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