xref: /linux/drivers/gpu/drm/i915/i915_memcpy.h (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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, const 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