| /* |
| * helper functions for physically contiguous capture buffers |
| * |
| * The functions support hardware lacking scatter gather support |
| * (i.e. the buffers must be linear in physical memory) |
| * |
| * Copyright (c) 2008 Magnus Damm |
| * |
| * Based on videobuf-vmalloc.c, |
| * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/mm.h> |
| #include <linux/pagemap.h> |
| #include <linux/dma-mapping.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <media/videobuf-dma-contig.h> |
| |
| struct videobuf_dma_contig_memory { |
| u32 magic; |
| void *vaddr; |
| dma_addr_t dma_handle; |
| unsigned long size; |
| int is_userptr; |
| }; |
| |
| #define MAGIC_DC_MEM 0x0733ac61 |
| #define MAGIC_CHECK(is, should) \ |
| if (unlikely((is) != (should))) { \ |
| pr_err("magic mismatch: %x expected %x\n", (is), (should)); \ |
| BUG(); \ |
| } |
| |
| static void |
| videobuf_vm_open(struct vm_area_struct *vma) |
| { |
| struct videobuf_mapping *map = vma->vm_private_data; |
| |
| dev_dbg(map->q->dev, "vm_open %p [count=%u,vma=%08lx-%08lx]\n", |
| map, map->count, vma->vm_start, vma->vm_end); |
| |
| map->count++; |
| } |
| |
| static void videobuf_vm_close(struct vm_area_struct *vma) |
| { |
| struct videobuf_mapping *map = vma->vm_private_data; |
| struct videobuf_queue *q = map->q; |
| int i; |
| |
| dev_dbg(map->q->dev, "vm_close %p [count=%u,vma=%08lx-%08lx]\n", |
| map, map->count, vma->vm_start, vma->vm_end); |
| |
| map->count--; |
| if (0 == map->count) { |
| struct videobuf_dma_contig_memory *mem; |
| |
| dev_dbg(map->q->dev, "munmap %p q=%p\n", map, q); |
| mutex_lock(&q->vb_lock); |
| |
| /* We need first to cancel streams, before unmapping */ |
| if (q->streaming) |
| videobuf_queue_cancel(q); |
| |
| for (i = 0; i < VIDEO_MAX_FRAME; i++) { |
| if (NULL == q->bufs[i]) |
| continue; |
| |
| if (q->bufs[i]->map != map) |
| continue; |
| |
| mem = q->bufs[i]->priv; |
| if (mem) { |
| /* This callback is called only if kernel has |
| allocated memory and this memory is mmapped. |
| In this case, memory should be freed, |
| in order to do memory unmap. |
| */ |
| |
| MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| |
| /* vfree is not atomic - can't be |
| called with IRQ's disabled |
| */ |
| dev_dbg(map->q->dev, "buf[%d] freeing %p\n", |
| i, mem->vaddr); |
| |
| dma_free_coherent(q->dev, mem->size, |
| mem->vaddr, mem->dma_handle); |
| mem->vaddr = NULL; |
| } |
| |
| q->bufs[i]->map = NULL; |
| q->bufs[i]->baddr = 0; |
| } |
| |
| kfree(map); |
| |
| mutex_unlock(&q->vb_lock); |
| } |
| } |
| |
| static const struct vm_operations_struct videobuf_vm_ops = { |
| .open = videobuf_vm_open, |
| .close = videobuf_vm_close, |
| }; |
| |
| /** |
| * videobuf_dma_contig_user_put() - reset pointer to user space buffer |
| * @mem: per-buffer private videobuf-dma-contig data |
| * |
| * This function resets the user space pointer |
| */ |
| static void videobuf_dma_contig_user_put(struct videobuf_dma_contig_memory *mem) |
| { |
| mem->is_userptr = 0; |
| mem->dma_handle = 0; |
| mem->size = 0; |
| } |
| |
| /** |
| * videobuf_dma_contig_user_get() - setup user space memory pointer |
