| /* |
| * helper functions for SG DMA video4linux capture buffers |
| * |
| * The functions expect the hardware being able to scatter gather |
| * (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/sched.h> |
| #include <linux/slab.h> |
| #include <linux/interrupt.h> |
| |
| #include <linux/dma-mapping.h> |
| #include <linux/vmalloc.h> |
| #include <linux/pagemap.h> |
| #include <linux/scatterlist.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; |
| module_param(debug, int, 0644); |
| |
| MODULE_DESCRIPTION("helper module to manage video4linux 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) |
| |
| /* --------------------------------------------------------------------- */ |
| |
| /* |
| * Return a scatterlist for some page-aligned vmalloc()'ed memory |
| * block (NULL on errors). Memory for the scatterlist is allocated |
| * using kmalloc. The caller must free the memory. |
| */ |
| static struct scatterlist *videobuf_vmalloc_to_sg(unsigned char *virt, |
| int nr_pages) |
| { |
| struct scatterlist *sglist; |
| struct page *pg; |
| int i; |
| |
| sglist = vzalloc(nr_pages * sizeof(*sglist)); |
| if (NULL == sglist) |
| return NULL; |
| sg_init_table(sglist, nr_pages); |
| for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) { |
| pg = vmalloc_to_page(virt); |
| if (NULL == pg) |
| goto err; |
| BUG_ON(PageHighMem(pg)); |
| sg_set_page(&sglist[i], pg, PAGE_SIZE, 0); |
| } |
| return sglist; |
| |
| err: |
| vfree(sglist); |
| return NULL; |
| } |
| |
| /* |
| * Return a scatterlist for a an array of userpages (NULL on errors). |
| * Memory for the scatterlist is allocated using kmalloc. The caller |
| * must free the memory. |
| */ |
| static struct scatterlist *videobuf_pages_to_sg(struct page **pages, |
| int nr_pages, int offset, size_t size) |
| { |
| struct scatterlist *sglist; |
| int i; |
| |
| if (NULL == pages[0]) |
| return NULL; |
| sglist = vmalloc(nr_pages * sizeof(*sglist)); |
| if (NULL == sglist) |
| return NULL; |
| sg_init_table(sglist, nr_pages); |
| |
| if (PageHighMem(pages[0])) |
| /* DMA to highmem pages might not work */ |
| goto highmem; |
| sg_set_page(&sglist[0], pages[0], |
| min_t(size_t, PAGE_SIZE - offset, size), offset); |
| size -= min_t(size_t, PAGE_SIZE - offset, size); |
| for (i = 1; i < nr_pages; i++) { |
| if (NULL == pages[i]) |
| goto nopage; |
| if (PageHighMem(pages[i])) |
| goto highmem; |
| sg_set_page(&sglist[i], pages[i], min_t(size_t, PAGE_SIZE, size), 0); |
| size -= min_t(size_t, PAGE_SIZE, size); |
| } |
| return sglist; |
| |
| nopage: |
| dprintk(2, "sgl: oops - no page\n"); |
| vfree(sglist); |
| return NULL; |
| |
| highmem: |
| dprintk(2, "sgl: oops - highmem page\n"); |
| vfree(sglist); |
| return NULL; |
| } |
| |
| /* --------------------------------------------------------------------- */ |
| |
| struct videobuf_dmabuf *videobuf_to_dma(struct videobuf_buffer *buf) |
| { |
| struct videobuf_dma_sg_memory *mem = buf->priv; |
| BUG_ON(!mem); |
| |
| MAGIC_CHECK(mem->magic, MAGIC_SG_MEM); |
| |
| return &mem->dma; |
| } |
| EXPORT_SYMBOL_GPL(videobuf_to_dma); |
| |
| static 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 DMA_FROM_DEVICE: |
