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