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> |
Guennadi Liakhovetski | f39c1ab | 2009-11-09 16:11:34 -0300 | [diff] [blame] | 22 | #include <linux/sched.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 23 | #include <linux/slab.h> |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 24 | #include <media/videobuf-dma-contig.h> |
| 25 | |
| 26 | struct videobuf_dma_contig_memory { |
| 27 | u32 magic; |
| 28 | void *vaddr; |
| 29 | dma_addr_t dma_handle; |
| 30 | unsigned long size; |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame] | 31 | int is_userptr; |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 32 | }; |
| 33 | |
| 34 | #define MAGIC_DC_MEM 0x0733ac61 |
Guennadi Liakhovetski | c60f2b5 | 2008-07-17 17:30:47 -0300 | [diff] [blame] | 35 | #define MAGIC_CHECK(is, should) \ |
| 36 | if (unlikely((is) != (should))) { \ |
| 37 | pr_err("magic mismatch: %x expected %x\n", (is), (should)); \ |
| 38 | BUG(); \ |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 39 | } |
| 40 | |
| 41 | static void |
| 42 | videobuf_vm_open(struct vm_area_struct *vma) |
| 43 | { |
| 44 | struct videobuf_mapping *map = vma->vm_private_data; |
| 45 | |
| 46 | dev_dbg(map->q->dev, "vm_open %p [count=%u,vma=%08lx-%08lx]\n", |
| 47 | map, map->count, vma->vm_start, vma->vm_end); |
| 48 | |
| 49 | map->count++; |
| 50 | } |
| 51 | |
| 52 | static void videobuf_vm_close(struct vm_area_struct *vma) |
| 53 | { |
| 54 | struct videobuf_mapping *map = vma->vm_private_data; |
| 55 | struct videobuf_queue *q = map->q; |
| 56 | int i; |
| 57 | |
| 58 | dev_dbg(map->q->dev, "vm_close %p [count=%u,vma=%08lx-%08lx]\n", |
| 59 | map, map->count, vma->vm_start, vma->vm_end); |
| 60 | |
| 61 | map->count--; |
| 62 | if (0 == map->count) { |
| 63 | struct videobuf_dma_contig_memory *mem; |
| 64 | |
| 65 | dev_dbg(map->q->dev, "munmap %p q=%p\n", map, q); |
| 66 | mutex_lock(&q->vb_lock); |
| 67 | |
| 68 | /* We need first to cancel streams, before unmapping */ |
| 69 | if (q->streaming) |
| 70 | videobuf_queue_cancel(q); |
| 71 | |
| 72 | for (i = 0; i < VIDEO_MAX_FRAME; i++) { |
| 73 | if (NULL == q->bufs[i]) |
| 74 | continue; |
| 75 | |
| 76 | if (q->bufs[i]->map != map) |
| 77 | continue; |
| 78 | |
| 79 | mem = q->bufs[i]->priv; |
| 80 | if (mem) { |
| 81 | /* This callback is called only if kernel has |
| 82 | allocated memory and this memory is mmapped. |
| 83 | In this case, memory should be freed, |
| 84 | in order to do memory unmap. |
| 85 | */ |
| 86 | |
| 87 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 88 | |
| 89 | /* vfree is not atomic - can't be |
| 90 | called with IRQ's disabled |
| 91 | */ |
| 92 | dev_dbg(map->q->dev, "buf[%d] freeing %p\n", |
| 93 | i, mem->vaddr); |
| 94 | |
| 95 | dma_free_coherent(q->dev, mem->size, |
| 96 | mem->vaddr, mem->dma_handle); |
| 97 | mem->vaddr = NULL; |
| 98 | } |
| 99 | |
| 100 | q->bufs[i]->map = NULL; |
| 101 | q->bufs[i]->baddr = 0; |
| 102 | } |
| 103 | |
| 104 | kfree(map); |
| 105 | |
| 106 | mutex_unlock(&q->vb_lock); |
| 107 | } |
| 108 | } |
| 109 | |
Alexey Dobriyan | f0f37e2 | 2009-09-27 22:29:37 +0400 | [diff] [blame] | 110 | static const struct vm_operations_struct videobuf_vm_ops = { |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 111 | .open = videobuf_vm_open, |
| 112 | .close = videobuf_vm_close, |
| 113 | }; |
| 114 | |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame] | 115 | /** |
| 116 | * videobuf_dma_contig_user_put() - reset pointer to user space buffer |
| 117 | * @mem: per-buffer private videobuf-dma-contig data |
| 118 | * |
| 119 | * This function resets the user space pointer |
| 120 | */ |
| 121 | static void videobuf_dma_contig_user_put(struct videobuf_dma_contig_memory *mem) |
| 122 | { |
| 123 | mem->is_userptr = 0; |
