linux/drivers/gpu/drm/i915/i915_memcpy.h
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   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
  11struct drm_i915_private;
  12
  13void i915_memcpy_init_early(struct drm_i915_private *i915);
  14
  15bool i915_memcpy_from_wc(void *dst, const void *src, unsigned long len);
  16void 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__ */
  35