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, dma_dir == DMA_FROM_DEVICE || 91 dma_dir == DMA_BIDIRECTIONAL); 92 if (IS_ERR(vec)) { 93 ret = PTR_ERR(vec); 94 goto fail_pfnvec_create; 95 } 96 buf->vec = vec; 97 n_pages = frame_vector_count(vec); 98 if (frame_vector_to_pages(vec) < 0) { 99 unsigned long *nums = frame_vector_pfns(vec); 100 101 /* 102 * We cannot get page pointers for these pfns. Check memory is 103 * physically contiguous and use direct mapping. 104 */ 105 for (i = 1; i < n_pages; i++) 106 if (nums[i-1] + 1 != nums[i]) 107 goto fail_map; 108 buf->vaddr = (__force void *) 109 ioremap_nocache(__pfn_to_phys(nums[0]), size + offset); 110 } else { 111 buf->vaddr = vm_map_ram(frame_vector_pages(vec), n_pages, -1, 112 PAGE_KERNEL); 113 } 114 115 if (!buf->vaddr) 116 goto fail_map; 117 buf->vaddr += offset; 118 return buf; 119 120 fail_map: 121 vb2_destroy_framevec(vec); 122 fail_pfnvec_create: 123 kfree(buf); 124 125 return ERR_PTR(ret); 126 } 127 128 static void vb2_vmalloc_put_userptr(void *buf_priv) 129 { 130 struct vb2_vmalloc_buf *buf = buf_priv; 131 unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK; 132 unsigned int i; 133 struct page **pages; 134 unsigned int n_pages; 135 136 if (!buf->vec->is_pfns) { 137 n_pages = frame_vector_count(buf->vec); 138 pages = frame_vector_pages(buf->vec); 139 if (vaddr) 140 vm_unmap_ram((void *)vaddr, n_pages); 141 if (buf->dma_dir == DMA_FROM_DEVICE || 142 buf->dma_dir == DMA_BIDIRECTIONAL) 143 for (i = 0; i < n_pages; i++) 144 set_page_dirty_lock(pages[i]); 145 } else { 146 iounmap((__force void __iomem *)buf->vaddr); 147 } 148 vb2_destroy_framevec(buf->vec); 149 kfree(buf); 150 } 151 152 static void *vb2_vmalloc_vaddr(void *buf_priv) 153 { 154 struct vb2_vmalloc_buf *buf = buf_priv; 155 156 if (!buf->vaddr) { 157 pr_err("Address of an unallocated plane requested or cannot map user pointer\n"); 158 return NULL; 159 } 160 161 return buf->vaddr; 162 } 163 164 static unsigned int vb2_vmalloc_num_users(void *buf_priv) 165 { 166 struct vb2_vmalloc_buf *buf = buf_priv; 167 return refcount_read(&buf->refcount); 168 } 169 170 static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma) 171 { 172 struct vb2_vmalloc_buf *buf = buf_priv; 173 int ret; 174 175 if (!buf) { 176 pr_err("No memory to map\n"); 177 return -EINVAL; 178 } 179 180 ret = remap_vmalloc_range(vma, buf->vaddr, 0); 181 if (ret) { 182 pr_err("Remapping vmalloc memory, error: %d\n", ret); 183 return ret; 184 } 185 186 /* 187 * Make sure that vm_areas for 2 buffers won't be merged together 188 */ 189 vma->vm_flags |= VM_DONTEXPAND; 190 191 /* 192 * Use common vm_area operations to track buffer refcount. 193 */ 194 vma->vm_private_data = &buf->handler; 195 vma->vm_ops = &vb2_common_vm_ops; 196 197 vma->vm_ops->open(vma); 198 199 return 0; 200 } 201 202 #ifdef CONFIG_HAS_DMA 203 /*********************************************/ 204 /* DMABUF ops for exporters */ 205 /*********************************************/ 206 207 struct vb2_vmalloc_attachment { 208 struct sg_table sgt; 209 enum dma_data_direction dma_dir; 210 }; 211 212 static int vb2_vmalloc_dmabuf_ops_attach(struct dma_buf *dbuf, 213 