 typedef struct { 136 u32 reg; 137 } i915_mcr_reg_t; 138 139 #define INVALID_MMIO_REG _MMIO(0) 140 141 /* 142 * These macros can be used on either i915_reg_t or i915_mcr_reg_t since they're 143 * simply operations on the register's offset and don't care about the MCR vs 144 * non-MCR nature of the register. 145 */ 146 #define i915_mmio_reg_offset(r) \ 147 _Generic((r), i915_reg_t: (r).reg, i915_mcr_reg_t: (r).reg) 148 #define i915_mmio_reg_equal(a, b) (i915_mmio_reg_offset(a) == i915_mmio_reg_offset(b)) 149 #define i915_mmio_reg_valid(r) (!i915_mmio_reg_equal(r, INVALID_MMIO_REG)) 150 151 #endif /* __I915_REG_DEFS__ */ 152