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drm_cache.c revision 1.1 
      1 /**************************************************************************
      2  *
      3  * Copyright (c) 2006-2007 Tungsten Graphics, Inc., Cedar Park, TX., USA
      4  * All Rights Reserved.
      5  *
      6  * Permission is hereby granted, free of charge, to any person obtaining a
      7  * copy of this software and associated documentation files (the
      8  * "Software"), to deal in the Software without restriction, including
      9  * without limitation the rights to use, copy, modify, merge, publish,
     10  * distribute, sub license, and/or sell copies of the Software, and to
     11  * permit persons to whom the Software is furnished to do so, subject to
     12  * the following conditions:
     13  *
     14  * The above copyright notice and this permission notice (including the
     15  * next paragraph) shall be included in all copies or substantial portions
     16  * of the Software.
     17  *
     18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
     21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
     22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
     23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
     24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
     25  *
     26  **************************************************************************/
     27 /*
     28  * Authors: Thomas Hellstrm <thomas-at-tungstengraphics-dot-com>
     29  */
     30 
     31 #include <linux/export.h>
     32 #include <drm/drmP.h>
     33 
     34 #if defined(CONFIG_X86)
     35 static void
     36 drm_clflush_page(struct page *page)
     37 {
     38 	uint8_t *page_virtual;
     39 	unsigned int i;
     40 	const int size = boot_cpu_data.x86_clflush_size;
     41 
     42 	if (unlikely(page == NULL))
     43 		return;
     44 
     45 	page_virtual = kmap_atomic(page);
     46 	for (i = 0; i < PAGE_SIZE; i += size)
     47 		clflush(page_virtual + i);
     48 	kunmap_atomic(page_virtual);
     49 }
     50 
     51 static void drm_cache_flush_clflush(struct page *pages[],
     52 				    unsigned long num_pages)
     53 {
     54 	unsigned long i;
     55 
     56 	mb();
     57 	for (i = 0; i < num_pages; i++)
     58 		drm_clflush_page(*pages++);
     59 	mb();
     60 }
     61 
     62 static void
     63 drm_clflush_ipi_handler(void *null)
     64 {
     65 	wbinvd();
     66 }
     67 #endif
     68 
     69 void
     70 drm_clflush_pages(struct page *pages[], unsigned long num_pages)
     71 {
     72 
     73 #if defined(CONFIG_X86)
     74 	if (cpu_has_clflush) {
     75 		drm_cache_flush_clflush(pages, num_pages);
     76 		return;
     77 	}
     78 
     79 	if (on_each_cpu(drm_clflush_ipi_handler, NULL, 1) != 0)
     80 		printk(KERN_ERR "Timed out waiting for cache flush.\n");
     81 
     82 #elif defined(__powerpc__)
     83 	unsigned long i;
     84 	for (i = 0; i < num_pages; i++) {
     85 		struct page *page = pages[i];
     86 		void *page_virtual;
     87 
     88 		if (unlikely(page == NULL))
     89 			continue;
     90 
     91 		page_virtual = kmap_atomic(page);
     92 		flush_dcache_range((unsigned long)page_virtual,
     93 				   (unsigned long)page_virtual + PAGE_SIZE);
     94 		kunmap_atomic(page_virtual);
     95 	}
     96 #else
     97 	printk(KERN_ERR "Architecture has no drm_cache.c support\n");
     98 	WARN_ON_ONCE(1);
     99 #endif
    100 }
    101 EXPORT_SYMBOL(drm_clflush_pages);
    102 
    103 void
    104 drm_clflush_sg(struct sg_table *st)
    105 {
    106 #if defined(CONFIG_X86)
    107 	if (cpu_has_clflush) {
    108 		struct scatterlist *sg;
    109 		int i;
    110 
    111 		mb();
    112 		for_each_sg(st->sgl, sg, st->nents, i)
    113 			drm_clflush_page(sg_page(sg));
    114 		mb();
    115 
    116 		return;
    117 	}
    118 
    119 	if (on_each_cpu(drm_clflush_ipi_handler, NULL, 1) != 0)
    120 		printk(KERN_ERR "Timed out waiting for cache flush.\n");
    121 #else
    122 	printk(KERN_ERR "Architecture has no drm_cache.c support\n");
    123 	WARN_ON_ONCE(1);
    124 #endif
    125 }
    126 EXPORT_SYMBOL(drm_clflush_sg);
    127 
    128 void
    129 drm_clflush_virt_range(char *addr, unsigned long length)
    130 {
    131 #if defined(CONFIG_X86)
    132 	if (cpu_has_clflush) {
    133 		char *end = addr + length;
    134 		mb();
    135 		for (; addr < end; addr += boot_cpu_data.x86_clflush_size)
    136 			clflush(addr);
    137 		clflush(end - 1);
    138 		mb();
    139 		return;
    140 	}
    141 
    142 	if (on_each_cpu(drm_clflush_ipi_handler, NULL, 1) != 0)
    143 		printk(KERN_ERR "Timed out waiting for cache flush.\n");
    144 #else
    145 	printk(KERN_ERR "Architecture has no drm_cache.c support\n");
    146 	WARN_ON_ONCE(1);
    147 #endif
    148 }
    149 EXPORT_SYMBOL(drm_clflush_virt_range);
    150