drivers/media/common/videobuf2/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/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         buf->dma_dir = dma_dir;
  50         buf->handler.refcount = &buf->refcount;
  51         buf->handler.put = vb2_vmalloc_put;
  52         buf->handler.arg = buf;
  53
  54         if (!buf->vaddr) {
  55                 pr_debug("vmalloc of size %ld failed\n", buf->size);
  56                 kfree(buf);
  57                 return ERR_PTR(-ENOMEM);
  58         }
  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(nums[0] << PAGE_SHIFT, size);
 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, struct device *dev,
 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         .map_atomic = vb2_vmalloc_dmabuf_ops_kmap,
 350         .vmap = vb2_vmalloc_dmabuf_ops_vmap,
 351         .mmap = vb2_vmalloc_dmabuf_ops_mmap,
 352         .release = vb2_vmalloc_dmabuf_ops_release,
 353 };
 354
 355 static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flags)
 356 {
 357         struct vb2_vmalloc_buf *buf = buf_priv;
 358         struct dma_buf *dbuf;
 359         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 360
 361         exp_info.ops = &vb2_vmalloc_dmabuf_ops;
 362         exp_info.size = buf->size;
 363         exp_info.flags = flags;
 364         exp_info.priv = buf;
 365
 366         if (WARN_ON(!buf->vaddr))
 367                 return NULL;
 368
 369         dbuf = dma_buf_export(&exp_info);
 370         if (IS_ERR(dbuf))
 371                 return NULL;
 372
 373         /* dmabuf keeps reference to vb2 buffer */
 374         refcount_inc(&buf->refcount);
 375
 376         return dbuf;
 377 }
 378 #endif /* CONFIG_HAS_DMA */
 379
 380
 381 /*********************************************/
 382 /*       callbacks for DMABUF buffers        */
 383 /*********************************************/
 384
 385 static int vb2_vmalloc_map_dmabuf(void *mem_priv)
 386 {
 387         struct vb2_vmalloc_buf *buf = mem_priv;
 388
 389         buf->vaddr = dma_buf_vmap(buf->dbuf);
 390
 391         return buf->vaddr ? 0 : -EFAULT;
 392 }
 393
 394 static void vb2_vmalloc_unmap_dmabuf(void *mem_priv)
 395 {
 396         struct vb2_vmalloc_buf *buf = mem_priv;
 397
 398         dma_buf_vunmap(buf->dbuf, buf->vaddr);
 399         buf->vaddr = NULL;
 400 }
 401
 402 static void vb2_vmalloc_detach_dmabuf(void *mem_priv)
 403 {
 404         struct vb2_vmalloc_buf *buf = mem_priv;
 405
 406         if (buf->vaddr)
 407                 dma_buf_vunmap(buf->dbuf, buf->vaddr);
 408
 409         kfree(buf);
 410 }
 411
 412 static void *vb2_vmalloc_attach_dmabuf(struct device *dev, struct dma_buf *dbuf,
 413         unsigned long size, enum dma_data_direction dma_dir)
 414 {
 415         struct vb2_vmalloc_buf *buf;
 416
 417         if (dbuf->size < size)
 418                 return ERR_PTR(-EFAULT);
 419
 420         buf = kzalloc(sizeof(*buf), GFP_KERNEL);
 421         if (!buf)
 422                 return ERR_PTR(-ENOMEM);
 423
 424         buf->dbuf = dbuf;
 425         buf->dma_dir = dma_dir;
 426         buf->size = size;
 427
 428         return buf;
 429 }
 430
 431
 432 const struct vb2_mem_ops vb2_vmalloc_memops = {
 433         .alloc          = vb2_vmalloc_alloc,
 434         .put            = vb2_vmalloc_put,
 435         .get_userptr    = vb2_vmalloc_get_userptr,
 436         .put_userptr    = vb2_vmalloc_put_userptr,
 437 #ifdef CONFIG_HAS_DMA
 438         .get_dmabuf     = vb2_vmalloc_get_dmabuf,
 439 #endif
 440         .map_dmabuf     = vb2_vmalloc_map_dmabuf,
 441         .unmap_dmabuf   = vb2_vmalloc_unmap_dmabuf,
 442         .attach_dmabuf  = vb2_vmalloc_attach_dmabuf,
 443         .detach_dmabuf  = vb2_vmalloc_detach_dmabuf,
 444         .vaddr          = vb2_vmalloc_vaddr,
 445         .mmap           = vb2_vmalloc_mmap,
 446         .num_users      = vb2_vmalloc_num_users,
 447 };
 448 EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
 449
 450 MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
 451 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
 452 MODULE_LICENSE("GPL");