drm_cache.c

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/**************************************************************************
 *
 * 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 <drm/drmP.h>

#if defined(CONFIG_X86)
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)
{

#if defined(CONFIG_X86)
    if (cpu_has_clflush) {
        drm_cache_flush_clflush(pages, num_pages);
        return;
    }

    if (on_each_cpu(drm_clflush_ipi_handler, NULL, 1) != 0)
        printk(KERN_ERR "Timed out waiting for cache flush.\n");

#elif defined(__powerpc__)
    unsigned long i;
    for (i = 0; i < num_pages; i++) {
        struct page *page = pages[i];
        void *page_virtual;

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

        page_virtual = kmap_atomic(page);
        flush_dcache_range((unsigned long)page_virtual,
                   (unsigned long)page_virtual + PAGE_SIZE);
        kunmap_atomic(page_virtual);
    }
#else
    printk(KERN_ERR "Architecture has no drm_cache.c support\n");
    WARN_ON_ONCE(1);
#endif
}
EXPORT_SYMBOL(drm_clflush_pages);

void
drm_clflush_sg(struct sg_table *st)
{
#if defined(CONFIG_X86)
    if (cpu_has_clflush) {
        struct scatterlist *sg;
        int i;

        mb();
        for_each_sg(st->sgl, sg, st->nents, i)
            drm_clflush_page(sg_page(sg));
        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_sg);

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);