| * @mem: per-buffer private videobuf-dma-contig data |
| * @vb: video buffer to map |
| * |
| * This function validates and sets up a pointer to user space memory. |
| * Only physically contiguous pfn-mapped memory is accepted. |
| * |
| * Returns 0 if successful. |
| */ |
| static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem, |
| struct videobuf_buffer *vb) |
| { |
| struct mm_struct *mm = current->mm; |
| struct vm_area_struct *vma; |
| unsigned long prev_pfn, this_pfn; |
| unsigned long pages_done, user_address; |
| unsigned int offset; |
| int ret; |
| |
| offset = vb->baddr & ~PAGE_MASK; |
| mem->size = PAGE_ALIGN(vb->size + offset); |
| mem->is_userptr = 0; |
| ret = -EINVAL; |
| |
| down_read(&mm->mmap_sem); |
| |
| vma = find_vma(mm, vb->baddr); |
| if (!vma) |
| goto out_up; |
| |
| if ((vb->baddr + mem->size) > vma->vm_end) |
| goto out_up; |
| |
| pages_done = 0; |
| prev_pfn = 0; /* kill warning */ |
| user_address = vb->baddr; |
| |
| while (pages_done < (mem->size >> PAGE_SHIFT)) { |
| ret = follow_pfn(vma, user_address, &this_pfn); |
| if (ret) |
| break; |
| |
| if (pages_done == 0) |
| mem->dma_handle = (this_pfn << PAGE_SHIFT) + offset; |
| else if (this_pfn != (prev_pfn + 1)) |
| ret = -EFAULT; |
| |
| if (ret) |
| break; |
| |
| prev_pfn = this_pfn; |
| user_address += PAGE_SIZE; |
| pages_done++; |
| } |
| |
| if (!ret) |
| mem->is_userptr = 1; |
| |
| out_up: |
| up_read(¤t->mm->mmap_sem); |
| |
| return ret; |
| } |
| |
| static void *__videobuf_alloc(size_t size) |
| { |
| struct videobuf_dma_contig_memory *mem; |
| struct videobuf_buffer *vb; |
| |
| vb = kzalloc(size + sizeof(*mem), GFP_KERNEL); |
| if (vb) { |
| mem = vb->priv = ((char *)vb) + size; |
| mem->magic = MAGIC_DC_MEM; |
| } |
| |
| return vb; |
| } |
| |
| static void *__videobuf_to_vmalloc(struct videobuf_buffer *buf) |
| { |
| struct videobuf_dma_contig_memory *mem = buf->priv; |
| |
| BUG_ON(!mem); |
| MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| |
| return mem->vaddr; |
| } |
| |
| static int __videobuf_iolock(struct videobuf_queue *q, |
| struct videobuf_buffer *vb, |
| struct v4l2_framebuffer *fbuf) |
| { |
| struct videobuf_dma_contig_memory *mem = vb->priv; |
| |
| BUG_ON(!mem); |
| MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| |
| switch (vb->memory) { |
| case V4L2_MEMORY_MMAP: |
| dev_dbg(q->dev, "%s memory method MMAP\n", __func__); |
| |
| /* All handling should be done by __videobuf_mmap_mapper() */ |
| if (!mem->vaddr) { |
| dev_err(q->dev, "memory is not alloced/mmapped.\n"); |
| return -EINVAL; |
| } |
| break; |
| case V4L2_MEMORY_USERPTR: |
| dev_dbg(q->dev, "%s memory method USERPTR\n", __func__); |
| |
| /* handle pointer from user space */ |
| if (vb->baddr) |
| return videobuf_dma_contig_user_get(mem, vb); |
| |
| /* allocate memory for the read() method */ |
| mem->size = PAGE_ALIGN(vb->size); |
| mem->vaddr = dma_alloc_coherent(q->dev, mem->size, |
| &mem->dma_handle, GFP_KERNEL); |
| if (!mem->vaddr) { |
| dev_err(q->dev, "dma_alloc_coherent %ld failed\n", |
| mem->size); |
| return -ENOMEM; |
| } |
| |
| dev_dbg(q->dev, "dma_alloc_coherent data is at %p (%ld)\n", |
