1 /* $NetBSD: bus_dma_hacks.h,v 1.25 2022/07/19 23:19:44 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 #ifndef _DRM_BUS_DMA_HACKS_H_ 33 #define _DRM_BUS_DMA_HACKS_H_ 34 35 #include <sys/cdefs.h> 36 #include <sys/bus.h> 37 #include <sys/kmem.h> 38 #include <sys/queue.h> 39 40 #include <uvm/uvm.h> 41 #include <uvm/uvm_extern.h> 42 43 #include <linux/mm_types.h> /* XXX struct page */ 44 45 #if defined(__i386__) || defined(__x86_64__) 46 # include <x86/bus_private.h> 47 # include <x86/machdep.h> 48 # define PHYS_TO_BUS_MEM(dmat, paddr) ((bus_addr_t)(paddr)) 49 # define BUS_MEM_TO_PHYS(dmat, baddr) ((paddr_t)(baddr)) 50 #elif defined(__arm__) || defined(__aarch64__) 51 static inline bus_addr_t 52 PHYS_TO_BUS_MEM(bus_dma_tag_t dmat, paddr_t pa) 53 { 54 unsigned i; 55 56 if (dmat->_nranges == 0) 57 return (bus_addr_t)pa; 58 59 for (i = 0; i < dmat->_nranges; i++) { 60 const struct arm32_dma_range *dr = &dmat->_ranges[i]; 61 62 if (dr->dr_sysbase <= pa && pa - dr->dr_sysbase <= dr->dr_len) 63 return pa - dr->dr_sysbase + dr->dr_busbase; 64 } 65 panic("paddr has no bus address in dma tag %p: %"PRIxPADDR, dmat, pa); 66 } 67 static inline paddr_t 68 BUS_MEM_TO_PHYS(bus_dma_tag_t dmat, bus_addr_t ba) 69 { 70 unsigned i; 71 72 if (dmat->_nranges == 0) 73 return (paddr_t)ba; 74 75 for (i = 0; i < dmat->_nranges; i++) { 76 const struct arm32_dma_range *dr = &dmat->_ranges[i]; 77 78 if (dr->dr_busbase <= ba && ba - dr->dr_busbase <= dr->dr_len) 79 return ba - dr->dr_busbase + dr->dr_sysbase; 80 } 81 panic("bus addr has no bus address in dma tag %p: %"PRIxPADDR, dmat, 82 ba); 83 } 84 #elif defined(__sparc__) || defined(__sparc64__) 85 # define PHYS_TO_BUS_MEM(dmat, paddr) ((bus_addr_t)(paddr)) 86 # define BUS_MEM_TO_PHYS(dmat, baddr) ((paddr_t)(baddr)) 87 #elif defined(__powerpc__) 88 #elif defined(__alpha__) 89 # define PHYS_TO_BUS_MEM(dmat, paddr) \ 90 ((bus_addr_t)(paddr) | (dmat)->_wbase) 91 # define BUS_MEM_TO_PHYS(dmat, baddr) \ 92 ((paddr_t)((baddr) & ~(bus_addr_t)(dmat)->_wbase)) 93 #else 94 # error DRM GEM/TTM need new MI bus_dma APIs! Halp! 95 #endif 96 97 static inline int 98 bus_dmamem_pgfl(bus_dma_tag_t tag) 99 { 100 #if defined(__i386__) || defined(__x86_64__) 101 return x86_select_freelist(tag->_bounce_alloc_hi - 1); 102 #else 103 return VM_FREELIST_DEFAULT; 104 #endif 105 } 106 107 static inline bool 108 bus_dmatag_bounces_paddr(bus_dma_tag_t dmat, paddr_t pa) 109 { 110 #if defined(__i386__) || defined(__x86_64__) 111 return pa < dmat->_bounce_alloc_lo || dmat->_bounce_alloc_hi <= pa; 112 #elif defined(__arm__) || defined(__aarch64__) 113 unsigned i; 114 115 for (i = 0; i < dmat->_nranges; i++) { 116 const struct arm32_dma_range *dr = &dmat->_ranges[i]; 117 if (dr->dr_sysbase <= pa && pa - dr->dr_sysbase <= dr->dr_len) 118 return false; 119 } 120 return true; 121 #elif defined(__powerpc__) 122 return dmat->_bounce_thresh && pa >= dmat->_bounce_thresh; 123 #elif defined(__sparc__) || defined(__sparc64__) 124 return false; /* no bounce buffers ever */ 125 #elif defined(__alpha__) 126 return (dmat->_wsize == 0 ? false : pa >= dmat->_wsize); 127 #endif 128 } 129 130 #define MAX_STACK_SEGS 32 /* XXXMRG: 512 bytes on 16 byte seg platforms */ 131 132 /* 133 * XXX This should really take an array of struct vm_page pointers, but 134 * Linux drm code stores arrays of struct page pointers, and these two 135 * types (struct page ** and struct vm_page **) are not compatible so 136 * naive conversion would violate strict aliasing rules. 