1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) 2 /* 3 * Copyright (c) 2020 Intel Corporation. All rights reserved. 4 */ 5 6 #include <linux/dma-buf.h> 7 #include <linux/dma-resv.h> 8 #include <linux/dma-mapping.h> 9 #include <linux/module.h> 10 11 #include "uverbs.h" 12 13 MODULE_IMPORT_NS("DMA_BUF"); 14 15 int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf) 16 { 17 struct sg_table *sgt; 18 struct scatterlist *sg; 19 unsigned long start, end, cur = 0; 20 unsigned int nmap = 0; 21 long ret; 22 int i; 23 24 dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv); 25 26 if (umem_dmabuf->revoked) 27 return -EINVAL; 28 29 if (umem_dmabuf->sgt) 30 goto wait_fence; 31 32 sgt = dma_buf_map_attachment(umem_dmabuf->attach, 33 DMA_BIDIRECTIONAL); 34 if (IS_ERR(sgt)) 35 return PTR_ERR(sgt); 36 37 /* modify the sg list in-place to match umem address and length */ 38 39 start = ALIGN_DOWN(umem_dmabuf->umem.address, PAGE_SIZE); 40 end = ALIGN(umem_dmabuf->umem.address + umem_dmabuf->umem.length, 41 PAGE_SIZE); 42 for_each_sgtable_dma_sg(sgt, sg, i) { 43 if (start < cur + sg_dma_len(sg) && cur < end) 44 nmap++; 45 if (cur <= start && start < cur + sg_dma_len(sg)) { 46 unsigned long offset = start - cur; 47 48 umem_dmabuf->first_sg = sg; 49 umem_dmabuf->first_sg_offset = offset; 50 sg_dma_address(sg) += offset; 51 sg_dma_len(sg) -= offset; 52 cur += offset; 53 } 54 if (cur < end && end <= cur + sg_dma_len(sg)) { 55 unsigned long trim = cur + sg_dma_len(sg) - end; 56 57 umem_dmabuf->last_sg = sg; 58 umem_dmabuf->last_sg_trim = trim; 59 sg_dma_len(sg) -= trim; 60 break; 61 } 62 cur += sg_dma_len(sg); 63 } 64 65 umem_dmabuf->umem.sgt_append.sgt.sgl = umem_dmabuf->first_sg; 66 umem_dmabuf->umem.sgt_append.sgt.nents = nmap; 67 umem_dmabuf->sgt = sgt; 68 69 wait_fence: 70 /* 71 * Although the sg list is valid now, the content of the pages 72 * may be not up-to-date. Wait for the exporter to finish 73 * the migration. 74 */ 75 ret = dma_resv_wait_timeout(umem_dmabuf->attach->dmabuf->resv, 76 DMA_RESV_USAGE_KERNEL, 77 false, MAX_SCHEDULE_TIMEOUT); 78 if (ret < 0) 79 return ret; 80 if (ret == 0) 81 return -ETIMEDOUT; 82 return 0; 83 } 84 EXPORT_SYMBOL(ib_umem_dmabuf_map_pages); 85 86 void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) 87 { 88 dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv); 89 90 if (!umem_dmabuf->sgt) 91 return; 92 93 /* retore the original sg list */ 94 if (umem_dmabuf->first_sg) { 95 sg_dma_address(umem_dmabuf->first_sg) -= 96 umem_dmabuf->first_sg_offset; 97 sg_dma_len(umem_dmabuf->first_sg) += 98 umem_dmabuf->first_sg_offset; 99 umem_dmabuf->first_sg = NULL; 100 umem_dmabuf->first_sg_offset = 0; 101 } 102 if (umem_dmabuf->last_sg) { 103 sg_dma_len(umem_dmabuf->last_sg) += 104 umem_dmabuf->last_sg_trim; 105 umem_dmabuf->last_sg = NULL; 106 umem_dmabuf->last_sg_trim = 0; 107 } 108 109 dma_buf_unmap_attachment(umem_dmabuf->attach, umem_dmabuf->sgt, 110 DMA_BIDIRECTIONAL); 111 112 umem_dmabuf->sgt = NULL; 113 } 114 EXPORT_SYMBOL(ib_umem_dmabuf_unmap_pages); 115 116 static struct ib_umem_dmabuf * 117 ib_umem_dmabuf_get_with_dma_device(struct ib_device *device, 118 struct device *dma_device, 119 unsigned long offset, size_t size, 120 int fd, int access, 121 const struct dma_buf_attach_ops *ops) 122 { 123 struct dma_buf *dmabuf; 124 struct ib_umem_dmabuf *umem_dmabuf; 125 struct ib_umem *umem; 126 unsigned long end; 127 struct ib_umem_dmabuf *ret = ERR_PTR(-EINVAL); 128 129 if (check_add_overflow(offset, (unsigned long)size, &end)) 130 return ret; 131 132 dmabuf = dma_buf_get(fd); 133 if (IS_ERR(dmabuf)) 134 return ERR_CAST(dmabuf); 135 136 if (dmabuf->size < end) 137 goto out_release_dmabuf; 138 139 umem_dmabuf = kzalloc_obj(*umem_dmabuf); 