| 124 | mem->dma_handle = 0; |
| 125 | mem->size = 0; |
| 126 | } |
| 127 | |
| 128 | /** |
| 129 | * videobuf_dma_contig_user_get() - setup user space memory pointer |
| 130 | * @mem: per-buffer private videobuf-dma-contig data |
| 131 | * @vb: video buffer to map |
| 132 | * |
| 133 | * This function validates and sets up a pointer to user space memory. |
| 134 | * Only physically contiguous pfn-mapped memory is accepted. |
| 135 | * |
| 136 | * Returns 0 if successful. |
| 137 | */ |
| 138 | static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem, |
| 139 | struct videobuf_buffer *vb) |
| 140 | { |
| 141 | struct mm_struct *mm = current->mm; |
| 142 | struct vm_area_struct *vma; |
| 143 | unsigned long prev_pfn, this_pfn; |
| 144 | unsigned long pages_done, user_address; |
Muralidharan Karicheri | 31bedfa | 2009-12-10 16:47:48 -0300 | [diff] [blame] | 145 | unsigned int offset; |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame] | 146 | int ret; |
| 147 | |
Muralidharan Karicheri | 31bedfa | 2009-12-10 16:47:48 -0300 | [diff] [blame] | 148 | offset = vb->baddr & ~PAGE_MASK; |
| 149 | mem->size = PAGE_ALIGN(vb->size + offset); |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame] | 150 | mem->is_userptr = 0; |
| 151 | ret = -EINVAL; |
| 152 | |
| 153 | down_read(&mm->mmap_sem); |
| 154 | |
| 155 | vma = find_vma(mm, vb->baddr); |
| 156 | if (!vma) |
| 157 | goto out_up; |
| 158 | |
| 159 | if ((vb->baddr + mem->size) > vma->vm_end) |
| 160 | goto out_up; |
| 161 | |
| 162 | pages_done = 0; |
| 163 | prev_pfn = 0; /* kill warning */ |
| 164 | user_address = vb->baddr; |
| 165 | |
| 166 | while (pages_done < (mem->size >> PAGE_SHIFT)) { |
| 167 | ret = follow_pfn(vma, user_address, &this_pfn); |
| 168 | if (ret) |
| 169 | break; |
| 170 | |
| 171 | if (pages_done == 0) |
Muralidharan Karicheri | 31bedfa | 2009-12-10 16:47:48 -0300 | [diff] [blame] | 172 | mem->dma_handle = (this_pfn << PAGE_SHIFT) + offset; |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame] | 173 | else if (this_pfn != (prev_pfn + 1)) |
| 174 | ret = -EFAULT; |
| 175 | |
| 176 | if (ret) |
| 177 | break; |
| 178 | |
| 179 | prev_pfn = this_pfn; |
| 180 | user_address += PAGE_SIZE; |
| 181 | pages_done++; |
| 182 | } |
| 183 | |
| 184 | if (!ret) |
| 185 | mem->is_userptr = 1; |
| 186 | |
| 187 | out_up: |
| 188 | up_read(¤t->mm->mmap_sem); |
| 189 | |
| 190 | return ret; |
| 191 | } |
| 192 | |
Hans Verkuil | a4cf4ca | 2010-03-28 08:09:44 -0300 | [diff] [blame] | 193 | static struct videobuf_buffer *__videobuf_alloc(size_t size) |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 194 | { |
| 195 | struct videobuf_dma_contig_memory *mem; |
| 196 | struct videobuf_buffer *vb; |
| 197 | |
| 198 | vb = kzalloc(size + sizeof(*mem), GFP_KERNEL); |
| 199 | if (vb) { |
| 200 | mem = vb->priv = ((char *)vb) + size; |
| 201 | mem->magic = MAGIC_DC_MEM; |
| 202 | } |
| 203 | |
| 204 | return vb; |
| 205 | } |
| 206 | |
Hans Verkuil | 037c75e | 2010-03-28 08:18:37 -0300 | [diff] [blame] | 207 | static void *__videobuf_to_vaddr(struct videobuf_buffer *buf) |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 208 | { |
| 209 | struct videobuf_dma_contig_memory *mem = buf->priv; |
| 210 | |
| 211 | BUG_ON(!mem); |
| 212 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 213 | |
| 214 | return mem->vaddr; |
| 215 | } |
| 216 | |
| 217 | static int __videobuf_iolock(struct videobuf_queue *q, |
| 218 | struct videobuf_buffer *vb, |
| 219 | struct v4l2_framebuffer *fbuf) |
| 220 | { |
| 221 | struct videobuf_dma_contig_memory *mem = vb->priv; |
| 222 | |
| 223 | BUG_ON(!mem); |
| 224 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 225 | |
| 226 | switch (vb->memory) { |
| 227 | case V4L2_MEMORY_MMAP: |
