1 /* 2 * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2 3 * 4 * Copyright (C) 2010 Samsung Electronics 5 * 6 * Author: Pawel Osciak <pawel@osciak.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation. 11 */ 12 13 #include <linux/io.h> 14 #include <linux/module.h> 15 #include <linux/mm.h> 16 #include <linux/refcount.h> 17 #include <linux/sched.h> 18 #include <linux/slab.h> 19 #include <linux/vmalloc.h> 20 21 #include <media/videobuf2-v4l2.h> 22 #include <media/videobuf2-vmalloc.h> 23 #include <media/videobuf2-memops.h> 24 25 struct vb2_vmalloc_buf { 26 void *vaddr; 27 struct frame_vector *vec; 28 enum dma_data_direction dma_dir; 29 unsigned long size; 30 refcount_t refcount; 31 struct vb2_vmarea_handler handler; 32 struct dma_buf *dbuf; 33 }; 34 35 static void vb2_vmalloc_put(void *buf_priv); 36 37 static void *vb2_vmalloc_alloc(struct device *dev, unsigned long attrs, 38 unsigned long size, enum dma_data_direction dma_dir, 39 gfp_t gfp_flags) 40 { 41 struct vb2_vmalloc_buf *buf; 42 43 buf = kzalloc(sizeof(*buf), GFP_KERNEL | gfp_flags); 44 if (!buf) 45 return ERR_PTR(-ENOMEM); 46 47 buf->size = size; 48 buf->vaddr = vmalloc_user(buf->size); 49 if (!buf->vaddr) { 50 pr_debug("vmalloc of size %ld failed\n", buf->size); 51 kfree(buf); 52 return ERR_PTR(-ENOMEM); 53 } 54 55 buf->dma_dir = dma_dir; 56 buf->handler.refcount = &buf->refcount; 57 buf->handler.put = vb2_vmalloc_put; 58 buf->handler.arg = buf; 59 60 refcount_set(&buf->refcount, 1); 61 return buf; 62 } 63 64 static void vb2_vmalloc_put(void *buf_priv) 65 { 66 struct vb2_vmalloc_buf *buf = buf_priv; 67 68 if (refcount_dec_and_test(&buf->refcount)) { 69 vfree(buf->vaddr); 70 kfree(buf); 71 } 72 } 73 74 static void *vb2_vmalloc_get_userptr(struct device *dev, unsigned long vaddr, 75 unsigned long size, 76 enum dma_data_direction dma_dir) 77 { 78 struct vb2_vmalloc_buf *buf; 79 struct frame_vector *vec; 80 int n_pages, offset, i; 81 int ret = -ENOMEM; 82 83 buf = kzalloc(sizeof(*buf), GFP_KERNEL); 84 if (!buf) 85 return ERR_PTR(-ENOMEM); 86 87 buf->dma_dir = dma_dir; 88 offset = vaddr & ~PAGE_MASK; 89 buf->size = size; 90 vec = vb2_create_framevec(vaddr, size); 91 if (IS_ERR(vec)) { 92 ret = PTR_ERR(vec); 93 goto fail_pfnvec_create; 94 } 95 buf->vec = vec; 96 n_pages = frame_vector_count(vec); 97 if (frame_vector_to_pages(vec) < 0) { 98 unsigned long *nums = frame_vector_pfns(vec); 99 100 /* 101 * We cannot get page pointers for these pfns. Check memory is 102 * physically contiguous and use direct mapping. 103 */ 104 for (i = 1; i < n_pages; i++) 105 if (nums[i-1] + 1 != nums[i]) 106 goto fail_map; 107 buf->vaddr = (__force void *) 108 ioremap(__pfn_to_phys(nums[0]), size + offset); 109 } else { 110 buf->vaddr = vm_map_ram(frame_vector_pages(vec), n_pages, -1, 111 PAGE_KERNEL); 112 } 113 114 if (!buf->vaddr) 115 goto fail_map; 116 buf->vaddr += offset; 117 return buf; 118 119 fail_map: 120 vb2_destroy_framevec(vec); 121 fail_pfnvec_create: 122 kfree(buf); 123 124 return ERR_PTR(ret); 125 } 126 127 static void vb2_vmalloc_put_userptr(void *buf_priv) 128 { 129 struct vb2_vmalloc_buf *buf = buf_priv; 130 unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK; 131 unsigned int i; 132 struct page **pages; 133 unsigned int n_pages; 134 135 if (!buf->vec->is_pfns) { 136 n_pages = frame_vector_count(buf->vec); 137 pages = frame_vector_pages(buf->vec); 138 if (vaddr) 139 vm_unmap_ram((void *)vaddr, n_pages); 140 if (buf->dma_dir == DMA_FROM_DEVICE || 141 buf->dma_dir == DMA_BIDIRECTIONAL) 142 for (i = 0; i < n_pages; i++) 143 set_page_dirty_lock(pages[i]); 144 } else { 145 iounmap((__force void __iomem *)buf->vaddr); 146 } 147 vb2_destroy_framevec(buf->vec); 148 kfree(buf); 149 } 150 151 static void *vb2_vmalloc_vaddr(void *buf_priv) 152 { 