| mem->vaddr, mem->size); |
| break; |
| case V4L2_MEMORY_OVERLAY: |
| default: |
| dev_dbg(q->dev, "%s memory method OVERLAY/unknown\n", |
| __func__); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static int __videobuf_mmap_mapper(struct videobuf_queue *q, |
| struct vm_area_struct *vma) |
| { |
| struct videobuf_dma_contig_memory *mem; |
| struct videobuf_mapping *map; |
| unsigned int first; |
| int retval; |
| unsigned long size, offset = vma->vm_pgoff << PAGE_SHIFT; |
| |
| dev_dbg(q->dev, "%s\n", __func__); |
| if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) |
| return -EINVAL; |
| |
| /* look for first buffer to map */ |
| for (first = 0; first < VIDEO_MAX_FRAME; first++) { |
| if (!q->bufs[first]) |
| continue; |
| |
| if (V4L2_MEMORY_MMAP != q->bufs[first]->memory) |
| continue; |
| if (q->bufs[first]->boff == offset) |
| break; |
| } |
| if (VIDEO_MAX_FRAME == first) { |
| dev_dbg(q->dev, "invalid user space offset [offset=0x%lx]\n", |
| offset); |
| return -EINVAL; |
| } |
| |
| /* create mapping + update buffer list */ |
| map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL); |
| if (!map) |
| return -ENOMEM; |
| |
| q->bufs[first]->map = map; |
| map->start = vma->vm_start; |
| map->end = vma->vm_end; |
| map->q = q; |
| |
| q->bufs[first]->baddr = vma->vm_start; |
| |
| mem = q->bufs[first]->priv; |
| BUG_ON(!mem); |
| MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| |
| mem->size = PAGE_ALIGN(q->bufs[first]->bsize); |
| mem->vaddr = dma_alloc_coherent(q->dev, mem->size, |
| &mem->dma_handle, GFP_KERNEL); |
| if (!mem->vaddr) { |
| dev_err(q->dev, "dma_alloc_coherent size %ld failed\n", |
| mem->size); |
| goto error; |
| } |
| dev_dbg(q->dev, "dma_alloc_coherent data is at addr %p (size %ld)\n", |
| mem->vaddr, mem->size); |
| |
| /* Try to remap memory */ |
| |
| size = vma->vm_end - vma->vm_start; |
| size = (size < mem->size) ? size : mem->size; |
| |
| vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
| retval = remap_pfn_range(vma, vma->vm_start, |
| mem->dma_handle >> PAGE_SHIFT, |
| size, vma->vm_page_prot); |
| if (retval) { |
| dev_err(q->dev, "mmap: remap failed with error %d. ", retval); |
| dma_free_coherent(q->dev, mem->size, |
| mem->vaddr, mem->dma_handle); |
| goto error; |
| } |
| |
| vma->vm_ops = &videobuf_vm_ops; |
| vma->vm_flags |= VM_DONTEXPAND; |
| vma->vm_private_data = map; |
| |
| dev_dbg(q->dev, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n", |
| map, q, vma->vm_start, vma->vm_end, |
| (long int) q->bufs[first]->bsize, |
| vma->vm_pgoff, first); |
| |
| videobuf_vm_open(vma); |
| |
| return 0; |
| |
| error: |
| kfree(map); |
| return -ENOMEM; |
| } |
| |
| static int __videobuf_copy_to_user(struct videobuf_queue *q, |
| char __user *data, size_t count, |
| int nonblocking) |
| { |
| struct videobuf_dma_contig_memory *mem = q->read_buf->priv; |
| void *vaddr; |
| |
| BUG_ON(!mem); |
| MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| BUG_ON(!mem->vaddr); |
| |
| /* copy to userspace */ |
| if (count > q->read_buf->size - q->read_off) |
| count = q->read_buf->size - q->read_off; |
