Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 1 | /* |
| 2 | * helper functions for physically contiguous capture buffers |
| 3 | * |
| 4 | * The functions support hardware lacking scatter gather support |
| 5 | * (i.e. the buffers must be linear in physical memory) |
| 6 | * |
| 7 | * Copyright (c) 2008 Magnus Damm |
| 8 | * |
| 9 | * Based on videobuf-vmalloc.c, |
| 10 | * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org> |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU General Public License as published by |
| 14 | * the Free Software Foundation; either version 2 |
| 15 | */ |
| 16 | |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/module.h> |
Hans Verkuil | f19ad39 | 2008-07-18 02:02:50 -0300 | [diff] [blame] | 19 | #include <linux/mm.h> |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame^] | 20 | #include <linux/pagemap.h> |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 21 | #include <linux/dma-mapping.h> |
| 22 | #include <media/videobuf-dma-contig.h> |
| 23 | |
| 24 | struct videobuf_dma_contig_memory { |
| 25 | u32 magic; |
| 26 | void *vaddr; |
| 27 | dma_addr_t dma_handle; |
| 28 | unsigned long size; |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame^] | 29 | int is_userptr; |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 30 | }; |
| 31 | |
| 32 | #define MAGIC_DC_MEM 0x0733ac61 |
Guennadi Liakhovetski | c60f2b5 | 2008-07-17 17:30:47 -0300 | [diff] [blame] | 33 | #define MAGIC_CHECK(is, should) \ |
| 34 | if (unlikely((is) != (should))) { \ |
| 35 | pr_err("magic mismatch: %x expected %x\n", (is), (should)); \ |
| 36 | BUG(); \ |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 37 | } |
| 38 | |
| 39 | static void |
| 40 | videobuf_vm_open(struct vm_area_struct *vma) |
| 41 | { |
| 42 | struct videobuf_mapping *map = vma->vm_private_data; |
| 43 | |
| 44 | dev_dbg(map->q->dev, "vm_open %p [count=%u,vma=%08lx-%08lx]\n", |
| 45 | map, map->count, vma->vm_start, vma->vm_end); |
| 46 | |
| 47 | map->count++; |
| 48 | } |
| 49 | |
| 50 | static void videobuf_vm_close(struct vm_area_struct *vma) |
| 51 | { |
| 52 | struct videobuf_mapping *map = vma->vm_private_data; |
| 53 | struct videobuf_queue *q = map->q; |
| 54 | int i; |
| 55 | |
| 56 | dev_dbg(map->q->dev, "vm_close %p [count=%u,vma=%08lx-%08lx]\n", |
| 57 | map, map->count, vma->vm_start, vma->vm_end); |
| 58 | |
| 59 | map->count--; |
| 60 | if (0 == map->count) { |
| 61 | struct videobuf_dma_contig_memory *mem; |
| 62 | |
| 63 | dev_dbg(map->q->dev, "munmap %p q=%p\n", map, q); |
| 64 | mutex_lock(&q->vb_lock); |
| 65 | |
| 66 | /* We need first to cancel streams, before unmapping */ |
| 67 | if (q->streaming) |
| 68 | videobuf_queue_cancel(q); |
| 69 | |
| 70 | for (i = 0; i < VIDEO_MAX_FRAME; i++) { |
| 71 | if (NULL == q->bufs[i]) |
| 72 | continue; |
| 73 | |
| 74 | if (q->bufs[i]->map != map) |
| 75 | continue; |
| 76 | |
| 77 | mem = q->bufs[i]->priv; |
| 78 | if (mem) { |
| 79 | /* This callback is called only if kernel has |
| 80 | allocated memory and this memory is mmapped. |
| 81 | In this case, memory should be freed, |
| 82 | in order to do memory unmap. |
| 83 | */ |
| 84 | |
| 85 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 86 | |
| 87 | /* vfree is not atomic - can't be |
| 88 | called with IRQ's disabled |
| 89 | */ |
| 90 | dev_dbg(map->q->dev, "buf[%d] freeing %p\n", |
| 91 | i, mem->vaddr); |
| 92 | |
| 93 | dma_free_coherent(q->dev, mem->size, |
