linux/drivers/gpu/drm/drm_cache.c
Imre Deak 2db76d7c3c lib/scatterlist: sg_page_iter: support sg lists w/o backing pages
The i915 driver uses sg lists for memory without backing 'struct page'
pages, similarly to other IO memory regions, setting only the DMA
address for these. It does this, so that it can program the HW MMU
tables in a uniform way both for sg lists with and without backing pages.

Without a valid page pointer we can't call nth_page to get the current
page in __sg_page_iter_next, so add a helper that relevant users can
call separately. Also add a helper to get the DMA address of the current
page (idea from Daniel).

Convert all places in i915, to use the new API.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-03-27 17:13:44 +01:00

149 lines
3.8 KiB
C

/**************************************************************************
*
* 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 sg_page_iter sg_iter;
mb();
for_each_sg_page(st->sgl, &sg_iter, st->nents, 0)
drm_clflush_page(sg_page_iter_page(&sg_iter));
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);