1 /* 2 * Copyright © 2016 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 * 23 */ 24 25 #ifndef __I915_UTILS_H 26 #define __I915_UTILS_H 27 28 #if GCC_VERSION >= 70000 29 #define add_overflows(A, B) \ 30 __builtin_add_overflow_p((A), (B), (typeof((A) + (B)))0) 31 #else 32 #define add_overflows(A, B) ({ \ 33 typeof(A) a = (A); \ 34 typeof(B) b = (B); \ 35 a + b < a; \ 36 }) 37 #endif 38 39 #define range_overflows(start, size, max) ({ \ 40 typeof(start) start__ = (start); \ 41 typeof(size) size__ = (size); \ 42 typeof(max) max__ = (max); \ 43 (void)(&start__ == &size__); \ 44 (void)(&start__ == &max__); \ 45 start__ > max__ || size__ > max__ - start__; \ 46 }) 47 48 #define range_overflows_t(type, start, size, max) \ 49 range_overflows((type)(start), (type)(size), (type)(max)) 50 51 /* Note we don't consider signbits :| */ 52 #define overflows_type(x, T) \ 53 (sizeof(x) > sizeof(T) && (x) >> (sizeof(T) * BITS_PER_BYTE)) 54 55 #define ptr_mask_bits(ptr) ({ \ 56 unsigned long __v = (unsigned long)(ptr); \ 57 (typeof(ptr))(__v & PAGE_MASK); \ 58 }) 59 60 #define ptr_unpack_bits(ptr, bits) ({ \ 61 unsigned long __v = (unsigned long)(ptr); \ 62 (bits) = __v & ~PAGE_MASK; \ 63 (typeof(ptr))(__v & PAGE_MASK); \ 64 }) 65 66 #define ptr_pack_bits(ptr, bits) \ 67 ((typeof(ptr))((unsigned long)(ptr) | (bits))) 68 69 #define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member) 70 71 #define fetch_and_zero(ptr) ({ \ 72 typeof(*ptr) __T = *(ptr); \ 73 *(ptr) = (typeof(*ptr))0; \ 74 __T; \ 75 }) 76 77 #endif /* !__I915_UTILS_H */ 78