| 94 | mem->vaddr, mem->dma_handle); |
| 95 | mem->vaddr = NULL; |
| 96 | } |
| 97 | |
| 98 | q->bufs[i]->map = NULL; |
| 99 | q->bufs[i]->baddr = 0; |
| 100 | } |
| 101 | |
| 102 | kfree(map); |
| 103 | |
| 104 | mutex_unlock(&q->vb_lock); |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | static struct vm_operations_struct videobuf_vm_ops = { |
| 109 | .open = videobuf_vm_open, |
| 110 | .close = videobuf_vm_close, |
| 111 | }; |
| 112 | |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame^] | 113 | /** |
| 114 | * videobuf_dma_contig_user_put() - reset pointer to user space buffer |
| 115 | * @mem: per-buffer private videobuf-dma-contig data |
| 116 | * |
| 117 | * This function resets the user space pointer |
| 118 | */ |
| 119 | static void videobuf_dma_contig_user_put(struct videobuf_dma_contig_memory *mem) |
| 120 | { |
| 121 | mem->is_userptr = 0; |
| 122 | mem->dma_handle = 0; |
| 123 | mem->size = 0; |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * videobuf_dma_contig_user_get() - setup user space memory pointer |
| 128 | * @mem: per-buffer private videobuf-dma-contig data |
| 129 | * @vb: video buffer to map |
| 130 | * |
| 131 | * This function validates and sets up a pointer to user space memory. |
| 132 | * Only physically contiguous pfn-mapped memory is accepted. |
| 133 | * |
| 134 | * Returns 0 if successful. |
| 135 | */ |
| 136 | static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem, |
| 137 | struct videobuf_buffer *vb) |
| 138 | { |
| 139 | struct mm_struct *mm = current->mm; |
| 140 | struct vm_area_struct *vma; |
| 141 | unsigned long prev_pfn, this_pfn; |
| 142 | unsigned long pages_done, user_address; |
| 143 | int ret; |
| 144 | |
| 145 | mem->size = PAGE_ALIGN(vb->size); |
| 146 | mem->is_userptr = 0; |
| 147 | ret = -EINVAL; |
| 148 | |
| 149 | down_read(&mm->mmap_sem); |
| 150 | |
| 151 | vma = find_vma(mm, vb->baddr); |
| 152 | if (!vma) |
| 153 | goto out_up; |
| 154 | |
| 155 | if ((vb->baddr + mem->size) > vma->vm_end) |
| 156 | goto out_up; |
| 157 | |
| 158 | pages_done = 0; |
| 159 | prev_pfn = 0; /* kill warning */ |
| 160 | user_address = vb->baddr; |
| 161 | |
| 162 | while (pages_done < (mem->size >> PAGE_SHIFT)) { |
| 163 | ret = follow_pfn(vma, user_address, &this_pfn); |
| 164 | if (ret) |
| 165 | break; |
| 166 | |
| 167 | if (pages_done == 0) |
| 168 | mem->dma_handle = this_pfn << PAGE_SHIFT; |
| 169 | else if (this_pfn != (prev_pfn + 1)) |
| 170 | ret = -EFAULT; |
| 171 | |
| 172 | if (ret) |
| 173 | break; |
| 174 | |
| 175 | prev_pfn = this_pfn; |
| 176 | user_address += PAGE_SIZE; |
| 177 | pages_done++; |
| 178 | } |
| 179 | |
| 180 | if (!ret) |
| 181 | mem->is_userptr = 1; |
| 182 | |
| 183 | out_up: |
| 184 | up_read(¤t->mm->mmap_sem); |
| 185 | |
| 186 | return ret; |
| 187 | } |
| 188 | |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 189 | static void *__videobuf_alloc(size_t size) |
| 190 | { |
| 191 | struct videobuf_dma_contig_memory *mem; |
| 192 | struct videobuf_buffer *vb; |
| 193 | |
| 194 | vb = kzalloc(size + sizeof(*mem), GFP_KERNEL); |
| 195 | if (vb) { |
| 196 | mem = vb->priv = ((char *)vb) + size; |
| 197 | mem->magic = MAGIC_DC_MEM; |
| 198 | } |
| 199 | |
| 200 | return vb; |
| 201 | } |
| 202 | |
| 203 | static void *__videobuf_to_vmalloc(struct videobuf_buffer *buf) |
| 204 | { |
| 205 | struct videobuf_dma_contig_memory *mem = buf->priv; |
| 206 | |
| 207 | BUG_ON(!mem); |
| 208 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 209 | |