153 struct vb2_vmalloc_buf *buf = buf_priv; 154 155 if (!buf->vaddr) { 156 pr_err("Address of an unallocated plane requested or cannot map user pointer\n"); 157 return NULL; 158 } 159 160 return buf->vaddr; 161 } 162 163 static unsigned int vb2_vmalloc_num_users(void *buf_priv) 164 { 165 struct vb2_vmalloc_buf *buf = buf_priv; 166 return refcount_read(&buf->refcount); 167 } 168 169 static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma) 170 { 171 struct vb2_vmalloc_buf *buf = buf_priv; 172 int ret; 173 174 if (!buf) { 175 pr_err("No memory to map\n"); 176 return -EINVAL; 177 } 178 179 ret = remap_vmalloc_range(vma, buf->vaddr, 0); 180 if (ret) { 181 pr_err("Remapping vmalloc memory, error: %d\n", ret); 182 return ret; 183 } 184 185 /* 186 * Make sure that vm_areas for 2 buffers won't be merged together 187 */ 188 vma->vm_flags |= VM_DONTEXPAND; 189 190 /* 191 * Use common vm_area operations to track buffer refcount. 192 */ 193 vma->vm_private_data = &buf->handler; 194 vma->vm_ops = &vb2_common_vm_ops; 195 196 vma->vm_ops->open(vma); 197 198 return 0; 199 } 200 201 #ifdef CONFIG_HAS_DMA 202 /*********************************************/ 203 /* DMABUF ops for exporters */ 204 /*********************************************/ 205 206 struct vb2_vmalloc_attachment { 207 struct sg_table sgt; 208 enum dma_data_direction dma_dir; 209 }; 210 211 static int vb2_vmalloc_dmabuf_ops_attach(struct dma_buf *dbuf, 212 struct dma_buf_attachment *dbuf_attach) 213 { 214 struct vb2_vmalloc_attachment *attach; 215 struct vb2_vmalloc_buf *buf = dbuf->priv; 216 int num_pages = PAGE_ALIGN(buf->size) / PAGE_SIZE; 217 struct sg_table *sgt; 218 struct scatterlist *sg; 219 void *vaddr = buf->vaddr; 220 int ret; 221 int i; 222 223 attach = kzalloc(sizeof(*attach), GFP_KERNEL); 224 if (!attach) 225 return -ENOMEM; 226 227 sgt = &attach->sgt; 228 ret = sg_alloc_table(sgt, num_pages, GFP_KERNEL); 229 if (ret) { 230 kfree(attach); 231 return ret; 232 } 233 for_each_sg(sgt->sgl, sg, sgt->nents, i) { 234 struct page *page = vmalloc_to_page(vaddr); 235 236 if (!page) { 237 sg_free_table(sgt); 238 kfree(attach); 239 return -ENOMEM; 240 } 241 sg_set_page(sg, page, PAGE_SIZE, 0); 242 vaddr += PAGE_SIZE; 243 } 244 245 attach->dma_dir = DMA_NONE; 246 dbuf_attach->priv = attach; 247 return 0; 248 } 249 250 static void vb2_vmalloc_dmabuf_ops_detach(struct dma_buf *dbuf, 251 struct dma_buf_attachment *db_attach) 252 { 253 struct vb2_vmalloc_attachment *attach = db_attach->priv; 254 struct sg_table *sgt; 255 256 if (!attach) 257 return; 258 259 sgt = &attach->sgt; 260 261 /* release the scatterlist cache */ 262 if (attach->dma_dir != DMA_NONE) 263 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, 264 attach->dma_dir); 265 sg_free_table(sgt); 266 kfree(attach); 267 db_attach->priv = NULL; 268 } 269 270 static struct sg_table *vb2_vmalloc_dmabuf_ops_map( 271 struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir) 272 { 273 struct vb2_vmalloc_attachment *attach = db_attach->priv; 274 /* stealing dmabuf mutex to serialize map/unmap operations */ 275 struct mutex *lock = &db_attach->dmabuf->lock; 276 struct sg_table *sgt; 277 278 mutex_lock(lock); 279 280 sgt = &attach->sgt; 281 /* return previously mapped sg table */ 282 if (attach->dma_dir == dma_dir) { 283 mutex_unlock(lock); 284 return sgt; 285 } 286 287 /* release any previous cache */ 288 if (attach->dma_dir != DMA_NONE) { 289 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, 290 attach->dma_dir); 291 attach->dma_dir = DMA_NONE; 292 } 293 294 /* mapping to the client with new direction */ 295 sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, 296 dma_dir); 297 if (!sgt->nents) { 298 pr_err("failed to map scatterlist\n"); 299 mutex_unlock(lock); 300 return ERR_PTR(-EIO); 