mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-29 05:44:11 +00:00
6aacb5a3b0
The movntqda requires 16-byte alignment for the source pointer. Avoid falling back to clflush if the source pointer is misaligned by doing the doing a small uncached memcpy to fixup the alignments. v2: Turn the unaligned copy into a genuine helper Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191211110437.4082687-5-chris@chris-wilson.co.uk
34 lines
1.2 KiB
C
34 lines
1.2 KiB
C
/* SPDX-License-Identifier: MIT */
|
|
/*
|
|
* Copyright © 2019 Intel Corporation
|
|
*/
|
|
|
|
#ifndef __I915_MEMCPY_H__
|
|
#define __I915_MEMCPY_H__
|
|
|
|
#include <linux/types.h>
|
|
|
|
struct drm_i915_private;
|
|
|
|
void i915_memcpy_init_early(struct drm_i915_private *i915);
|
|
|
|
bool i915_memcpy_from_wc(void *dst, const void *src, unsigned long len);
|
|
void i915_unaligned_memcpy_from_wc(void *dst, void *src, unsigned long len);
|
|
|
|
/* The movntdqa instructions used for memcpy-from-wc require 16-byte alignment,
|
|
* as well as SSE4.1 support. i915_memcpy_from_wc() will report if it cannot
|
|
* perform the operation. To check beforehand, pass in the parameters to
|
|
* to i915_can_memcpy_from_wc() - since we only care about the low 4 bits,
|
|
* you only need to pass in the minor offsets, page-aligned pointers are
|
|
* always valid.
|
|
*
|
|
* For just checking for SSE4.1, in the foreknowledge that the future use
|
|
* will be correctly aligned, just use i915_has_memcpy_from_wc().
|
|
*/
|
|
#define i915_can_memcpy_from_wc(dst, src, len) \
|
|
i915_memcpy_from_wc((void *)((unsigned long)(dst) | (unsigned long)(src) | (len)), NULL, 0)
|
|
|
|
#define i915_has_memcpy_from_wc() \
|
|
i915_memcpy_from_wc(NULL, NULL, 0)
|
|
|
|
#endif /* __I915_MEMCPY_H__ */
|