| 210 | return mem->vaddr; |
| 211 | } |
| 212 | |
| 213 | static int __videobuf_iolock(struct videobuf_queue *q, |
| 214 | struct videobuf_buffer *vb, |
| 215 | struct v4l2_framebuffer *fbuf) |
| 216 | { |
| 217 | struct videobuf_dma_contig_memory *mem = vb->priv; |
| 218 | |
| 219 | BUG_ON(!mem); |
| 220 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 221 | |
| 222 | switch (vb->memory) { |
| 223 | case V4L2_MEMORY_MMAP: |
| 224 | dev_dbg(q->dev, "%s memory method MMAP\n", __func__); |
| 225 | |
| 226 | /* All handling should be done by __videobuf_mmap_mapper() */ |
| 227 | if (!mem->vaddr) { |
| 228 | dev_err(q->dev, "memory is not alloced/mmapped.\n"); |
| 229 | return -EINVAL; |
| 230 | } |
| 231 | break; |
| 232 | case V4L2_MEMORY_USERPTR: |
| 233 | dev_dbg(q->dev, "%s memory method USERPTR\n", __func__); |
| 234 | |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame^] | 235 | /* handle pointer from user space */ |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 236 | if (vb->baddr) |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame^] | 237 | return videobuf_dma_contig_user_get(mem, vb); |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 238 | |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame^] | 239 | /* allocate memory for the read() method */ |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 240 | mem->size = PAGE_ALIGN(vb->size); |
| 241 | mem->vaddr = dma_alloc_coherent(q->dev, mem->size, |
| 242 | &mem->dma_handle, GFP_KERNEL); |
| 243 | if (!mem->vaddr) { |
| 244 | dev_err(q->dev, "dma_alloc_coherent %ld failed\n", |
| 245 | mem->size); |
| 246 | return -ENOMEM; |
| 247 | } |
| 248 | |
| 249 | dev_dbg(q->dev, "dma_alloc_coherent data is at %p (%ld)\n", |
| 250 | mem->vaddr, mem->size); |
| 251 | break; |
| 252 | case V4L2_MEMORY_OVERLAY: |
| 253 | default: |
| 254 | dev_dbg(q->dev, "%s memory method OVERLAY/unknown\n", |
| 255 | __func__); |
| 256 | return -EINVAL; |
| 257 | } |
| 258 | |
| 259 | return 0; |
| 260 | } |
| 261 | |
| 262 | static int __videobuf_sync(struct videobuf_queue *q, |
| 263 | struct videobuf_buffer *buf) |
| 264 | { |
| 265 | struct videobuf_dma_contig_memory *mem = buf->priv; |
| 266 | |
| 267 | BUG_ON(!mem); |
| 268 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 269 | |
| 270 | dma_sync_single_for_cpu(q->dev, mem->dma_handle, mem->size, |
| 271 | DMA_FROM_DEVICE); |
| 272 | return 0; |
| 273 | } |
| 274 | |
| 275 | static int __videobuf_mmap_free(struct videobuf_queue *q) |
| 276 | { |
| 277 | unsigned int i; |
| 278 | |
| 279 | dev_dbg(q->dev, "%s\n", __func__); |
| 280 | for (i = 0; i < VIDEO_MAX_FRAME; i++) { |
| 281 | if (q->bufs[i] && q->bufs[i]->map) |
| 282 | return -EBUSY; |
| 283 | } |
| 284 | |
| 285 | return 0; |
| 286 | } |
| 287 | |
| 288 | static int __videobuf_mmap_mapper(struct videobuf_queue *q, |
| 289 | struct vm_area_struct *vma) |
| 290 | { |
| 291 | struct videobuf_dma_contig_memory *mem; |
| 292 | struct videobuf_mapping *map; |
| 293 | unsigned int first; |
| 294 | int retval; |
| 295 | unsigned long size, offset = vma->vm_pgoff << PAGE_SHIFT; |
| 296 | |
| 297 | dev_dbg(q->dev, "%s\n", __func__); |
| 298 | if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) |
| 299 | return -EINVAL; |
| 300 | |
| 301 | /* look for first buffer to map */ |
| 302 | for (first = 0; first < VIDEO_MAX_FRAME; first++) { |
| 303 | if (!q->bufs[first]) |
| 304 | continue; |
| 305 | |
