drivers/media/v4l2-core/videobuf2-vmalloc.c

   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/sched.h>
  17 #include <linux/slab.h>
  18 #include <linux/vmalloc.h>
  19
  20 #include <media/videobuf2-v4l2.h>
  21 #include <media/videobuf2-vmalloc.h>
  22 #include <media/videobuf2-memops.h>
  23
  24 struct vb2_vmalloc_buf {
  25         void                            *vaddr;
  26         struct frame_vector             *vec;
  27         enum dma_data_direction         dma_dir;
  28         unsigned long                   size;
  29         atomic_t                        refcount;
  30         struct vb2_vmarea_handler       handler;
  31         struct dma_buf                  *dbuf;
  32 };
  33
  34 static void vb2_vmalloc_put(void *buf_priv);
  35
  36 static void *vb2_vmalloc_alloc(struct device *dev, unsigned long attrs,
  37                                unsigned long size, enum dma_data_direction dma_dir,
  38                                gfp_t gfp_flags)
  39 {
  40         struct vb2_vmalloc_buf *buf;
  41
  42         buf = kzalloc(sizeof(*buf), GFP_KERNEL | gfp_flags);
  43         if (!buf)
  44                 return ERR_PTR(-ENOMEM);
  45
  46         buf->size = size;
  47         buf->vaddr = vmalloc_user(buf->size);
  48         buf->dma_dir = dma_dir;
  49         buf->handler.refcount = &buf->refcount;
  50         buf->handler.put = vb2_vmalloc_put;
  51         buf->handler.arg = buf;
  52
  53         if (!buf->vaddr) {
  54                 pr_debug("vmalloc of size %ld failed\n", buf->size);
  55                 kfree(buf);
  56                 return ERR_PTR(-ENOMEM);
  57         }
  58
  59         atomic_inc(&buf->refcount);
  60         return buf;
  61 }
  62
  63 static void vb2_vmalloc_put(void *buf_priv)
  64 {
  65         struct vb2_vmalloc_buf *buf = buf_priv;
  66
  67         if (atomic_dec_and_test(&buf->refcount)) {
  68                 vfree(buf->vaddr);
  69                 kfree(buf);
  70         }
  71 }
  72
  73 static void *vb2_vmalloc_get_userptr(struct device *dev, unsigned long vaddr,
  74                                      unsigned long size,
  75                                      enum dma_data_direction dma_dir)
  76 {
  77         struct vb2_vmalloc_buf *buf;
  78         struct frame_vector *vec;
  79         int n_pages, offset, i;
  80         int ret = -ENOMEM;
  81
  82         buf = kzalloc(sizeof(*buf), GFP_KERNEL);
  83         if (!buf)
  84                 return ERR_PTR(-ENOMEM);
  85
  86         buf->dma_dir = dma_dir;
  87         offset = vaddr & ~PAGE_MASK;
  88         buf->size = size;
  89         vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE);
  90         if (IS_ERR(vec)) {
  91                 ret = PTR_ERR(vec);
  92                 goto fail_pfnvec_create;
  93         }
  94         buf->vec = vec;
  95         n_pages = frame_vector_count(vec);
  96         if (frame_vector_to_pages(vec) < 0) {
  97                 unsigned long *nums = frame_vector_pfns(vec);
  98
  99                 /*
 100                  * We cannot get page pointers for these pfns. Check memory is
 101                  * physically contiguous and use direct mapping.