140 if (!umem_dmabuf) { 141 ret = ERR_PTR(-ENOMEM); 142 goto out_release_dmabuf; 143 } 144 145 umem = &umem_dmabuf->umem; 146 umem->ibdev = device; 147 umem->length = size; 148 umem->address = offset; 149 umem->writable = ib_access_writable(access); 150 umem->is_dmabuf = 1; 151 152 if (!ib_umem_num_pages(umem)) 153 goto out_free_umem; 154 155 umem_dmabuf->attach = dma_buf_dynamic_attach( 156 dmabuf, 157 dma_device, 158 ops, 159 umem_dmabuf); 160 if (IS_ERR(umem_dmabuf->attach)) { 161 ret = ERR_CAST(umem_dmabuf->attach); 162 goto out_free_umem; 163 } 164 return umem_dmabuf; 165 166 out_free_umem: 167 kfree(umem_dmabuf); 168 169 out_release_dmabuf: 170 dma_buf_put(dmabuf); 171 return ret; 172 } 173 174 struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device, 175 unsigned long offset, size_t size, 176 int fd, int access, 177 const struct dma_buf_attach_ops *ops) 178 { 179 return ib_umem_dmabuf_get_with_dma_device(device, device->dma_device, 180 offset, size, fd, access, ops); 181 } 182 EXPORT_SYMBOL(ib_umem_dmabuf_get); 183 184 static void 185 ib_umem_dmabuf_unsupported_move_notify(struct dma_buf_attachment *attach) 186 { 187 struct ib_umem_dmabuf *umem_dmabuf = attach->importer_priv; 188 189 ibdev_warn_ratelimited(umem_dmabuf->umem.ibdev, 190 "Invalidate callback should not be called when memory is pinned\n"); 191 } 192 193 static struct dma_buf_attach_ops ib_umem_dmabuf_attach_pinned_ops = { 194 .allow_peer2peer = true, 195 .move_notify = ib_umem_dmabuf_unsupported_move_notify, 196 }; 197 198 struct ib_umem_dmabuf * 199 ib_umem_dmabuf_get_pinned_with_dma_device(struct ib_device *device, 200 struct device *dma_device, 201 unsigned long offset, size_t size, 202 int fd, int access) 203 { 204 struct ib_umem_dmabuf *umem_dmabuf; 205 int err; 206 207 umem_dmabuf = ib_umem_dmabuf_get_with_dma_device(device, dma_device, offset, 208 size, fd, access, 209 &ib_umem_dmabuf_attach_pinned_ops); 210 if (IS_ERR(umem_dmabuf)) 211 return umem_dmabuf; 212 213 dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL); 214 err = dma_buf_pin(umem_dmabuf->attach); 215 if (err) 216 goto err_release; 217 umem_dmabuf->pinned = 1; 218 219 err = ib_umem_dmabuf_map_pages(umem_dmabuf); 220 if (err) 221 goto err_unpin; 222 dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv); 223 224 return umem_dmabuf; 225 226 err_unpin: 227 dma_buf_unpin(umem_dmabuf->attach); 228 err_release: 229 dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv); 230 ib_umem_release(&umem_dmabuf->umem); 231 return ERR_PTR(err); 232 } 233 EXPORT_SYMBOL(ib_umem_dmabuf_get_pinned_with_dma_device); 234 235 struct ib_umem_dmabuf *ib_umem_dmabuf_get_pinned(struct ib_device *device, 236 unsigned long offset, 237 size_t size, int fd, 238 int access) 239 { 240 return ib_umem_dmabuf_get_pinned_with_dma_device(device, device->dma_device, 241 offset, size, fd, access); 242 } 243 EXPORT_SYMBOL(ib_umem_dmabuf_get_pinned); 244 245 void ib_umem_dmabuf_revoke(struct ib_umem_dmabuf *umem_dmabuf) 246 { 247 struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf; 248 249 dma_resv_lock(dmabuf->resv, NULL); 250 if (umem_dmabuf->revoked) 251 goto end; 252 ib_umem_dmabuf_unmap_pages(umem_dmabuf); 253 if (umem_dmabuf->pinned) { 254 dma_buf_unpin(umem_dmabuf->attach); 255 umem_dmabuf->pinned = 0; 256 } 257 umem_dmabuf->revoked = 1; 258 end: 259 dma_resv_unlock(dmabuf->resv); 260 } 261 EXPORT_SYMBOL(ib_umem_dmabuf_revoke); 262 263 void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) 264 { 265 struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf; 266 267 ib_umem_dmabuf_revoke(umem_dmabuf); 268 269 dma_buf_detach(dmabuf, umem_dmabuf->attach); 270 dma_buf_put(dmabuf); 271 kfree(umem_dmabuf); 272 } 273