struct dma_buf_attachment *dbuf_attach) 214 { 215 struct vb2_vmalloc_attachment *attach; 216 struct vb2_vmalloc_buf *buf = dbuf->priv; 217 int num_pages = PAGE_ALIGN(buf->size) / PAGE_SIZE; 218 struct sg_table *sgt; 219 struct scatterlist *sg; 220 void *vaddr = buf->vaddr; 221 int ret; 222 int i; 223 224 attach = kzalloc(sizeof(*attach), GFP_KERNEL); 225 if (!attach) 226 return -ENOMEM; 227 228 sgt = &attach->sgt; 229 ret = sg_alloc_table(sgt, num_pages, GFP_KERNEL); 230 if (ret) { 231 kfree(attach); 232 return ret; 233 } 234 for_each_sg(sgt->sgl, sg, sgt->nents, i) { 235 struct page *page = vmalloc_to_page(vaddr); 236 237 if (!page) { 238 sg_free_table(sgt); 239 kfree(attach); 240 return -ENOMEM; 241 } 242 sg_set_page(sg, page, PAGE_SIZE, 0); 243 vaddr += PAGE_SIZE; 244 } 245 246 attach->dma_dir = DMA_NONE; 247 dbuf_attach->priv = attach; 248 return 0; 249 } 250 251 static void vb2_vmalloc_dmabuf_ops_detach(struct dma_buf *dbuf, 252 struct dma_buf_attachment *db_attach) 253 { 254 struct vb2_vmalloc_attachment *attach = db_attach->priv; 255 struct sg_table *sgt; 256 257 if (!attach) 258 return; 259 260 sgt = &attach->sgt; 261 262 /* release the scatterlist cache */ 263 if (attach->dma_dir != DMA_NONE) 264 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, 265 attach->dma_dir); 266 sg_free_table(sgt); 267 kfree(attach); 268 db_attach->priv = NULL; 269 } 270 271 static struct sg_table *vb2_vmalloc_dmabuf_ops_map( 272 struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir) 273 { 274 struct vb2_vmalloc_attachment *attach = db_attach->priv; 275 /* stealing dmabuf mutex to serialize map/unmap operations */ 276 struct mutex *lock = &db_attach->dmabuf->lock; 277 struct sg_table *sgt; 278 279 mutex_lock(lock); 280 281 sgt = &attach->sgt; 282 /* return previously mapped sg table */ 283 if (attach->dma_dir == dma_dir) { 284 mutex_unlock(lock); 285 return sgt; 286 } 287 288 /* release any previous cache */ 289 if (attach->dma_dir != DMA_NONE) { 290 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, 291 attach->dma_dir); 292 attach->dma_dir = DMA_NONE; 293 } 294 295 /* mapping to the client with new direction */ 296 sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, 297 dma_dir); 298 if (!sgt->nents) { 299 pr_err("failed to map scatterlist\n"); 300 mutex_unlock(lock); 301 return ERR_PTR(-EIO); 302 } 303 304 attach->dma_dir = dma_dir; 305 306 mutex_unlock(lock); 307 308 return sgt; 309 } 310 311 static void vb2_vmalloc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach, 312 struct sg_table *sgt, enum dma_data_direction dma_dir) 313 { 314 /* nothing to be done here */ 315 } 316 317 static void vb2_vmalloc_dmabuf_ops_release(struct dma_buf *dbuf) 318 { 319 /* drop reference obtained in vb2_vmalloc_get_dmabuf */ 320 vb2_vmalloc_put(dbuf->priv); 321 } 322 323 static void *vb2_vmalloc_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum) 324 { 325 struct vb2_vmalloc_buf *buf = dbuf->priv; 326 327 return buf->vaddr + pgnum * PAGE_SIZE; 328 } 329 330 static void *vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf *dbuf) 331 { 332 struct vb2_vmalloc_buf *buf = dbuf->priv; 333 334 return buf->vaddr; 335 } 336 337 static int vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf *dbuf, 338 struct vm_area_struct *vma) 339 { 340 return vb2_vmalloc_mmap(dbuf->priv, vma); 341 } 342 343 static const struct dma_buf_ops vb2_vmalloc_dmabuf_ops = { 344 .attach = vb2_vmalloc_dmabuf_ops_attach, 345 .detach = vb2_vmalloc_dmabuf_ops_detach, 346 .map_dma_buf = vb2_vmalloc_dmabuf_ops_map, 347 .unmap_dma_buf = vb2_vmalloc_dmabuf_ops_unmap, 348 .map = vb2_vmalloc_dmabuf_ops_kmap, 349 .vmap = vb2_vmalloc_dmabuf_ops_vmap, 350 .mmap = vb2_vmalloc_dmabuf_ops_mmap, 351 .release = vb2_vmalloc_dmabuf_ops_release, 352 }; 353 354 static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flags) 355 { 356 struct vb2_vmalloc_buf *buf = buf_priv; 357 struct dma_buf *dbuf; 358 DEFINE_DMA_BUF_EXPORT_INFO(exp_info); 359 360 exp_info.ops = &vb2_vmalloc_dmabuf_ops; 361 exp_info.size = buf->size; 362 exp_info.flags = flags; 363 exp_info.priv = buf; 364 365 if (WARN_ON(!buf->vaddr)) 366 return NULL; 367 368 dbuf = dma_buf_export(&exp_info); 369 if (IS_ERR(dbuf)) 370 return NULL; 371 372 /* dmabuf keeps reference to vb2 buffer */ 373 refcount_inc(&buf->refcount); 374 375 return dbuf; 376 } 377 #endif /* CONFIG_HAS_DMA */ 378 379 380 /*********************************************/ 381 /* callbacks for DMABUF buffers */ 382 /*********************************************/ 383 384 static int vb2_vmalloc_map_dmabuf(void *mem_priv) 385 { 386 struct vb2_vmalloc_buf *buf = mem_priv; 387 388 buf->vaddr = dma_buf_vmap(buf->dbuf); 389 390 return buf->vaddr ? 0 : -EFAULT; 391 } 392 393 static void vb2_vmalloc_unmap_dmabuf(void *mem_priv) 394 { 395 struct vb2_vmalloc_buf *buf = mem_priv; 396 397 dma_buf_vunmap(buf->dbuf, buf->vaddr); 398 buf->vaddr = NULL; 399 } 400 401 static void vb2_vmalloc_detach_dmabuf(void *mem_priv) 402 { 403 struct vb2_vmalloc_buf *buf = mem_priv; 404 405 if (buf->vaddr) 406 dma_buf_vunmap(buf->dbuf, buf->vaddr); 407 408 kfree(buf); 409 } 410 411 static void *vb2_vmalloc_attach_dmabuf(struct device *dev, struct dma_buf *dbuf, 412 unsigned long size, enum dma_data_direction dma_dir) 413 { 414 struct vb2_vmalloc_buf *buf; 415 416 if (dbuf->size < size) 417 return ERR_PTR(-EFAULT); 418 419 buf = kzalloc(sizeof(*buf), GFP_KERNEL); 420 if (!buf) 421 return ERR_PTR(-ENOMEM); 422 423 buf->dbuf = dbuf; 424 buf->dma_dir = dma_dir; 425 buf->size = size; 426 427 return buf; 428 } 429 430 431 const struct vb2_mem_ops vb2_vmalloc_memops = { 432 .alloc = vb2_vmalloc_alloc, 433 .put = vb2_vmalloc_put, 434 .get_userptr = vb2_vmalloc_get_userptr, 435 .put_userptr = vb2_vmalloc_put_userptr, 436 #ifdef CONFIG_HAS_DMA 437 .get_dmabuf = vb2_vmalloc_get_dmabuf, 438 #endif 439 .map_dmabuf = vb2_vmalloc_map_dmabuf, 440 .unmap_dmabuf = vb2_vmalloc_unmap_dmabuf, 441 .attach_dmabuf = vb2_vmalloc_attach_dmabuf, 442 .detach_dmabuf = vb2_vmalloc_detach_dmabuf, 443 .vaddr = vb2_vmalloc_vaddr, 444 .mmap = vb2_vmalloc_mmap, 445 .num_users = vb2_vmalloc_num_users, 446 }; 447 EXPORT_SYMBOL_GPL(vb2_vmalloc_memops); 448 449 MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2"); 450 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); 451 MODULE_LICENSE("GPL"); 452