/**************************************************************************
 *
 * 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/export.h>
#include <linux/scatterlist.h>
#include <drm/drmP.h>

extern int x86_clflush_size;

static inline void clflush(volatile void *__p)
{
    asm volatile("clflush %0" : "+m" (*(volatile char*)__p));
}

#if 0
static void
drm_clflush_page(struct page *page)
{
	uint8_t *page_virtual;
	unsigned int i;
	const int size = boot_cpu_data.x86_clflush_size;

	if (unlikely(page == NULL))
		return;

	page_virtual = kmap_atomic(page);
	for (i = 0; i < PAGE_SIZE; i += size)
		clflush(page_virtual + i);
	kunmap_atomic(page_virtual);
}

static void drm_cache_flush_clflush(struct page *pages[],
				    unsigned long num_pages)
{
	unsigned long i;

	mb();
	for (i = 0; i < num_pages; i++)
		drm_clflush_page(*pages++);
	mb();
}

static void
drm_clflush_ipi_handler(void *null)
{
	wbinvd();
}
#endif

void
drm_clflush_pages(struct page *pages[], unsigned long num_pages)
{
    uint8_t *pva;
    unsigned int i, j;

    pva = AllocKernelSpace(4096);

    if(pva != NULL)
    {
        dma_addr_t *src, *dst;
        u32 count;

        for (i = 0; i < num_pages; i++)
        {
            mb();
            MapPage(pva, page_to_phys(pages[i]), 0x001);
            for (j = 0; j < PAGE_SIZE; j += x86_clflush_size)
                clflush(pva + j);
        }
        FreeKernelSpace(pva);
    }
    mb();
}
EXPORT_SYMBOL(drm_clflush_pages);

void
drm_clflush_sg(struct sg_table *st)
{
		struct sg_page_iter sg_iter;
    struct page *page;

    uint8_t *pva;
    unsigned int i;

    pva = AllocKernelSpace(4096);
    if( pva != NULL)
    {
		mb();
		for_each_sg_page(st->sgl, &sg_iter, st->nents, 0)
        {
            page = sg_page_iter_page(&sg_iter);

            MapPage(pva,page_to_phys(page), 0x001);

            for (i = 0; i < PAGE_SIZE; i += x86_clflush_size)
                clflush(pva + i);
        };
        FreeKernelSpace(pva);
    };
    mb();
}
EXPORT_SYMBOL(drm_clflush_sg);

#if 0
void
drm_clflush_virt_range(char *addr, unsigned long length)
{
#if defined(CONFIG_X86)
	if (cpu_has_clflush) {
		char *end = addr + length;
		mb();
		for (; addr < end; addr += boot_cpu_data.x86_clflush_size)
			clflush(addr);
		clflush(end - 1);
		mb();
		return;
	}

	if (on_each_cpu(drm_clflush_ipi_handler, NULL, 1) != 0)
		printk(KERN_ERR "Timed out waiting for cache flush.\n");
#else
	printk(KERN_ERR "Architecture has no drm_cache.c support\n");
	WARN_ON_ONCE(1);
#endif
}
EXPORT_SYMBOL(drm_clflush_virt_range);

#endif