| Karl Meakin | 88851f9 | 2024-05-10 13:59:08 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2024 The Hafnium Authors. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style |
| 5 | * license that can be found in the LICENSE file or at |
| 6 | * https://opensource.org/licenses/BSD-3-Clause. |
| 7 | */ |
| 8 | |
| 9 | #include <stdbool.h> |
| 10 | #include <stdint.h> |
| 11 | |
| 12 | #if defined(__ASSEMBLY__) |
| 13 | #define STATIC_ASSERT(expr, msg) 0 |
| 14 | #else |
| 15 | #define STATIC_ASSERT(expr, msg) \ |
| 16 | __extension__({ \ |
| 17 | static_assert(expr, msg); \ |
| 18 | 0; \ |
| 19 | }) |
| 20 | #endif |
| 21 | |
| 22 | /** |
| 23 | * NOTE: The below macroos use the notation `[hi:lo]` to mean the bits |
| 24 | * from `lo` up-to and including `hi`. This matches the notation used in the |
| 25 | * FF-A specification. |
| 26 | * Examples: |
| 27 | * - bits `[4:0]` of `0xAF` are `1111`, |
| 28 | * - bits `[7:4]` of `0xAF` are `1010`, |
| 29 | * - bits `[31:0]` means the lower half of a 64-bit integer |
| 30 | * - bits `[63:32]` means the upper half of a 64-bit integer |
| 31 | * - bits `[63:0]` means the whole 64-bit integer |
| 32 | */ |
| 33 | |
| 34 | /** |
| 35 | * Isolate the `n`th bit of `value`. |
| 36 | */ |
| 37 | #define GET_BIT(value, n) \ |
| 38 | (STATIC_ASSERT((n) < 64, "n out of bounds") + \ |
| 39 | ((value) & (UINT64_C(1) << (n)))) |
| 40 | |
| 41 | /** |
| 42 | * Return true if the `n`th bit of `value` is 1. |
| 43 | */ |
| 44 | #define IS_BIT_SET(value, n) (GET_BIT(value, n) != 0) |
| 45 | |
| 46 | /** |
| 47 | * Return true if the `n`th bit of `value` is 0. |
| 48 | */ |
| 49 | #define IS_BIT_UNSET(value, n) (GET_BIT(value, n) == 0) |
| 50 | |
| 51 | /** |
| 52 | * Return a mask suitable for isolating bits `[hi:lo]` of a 64-bit |
| 53 | * integer. |
| 54 | */ |
| 55 | #define GET_BITS_MASK(hi, lo) \ |
| 56 | (STATIC_ASSERT((hi) < 64, "hi out of bounds") + \ |
| 57 | STATIC_ASSERT((hi) >= (lo), "hi must be >= lo") + \ |
| 58 | (((~UINT64_C(0)) - (UINT64_C(1) << (lo)) + 1) & \ |
| 59 | (~UINT64_C(0) >> (64 - 1 - (hi))))) |
| 60 | |
| 61 | /** |
| 62 | * Isolate bits `[hi:lo]` of `value`. |
| 63 | */ |
| 64 | #define GET_BITS(value, hi, lo) ((value)&GET_BITS_MASK(hi, lo)) |
| 65 | |
| 66 | /** |
| 67 | * Return true if any bits `[lo:hi]` of `value` are 1. |
| 68 | */ |
| 69 | #define ANY_BITS_SET(value, hi, lo) (GET_BITS(value, hi, lo) != 0) |
| 70 | |
| 71 | /** |
| 72 | * Return true if all bits `[lo:hi]` of `value` are 1. |
| 73 | */ |
| 74 | #define ALL_BITS_SET(value, hi, lo) \ |
| 75 | (GET_BITS(value, hi, lo) == GET_BITS_MASK(hi, lo)) |
| 76 | |
| 77 | /** |
| 78 | * Return true if any bits `[lo:hi]` of `value` are 0. |
| 79 | */ |
| 80 | #define ANY_BITS_UNSET(value, hi, lo) (!ALL_BITS_SET(value, hi, lo)) |
| 81 | |
| 82 | /** |
| 83 | * Return true if all bits `[lo:hi]` of `value` are 0. |
| 84 | */ |
| 85 | #define ALL_BITS_UNSET(value, hi, lo) (!ANY_BITS_SET(value, hi, lo)) |