| |
| vaddr = mem->vaddr; |
| |
| if (copy_to_user(data, vaddr + q->read_off, count)) |
| return -EFAULT; |
| |
| return count; |
| } |
| |
| static int __videobuf_copy_stream(struct videobuf_queue *q, |
| char __user *data, size_t count, size_t pos, |
| int vbihack, int nonblocking) |
| { |
| unsigned int *fc; |
| struct videobuf_dma_contig_memory *mem = q->read_buf->priv; |
| |
| BUG_ON(!mem); |
| MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| |
| if (vbihack) { |
| /* dirty, undocumented hack -- pass the frame counter |
| * within the last four bytes of each vbi data block. |
| * We need that one to maintain backward compatibility |
| * to all vbi decoding software out there ... */ |
| fc = (unsigned int *)mem->vaddr; |
| fc += (q->read_buf->size >> 2) - 1; |
| *fc = q->read_buf->field_count >> 1; |
| dev_dbg(q->dev, "vbihack: %d\n", *fc); |
| } |
| |
| /* copy stuff using the common method */ |
| count = __videobuf_copy_to_user(q, data, count, nonblocking); |
| |
| if ((count == -EFAULT) && (pos == 0)) |
| return -EFAULT; |
| |
| return count; |
| } |
| |
| static struct videobuf_qtype_ops qops = { |
| .magic = MAGIC_QTYPE_OPS, |
| |
| .alloc = __videobuf_alloc, |
| .iolock = __videobuf_iolock, |
| .mmap_mapper = __videobuf_mmap_mapper, |
| .video_copy_to_user = __videobuf_copy_to_user, |
| .copy_stream = __videobuf_copy_stream, |
| .vmalloc = __videobuf_to_vmalloc, |
| }; |
| |
| void videobuf_queue_dma_contig_init(struct videobuf_queue *q, |
| const struct videobuf_queue_ops *ops, |
| struct device *dev, |
| spinlock_t *irqlock, |
| enum v4l2_buf_type type, |
| enum v4l2_field field, |
| unsigned int msize, |
| void *priv) |
| { |
| videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize, |
| priv, &qops); |
| } |
| EXPORT_SYMBOL_GPL(videobuf_queue_dma_contig_init); |
| |
| dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf) |
| { |
| struct videobuf_dma_contig_memory *mem = buf->priv; |
| |
| BUG_ON(!mem); |
| MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| |
| return mem->dma_handle; |
| } |
| EXPORT_SYMBOL_GPL(videobuf_to_dma_contig); |
| |
| void videobuf_dma_contig_free(struct videobuf_queue *q, |
| struct videobuf_buffer *buf) |
| { |
| struct videobuf_dma_contig_memory *mem = buf->priv; |
| |
| /* mmapped memory can't be freed here, otherwise mmapped region |
| would be released, while still needed. In this case, the memory |
| release should happen inside videobuf_vm_close(). |
| So, it should free memory only if the memory were allocated for |
| read() operation. |
| */ |
| if (buf->memory != V4L2_MEMORY_USERPTR) |
| return; |
| |
| if (!mem) |
| return; |
| |
| MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); |
| |
| /* handle user space pointer case */ |
| if (buf->baddr) { |
| videobuf_dma_contig_user_put(mem); |
| return; |
| } |
| |
| /* read() method */ |
| dma_free_coherent(q->dev, mem->size, mem->vaddr, mem->dma_handle); |
| mem->vaddr = NULL; |
| } |
| EXPORT_SYMBOL_GPL(videobuf_dma_contig_free); |
| |
| MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers"); |
| MODULE_AUTHOR("Magnus Damm"); |
| MODULE_LICENSE("GPL"); |