 102                  */
 103                 for (i = 1; i < n_pages; i++)
 104                         if (nums[i-1] + 1 != nums[i])
 105                                 goto fail_map;
 106                 buf->vaddr = (__force void *)
 107                                 ioremap_nocache(nums[0] << PAGE_SHIFT, size);
 108         } else {
 109                 buf->vaddr = vm_map_ram(frame_vector_pages(vec), n_pages, -1,
 110                                         PAGE_KERNEL);
 111         }
 112
 113         if (!buf->vaddr)
 114                 goto fail_map;
 115         buf->vaddr += offset;
 116         return buf;
 117
 118 fail_map:
 119         vb2_destroy_framevec(vec);
 120 fail_pfnvec_create:
 121         kfree(buf);
 122
 123         return ERR_PTR(ret);
 124 }
 125
 126 static void vb2_vmalloc_put_userptr(void *buf_priv)
 127 {
 128         struct vb2_vmalloc_buf *buf = buf_priv;
 129         unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
 130         unsigned int i;
 131         struct page **pages;
 132         unsigned int n_pages;
 133
 134         if (!buf->vec->is_pfns) {
 135                 n_pages = frame_vector_count(buf->vec);
 136                 pages = frame_vector_pages(buf->vec);
 137                 if (vaddr)
 138                         vm_unmap_ram((void *)vaddr, n_pages);
 139                 if (buf->dma_dir == DMA_FROM_DEVICE)
 140                         for (i = 0; i < n_pages; i++)
 141                                 set_page_dirty_lock(pages[i]);
 142         } else {
 143                 iounmap((__force void __iomem *)buf->vaddr);
 144         }
 145         vb2_destroy_framevec(buf->vec);
 146         kfree(buf);
 147 }
 148
 149 static void *vb2_vmalloc_vaddr(void *buf_priv)
 150 {
 151         struct vb2_vmalloc_buf *buf = buf_priv;
 152
 153         if (!buf->vaddr) {
 154                 pr_err("Address of an unallocated plane requested "
 155                        "or cannot map user pointer\n");
 156                 return NULL;
 157         }
 158
 159         return buf->vaddr;
 160 }
 161
 162 static unsigned int vb2_vmalloc_num_users(void *buf_priv)
 163 {
 164         struct vb2_vmalloc_buf *buf = buf_priv;
 165         return atomic_read(&buf->refcount);
 166 }
 167
 168 static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
 169 {
 170         struct vb2_vmalloc_buf *buf = buf_priv;
 171         int ret;
 172
 173         if (!buf) {
 174                 pr_err("No memory to map\n");
 175                 return -EINVAL;
 176         }
 177
 178         ret = remap_vmalloc_range(vma, buf->vaddr, 0);
 179         if (ret) {
 180                 pr_err("Remapping vmalloc memory, error: %d\n", ret);
 181                 return ret;
 182         }
 183
 184         /*
 185          * Make sure that vm_areas for 2 buffers won't be merged together
 186          */
 187         vma->vm_flags           |= VM_DONTEXPAND;
 188
 189         /*
 190          * Use common vm_area operations to track buffer refcount.
 191          */
 192         vma->vm_private_data    = &buf->handler;
 193         vma->vm_ops             = &vb2_common_vm_ops;
 194
 195         vma->vm_ops->open(vma);
 196
 197         return 0;
 198 }
 199
 200 #ifdef CONFIG_HAS_DMA
 201 /*********************************************/
 202 /*         DMABUF ops for exporters          */
 203 /*********************************************/
 204
 205 struct vb2_vmalloc_attachment {
 206         struct sg_table sgt;
 207         enum dma_data_direction dma_dir;
 208 };
 209
 210 static int vb2_vmalloc_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev,
 211         struct dma_buf_attachment *dbuf_attach)
 212 {
 213         struct vb2_vmalloc_attachment *attach;
 214         struct vb2_vmalloc_buf *buf = dbuf->priv;
 215         int num_pages = PAGE_ALIGN(buf->size) / PAGE_SIZE;
 216         struct sg_table *sgt;