| rw = READ; |
| break; |
| case DMA_TO_DEVICE: |
| 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->size = size; |
| 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); |
| |
| err = get_user_pages(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; |
| } |
| |
| static 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; |
| } |
| |
| static int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction, |
| int nr_pages) |
| { |
| int i; |
| |
| dprintk(1, "init kernel [%d pages]\n", nr_pages); |
| |
| dma->direction = direction; |
| dma->vaddr_pages = kcalloc(nr_pages, sizeof(*dma->vaddr_pages), |
| GFP_KERNEL); |
| if (!dma->vaddr_pages) |
| return -ENOMEM; |
| |
| dma->dma_addr = kcalloc(nr_pages, sizeof(*dma->dma_addr), GFP_KERNEL); |
| if (!dma->dma_addr) { |
| kfree(dma->vaddr_pages); |
| return -ENOMEM; |
| } |
| for (i = 0; i < nr_pages; i++) { |
| void *addr; |
| |
| addr = dma_alloc_coherent(dma->dev, PAGE_SIZE, |
| &(dma->dma_addr[i]), GFP_KERNEL); |
| if (addr == NULL) |
| goto out_free_pages; |
| |
| dma->vaddr_pages[i] = virt_to_page(addr); |
| } |
| dma->vaddr = vmap(dma->vaddr_pages, nr_pages, VM_MAP | VM_IOREMAP, |
| PAGE_KERNEL); |
| if (NULL == dma->vaddr) { |
| dprintk(1, "vmalloc_32(%d pages) failed\n", nr_pages); |
| goto out_free_pages; |
| } |
| |
| dprintk(1, "vmalloc is at addr 0x%08lx, size=%d\n", |
| (unsigned long)dma->vaddr, |
| nr_pages << PAGE_SHIFT); |
| |
| memset(dma->vaddr, 0, nr_pages << PAGE_SHIFT); |
| dma->nr_pages = nr_pages; |
| |
| return 0; |
| out_free_pages: |
| while (i > 0) { |
| void *addr; |
| |
| i--; |
| addr = page_address(dma->vaddr_pages[i]); |
| dma_free_coherent(dma->dev, PAGE_SIZE, addr, dma->dma_addr[i]); |
| } |
| kfree(dma->dma_addr); |
| dma->dma_addr = NULL; |
| kfree(dma->vaddr_pages); |
| dma->vaddr_pages = NULL; |
| |
| return -ENOMEM; |
| |
| } |
| |
| static 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; |
| } |
| |
| static int videobuf_dma_map(struct device *dev, struct videobuf_dmabuf *dma) |
| { |
| 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, dma->size); |
| } |
| if (dma->vaddr) { |
| dma->sglist = videobuf_vmalloc_to_sg(dma->vaddr, |
| dma->nr_pages); |
| } |
| if (dma->bus_addr) { |
| dma->sglist = vmalloc(sizeof(*dma->sglist)); |
| 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 = dma_map_sg(dev, dma->sglist, |
| dma->nr_pages, dma->direction); |
| if (0 == dma->sglen) { |
| printk(KERN_WARNING |
| "%s: videobuf_map_sg failed\n", __func__); |
| vfree(dma->sglist); |
| dma->sglist = NULL; |
| dma->sglen = 0; |
| return -ENOMEM; |
| } |
| } |
| |
| return 0; |
| } |
| |
| int videobuf_dma_unmap(struct device *dev, struct videobuf_dmabuf *dma) |
| { |
| MAGIC_CHECK(dma->magic, MAGIC_DMABUF); |
| |
| if (!dma->sglen) |
| return 0; |
| |
| dma_unmap_sg(dev, dma->sglist, dma->sglen, dma->direction); |
| |
| vfree(dma->sglist); |
| dma->sglist = NULL; |
| dma->sglen = 0; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(videobuf_dma_unmap); |
| |
| int videobuf_dma_free(struct videobuf_dmabuf *dma) |
| { |
| int i; |
| MAGIC_CHECK(dma->magic, MAGIC_DMABUF); |
