diff options
Diffstat (limited to 'drivers/media/video/videobuf-dma-sg.c')
-rw-r--r-- | drivers/media/video/videobuf-dma-sg.c | 726 |
1 files changed, 726 insertions, 0 deletions
diff --git a/drivers/media/video/videobuf-dma-sg.c b/drivers/media/video/videobuf-dma-sg.c new file mode 100644 index 00000000000..8bb7fdd306d --- /dev/null +++ b/drivers/media/video/videobuf-dma-sg.c @@ -0,0 +1,726 @@ +/* + * helper functions for PCI DMA video4linux capture buffers + * + * The functions expect the hardware being able to scatter gatter + * (i.e. the buffers are not linear in physical memory, but fragmented + * into PAGE_SIZE chunks). They also assume the driver does not need + * to touch the video data. + * + * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org> + * + * Highly based on video-buf written originally by: + * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org> + * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org> + * (c) 2006 Ted Walther and John Sokol + * + * 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/moduleparam.h> +#include <linux/slab.h> +#include <linux/interrupt.h> + +#include <linux/pci.h> +#include <linux/vmalloc.h> +#include <linux/pagemap.h> +#include <asm/page.h> +#include <asm/pgtable.h> + +#include <media/videobuf-dma-sg.h> + +#define MAGIC_DMABUF 0x19721112 +#define MAGIC_SG_MEM 0x17890714 + +#define MAGIC_CHECK(is,should) if (unlikely((is) != (should))) \ + { printk(KERN_ERR "magic mismatch: %x (expected %x)\n",is,should); BUG(); } + +static int debug = 0; +module_param(debug, int, 0644); + +MODULE_DESCRIPTION("helper module to manage video4linux pci dma sg buffers"); +MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>"); +MODULE_LICENSE("GPL"); + +#define dprintk(level, fmt, arg...) if (debug >= level) \ + printk(KERN_DEBUG "vbuf-sg: " fmt , ## arg) + +/* --------------------------------------------------------------------- */ + +struct scatterlist* +videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages) +{ + struct scatterlist *sglist; + struct page *pg; + int i; + + sglist = kcalloc(nr_pages, sizeof(struct scatterlist), GFP_KERNEL); + if (NULL == sglist) + return NULL; + for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) { + pg = vmalloc_to_page(virt); + if (NULL == pg) + goto err; + BUG_ON(PageHighMem(pg)); + sglist[i].page = pg; + sglist[i].length = PAGE_SIZE; + } + return sglist; + + err: + kfree(sglist); + return NULL; +} + +struct scatterlist* +videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset) +{ + struct scatterlist *sglist; + int i = 0; + + if (NULL == pages[0]) + return NULL; + sglist = kcalloc(nr_pages, sizeof(*sglist), GFP_KERNEL); + if (NULL == sglist) + return NULL; + + if (NULL == pages[0]) + goto nopage; + if (PageHighMem(pages[0])) + /* DMA to highmem pages might not work */ + goto highmem; + sglist[0].page = pages[0]; + sglist[0].offset = offset; + sglist[0].length = PAGE_SIZE - offset; + for (i = 1; i < nr_pages; i++) { + if (NULL == pages[i]) + goto nopage; + if (PageHighMem(pages[i])) + goto highmem; + sglist[i].page = pages[i]; + sglist[i].length = PAGE_SIZE; + } + return sglist; + + nopage: + dprintk(2,"sgl: oops - no page\n"); + kfree(sglist); + return NULL; + + highmem: + dprintk(2,"sgl: oops - highmem page\n"); + kfree(sglist); + return NULL; +} + +/* --------------------------------------------------------------------- */ + +struct videobuf_dmabuf *videobuf_to_dma (struct videobuf_buffer *buf) +{ + struct videbuf_pci_sg_memory *mem=buf->priv; + BUG_ON (!mem); + + MAGIC_CHECK(mem->magic,MAGIC_SG_MEM); + + return &mem->dma; +} + +void videobuf_dma_init(struct videobuf_dmabuf *dma) +{ + memset(dma,0,sizeof(*dma)); + dma->magic = MAGIC_DMABUF; +} + +static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma, + int direction, unsigned long data, unsigned long size) +{ + unsigned long first,last; + int err, rw = 0; + + dma->direction = direction; + switch (dma->direction) { + case PCI_DMA_FROMDEVICE: rw = READ; break; + case PCI_DMA_TODEVICE: rw = WRITE; break; + default: BUG(); + } + + first = (data & PAGE_MASK) >> PAGE_SHIFT; + last = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT; + dma->offset = data & ~PAGE_MASK; + dma->nr_pages = last-first+1; + dma->pages = kmalloc(dma->nr_pages * sizeof(struct page*), + GFP_KERNEL); + if (NULL == dma->pages) + return -ENOMEM; + dprintk(1,"init user [0x%lx+0x%lx => %d pages]\n", + data,size,dma->nr_pages); + + dma->varea = (void *) data; + + + err = get_user_pages(current,current->mm, + data & PAGE_MASK, dma->nr_pages, + rw == READ, 1, /* force */ + dma->pages, NULL); + + if (err != dma->nr_pages) { + dma->nr_pages = (err >= 0) ? err : 0; + dprintk(1,"get_user_pages: err=%d [%d]\n",err,dma->nr_pages); + return err < 0 ? err : -EINVAL; + } + return 0; +} + +int videobuf_dma_init_user(struct videobuf_dmabuf *dma, int direction, + unsigned long data, unsigned long size) +{ + int ret; + down_read(¤t->mm->mmap_sem); + ret = videobuf_dma_init_user_locked(dma, direction, data, size); + up_read(¤t->mm->mmap_sem); + + return ret; +} + +int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction, + int nr_pages) +{ + dprintk(1,"init kernel [%d pages]\n",nr_pages); + dma->direction = direction; + dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT); + if (NULL == dma->vmalloc) { + dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages); + return -ENOMEM; + } + dprintk(1,"vmalloc is at addr 0x%08lx, size=%d\n", + (unsigned long)dma->vmalloc, + nr_pages << PAGE_SHIFT); + memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT); + dma->nr_pages = nr_pages; + return 0; +} + +int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction, + dma_addr_t addr, int nr_pages) +{ + dprintk(1,"init overlay [%d pages @ bus 0x%lx]\n", + nr_pages,(unsigned long)addr); + dma->direction = direction; + if (0 == addr) + return -EINVAL; + + dma->bus_addr = addr; + dma->nr_pages = nr_pages; + return 0; +} + +int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma) +{ + void *dev=q->dev; + + MAGIC_CHECK(dma->magic,MAGIC_DMABUF); + BUG_ON(0 == dma->nr_pages); + + if (dma->pages) { + dma->sglist = videobuf_pages_to_sg(dma->pages, dma->nr_pages, + dma->offset); + } + if (dma->vmalloc) { + dma->sglist = videobuf_vmalloc_to_sg + (dma->vmalloc,dma->nr_pages); + } + if (dma->bus_addr) { + dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL); + if (NULL != dma->sglist) { + dma->sglen = 1; + sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK; + dma->sglist[0].offset = dma->bus_addr & ~PAGE_MASK; + sg_dma_len(&dma->sglist[0]) = dma->nr_pages * PAGE_SIZE; + } + } + if (NULL == dma->sglist) { + dprintk(1,"scatterlist is NULL\n"); + return -ENOMEM; + } + if (!dma->bus_addr) { + dma->sglen = pci_map_sg(dev,dma->sglist, + dma->nr_pages, dma->direction); + if (0 == dma->sglen) { + printk(KERN_WARNING + "%s: videobuf_map_sg failed\n",__FUNCTION__); + kfree(dma->sglist); + dma->sglist = NULL; + dma->sglen = 0; + return -EIO; + } + } + return 0; +} + +int videobuf_dma_sync(struct videobuf_queue *q,struct