137 */ 138 static inline int 139 bus_dmamap_load_pages(bus_dma_tag_t tag, bus_dmamap_t map, 140 struct page **pgs, bus_size_t size, int flags) 141 { 142 km_flag_t kmflags; 143 bus_dma_segment_t *segs; 144 bus_dma_segment_t stacksegs[MAX_STACK_SEGS]; 145 int nsegs, seg; 146 struct vm_page *page; 147 int error; 148 149 KASSERT((size & (PAGE_SIZE - 1)) == 0); 150 151 if ((size >> PAGE_SHIFT) > INT_MAX) 152 return ENOMEM; 153 nsegs = size >> PAGE_SHIFT; 154 155 KASSERT(nsegs <= (SIZE_MAX / sizeof(segs[0]))); 156 if (nsegs > MAX_STACK_SEGS) { 157 switch (flags & (BUS_DMA_WAITOK|BUS_DMA_NOWAIT)) { 158 case BUS_DMA_WAITOK: 159 kmflags = KM_SLEEP; 160 break; 161 case BUS_DMA_NOWAIT: 162 kmflags = KM_NOSLEEP; 163 break; 164 default: 165 panic("invalid flags: %d", flags); 166 } 167 segs = kmem_alloc((nsegs * sizeof(segs[0])), kmflags); 168 if (segs == NULL) 169 return ENOMEM; 170 } else { 171 segs = stacksegs; 172 } 173 174 for (seg = 0; seg < nsegs; seg++) { 175 page = &pgs[seg]->p_vmp; 176 paddr_t paddr = VM_PAGE_TO_PHYS(page); 177 bus_addr_t baddr = PHYS_TO_BUS_MEM(tag, paddr); 178 179 segs[seg].ds_addr = baddr; 180 segs[seg].ds_len = PAGE_SIZE; 181 } 182 183 error = bus_dmamap_load_raw(tag, map, segs, nsegs, size, flags); 184 if (error) 185 goto fail0; 186 187 /* Success! */ 188 error = 0; 189 goto out; 190 191 fail1: __unused 192 bus_dmamap_unload(tag, map); 193 fail0: KASSERT(error); 194 out: if (segs != stacksegs) { 195 KASSERT(nsegs > MAX_STACK_SEGS); 196 kmem_free(segs, (nsegs * sizeof(segs[0]))); 197 } 198 return error; 199 } 200 201 static inline int 202 bus_dmamem_export_pages(bus_dma_tag_t dmat, const bus_dma_segment_t *segs, 203 int nsegs, struct page **pgs, unsigned npgs) 204 { 205 int seg; 206 unsigned pg; 207 208 pg = 0; 209 for (seg = 0; seg < nsegs; seg++) { 210 bus_addr_t baddr = segs[seg].ds_addr; 211 bus_size_t len = segs[seg].ds_len; 212 213 while (len >= PAGE_SIZE) { 214 paddr_t paddr = BUS_MEM_TO_PHYS(dmat, baddr); 215 216 KASSERT(pg < npgs); 217 pgs[pg++] = container_of(PHYS_TO_VM_PAGE(paddr), 218 struct page, p_vmp); 219 220 baddr += PAGE_SIZE; 221 len -= PAGE_SIZE; 222 } 223 KASSERT(len == 0); 224 } 225 KASSERT(pg == npgs); 226 227 return 0; 228 } 229 230 static inline int 231 bus_dmamem_import_pages(bus_dma_tag_t dmat, bus_dma_segment_t *segs, 232 int nsegs, int *rsegs, struct page *const *pgs, unsigned npgs) 233 { 234 int seg; 235 unsigned i; 236 237 seg = 0; 238 for (i = 0; i < npgs; i++) { 239 paddr_t paddr = VM_PAGE_TO_PHYS(&pgs[i]->p_vmp); 240 bus_addr_t baddr = PHYS_TO_BUS_MEM(dmat, paddr); 241 242 if (seg > 0 && segs[seg - 1].ds_addr + PAGE_SIZE == baddr) { 243 segs[seg - 1].ds_len += PAGE_SIZE; 244 } else { 245 KASSERT(seg < nsegs); 246 segs[seg].ds_addr = baddr; 247 segs[seg].ds_len = PAGE_SIZE; 248 seg++; 249 KASSERT(seg <= nsegs); 250 } 251 } 252 KASSERT(seg <= nsegs); 253 *rsegs = seg; 254 255 return 0; 256 } 257 258 #endif /* _DRM_BUS_DMA_HACKS_H_ */ 259
Indexes created Wed Sep 24 05:09:52 GMT 2025