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drm_cache.c revision 1.3.6.1 
      1 /*	$NetBSD: drm_cache.c,v 1.3.6.1 2015/04/06 15:18:17 skrll Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2013 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Taylor R. Campbell.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: drm_cache.c,v 1.3.6.1 2015/04/06 15:18:17 skrll Exp $");
     34 
     35 #include <sys/types.h>
     36 #include <sys/xcall.h>
     37 
     38 #include <uvm/uvm_extern.h>
     39 
     40 #include <machine/cpufunc.h>
     41 
     42 #include <linux/mm_types.h>
     43 
     44 #include <drm/drmP.h>
     45 
     46 static bool		drm_md_clflush_finegrained_p(void);
     47 static void		drm_md_clflush_all(void);
     48 static void		drm_md_clflush_page(struct page *);
     49 static void		drm_md_clflush_virt_range(const void *, size_t);
     50 
     51 void
     52 drm_clflush_pages(struct page **pages, unsigned long npages)
     53 {
     54 
     55 	if (drm_md_clflush_finegrained_p()) {
     56 		while (npages--)
     57 			drm_md_clflush_page(pages[npages]);
     58 	} else {
     59 		drm_md_clflush_all();
     60 	}
     61 }
     62 
     63 void
     64 drm_clflush_pglist(struct pglist *list)
     65 {
     66 
     67 	if (drm_md_clflush_finegrained_p()) {
     68 		struct vm_page *page;
     69 
     70 		TAILQ_FOREACH(page, list, pageq.queue)
     71 			drm_md_clflush_page(container_of(page, struct page,
     72 				p_vmp));
     73 	} else {
     74 		drm_md_clflush_all();
     75 	}
     76 }
     77 
     78 void
     79 drm_clflush_page(struct page *page)
     80 {
     81 
     82 	if (drm_md_clflush_finegrained_p())
     83 		drm_md_clflush_page(page);
     84 	else
     85 		drm_md_clflush_all();
     86 }
     87 
     88 void
     89 drm_clflush_virt_range(const void *vaddr, size_t nbytes)
     90 {
     91 
     92 	if (drm_md_clflush_finegrained_p())
     93 		drm_md_clflush_virt_range(vaddr, nbytes);
     94 	else
     95 		drm_md_clflush_all();
     96 }
     97 
     98 #if defined(__i386__) || defined(__x86_64__)
     99 
    100 static bool
    101 drm_md_clflush_finegrained_p(void)
    102 {
    103 	return ISSET(cpu_info_primary.ci_feat_val[0], CPUID_CFLUSH);
    104 }
    105 
    106 static void
    107 drm_x86_clflush(const void *vaddr)
    108 {
    109 	asm volatile ("clflush %0" : : "m" (*(const char *)vaddr));
    110 }
    111 
    112 static size_t
    113 drm_x86_clflush_size(void)
    114 {
    115 	KASSERT(drm_md_clflush_finegrained_p());
    116 	return cpu_info_primary.ci_cflush_lsize;
    117 }
    118 
    119 static void
    120 drm_x86_clflush_xc(void *arg0 __unused, void *arg1 __unused)
    121 {
    122 	wbinvd();
    123 }
    124 
    125 static void
    126 drm_md_clflush_all(void)
    127 {
    128 	xc_wait(xc_broadcast(0, &drm_x86_clflush_xc, NULL, NULL));
    129 }
    130 
    131 static void
    132 drm_md_clflush_page(struct page *page)
    133 {
    134 	void *const vaddr = kmap_atomic(page);
    135 
    136 	drm_md_clflush_virt_range(vaddr, PAGE_SIZE);
    137 
    138 	kunmap_atomic(vaddr);
    139 }
    140 
    141 static void
    142 drm_md_clflush_virt_range(const void *vaddr, size_t nbytes)
    143 {
    144 	const unsigned clflush_size = drm_x86_clflush_size();
    145 	const vaddr_t va = (vaddr_t)vaddr;
    146 	const char *const start = (const void *)rounddown(va, clflush_size);
    147 	const char *const end = (const void *)roundup(va + nbytes,
    148 	    clflush_size);
    149 	const char *p;
    150 
    151 	/* Support for CLFLUSH implies support for MFENCE.  */
    152 	KASSERT(drm_md_clflush_finegrained_p());
    153 	x86_mfence();
    154 	for (p = start; p < end; p += clflush_size)
    155 		drm_x86_clflush(p);
    156 	x86_mfence();
    157 }
    158 
    159 #endif	/* defined(__i386__) || defined(__x86_64__) */
    160