301 } 302 303 attach->dma_dir = dma_dir; 304 305 mutex_unlock(lock); 306 307 return sgt; 308 } 309 310 static void vb2_vmalloc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach, 311 struct sg_table *sgt, enum dma_data_direction dma_dir) 312 { 313 /* nothing to be done here */ 314 } 315 316 static void vb2_vmalloc_dmabuf_ops_release(struct dma_buf *dbuf) 317 { 318 /* drop reference obtained in vb2_vmalloc_get_dmabuf */ 319 vb2_vmalloc_put(dbuf->priv); 320 } 321 322 static void *vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf *dbuf) 323 { 324 struct vb2_vmalloc_buf *buf = dbuf->priv; 325 326 return buf->vaddr; 327 } 328 329 static int vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf *dbuf, 330 struct vm_area_struct *vma) 331 { 332 return vb2_vmalloc_mmap(dbuf->priv, vma); 333 } 334 335 static const struct dma_buf_ops vb2_vmalloc_dmabuf_ops = { 336 .attach = vb2_vmalloc_dmabuf_ops_attach, 337 .detach = vb2_vmalloc_dmabuf_ops_detach, 338 .map_dma_buf = vb2_vmalloc_dmabuf_ops_map, 339 .unmap_dma_buf = vb2_vmalloc_dmabuf_ops_unmap, 340 .vmap = vb2_vmalloc_dmabuf_ops_vmap, 341 .mmap = vb2_vmalloc_dmabuf_ops_mmap, 342 .release = vb2_vmalloc_dmabuf_ops_release, 343 }; 344 345 static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flags) 346 { 347 struct vb2_vmalloc_buf *buf = buf_priv; 348 struct dma_buf *dbuf; 349 DEFINE_DMA_BUF_EXPORT_INFO(exp_info); 350 351 exp_info.ops = &vb2_vmalloc_dmabuf_ops; 352 exp_info.size = buf->size; 353 exp_info.flags = flags; 354 exp_info.priv = buf; 355 356 if (WARN_ON(!buf->vaddr)) 357 return NULL; 358 359 dbuf = dma_buf_export(&exp_info); 360 if (IS_ERR(dbuf)) 361 return NULL; 362 363 /* dmabuf keeps reference to vb2 buffer */ 364 refcount_inc(&buf->refcount); 365 366 return dbuf; 367 } 368 #endif /* CONFIG_HAS_DMA */ 369 370 371 /*********************************************/ 372 /* callbacks for DMABUF buffers */ 373 /*********************************************/ 374 375 static int vb2_vmalloc_map_dmabuf(void *mem_priv) 376 { 377 struct vb2_vmalloc_buf *buf = mem_priv; 378 379 buf->vaddr = dma_buf_vmap(buf->dbuf); 380 381 return buf->vaddr ? 0 : -EFAULT; 382 } 383 384 static void vb2_vmalloc_unmap_dmabuf(void *mem_priv) 385 { 386 struct vb2_vmalloc_buf *buf = mem_priv; 387 388 dma_buf_vunmap(buf->dbuf, buf->vaddr); 389 buf->vaddr = NULL; 390 } 391 392 static void vb2_vmalloc_detach_dmabuf(void *mem_priv) 393 { 394 struct vb2_vmalloc_buf *buf = mem_priv; 395 396 if (buf->vaddr) 397 dma_buf_vunmap(buf->dbuf, buf->vaddr); 398 399 kfree(buf); 400 } 401 402 static void *vb2_vmalloc_attach_dmabuf(struct device *dev, struct dma_buf *dbuf, 403 unsigned long size, enum dma_data_direction dma_dir) 404 { 405 struct vb2_vmalloc_buf *buf; 406 407 if (dbuf->size < size) 408 return ERR_PTR(-EFAULT); 409 410 buf = kzalloc(sizeof(*buf), GFP_KERNEL); 411 if (!buf) 412 return ERR_PTR(-ENOMEM); 413 414 buf->dbuf = dbuf; 415 buf->dma_dir = dma_dir; 416 buf->size = size; 417 418 return buf; 419 } 420 421 422 const struct vb2_mem_ops vb2_vmalloc_memops = { 423 .alloc = vb2_vmalloc_alloc, 424 .put = vb2_vmalloc_put, 425 .get_userptr = vb2_vmalloc_get_userptr, 426 .put_userptr = vb2_vmalloc_put_userptr, 427 #ifdef CONFIG_HAS_DMA 428 .get_dmabuf = vb2_vmalloc_get_dmabuf, 429 #endif 430 .map_dmabuf = vb2_vmalloc_map_dmabuf, 431 .unmap_dmabuf = vb2_vmalloc_unmap_dmabuf, 432 .attach_dmabuf = vb2_vmalloc_attach_dmabuf, 433 .detach_dmabuf = vb2_vmalloc_detach_dmabuf, 434 .vaddr = vb2_vmalloc_vaddr, 435 .mmap = vb2_vmalloc_mmap, 436 .num_users = vb2_vmalloc_num_users, 437 }; 438 EXPORT_SYMBOL_GPL(vb2_vmalloc_memops); 439 440 MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2"); 441 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); 442 MODULE_LICENSE("GPL"); 443