videobuf_dmabuf *dma) +{ + void *dev=q->dev; + + MAGIC_CHECK(dma->magic,MAGIC_DMABUF); + BUG_ON(!dma->sglen); + + pci_dma_sync_sg_for_cpu (dev,dma->sglist,dma->nr_pages,dma->direction); + return 0; +} + +int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma) +{ + void *dev=q->dev; + + MAGIC_CHECK(dma->magic,MAGIC_DMABUF); + if (!dma->sglen) + return 0; + + pci_unmap_sg (dev,dma->sglist,dma->nr_pages,dma->direction); + + kfree(dma->sglist); + dma->sglist = NULL; + dma->sglen = 0; + return 0; +} + +int videobuf_dma_free(struct videobuf_dmabuf *dma) +{ + MAGIC_CHECK(dma->magic,MAGIC_DMABUF); + BUG_ON(dma->sglen); + + if (dma->pages) { + int i; + for (i=0; i < dma->nr_pages; i++) + page_cache_release(dma->pages[i]); + kfree(dma->pages); + dma->pages = NULL; + } + + vfree(dma->vmalloc); + dma->vmalloc = NULL; + dma->varea = NULL; + + if (dma->bus_addr) { + dma->bus_addr = 0; + } + dma->direction = PCI_DMA_NONE; + return 0; +} + +/* --------------------------------------------------------------------- */ + +int videobuf_pci_dma_map(struct pci_dev *pci,struct videobuf_dmabuf *dma) +{ + struct videobuf_queue q; + + q.dev=pci; + + return (videobuf_dma_map(&q,dma)); +} + +int videobuf_pci_dma_unmap(struct pci_dev *pci,struct videobuf_dmabuf *dma) +{ + struct videobuf_queue q; + + q.dev=pci; + + return (videobuf_dma_unmap(&q,dma)); +} + +/* --------------------------------------------------------------------- */ + +static void +videobuf_vm_open(struct vm_area_struct *vma) +{ + struct videobuf_mapping *map = vma->vm_private_data; + + dprintk(2,"vm_open %p [count=%d,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; + struct videbuf_pci_sg_memory *mem; + int i; + + dprintk(2,"vm_close %p [count=%d,vma=%08lx-%08lx]\n",map, + map->count,vma->vm_start,vma->vm_end); + + map->count--; + if (0 == map->count) { + dprintk(1,"munmap %p q=%p\n",map,q); + mutex_lock(&q->lock); + for (i = 0; i < VIDEO_MAX_FRAME; i++) { + if (NULL == q->bufs[i]) + continue; + mem=q->bufs[i]->priv; + + if (!mem) + continue; + + MAGIC_CHECK(mem->magic,MAGIC_SG_MEM); + + if (q->bufs[i]->map != map) + continue; + q->bufs[i]->map = NULL; + q->bufs[i]->baddr = 0; + q->ops->buf_release(q,q->bufs[i]); + } + mutex_unlock(&q->lock); + kfree(map); + } + return; +} + +/* + * Get a anonymous page for the mapping. Make sure we can DMA to that + * memory location with 32bit PCI devices (i.e. don't use highmem for + * now ...). Bounce buffers don't work very well for the data rates + * video capture has. + */ +static struct page* +videobuf_vm_nopage(struct vm_area_struct *vma, unsigned long vaddr, + int *type) +{ + struct page *page; + + dprintk(3,"nopage: fault @ %08lx [vma %08lx-%08lx]\n", + vaddr,vma->vm_start,vma->vm_end); + if (vaddr > vma->vm_end) + return NOPAGE_SIGBUS; + page = alloc_page(GFP_USER | __GFP_DMA32); + if (!page) + return NOPAGE_OOM; + clear_user_page(page_address(page), vaddr, page); + if (type) + *type = VM_FAULT_MINOR; + return page; +} + +static struct vm_operations_struct videobuf_vm_ops = +{ + .open = videobuf_vm_open, + .close = videobuf_vm_close, + .nopage = videobuf_vm_nopage, +}; + +/* --------------------------------------------------------------------- + * PCI handlers for the generic methods + */ + +/* Allocated area consists on 3 parts: + struct video_buffer + struct <driver>_buffer (cx88_buffer, saa7134_buf, ...) + struct videobuf_pci_sg_memory + */ + +static void *__videobuf_alloc(size_t size) +{ + struct videbuf_pci_sg_memory *mem; + struct videobuf_buffer *vb; + + vb = kzalloc(size+sizeof(*mem),GFP_KERNEL); + + mem = vb->priv = ((char *)vb)+size; + mem->magic=MAGIC_SG_MEM; + + videobuf_dma_init(&mem->dma); + + dprintk(1,"%s: allocated at %p(%ld+%ld) & %p(%ld)\n", + __FUNCTION__,vb,(long)sizeof(*vb),(long)size-sizeof(*vb), + mem,(long)sizeof(*mem)); + + return vb; +} + +static int __videobuf_iolock (struct videobuf_queue* q, + struct videobuf_buffer *vb, + struct v4l2_framebuffer *fbuf) +{ + int err,pages; + dma_addr_t bus; + struct videbuf_pci_sg_memory *mem=vb->priv; + BUG_ON(!mem); + + MAGIC_CHECK(mem->magic,MAGIC_SG_MEM); + + switch (vb->memory) { + case V4L2_MEMORY_MMAP: + case V4L2_MEMORY_USERPTR: + if (0 == vb->baddr) { + /* no userspace addr -- kernel bounce buffer */ + pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT; + err = videobuf_dma_init_kernel( &mem->dma, + PCI_DMA_FROMDEVICE, + pages ); + if (0 != err) + return err; + } else if (vb->memory == V4L2_MEMORY_USERPTR) { + /* dma directly to userspace */ + err = videobuf_dma_init_user( &mem->dma, + PCI_DMA_FROMDEVICE, + vb->baddr,vb->bsize ); + if (0 != err) + return err; + } else { + /* NOTE: HACK: videobuf_iolock on V4L2_MEMORY_MMAP + buffers can only be called from videobuf_qbuf + we take current->mm->mmap_sem there, to prevent + locking inversion, so don't take it here */ + + err = videobuf_dma_init_user_locked(&mem->dma, + PCI_DMA_FROMDEVICE, + vb->baddr, vb->bsize); + if (0 != err) + return err; + } + break; + case V4L2_MEMORY_OVERLAY: + if (NULL == fbuf) + return -EINVAL; + /* FIXME: need sanity checks for vb->boff */ + /* + * Using a double cast to avoid compiler warnings when + * building for PAE. Compiler doesn't like direct casting + * of a 32 bit ptr to 64 bit integer. + */ + bus = (dma_addr_t)(unsigned long)fbuf->base + vb->boff; + pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT; + err = videobuf_dma_init_overlay(&mem->dma,PCI_DMA_FROMDEVICE, + bus, pages); + if (0 != err) + return err; + break; + default: + BUG(); + } + err = videobuf_dma_map(q,&mem->dma); + if (0 != err) + return err; + + return 0; +} + +static int __videobuf_sync(struct videobuf_queue *q, + struct videobuf_buffer *buf) +{ + struct videbuf_pci_sg_memory *mem=buf->priv; + BUG_ON (!mem); + MAGIC_CHECK(mem->magic,MAGIC_SG_MEM); + + return videobuf_dma_sync(q,&mem->dma); +} + +static int __videobuf_mmap_free(struct videobuf_queue *q) +{ + int i; + + for (i = 0; i < VIDEO_MAX_FRAME; i++) { + if (q->bufs[i]) { + if (q->bufs[i]->map) + return -EBUSY; + } + } + + return 0; +} + +static int __videobuf_mmap_mapper(struct videobuf_queue *q, + struct vm_area_struct *vma) +{ + struct videbuf_pci_sg_memory *mem; + struct videobuf_mapping *map; + unsigned int first,last,size,i; + int retval; + + retval = -EINVAL; + if (!(vma->vm_flags & VM_WRITE)) { + dprintk(1,"mmap app bug: PROT_WRITE please\n"); + goto done; + } + if (!(vma->vm_flags & VM_SHARED)) { + dprintk(1,"mmap app bug: MAP_SHARED please\n"); + goto done; + } + + /* look for first buffer to map */ + for (first = 0; first < VIDEO_MAX_FRAME; first++) { + if (NULL == q->bufs[first]) + continue; + mem=q->bufs[first]->priv; + BUG_ON (!mem); + MAGIC_CHECK(mem->magic,MAGIC_SG_MEM); + + if (V4L2_MEMORY_MMAP != q->bufs[first]->memory) + continue; + if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT)) + break; + } + if (VIDEO_MAX_FRAME == first) { + dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n", + (vma->vm_pgoff << PAGE_SHIFT)); + goto done; + } + + /* look for last buffer to map */ + for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) { + if (NULL == q->bufs[last]) + continue; + if (V4L2_MEMORY_MMAP != q->bufs[last]->memory) + continue; + if (q->bufs[last]->map) { + retval = -EBUSY; + goto done; + } + size += q->bufs[last]->bsize; + if (size == (vma->vm_end - vma->vm_start)) + break; + } + if (VIDEO_MAX_FRAME == last) { + dprintk(1,"mmap app bug: size invalid [size=0x%lx]\n", + (vma->vm_end - vma->vm_start)); + goto done; + } + + /* create mapping + update buffer list */ + retval = -ENOMEM; + map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL); + if (NULL == map) + goto done; + for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) { + q->bufs[i]->map = map; + q->bufs[i]->baddr = vma->vm_start + size; + } + map->count = 1; + map->start = vma->vm_start; + map->end = vma->vm_end; + map->q = q; + vma->vm_ops = &videobuf_vm_ops; + vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED; + vma->vm_flags &= ~VM_IO; /* using shared anonymous pages */ + vma->vm_private_data = map; + dprintk(1,"mmap %p: q=%p %08lx-%08lx pgoff %08lx bufs %d-%d\n", + map,q,vma->vm_start,vma->vm_end,vma->vm_pgoff,first,last); + retval = 0; + + done: + return retval; +} + +static int __videobuf_copy_to_user ( struct videobuf_queue *q, + char __user *data, size_t count, + int nonblocking ) +{ + struct videbuf_pci_sg_memory *mem=q->read_buf->priv; + BUG_ON (!mem); + MAGIC_CHECK(mem->magic,MAGIC_SG_MEM); + + /* copy to userspace */ + if (count > q->read_buf->size - q->read_off) + count = q->read_buf->size - q->read_off; + + if (copy_to_user(data, mem->dma.vmalloc+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 videbuf_pci_sg_memory *mem=q->read_buf->priv; + BUG_ON (!mem); + MAGIC_CHECK(mem->magic,MAGIC_SG_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->dma.vmalloc; + fc += (q->read_buf->size>>2) -1; + *fc = q->read_buf->field_count >> 1; + dprintk(1,"vbihack: %d\n",*fc); + } + + /* copy stuff using the common method */ + count = __videobuf_copy_to_user (q,data,count,nonblocking); + + if ( (count==-EFAULT) && (0 == pos) ) + return -EFAULT; + + return count; +} + +static struct videobuf_qtype_ops pci_ops = { + .magic = MAGIC_QTYPE_OPS, + + .alloc = __videobuf_alloc, + .iolock = __videobuf_iolock, + .sync = __videobuf_sync, + .mmap_free = __videobuf_mmap_free, + .mmap_mapper = __videobuf_mmap_mapper, + .copy_to_user = __videobuf_copy_to_user, + .copy_stream = __videobuf_copy_stream, +}; + +void *videobuf_pci_alloc (size_t size) +{ + struct videobuf_queue q; + + /* Required to make generic handler to call __videobuf_alloc */ + q.int_ops=&pci_ops; + + q.msize=size; + + return videobuf_alloc (&q); +} + +void videobuf_queue_pci_init(struct videobuf_queue* q, + struct videobuf_queue_ops *ops, + void *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, &pci_ops); +} + +/* --------------------------------------------------------------------- */ + +EXPORT_SYMBOL_GPL(videobuf_vmalloc_to_sg); + +EXPORT_SYMBOL_GPL(videobuf_to_dma); +EXPORT_SYMBOL_GPL(videobuf_dma_init); +EXPORT_SYMBOL_GPL(videobuf_dma_init_user); +EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel); +EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay); +EXPORT_SYMBOL_GPL(videobuf_dma_map); +EXPORT_SYMBOL_GPL(videobuf_dma_sync); +EXPORT_SYMBOL_GPL(videobuf_dma_unmap); +EXPORT_SYMBOL_GPL(videobuf_dma_free); + +EXPORT_SYMBOL_GPL(videobuf_pci_dma_map); +EXPORT_SYMBOL_GPL(videobuf_pci_dma_unmap); +EXPORT_SYMBOL_GPL(videobuf_pci_alloc); + +EXPORT_SYMBOL_GPL(videobuf_queue_pci_init); + +/* + * Local variables: + * c-basic-offset: 8 + * End: + */ |