| BUG_ON(dma->sglen); |
| |
| if (dma->pages) { |
| for (i = 0; i < dma->nr_pages; i++) |
| page_cache_release(dma->pages[i]); |
| kfree(dma->pages); |
| dma->pages = NULL; |
| } |
| |
| if (dma->dma_addr) { |
| for (i = 0; i < dma->nr_pages; i++) { |
| void *addr; |
| |
| addr = page_address(dma->vaddr_pages[i]); |
| dma_free_coherent(dma->dev, PAGE_SIZE, addr, |
| dma->dma_addr[i]); |
| } |
| kfree(dma->dma_addr); |
| dma->dma_addr = NULL; |
| kfree(dma->vaddr_pages); |
| dma->vaddr_pages = NULL; |
| vunmap(dma->vaddr); |
| dma->vaddr = NULL; |
| } |
| |
| if (dma->bus_addr) |
| dma->bus_addr = 0; |
| dma->direction = DMA_NONE; |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(videobuf_dma_free); |
| |
| /* --------------------------------------------------------------------- */ |
| |
| 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 videobuf_dma_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); |
| videobuf_queue_lock(q); |
| 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]); |
| } |
| videobuf_queue_unlock(q); |
| 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 int videobuf_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
| { |
| struct page *page; |
| |
| dprintk(3, "fault: fault @ %08lx [vma %08lx-%08lx]\n", |
| (unsigned long)vmf->virtual_address, |
| vma->vm_start, vma->vm_end); |
| |
| page = alloc_page(GFP_USER | __GFP_DMA32); |
| if (!page) |
| return VM_FAULT_OOM; |
| clear_user_highpage(page, (unsigned long)vmf->virtual_address); |
| vmf->page = page; |
| |
| return 0; |
| } |
| |
| static const struct vm_operations_struct videobuf_vm_ops = { |
| .open = videobuf_vm_open, |
| .close = videobuf_vm_close, |
| .fault = videobuf_vm_fault, |
| }; |
| |
| /* --------------------------------------------------------------------- |
| * SG handlers for the generic methods |
| */ |
| |
| /* Allocated area consists on 3 parts: |
| struct video_buffer |
| struct <driver>_buffer (cx88_buffer, saa7134_buf, ...) |
| struct videobuf_dma_sg_memory |
| */ |
| |
| static struct videobuf_buffer *__videobuf_alloc_vb(size_t size) |
| { |
| struct videobuf_dma_sg_memory *mem; |
| struct videobuf_buffer *vb; |
| |
| vb = kzalloc(size + sizeof(*mem), GFP_KERNEL); |
| if (!vb) |
| return vb; |
| |
| 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", |
| __func__, vb, (long)sizeof(*vb), (long)size - sizeof(*vb), |
| mem, (long)sizeof(*mem)); |
| |
| return vb; |
| } |
| |
| static void *__videobuf_to_vaddr(struct videobuf_buffer *buf) |
| { |
| struct videobuf_dma_sg_memory *mem = buf->priv; |
| BUG_ON(!mem); |
| |
| MAGIC_CHECK(mem->magic, MAGIC_SG_MEM); |
| |
| return mem->dma.vaddr; |
| } |
| |
| static int __videobuf_iolock(struct videobuf_queue *q, |
| struct videobuf_buffer *vb, |
| struct v4l2_framebuffer *fbuf) |
| { |
| int err, pages; |
| dma_addr_t bus; |
| struct videobuf_dma_sg_memory *mem = vb->priv; |
| BUG_ON(!mem); |
| |
| MAGIC_CHECK(mem->magic, MAGIC_SG_MEM); |
| |
| if (!mem->dma.dev) |
| mem->dma.dev = q->dev; |
| else |
| WARN_ON(mem->dma.dev != q->dev); |
| |
| 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, |
| DMA_FROM_DEVICE, |
| pages); |