| 306 | if (V4L2_MEMORY_MMAP != q->bufs[first]->memory) |
| 307 | continue; |
| 308 | if (q->bufs[first]->boff == offset) |
| 309 | break; |
| 310 | } |
| 311 | if (VIDEO_MAX_FRAME == first) { |
| 312 | dev_dbg(q->dev, "invalid user space offset [offset=0x%lx]\n", |
| 313 | offset); |
| 314 | return -EINVAL; |
| 315 | } |
| 316 | |
| 317 | /* create mapping + update buffer list */ |
| 318 | map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL); |
| 319 | if (!map) |
| 320 | return -ENOMEM; |
| 321 | |
| 322 | q->bufs[first]->map = map; |
| 323 | map->start = vma->vm_start; |
| 324 | map->end = vma->vm_end; |
| 325 | map->q = q; |
| 326 | |
| 327 | q->bufs[first]->baddr = vma->vm_start; |
| 328 | |
| 329 | mem = q->bufs[first]->priv; |
| 330 | BUG_ON(!mem); |
| 331 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 332 | |
| 333 | mem->size = PAGE_ALIGN(q->bufs[first]->bsize); |
| 334 | mem->vaddr = dma_alloc_coherent(q->dev, mem->size, |
| 335 | &mem->dma_handle, GFP_KERNEL); |
| 336 | if (!mem->vaddr) { |
| 337 | dev_err(q->dev, "dma_alloc_coherent size %ld failed\n", |
| 338 | mem->size); |
| 339 | goto error; |
| 340 | } |
| 341 | dev_dbg(q->dev, "dma_alloc_coherent data is at addr %p (size %ld)\n", |
| 342 | mem->vaddr, mem->size); |
| 343 | |
| 344 | /* Try to remap memory */ |
| 345 | |
| 346 | size = vma->vm_end - vma->vm_start; |
| 347 | size = (size < mem->size) ? size : mem->size; |
| 348 | |
| 349 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
| 350 | retval = remap_pfn_range(vma, vma->vm_start, |
| 351 | mem->dma_handle >> PAGE_SHIFT, |
| 352 | size, vma->vm_page_prot); |
| 353 | if (retval) { |
| 354 | dev_err(q->dev, "mmap: remap failed with error %d. ", retval); |
| 355 | dma_free_coherent(q->dev, mem->size, |
| 356 | mem->vaddr, mem->dma_handle); |
| 357 | goto error; |
| 358 | } |
| 359 | |
| 360 | vma->vm_ops = &videobuf_vm_ops; |
| 361 | vma->vm_flags |= VM_DONTEXPAND; |
| 362 | vma->vm_private_data = map; |
| 363 | |
| 364 | dev_dbg(q->dev, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n", |
| 365 | map, q, vma->vm_start, vma->vm_end, |
| 366 | (long int) q->bufs[first]->bsize, |
| 367 | vma->vm_pgoff, first); |
| 368 | |
| 369 | videobuf_vm_open(vma); |
| 370 | |
| 371 | return 0; |
| 372 | |
| 373 | error: |
| 374 | kfree(map); |
| 375 | return -ENOMEM; |
| 376 | } |
| 377 | |
| 378 | static int __videobuf_copy_to_user(struct videobuf_queue *q, |
| 379 | char __user *data, size_t count, |
| 380 | int nonblocking) |
| 381 | { |
| 382 | struct videobuf_dma_contig_memory *mem = q->read_buf->priv; |
| 383 | void *vaddr; |
| 384 | |
| 385 | BUG_ON(!mem); |
| 386 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 387 | BUG_ON(!mem->vaddr); |
| 388 | |
| 389 | /* copy to userspace */ |
| 390 | if (count > q->read_buf->size - q->read_off) |
| 391 | count = q->read_buf->size - q->read_off; |
| 392 | |
| 393 | vaddr = mem->vaddr; |
| 394 | |
| 395 | if (copy_to_user(data, vaddr + q->read_off, count)) |
| 396 | return -EFAULT; |
| 397 | |
| 398 | return count; |
| 399 | } |
| 400 | |
| 401 | static int __videobuf_copy_stream(struct videobuf_queue *q, |
| 402 | char __user *data, size_t count, size_t pos, |
| 403 | int vbihack, int nonblocking) |
| 404 | { |
| 405 | unsigned int *fc; |
| 406 | struct videobuf_dma_contig_memory *mem = q->read_buf->priv; |
| 407 | |
| 408 | BUG_ON(!mem); |
| 409 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 410 | |
| 411 | if (vbihack) { |
