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 if (unlikely(!ops || !ops->move_notify)) 133 return ret; 134 135 dmabuf = dma_buf_get(fd); 136 if (IS_ERR(dmabuf)) 137 return ERR_CAST(dmabuf); 138 139 if (dmabuf->size < end) 140 goto out_release_dmabuf; 141 142 umem_dmabuf = kzalloc(sizeof(*umem_dmabuf), GFP_KERNEL); 143 if (!umem_dmabuf) { 144 ret = ERR_PTR(-ENOMEM); 145 goto out_release_dmabuf; 146 } 147 148 umem = &umem_dmabuf->umem; 149 umem->ibdev = device; 150 umem->length = size; 151 umem->address = offset; 152 umem->writable = ib_access_writable(access); 153 umem->is_dmabuf = 1; 154 155 if (!ib_umem_num_pages(umem)) 156 goto out_free_umem; 157 158 umem_dmabuf->attach = dma_buf_dynamic_attach( 159 dmabuf, 160 dma_device, 161 ops, 162 umem_dmabuf); 163 if (IS_ERR(umem_dmabuf->attach)) { 164 ret = ERR_CAST(umem_dmabuf->attach); 165 goto out_free_umem; 166 } 167 return umem_dmabuf; 168 169 out_free_umem: 170 kfree(umem_dmabuf); 171 172 out_release_dmabuf: 173 dma_buf_put(dmabuf); 174 return ret; 175 } 176 177 struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device, 178 unsigned long offset, size_t size, 179 int fd, int access, 180 const struct dma_buf_attach_ops *ops) 181 { 182 return ib_umem_dmabuf_get_with_dma_device(device, device->dma_device, 183 offset, size, fd, access, ops); 184 } 185 EXPORT_SYMBOL(ib_umem_dmabuf_get); 186 187 static void 188 ib_umem_dmabuf_unsupported_move_notify(struct dma_buf_attachment *attach) 189 { 190 struct ib_umem_dmabuf *umem_dmabuf = attach->importer_priv; 191 192 ibdev_warn_ratelimited(umem_dmabuf->umem.ibdev, 193 "Invalidate callback should not be called when memory is pinned\n"); 194 } 195 196 static struct dma_buf_attach_ops ib_umem_dmabuf_attach_pinned_ops = { 197 .allow_peer2peer = true, 198 .move_notify = ib_umem_dmabuf_unsupported_move_notify, 199 }; 200 201 struct ib_umem_dmabuf * 202 ib_umem_dmabuf_get_pinned_with_dma_device(struct ib_device *device, 203 struct device *dma_device, 204 unsigned long offset, size_t size, 205 int fd, int access) 206 { 207 struct ib_umem_dmabuf *umem_dmabuf; 208 int err; 209 210 umem_dmabuf = ib_umem_dmabuf_get_with_dma_device(device, dma_device, offset, 211 size, fd, access, 212 &ib_umem_dmabuf_attach_pinned_ops); 213 if (IS_ERR(umem_dmabuf)) 214 return umem_dmabuf; 215 216 dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL); 217 err = dma_buf_pin(umem_dmabuf->attach); 218 if (err) 219 goto err_release; 220 umem_dmabuf->pinned = 1; 221 222 err = ib_umem_dmabuf_map_pages(umem_dmabuf); 223 if (err) 224 goto err_unpin; 225 dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv); 226 227 return umem_dmabuf; 228 229 err_unpin: 230 dma_buf_unpin(umem_dmabuf->attach); 231 err_release: 232 dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv); 233 ib_umem_release(&umem_dmabuf->umem); 234 return ERR_PTR(err); 235 } 236 EXPORT_SYMBOL(ib_umem_dmabuf_get_pinned_with_dma_device); 237 238 struct ib_umem_dmabuf *ib_umem_dmabuf_get_pinned(struct ib_device *device, 239 unsigned long offset, 240 size_t size, int fd, 241 int access) 242 { 243 return ib_umem_dmabuf_get_pinned_with_dma_device(device, device->dma_device, 244 offset, size, fd, access); 245 } 246 EXPORT_SYMBOL(ib_umem_dmabuf_get_pinned); 247 248 void ib_umem_dmabuf_revoke(struct ib_umem_dmabuf *umem_dmabuf) 249 { 250 struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf; 251 252 dma_resv_lock(dmabuf->resv, NULL); 253 if (umem_dmabuf->revoked) 254 goto end; 255 ib_umem_dmabuf_unmap_pages(umem_dmabuf); 256 if (umem_dmabuf->pinned) { 257 dma_buf_unpin(umem_dmabuf->attach); 258 umem_dmabuf->pinned = 0; 259 } 260 umem_dmabuf->revoked = 1; 261 end: 262 dma_resv_unlock(dmabuf->resv); 263 } 264 EXPORT_SYMBOL(ib_umem_dmabuf_revoke); 265 266 void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) 267 { 268 struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf; 269 270 ib_umem_dmabuf_revoke(umem_dmabuf); 271 272 dma_buf_detach(dmabuf, umem_dmabuf->attach); 273 dma_buf_put(dmabuf); 274 kfree(umem_dmabuf); 275 } 276