drm_cache.c | Explore in Territory

/**************************************************************************
 *
 * Copyright (c) 2006-2007 Tungsten Graphics, Inc., Cedar Park, TX., USA
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/
/*
 * Authors: Thomas Hellström <thomas-at-tungstengraphics-dot-com>
 */
#include <linux/cc_platform.h>
#include <linux/export.h>
#include <linux/highmem.h>
#include <linux/ioport.h>
#include <linux/iosys-map.h>
#include <xen/xen.h>

#include <drm/drm_cache.h>

/* A small bounce buffer that fits on the stack. */
#define MEMCPY_BOUNCE_SIZE …

#if defined(CONFIG_X86)
#include <asm/smp.h>

/*
 * clflushopt is an unordered instruction which needs fencing with mfence or
 * sfence to avoid ordering issues.  For drm_clflush_page this fencing happens
 * in the caller.
 */
static void
drm_clflush_page(struct page *page)
{ … }

static void drm_cache_flush_clflush(struct page *pages[],
				    unsigned long num_pages)
{ … }
#endif

/**
 * drm_clflush_pages - Flush dcache lines of a set of pages.
 * @pages: List of pages to be flushed.
 * @num_pages: Number of pages in the array.
 *
 * Flush every data cache line entry that points to an address belonging
 * to a page in the array.
 */
void
drm_clflush_pages(struct page *pages[], unsigned long num_pages)
{ … }
EXPORT_SYMBOL(…);

/**
 * drm_clflush_sg - Flush dcache lines pointing to a scather-gather.
 * @st: struct sg_table.
 *
 * Flush every data cache line entry that points to an address in the
 * sg.
 */
void
drm_clflush_sg(struct sg_table *st)
{ … }
EXPORT_SYMBOL(…);

/**
 * drm_clflush_virt_range - Flush dcache lines of a region
 * @addr: Initial kernel memory address.
 * @length: Region size.
 *
 * Flush every data cache line entry that points to an address in the
 * region requested.
 */
void
drm_clflush_virt_range(void *addr, unsigned long length)
{ … }
EXPORT_SYMBOL(…);

bool drm_need_swiotlb(int dma_bits)
{ … }
EXPORT_SYMBOL(…);

static void memcpy_fallback(struct iosys_map *dst,
			    const struct iosys_map *src,
			    unsigned long len)
{ … }

#ifdef CONFIG_X86

static DEFINE_STATIC_KEY_FALSE(has_movntdqa);

static void __memcpy_ntdqa(void *dst, const void *src, unsigned long len)
{ … }

/*
 * __drm_memcpy_from_wc copies @len bytes from @src to @dst using
 * non-temporal instructions where available. Note that all arguments
 * (@src, @dst) must be aligned to 16 bytes and @len must be a multiple
 * of 16.
 */
static void __drm_memcpy_from_wc(void *dst, const void *src, unsigned long len)
{ … }

/**
 * drm_memcpy_from_wc - Perform the fastest available memcpy from a source
 * that may be WC.
 * @dst: The destination pointer
 * @src: The source pointer
 * @len: The size of the area o transfer in bytes
 *
 * Tries an arch optimized memcpy for prefetching reading out of a WC region,
 * and if no such beast is available, falls back to a normal memcpy.
 */
void drm_memcpy_from_wc(struct iosys_map *dst,
			const struct iosys_map *src,
			unsigned long len)
{ … }
EXPORT_SYMBOL(…);

/*
 * drm_memcpy_init_early - One time initialization of the WC memcpy code
 */
void drm_memcpy_init_early(void)
{ … }
#else
void drm_memcpy_from_wc(struct iosys_map *dst,
			const struct iosys_map *src,
			unsigned long len)
{
	WARN_ON(in_interrupt());

	memcpy_fallback(dst, src, len);
}
EXPORT_SYMBOL(drm_memcpy_from_wc);

void drm_memcpy_init_early(void)
{
}
#endif /* CONFIG_X86 */
linux/drivers/gpu/drm/drm_cache.c
