drivers/gpu/drm/i915/i915_memcpy.h

   1 /* SPDX-License-Identifier: MIT */
   2 /*
   3  * Copyright © 2019 Intel Corporation
   4  */
   5
   6 #ifndef __I915_MEMCPY_H__
   7 #define __I915_MEMCPY_H__
   8
   9 #include <linux/types.h>
  10
  11 struct drm_i915_private;
  12
  13 void i915_memcpy_init_early(struct drm_i915_private *i915);
  14
  15 bool i915_memcpy_from_wc(void *dst, const void *src, unsigned long len);
  16 void i915_unaligned_memcpy_from_wc(void *dst, void *src, unsigned long len);
  17
  18 /* The movntdqa instructions used for memcpy-from-wc require 16-byte alignment,
  19  * as well as SSE4.1 support. i915_memcpy_from_wc() will report if it cannot
  20  * perform the operation. To check beforehand, pass in the parameters to
  21  * to i915_can_memcpy_from_wc() - since we only care about the low 4 bits,
  22  * you only need to pass in the minor offsets, page-aligned pointers are
  23  * always valid.
  24  *
  25  * For just checking for SSE4.1, in the foreknowledge that the future use
  26  * will be correctly aligned, just use i915_has_memcpy_from_wc().
  27  */
  28 #define i915_can_memcpy_from_wc(dst, src, len) \
  29         i915_memcpy_from_wc((void *)((unsigned long)(dst) | (unsigned long)(src) | (len)), NULL, 0)
  30
  31 #define i915_has_memcpy_from_wc() \
  32         i915_memcpy_from_wc(NULL, NULL, 0)
  33
  34 #endif /* __I915_MEMCPY_H__ */