| if (0 != err) |
| return err; |
| } else if (vb->memory == V4L2_MEMORY_USERPTR) { |
| /* dma directly to userspace */ |
| err = videobuf_dma_init_user(&mem->dma, |
| DMA_FROM_DEVICE, |
| 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, |
| DMA_FROM_DEVICE, |
| 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, DMA_FROM_DEVICE, |
| bus, pages); |
| if (0 != err) |
| return err; |
| break; |
| default: |
| BUG(); |
| } |
| err = videobuf_dma_map(q->dev, &mem->dma); |
| if (0 != err) |
| return err; |
| |
| return 0; |
| } |
| |
| static int __videobuf_sync(struct videobuf_queue *q, |
| struct videobuf_buffer *buf) |
| { |
| struct videobuf_dma_sg_memory *mem = buf->priv; |
| BUG_ON(!mem || !mem->dma.sglen); |
| |
| MAGIC_CHECK(mem->magic, MAGIC_SG_MEM); |
| MAGIC_CHECK(mem->dma.magic, MAGIC_DMABUF); |
| |
| dma_sync_sg_for_cpu(q->dev, mem->dma.sglist, |
| mem->dma.sglen, mem->dma.direction); |
| |
| return 0; |
| } |
| |
| static int __videobuf_mmap_mapper(struct videobuf_queue *q, |
| struct videobuf_buffer *buf, |
| struct vm_area_struct *vma) |
| { |
| struct videobuf_dma_sg_memory *mem = buf->priv; |
| struct videobuf_mapping *map; |
| unsigned int first, last, size = 0, i; |
| int retval; |
| |
| retval = -EINVAL; |
| |
| BUG_ON(!mem); |
| MAGIC_CHECK(mem->magic, MAGIC_SG_MEM); |
| |
| /* look for first buffer to map */ |
| for (first = 0; first < VIDEO_MAX_FRAME; first++) { |
| if (buf == q->bufs[first]) { |
| size = PAGE_ALIGN(q->bufs[first]->bsize); |
| break; |
| } |
| } |
| |
| /* paranoia, should never happen since buf is always valid. */ |
| if (!size) { |
| dprintk(1, "mmap app bug: offset invalid [offset=0x%lx]\n", |
| (vma->vm_pgoff << PAGE_SHIFT)); |
| goto done; |
| } |
| |
| last = first; |
| |
| /* create mapping + update buffer list */ |
| retval = -ENOMEM; |
| map = kmalloc(sizeof(struct videobuf_mapping), GFP_KERNEL); |
| if (NULL == map) |
| goto done; |
| |
| size = 0; |
| for (i = first; i <= last; i++) { |
| if (NULL == q->bufs[i]) |
| continue; |
| q->bufs[i]->map = map; |
| q->bufs[i]->baddr = vma->vm_start + size; |
| size += PAGE_ALIGN(q->bufs[i]->bsize); |
| } |
| |
| map->count = 1; |
| map->q = q; |
| vma->vm_ops = &videobuf_vm_ops; |
| vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; |
| 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 struct videobuf_qtype_ops sg_ops = { |
| .magic = MAGIC_QTYPE_OPS, |
| |
| .alloc_vb = __videobuf_alloc_vb, |
| .iolock = __videobuf_iolock, |
| .sync = __videobuf_sync, |
| .mmap_mapper = __videobuf_mmap_mapper, |
| .vaddr = __videobuf_to_vaddr, |
| }; |
| |
| void *videobuf_sg_alloc(size_t size) |
| { |
| struct videobuf_queue q; |
| |
| /* Required to make generic handler to call __videobuf_alloc */ |
| q.int_ops = &sg_ops; |
| |
| q.msize = size; |
| |
| return videobuf_alloc_vb(&q); |
| } |
| EXPORT_SYMBOL_GPL(videobuf_sg_alloc); |
| |
| void videobuf_queue_sg_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, |
| struct mutex *ext_lock) |
| { |
| videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize, |
| priv, &sg_ops, ext_lock); |
| } |
| EXPORT_SYMBOL_GPL(videobuf_queue_sg_init); |
| |