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 struct dma_fence *fence; 20 unsigned long start, end, cur = 0; 21 unsigned int nmap = 0; 22 int i; 23 24 dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv); 25 26 if (umem_dmabuf->sgt) 27 goto wait_fence; 28 29 sgt = dma_buf_map_attachment(umem_dmabuf->attach, DMA_BIDIRECTIONAL); 30 if (IS_ERR(sgt)) 31 return PTR_ERR(sgt); 32 33 /* modify the sg list in-place to match umem address and length */ 34 35 start = ALIGN_DOWN(umem_dmabuf->umem.address, PAGE_SIZE); 36 end = ALIGN(umem_dmabuf->umem.address + umem_dmabuf->umem.length, 37 PAGE_SIZE); 38 for_each_sgtable_dma_sg(sgt, sg, i) { 39 if (start < cur + sg_dma_len(sg) && cur < end) 40 nmap++; 41 if (cur <= start && start < cur + sg_dma_len(sg)) { 42 unsigned long offset = start - cur; 43 44 umem_dmabuf->first_sg = sg; 45 umem_dmabuf->first_sg_offset = offset; 46 sg_dma_address(sg) += offset; 47 sg_dma_len(sg) -= offset; 48 cur += offset; 49 } 50 if (cur < end && end <= cur + sg_dma_len(sg)) { 51 unsigned long trim = cur + sg_dma_len(sg) - end; 52 53 umem_dmabuf->last_sg = sg; 54 umem_dmabuf->last_sg_trim = trim; 55 sg_dma_len(sg) -= trim; 56 break; 57 } 58 cur += sg_dma_len(sg); 59 } 60 61 umem_dmabuf->umem.sgt_append.sgt.sgl = umem_dmabuf->first_sg; 62 umem_dmabuf->umem.sgt_append.sgt.nents = nmap; 63 umem_dmabuf->sgt = sgt; 64 65 wait_fence: 66 /* 67 * Although the sg list is valid now, the content of the pages 68 * may be not up-to-date. Wait for the exporter to finish 69 * the migration. 70 */ 71 fence = dma_resv_excl_fence(umem_dmabuf->attach->dmabuf->resv); 72 if (fence) 73 return dma_fence_wait(fence, false); 74 75 return 0; 76 } 77 EXPORT_SYMBOL(ib_umem_dmabuf_map_pages); 78 79 void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf) 80 { 81 dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv); 82 83 if (!umem_dmabuf->sgt) 84 return; 85 86 /* retore the original sg list */ 87 if (umem_dmabuf->first_sg) { 88 sg_dma_address(umem_dmabuf->first_sg) -= 89 umem_dmabuf->first_sg_offset; 90 sg_dma_len(umem_dmabuf->first_sg) += 91 umem_dmabuf->first_sg_offset; 92 umem_dmabuf->first_sg = NULL; 93 umem_dmabuf->first_sg_offset = 0; 94 } 95 if (umem_dmabuf->last_sg) { 96 sg_dma_len(umem_dmabuf->last_sg) += 97 umem_dmabuf->last_sg_trim; 98 umem_dmabuf->last_sg = NULL; 99 umem_dmabuf->last_sg_trim = 0; 100 } 101 102 dma_buf_unmap_attachment(umem_dmabuf->attach, umem_dmabuf->sgt, 103 DMA_BIDIRECTIONAL); 104 105 umem_dmabuf->sgt = NULL; 106 } 107 EXPORT_SYMBOL(ib_umem_dmabuf_unmap_pages); 108 109 struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device, 110 unsigned long offset, size_t size, 111 int fd, int access, 112 const struct dma_buf_attach_ops *ops) 113 { 114 struct dma_buf *dmabuf; 115 struct ib_umem_dmabuf *umem_dmabuf; 116 struct ib_umem *umem; 117 unsigned long end; 118 struct ib_umem_dmabuf *ret = ERR_PTR(-EINVAL); 119 120 if (check_add_overflow(offset, (unsigned long)size, &end)) 