 217         struct scatterlist *sg;
 218         void *vaddr = buf->vaddr;
 219         int ret;
 220         int i;
 221
 222         attach = kzalloc(sizeof(*attach), GFP_KERNEL);
 223         if (!attach)
 224                 return -ENOMEM;
 225
 226         sgt = &attach->sgt;
 227         ret = sg_alloc_table(sgt, num_pages, GFP_KERNEL);
 228         if (ret) {
 229                 kfree(attach);
 230                 return ret;
 231         }
 232         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 233                 struct page *page = vmalloc_to_page(vaddr);
 234
 235                 if (!page) {
 236                         sg_free_table(sgt);
 237                         kfree(attach);
 238                         return -ENOMEM;
 239                 }
 240                 sg_set_page(sg, page, PAGE_SIZE, 0);
 241                 vaddr += PAGE_SIZE;
 242         }
 243
 244         attach->dma_dir = DMA_NONE;
 245         dbuf_attach->priv = attach;
 246         return 0;
 247 }
 248
 249 static void vb2_vmalloc_dmabuf_ops_detach(struct dma_buf *dbuf,
 250         struct dma_buf_attachment *db_attach)
 251 {
 252         struct vb2_vmalloc_attachment *attach = db_attach->priv;
 253         struct sg_table *sgt;
 254
 255         if (!attach)
 256                 return;
 257
 258         sgt = &attach->sgt;
 259
 260         /* release the scatterlist cache */
 261         if (attach->dma_dir != DMA_NONE)
 262                 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
 263                         attach->dma_dir);
 264         sg_free_table(sgt);
 265         kfree(attach);
 266         db_attach->priv = NULL;
 267 }
 268
 269 static struct sg_table *vb2_vmalloc_dmabuf_ops_map(
 270         struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
 271 {
 272         struct vb2_vmalloc_attachment *attach = db_attach->priv;
 273         /* stealing dmabuf mutex to serialize map/unmap operations */
 274         struct mutex *lock = &db_attach->dmabuf->lock;
 275         struct sg_table *sgt;
 276
 277         mutex_lock(lock);
 278
 279         sgt = &attach->sgt;
 280         /* return previously mapped sg table */
 281         if (attach->dma_dir == dma_dir) {
 282                 mutex_unlock(lock);
 283                 return sgt;
 284         }
 285
 286         /* release any previous cache */
 287         if (attach->dma_dir != DMA_NONE) {
 288                 dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
 289                         attach->dma_dir);
 290                 attach->dma_dir = DMA_NONE;
 291         }
 292
 293         /* mapping to the client with new direction */
 294         sgt->nents = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
 295                                 dma_dir);
 296         if (!sgt->nents) {
 297                 pr_err("failed to map scatterlist\n");
 298                 mutex_unlock(lock);
 299                 return ERR_PTR(-EIO);
 300         }
 301
 302         attach->dma_dir = dma_dir;
 303
 304         mutex_unlock(lock);
 305
 306         return sgt;
 307 }
 308
 309 static void vb2_vmalloc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
 310         struct sg_table *sgt, enum dma_data_direction dma_dir)
 311 {
 312         /* nothing to be done here */
 313 }
 314
 315 static void vb2_vmalloc_dmabuf_ops_release(struct dma_buf *dbuf)
 316 {
 317         /* drop reference obtained in vb2_vmalloc_get_dmabuf */
 318         vb2_vmalloc_put(dbuf->priv);
 319 }
 320
 321 static void *vb2_vmalloc_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum)
 322 {
 323         struct vb2_vmalloc_buf *buf = dbuf->priv;
 324
 325         return buf->vaddr + pgnum * PAGE_SIZE;
 326 }
 327
 328 static void *vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf *dbuf)
 329 {
 330         struct vb2_vmalloc_buf *buf = dbuf->priv;
 331
 332         return buf->vaddr;
 333 }
 334