| 228 | dev_dbg(q->dev, "%s memory method MMAP\n", __func__); |
| 229 | |
| 230 | /* All handling should be done by __videobuf_mmap_mapper() */ |
| 231 | if (!mem->vaddr) { |
| 232 | dev_err(q->dev, "memory is not alloced/mmapped.\n"); |
| 233 | return -EINVAL; |
| 234 | } |
| 235 | break; |
| 236 | case V4L2_MEMORY_USERPTR: |
| 237 | dev_dbg(q->dev, "%s memory method USERPTR\n", __func__); |
| 238 | |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame] | 239 | /* handle pointer from user space */ |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 240 | if (vb->baddr) |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame] | 241 | return videobuf_dma_contig_user_get(mem, vb); |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 242 | |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame] | 243 | /* allocate memory for the read() method */ |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 244 | mem->size = PAGE_ALIGN(vb->size); |
| 245 | mem->vaddr = dma_alloc_coherent(q->dev, mem->size, |
| 246 | &mem->dma_handle, GFP_KERNEL); |
| 247 | if (!mem->vaddr) { |
| 248 | dev_err(q->dev, "dma_alloc_coherent %ld failed\n", |
| 249 | mem->size); |
| 250 | return -ENOMEM; |
| 251 | } |
| 252 | |
| 253 | dev_dbg(q->dev, "dma_alloc_coherent data is at %p (%ld)\n", |
| 254 | mem->vaddr, mem->size); |
| 255 | break; |
| 256 | case V4L2_MEMORY_OVERLAY: |
| 257 | default: |
| 258 | dev_dbg(q->dev, "%s memory method OVERLAY/unknown\n", |
| 259 | __func__); |
| 260 | return -EINVAL; |
| 261 | } |
| 262 | |
| 263 | return 0; |
| 264 | } |
| 265 | |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 266 | static int __videobuf_mmap_mapper(struct videobuf_queue *q, |
| 267 | struct vm_area_struct *vma) |
| 268 | { |
| 269 | struct videobuf_dma_contig_memory *mem; |
| 270 | struct videobuf_mapping *map; |
| 271 | unsigned int first; |
| 272 | int retval; |
| 273 | unsigned long size, offset = vma->vm_pgoff << PAGE_SHIFT; |
| 274 | |
| 275 | dev_dbg(q->dev, "%s\n", __func__); |
| 276 | if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) |
| 277 | return -EINVAL; |
| 278 | |
| 279 | /* look for first buffer to map */ |
| 280 | for (first = 0; first < VIDEO_MAX_FRAME; first++) { |
| 281 | if (!q->bufs[first]) |
| 282 | continue; |
| 283 | |
| 284 | if (V4L2_MEMORY_MMAP != q->bufs[first]->memory) |
| 285 | continue; |
| 286 | if (q->bufs[first]->boff == offset) |
| 287 | break; |
| 288 | } |
| 289 | if (VIDEO_MAX_FRAME == first) { |
| 290 | dev_dbg(q->dev, "invalid user space offset [offset=0x%lx]\n", |
| 291 | offset); |
| 292 | return -EINVAL; |
| 293 | } |
| 294 | |
| 295 | /* create mapping + update buffer list */ |
| 296 | map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL); |
| 297 | if (!map) |
| 298 | return -ENOMEM; |
| 299 | |
| 300 | q->bufs[first]->map = map; |
| 301 | map->start = vma->vm_start; |
| 302 | map->end = vma->vm_end; |
| 303 | map->q = q; |
| 304 | |
| 305 | q->bufs[first]->baddr = vma->vm_start; |
| 306 | |
| 307 | mem = q->bufs[first]->priv; |
| 308 | BUG_ON(!mem); |
| 309 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 310 | |
| 311 | mem->size = PAGE_ALIGN(q->bufs[first]->bsize); |
| 312 | mem->vaddr = dma_alloc_coherent(q->dev, mem->size, |
| 313 | &mem->dma_handle, GFP_KERNEL); |
| 314 | if (!mem->vaddr) { |
| 315 | dev_err(q->dev, "dma_alloc_coherent size %ld failed\n", |
| 316 | mem->size); |
| 317 | goto error; |
| 318 | } |
| 319 | dev_dbg(q->dev, "dma_alloc_coherent data is at addr %p (size %ld)\n", |
| 320 | mem->vaddr, mem->size); |
| 321 | |
| 322 | /* Try to remap memory */ |
| 323 | |
| 324 | size = vma->vm_end - vma->vm_start; |
| 325 | size = (size < mem->size) ? size : mem->size; |
| 326 | |
| 327 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