121 return ret; 122 123 if (unlikely(!ops || !ops->move_notify)) 124 return ret; 125 126 dmabuf = dma_buf_get(fd); 127 if (IS_ERR(dmabuf)) 128 return ERR_CAST(dmabuf); 129 130 if (dmabuf->size < end) 131 goto out_release_dmabuf; 132 133 umem_dmabuf = kzalloc(sizeof(*umem_dmabuf), GFP_KERNEL); 134 if (!umem_dmabuf) { 135 ret = ERR_PTR(-ENOMEM); 136 goto out_release_dmabuf; 137 } 138 139 umem = &umem_dmabuf->umem; 140 umem->ibdev = device; 141 umem->length = size; 142 umem->address = offset; 143 umem->writable = ib_access_writable(access); 144 umem->is_dmabuf = 1; 145 146 if (!ib_umem_num_pages(umem)) 147 goto out_free_umem; 148 149 umem_dmabuf->attach = dma_buf_dynamic_attach( 150 dmabuf, 151 device->dma_device, 152 ops, 153 umem_dmabuf); 154 if (IS_ERR(umem_dmabuf->attach)) { 155 ret = ERR_CAST(umem_dmabuf->attach); 156 goto out_free_umem; 157 } 158 return umem_dmabuf; 159 160 out_free_umem: 161 kfree(umem_dmabuf); 162 163 out_release_dmabuf: 164 dma_buf_put(dmabuf); 165 return ret; 166 } 167 EXPORT_SYMBOL(ib_umem_dmabuf_get); 168 169 static void 170 ib_umem_dmabuf_unsupported_move_notify(struct dma_buf_attachment *attach) 171 { 172 struct ib_umem_dmabuf *umem_dmabuf = attach->importer_priv; 173 174 ibdev_warn_ratelimited(umem_dmabuf->umem.ibdev, 175 "Invalidate callback should not be called when memory is pinned\n"); 176 } 177 178 static struct dma_buf_attach_ops ib_umem_dmabuf_attach_pinned_ops = { 179 .allow_peer2peer = true, 180 .move_notify = ib_umem_dmabuf_unsupported_move_notify, 181 }; 182 183 struct ib_umem_dmabuf *ib_umem_dmabuf_get_pinned(struct ib_device *device, 184 unsigned long offset, 185 size_t size, int fd, 186 int access) 187 { 188 struct ib_umem_dmabuf *umem_dmabuf; 189 int err; 190 191 umem_dmabuf = ib_umem_dmabuf_get(device, offset, size, fd, access, 192 &ib_umem_dmabuf_attach_pinned_ops); 193 if (IS_ERR(umem_dmabuf)) 194 return umem_dmabuf; 195 196 dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL); 197 err = dma_buf_pin(umem_dmabuf->attach); 198 if (err) 199 goto err_release; 200 umem_dmabuf->pinned = 1; 201 202 err = ib_umem_dmabuf_map_pages(umem_dmabuf); 203 if (err) 204 goto err_unpin; 205 dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv); 206 207 return umem_dmabuf; 208 209 err_unpin: 210 dma_buf_unpin(umem_dmabuf->attach); 211 err_release: 212 dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv); 213 ib_umem_release(&umem_dmabuf->umem); 214 return ERR_PTR(err); 215 } 216 EXPORT_SYMBOL(ib_umem_dmabuf_get_pinned); 217 218 void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) 219 { 220 struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf; 221 222 dma_resv_lock(dmabuf->resv, NULL); 223 ib_umem_dmabuf_unmap_pages(umem_dmabuf); 224 if (umem_dmabuf->pinned) 225 dma_buf_unpin(umem_dmabuf->attach); 226 dma_resv_unlock(dmabuf->resv); 227 228 dma_buf_detach(dmabuf, umem_dmabuf->attach); 229 dma_buf_put(dmabuf); 230 kfree(umem_dmabuf); 231 } 232