i915_memcpy.h revision 1.2 1 /* $NetBSD: i915_memcpy.h,v 1.2 2021/12/18 23:45:28 riastradh Exp $ */
2
3 /* SPDX-License-Identifier: MIT */
4 /*
5 * Copyright 2019 Intel Corporation
6 */
7
8 #ifndef __I915_MEMCPY_H__
9 #define __I915_MEMCPY_H__
10
11 #include <linux/types.h>
12
13 struct drm_i915_private;
14
15 void i915_memcpy_init_early(struct drm_i915_private *i915);
16
17 bool i915_memcpy_from_wc(void *dst, const void *src, unsigned long len);
18 void i915_unaligned_memcpy_from_wc(void *dst, void *src, unsigned long len);
19
20 /* The movntdqa instructions used for memcpy-from-wc require 16-byte alignment,
21 * as well as SSE4.1 support. i915_memcpy_from_wc() will report if it cannot
22 * perform the operation. To check beforehand, pass in the parameters to
23 * to i915_can_memcpy_from_wc() - since we only care about the low 4 bits,
24 * you only need to pass in the minor offsets, page-aligned pointers are
25 * always valid.
26 *
27 * For just checking for SSE4.1, in the foreknowledge that the future use
28 * will be correctly aligned, just use i915_has_memcpy_from_wc().
29 */
30 #define i915_can_memcpy_from_wc(dst, src, len) \
31 i915_memcpy_from_wc((void *)((unsigned long)(dst) | (unsigned long)(src) | (len)), NULL, 0)
32
33 #define i915_has_memcpy_from_wc() \
34 i915_memcpy_from_wc(NULL, NULL, 0)
35
36 #endif /* __I915_MEMCPY_H__ */
37