drivers/gpu/drm/i915/i915_utils.h

   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 #undef WARN_ON
  29 /* Many gcc seem to no see through this and fall over :( */
  30 #if 0
  31 #define WARN_ON(x) ({ \
  32         bool __i915_warn_cond = (x); \
  33         if (__builtin_constant_p(__i915_warn_cond)) \
  34                 BUILD_BUG_ON(__i915_warn_cond); \
  35         WARN(__i915_warn_cond, "WARN_ON(" #x ")"); })
  36 #else
  37 #define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")")
  38 #endif
  39
  40 #undef WARN_ON_ONCE
  41 #define WARN_ON_ONCE(x) WARN_ONCE((x), "%s", "WARN_ON_ONCE(" __stringify(x) ")")
  42
  43 #define MISSING_CASE(x) WARN(1, "Missing switch case (%lu) in %s\n", \
  44                              (long)(x), __func__)
  45
  46 #if GCC_VERSION >= 70000
  47 #define add_overflows(A, B) \
  48         __builtin_add_overflow_p((A), (B), (typeof((A) + (B)))0)
  49 #else
  50 #define add_overflows(A, B) ({ \
  51         typeof(A) a = (A); \
  52         typeof(B) b = (B); \
  53         a + b < a; \
  54 })
  55 #endif
  56
  57 #define range_overflows(start, size, max) ({ \
  58         typeof(start) start__ = (start); \
  59         typeof(size) size__ = (size); \
  60         typeof(max) max__ = (max); \
  61         (void)(&start__ == &size__); \
  62         (void)(&start__ == &max__); \
  63         start__ > max__ || size__ > max__ - start__; \
  64 })
  65
  66 #define range_overflows_t(type, start, size, max) \
  67         range_overflows((type)(start), (type)(size), (type)(max))
  68
  69 /* Note we don't consider signbits :| */
  70 #define overflows_type(x, T) \
  71         (sizeof(x) > sizeof(T) && (x) >> (sizeof(T) * BITS_PER_BYTE))
  72
  73 #define ptr_mask_bits(ptr, n) ({                                        \
  74         unsigned long __v = (unsigned long)(ptr);                       \
  75         (typeof(ptr))(__v & -BIT(n));                                   \
  76 })
  77
  78 #define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
  79
  80 #define ptr_unpack_bits(ptr, bits, n) ({                                \
  81         unsigned long __v = (unsigned long)(ptr);                       \
  82         *(bits) = __v & (BIT(n) - 1);                                   \
  83         (typeof(ptr))(__v & -BIT(n));                                   \
  84 })
  85
  86 #define ptr_pack_bits(ptr, bits, n)                                     \
  87         ((typeof(ptr))((unsigned long)(ptr) | (bits)))
  88
  89 #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
  90 #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
  91 #define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
  92 #define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
  93
  94 #define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member)
  95
  96 #define fetch_and_zero(ptr) ({                                          \
  97         typeof(*ptr) __T = *(ptr);                                      \
  98         *(ptr) = (typeof(*ptr))0;                                       \
  99         __T;                                                            \
 100 })
 101
 102 #define u64_to_ptr(T, x) ({                                             \
 103         typecheck(u64, x);                                              \
 104         (T *)(uintptr_t)(x);                                            \
 105 })
 106
 107 #define __mask_next_bit(mask) ({                                        \
 108         int __idx = ffs(mask) - 1;                                      \
 109         mask &= ~BIT(__idx);                                            \
 110         __idx;                                                          \
 111 })
 112
 113 #include <linux/list.h>
 114
 115 static inline void __list_del_many(struct list_head *head,
 116                                    struct list_head *first)
 117 {
 118         first->prev = head;
 119         WRITE_ONCE(head->next, first);
 120 }
 121
 122 #endif /* !__I915_UTILS_H */