| 412 | /* dirty, undocumented hack -- pass the frame counter |
| 413 | * within the last four bytes of each vbi data block. |
| 414 | * We need that one to maintain backward compatibility |
| 415 | * to all vbi decoding software out there ... */ |
| 416 | fc = (unsigned int *)mem->vaddr; |
| 417 | fc += (q->read_buf->size >> 2) - 1; |
| 418 | *fc = q->read_buf->field_count >> 1; |
| 419 | dev_dbg(q->dev, "vbihack: %d\n", *fc); |
| 420 | } |
| 421 | |
| 422 | /* copy stuff using the common method */ |
| 423 | count = __videobuf_copy_to_user(q, data, count, nonblocking); |
| 424 | |
| 425 | if ((count == -EFAULT) && (pos == 0)) |
| 426 | return -EFAULT; |
| 427 | |
| 428 | return count; |
| 429 | } |
| 430 | |
| 431 | static struct videobuf_qtype_ops qops = { |
| 432 | .magic = MAGIC_QTYPE_OPS, |
| 433 | |
| 434 | .alloc = __videobuf_alloc, |
| 435 | .iolock = __videobuf_iolock, |
| 436 | .sync = __videobuf_sync, |
| 437 | .mmap_free = __videobuf_mmap_free, |
| 438 | .mmap_mapper = __videobuf_mmap_mapper, |
| 439 | .video_copy_to_user = __videobuf_copy_to_user, |
| 440 | .copy_stream = __videobuf_copy_stream, |
| 441 | .vmalloc = __videobuf_to_vmalloc, |
| 442 | }; |
| 443 | |
| 444 | void videobuf_queue_dma_contig_init(struct videobuf_queue *q, |
| 445 | struct videobuf_queue_ops *ops, |
| 446 | struct device *dev, |
| 447 | spinlock_t *irqlock, |
| 448 | enum v4l2_buf_type type, |
| 449 | enum v4l2_field field, |
| 450 | unsigned int msize, |
| 451 | void *priv) |
| 452 | { |
| 453 | videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize, |
| 454 | priv, &qops); |
| 455 | } |
| 456 | EXPORT_SYMBOL_GPL(videobuf_queue_dma_contig_init); |
| 457 | |
| 458 | dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf) |
| 459 | { |
| 460 | struct videobuf_dma_contig_memory *mem = buf->priv; |
| 461 | |
| 462 | BUG_ON(!mem); |
| 463 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 464 | |
| 465 | return mem->dma_handle; |
| 466 | } |
| 467 | EXPORT_SYMBOL_GPL(videobuf_to_dma_contig); |
| 468 | |
| 469 | void videobuf_dma_contig_free(struct videobuf_queue *q, |
| 470 | struct videobuf_buffer *buf) |
| 471 | { |
| 472 | struct videobuf_dma_contig_memory *mem = buf->priv; |
| 473 | |
| 474 | /* mmapped memory can't be freed here, otherwise mmapped region |
| 475 | would be released, while still needed. In this case, the memory |
| 476 | release should happen inside videobuf_vm_close(). |
| 477 | So, it should free memory only if the memory were allocated for |
| 478 | read() operation. |
| 479 | */ |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame^] | 480 | if (buf->memory != V4L2_MEMORY_USERPTR) |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 481 | return; |
| 482 | |
| 483 | if (!mem) |
| 484 | return; |
| 485 | |
| 486 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 487 | |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame^] | 488 | /* handle user space pointer case */ |
| 489 | if (buf->baddr) { |
| 490 | videobuf_dma_contig_user_put(mem); |
| 491 | return; |
| 492 | } |
| 493 | |
| 494 | /* read() method */ |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 495 | dma_free_coherent(q->dev, mem->size, mem->vaddr, mem->dma_handle); |
| 496 | mem->vaddr = NULL; |
| 497 | } |
| 498 | EXPORT_SYMBOL_GPL(videobuf_dma_contig_free); |
| 499 | |
| 500 | MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers"); |
| 501 | MODULE_AUTHOR("Magnus Damm"); |
| 502 | MODULE_LICENSE("GPL"); |