1/* $NetBSD: drm_cache.c,v 1.19 2022/07/19 23:19:27 riastradh 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 1.19 2022/07/19 23:19:27 riastradh Exp $"); 34 35#include <sys/param.h> 36#include <sys/types.h> 37#include <sys/xcall.h> 38 39#include <uvm/uvm_extern.h> 40 41#include <linux/highmem.h> 42#include <linux/mm_types.h> 43 44#include <drm/drm_cache.h> 45 46#if !defined(__arm__) && !defined(__aarch64__) && !defined(__alpha__) 47#define DRM_CLFLUSH 1 48#endif 49 50#if defined(DRM_CLFLUSH) 51static bool drm_md_clflush_finegrained_p(void); 52static void drm_md_clflush_all(void); 53static void drm_md_clflush_begin(void); 54static void drm_md_clflush_commit(void); 55static void drm_md_clflush_page(struct page *); 56static void drm_md_clflush_virt_range(const void *, size_t); 57#endif 58 59void 60drm_clflush_pages(struct page **pages, unsigned long npages) 61{ 62#if defined(DRM_CLFLUSH) 63 if (drm_md_clflush_finegrained_p()) { 64 drm_md_clflush_begin(); 65 while (npages--) 66 drm_md_clflush_page(pages[npages]); 67 drm_md_clflush_commit(); 68 } else { 69 drm_md_clflush_all(); 70 } 71#endif 72} 73 74void 75drm_clflush_sg(struct sg_table *sgt) 76{ 77 drm_clflush_pages(sgt->sgl->sg_pgs, sgt->sgl->sg_npgs); 78} 79 80void 81drm_clflush_virt_range(void *vaddr, unsigned long nbytes) 82{ 83#if defined(DRM_CLFLUSH) 84 if (drm_md_clflush_finegrained_p()) { 85 drm_md_clflush_begin(); 86 drm_md_clflush_virt_range(vaddr, nbytes); 87 drm_md_clflush_commit(); 88 } else { 89 drm_md_clflush_all(); 90 } 91#endif 92} 93 94#if defined(__i386__) || defined(__x86_64__) 95 96#include <machine/cpufunc.h> 97 98static bool 99drm_md_clflush_finegrained_p(void) 100{ 101 return ISSET(cpu_info_primary.ci_feat_val[0], CPUID_CLFSH); 102} 103 104static void 105drm_x86_clflush_xc(void *arg0 __unused, void *arg1 __unused) 106{ 107 wbinvd(); 108} 109 110static void 111drm_md_clflush_all(void) 112{ 113 xc_wait(xc_broadcast(0, &drm_x86_clflush_xc, NULL, NULL)); 114} 115 116static void 117drm_md_clflush_begin(void) 118{ 119 /* Support for CLFLUSH implies support for MFENCE. */ 120 x86_mfence(); 121} 122 123static void 124drm_md_clflush_commit(void) 125{ 126 x86_mfence(); 127} 128 129static void 130drm_md_clflush_page(struct page *page) 131{ 132 void *const vaddr = kmap_atomic(page); 133 134 drm_md_clflush_virt_range(vaddr, PAGE_SIZE); 135 136 kunmap_atomic(vaddr); 137} 138 139static void 140drm_md_clflush_virt_range(const void *ptr, size_t nbytes) 141{ 142 const unsigned clflush_size = cpu_info_primary.ci_cflush_lsize; 143 const vaddr_t vaddr = (vaddr_t)ptr; 144 const vaddr_t start = rounddown(vaddr, clflush_size); 145 const vaddr_t end = roundup(vaddr + nbytes, clflush_size); 146 vaddr_t va; 147 148 for (va = start; va < end; va += clflush_size) 149 asm volatile ("clflush %0" : : "m" (*(const char *)va)); 150} 151 152#elif defined(__sparc__) || defined(__sparc64__) 153 154#ifdef __sparc64__ 155#include <sparc64/sparc64/cache.h> 156#else 157#include <sparc/sparc/cache.h> 158#endif 159 160static bool 161drm_md_clflush_finegrained_p(void) 162{ 163 return true; 164} 165 166static void 167drm_md_clflush_all(void) 168{ 169 panic("don't know how to flush entire cache on sparc64"); 170} 171 172static void 173drm_md_clflush_begin(void) 174{ 175 membar_Sync(); /* unsure if needed */ 176} 177 178static void 179drm_md_clflush_commit(void) 180{ 181 membar_Sync(); /* unsure if needed */ 182} 183 184static void 185drm_md_clflush_page(struct page *page) 186{ 187#ifdef __sparc64__ 188 paddr_t pa = VM_PAGE_TO_PHYS(&page->p_vmp); 189 190 cache_flush_phys(pa, PAGE_SIZE, 0); 191#else 192 void *const vaddr = kmap_atomic(page); 193 194 cache_flush(vaddr, PAGE_SIZE); 195 196 kunmap_atomic(vaddr); 197#endif 198} 199 200static void 201drm_md_clflush_virt_range(const void *ptr, size_t nbytes) 202{ 203#ifdef __sparc64__ 204 /* XXX Mega-kludge -- doesn't seem to be a way to flush by vaddr. */ 205 blast_dcache(); 206#else 207 cache_flush(ptr, nbytes); 208#endif 209} 210 211#elif defined(__powerpc__) 212 213static bool 214drm_md_clflush_finegrained_p(void) 215{ 216 return true; 217} 218 219static void 220drm_md_clflush_all(void) 221{ 222 panic("don't know how to flush entire cache on powerpc"); 223} 224 225static void 226drm_md_clflush_begin(void) 227{ 228} 229 230static void 231drm_md_clflush_commit(void) 232{ 233 asm volatile ("sync" ::: "memory"); 234} 235 236static void 237drm_md_clflush_page(struct page *page) 238{ 239 void *const vaddr = kmap_atomic(page); 240 241 drm_md_clflush_virt_range(vaddr, PAGE_SIZE); 242 243 kunmap_atomic(vaddr); 244} 245 246static void 247drm_md_clflush_virt_range(const void *ptr, size_t nbytes) 248{ 249 const unsigned dcsize = curcpu()->ci_ci.dcache_line_size; 250 vaddr_t va = (vaddr_t)ptr; 251 vaddr_t start = rounddown(va, dcsize); 252 vaddr_t end = roundup(va + nbytes, dcsize); 253 vsize_t len = end - start; 254 vsize_t off; 255 256 for (off = 0; off < len; off += dcsize) 257 asm volatile ("dcbf\t%0,%1" : : "b"(start), "r"(off)); 258} 259 260#endif 261