 335 static int vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf *dbuf,
 336         struct vm_area_struct *vma)
 337 {
 338         return vb2_vmalloc_mmap(dbuf->priv, vma);
 339 }
 340
 341 static struct dma_buf_ops vb2_vmalloc_dmabuf_ops = {
 342         .attach = vb2_vmalloc_dmabuf_ops_attach,
 343         .detach = vb2_vmalloc_dmabuf_ops_detach,
 344         .map_dma_buf = vb2_vmalloc_dmabuf_ops_map,
 345         .unmap_dma_buf = vb2_vmalloc_dmabuf_ops_unmap,
 346         .kmap = vb2_vmalloc_dmabuf_ops_kmap,
 347         .kmap_atomic = vb2_vmalloc_dmabuf_ops_kmap,
 348         .vmap = vb2_vmalloc_dmabuf_ops_vmap,
 349         .mmap = vb2_vmalloc_dmabuf_ops_mmap,
 350         .release = vb2_vmalloc_dmabuf_ops_release,
 351 };
 352
 353 static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flags)
 354 {
 355         struct vb2_vmalloc_buf *buf = buf_priv;
 356         struct dma_buf *dbuf;
 357         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 358
 359         exp_info.ops = &vb2_vmalloc_dmabuf_ops;
 360         exp_info.size = buf->size;
 361         exp_info.flags = flags;
 362         exp_info.priv = buf;
 363
 364         if (WARN_ON(!buf->vaddr))
 365                 return NULL;
 366
 367         dbuf = dma_buf_export(&exp_info);
 368         if (IS_ERR(dbuf))
 369                 return NULL;
 370
 371         /* dmabuf keeps reference to vb2 buffer */
 372         atomic_inc(&buf->refcount);
 373
 374         return dbuf;
 375 }
 376 #endif /* CONFIG_HAS_DMA */
 377
 378
 379 /*********************************************/
 380 /*       callbacks for DMABUF buffers        */
 381 /*********************************************/
 382
 383 static int vb2_vmalloc_map_dmabuf(void *mem_priv)
 384 {
 385         struct vb2_vmalloc_buf *buf = mem_priv;
 386
 387         buf->vaddr = dma_buf_vmap(buf->dbuf);
 388
 389         return buf->vaddr ? 0 : -EFAULT;
 390 }
 391
 392 static void vb2_vmalloc_unmap_dmabuf(void *mem_priv)
 393 {
 394         struct vb2_vmalloc_buf *buf = mem_priv;
 395
 396         dma_buf_vunmap(buf->dbuf, buf->vaddr);
 397         buf->vaddr = NULL;
 398 }
 399
 400 static void vb2_vmalloc_detach_dmabuf(void *mem_priv)
 401 {
 402         struct vb2_vmalloc_buf *buf = mem_priv;
 403
 404         if (buf->vaddr)
 405                 dma_buf_vunmap(buf->dbuf, buf->vaddr);
 406
 407         kfree(buf);
 408 }
 409
 410 static void *vb2_vmalloc_attach_dmabuf(struct device *dev, struct dma_buf *dbuf,
 411         unsigned long size, enum dma_data_direction dma_dir)
 412 {
 413         struct vb2_vmalloc_buf *buf;
 414
 415         if (dbuf->size < size)
 416                 return ERR_PTR(-EFAULT);
 417
 418         buf = kzalloc(sizeof(*buf), GFP_KERNEL);
 419         if (!buf)
 420                 return ERR_PTR(-ENOMEM);
 421
 422         buf->dbuf = dbuf;
 423         buf->dma_dir = dma_dir;
 424         buf->size = size;
 425
 426         return buf;
 427 }
 428
 429
 430 const struct vb2_mem_ops vb2_vmalloc_memops = {
 431         .alloc          = vb2_vmalloc_alloc,
 432         .put            = vb2_vmalloc_put,
 433         .get_userptr    = vb2_vmalloc_get_userptr,
 434         .put_userptr    = vb2_vmalloc_put_userptr,
 435 #ifdef CONFIG_HAS_DMA
 436         .get_dmabuf     = vb2_vmalloc_get_dmabuf,
 437 #endif
 438         .map_dmabuf     = vb2_vmalloc_map_dmabuf,
 439         .unmap_dmabuf   = vb2_vmalloc_unmap_dmabuf,
 440         .attach_dmabuf  = vb2_vmalloc_attach_dmabuf,
 441         .detach_dmabuf  = vb2_vmalloc_detach_dmabuf,
 442         .vaddr          = vb2_vmalloc_vaddr,
 443         .mmap           = vb2_vmalloc_mmap,
 444         .num_users      = vb2_vmalloc_num_users,
 445 };
 446 EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
 447
 448 MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
 449 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
 450 MODULE_LICENSE("GPL");