| 328 | retval = remap_pfn_range(vma, vma->vm_start, |
| 329 | mem->dma_handle >> PAGE_SHIFT, |
| 330 | size, vma->vm_page_prot); |
| 331 | if (retval) { |
| 332 | dev_err(q->dev, "mmap: remap failed with error %d. ", retval); |
| 333 | dma_free_coherent(q->dev, mem->size, |
| 334 | mem->vaddr, mem->dma_handle); |
| 335 | goto error; |
| 336 | } |
| 337 | |
| 338 | vma->vm_ops = &videobuf_vm_ops; |
| 339 | vma->vm_flags |= VM_DONTEXPAND; |
| 340 | vma->vm_private_data = map; |
| 341 | |
| 342 | dev_dbg(q->dev, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n", |
| 343 | map, q, vma->vm_start, vma->vm_end, |
| 344 | (long int) q->bufs[first]->bsize, |
| 345 | vma->vm_pgoff, first); |
| 346 | |
| 347 | videobuf_vm_open(vma); |
| 348 | |
| 349 | return 0; |
| 350 | |
| 351 | error: |
| 352 | kfree(map); |
| 353 | return -ENOMEM; |
| 354 | } |
| 355 | |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 356 | static struct videobuf_qtype_ops qops = { |
| 357 | .magic = MAGIC_QTYPE_OPS, |
| 358 | |
| 359 | .alloc = __videobuf_alloc, |
| 360 | .iolock = __videobuf_iolock, |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 361 | .mmap_mapper = __videobuf_mmap_mapper, |
Hans Verkuil | 037c75e | 2010-03-28 08:18:37 -0300 | [diff] [blame] | 362 | .vaddr = __videobuf_to_vaddr, |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 363 | }; |
| 364 | |
| 365 | void videobuf_queue_dma_contig_init(struct videobuf_queue *q, |
Jonathan Corbet | 38a54f3 | 2009-11-17 19:43:41 -0300 | [diff] [blame] | 366 | const struct videobuf_queue_ops *ops, |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 367 | struct device *dev, |
| 368 | spinlock_t *irqlock, |
| 369 | enum v4l2_buf_type type, |
| 370 | enum v4l2_field field, |
| 371 | unsigned int msize, |
| 372 | void *priv) |
| 373 | { |
| 374 | videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize, |
| 375 | priv, &qops); |
| 376 | } |
| 377 | EXPORT_SYMBOL_GPL(videobuf_queue_dma_contig_init); |
| 378 | |
| 379 | dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf) |
| 380 | { |
| 381 | struct videobuf_dma_contig_memory *mem = buf->priv; |
| 382 | |
| 383 | BUG_ON(!mem); |
| 384 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 385 | |
| 386 | return mem->dma_handle; |
| 387 | } |
| 388 | EXPORT_SYMBOL_GPL(videobuf_to_dma_contig); |
| 389 | |
| 390 | void videobuf_dma_contig_free(struct videobuf_queue *q, |
| 391 | struct videobuf_buffer *buf) |
| 392 | { |
| 393 | struct videobuf_dma_contig_memory *mem = buf->priv; |
| 394 | |
| 395 | /* mmapped memory can't be freed here, otherwise mmapped region |
| 396 | would be released, while still needed. In this case, the memory |
| 397 | release should happen inside videobuf_vm_close(). |
| 398 | So, it should free memory only if the memory were allocated for |
| 399 | read() operation. |
| 400 | */ |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame] | 401 | if (buf->memory != V4L2_MEMORY_USERPTR) |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 402 | return; |
| 403 | |
| 404 | if (!mem) |
| 405 | return; |
| 406 | |
| 407 | MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| 408 | |
Magnus Damm | 720b17e | 2009-06-16 15:32:36 -0700 | [diff] [blame] | 409 | /* handle user space pointer case */ |
| 410 | if (buf->baddr) { |
| 411 | videobuf_dma_contig_user_put(mem); |
| 412 | return; |
| 413 | } |
| 414 | |
| 415 | /* read() method */ |
Magnus Damm | 2cc45cf | 2008-07-16 21:33:39 -0300 | [diff] [blame] | 416 | dma_free_coherent(q->dev, mem->size, mem->vaddr, mem->dma_handle); |
| 417 | mem->vaddr = NULL; |
| 418 | } |
| 419 | EXPORT_SYMBOL_GPL(videobuf_dma_contig_free); |
| 420 | |
| 421 | MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers"); |
| 422 | MODULE_AUTHOR("Magnus Damm"); |
| 423 | MODULE_LICENSE("GPL"); |