LXR linux/drivers/gpu/drm/i915/i915

   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
 115static 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 */
 123