diff --git a/drivers/staging/comedi/comedi_buf.c b/drivers/staging/comedi/comedi_buf.c index 4e26bd7fc84f..924fce977985 100644 --- a/drivers/staging/comedi/comedi_buf.c +++ b/drivers/staging/comedi/comedi_buf.c @@ -16,6 +16,7 @@ */ #include +#include #include "comedidev.h" #include "comedi_internal.h" @@ -26,31 +27,21 @@ #define COMEDI_PAGE_PROTECTION PAGE_KERNEL #endif -static void __comedi_buf_free(struct comedi_device *dev, - struct comedi_subdevice *s, - unsigned n_pages) +static void comedi_buf_map_kref_release(struct kref *kref) { - struct comedi_async *async = s->async; + struct comedi_buf_map *bm = + container_of(kref, struct comedi_buf_map, refcount); struct comedi_buf_page *buf; - unsigned i; + unsigned int i; - if (async->prealloc_buf) { - vunmap(async->prealloc_buf); - async->prealloc_buf = NULL; - async->prealloc_bufsz = 0; - } - - if (!async->buf_page_list) - return; - - for (i = 0; i < n_pages; ++i) { - buf = &async->buf_page_list[i]; - if (buf->virt_addr) { + if (bm->page_list) { + for (i = 0; i < bm->n_pages; i++) { + buf = &bm->page_list[i]; clear_bit(PG_reserved, &(virt_to_page(buf->virt_addr)->flags)); - if (s->async_dma_dir != DMA_NONE) { + if (bm->dma_dir != DMA_NONE) { #ifdef CONFIG_HAS_DMA - dma_free_coherent(dev->hw_dev, + dma_free_coherent(bm->dma_hw_dev, PAGE_SIZE, buf->virt_addr, buf->dma_addr); @@ -59,10 +50,26 @@ static void __comedi_buf_free(struct comedi_device *dev, free_page((unsigned long)buf->virt_addr); } } + vfree(bm->page_list); } - vfree(async->buf_page_list); - async->buf_page_list = NULL; - async->n_buf_pages = 0; + if (bm->dma_dir != DMA_NONE) + put_device(bm->dma_hw_dev); + kfree(bm); +} + +static void __comedi_buf_free(struct comedi_device *dev, + struct comedi_subdevice *s) +{ + struct comedi_async *async = s->async; + + if (async->prealloc_buf) { + vunmap(async->prealloc_buf); + async->prealloc_buf = NULL; + async->prealloc_bufsz = 0; + } + + comedi_buf_map_put(async->buf_map); + async->buf_map = NULL; } static void __comedi_buf_alloc(struct comedi_device *dev, @@ -71,6 +78,7 @@ static void __comedi_buf_alloc(struct comedi_device *dev, { struct comedi_async *async = s->async; struct page **pages = NULL; + struct comedi_buf_map *bm; struct comedi_buf_page *buf; unsigned i; @@ -80,18 +88,29 @@ static void __comedi_buf_alloc(struct comedi_device *dev, return; } - async->buf_page_list = vzalloc(sizeof(*buf) * n_pages); - if (async->buf_page_list) + bm = kzalloc(sizeof(*async->buf_map), GFP_KERNEL); + if (!bm) + return; + + async->buf_map = bm; + kref_init(&bm->refcount); + bm->dma_dir = s->async_dma_dir; + if (bm->dma_dir != DMA_NONE) + /* Need ref to hardware device to free buffer later. */ + bm->dma_hw_dev = get_device(dev->hw_dev); + + bm->page_list = vzalloc(sizeof(*buf) * n_pages); + if (bm->page_list) pages = vmalloc(sizeof(struct page *) * n_pages); if (!pages) return; for (i = 0; i < n_pages; i++) { - buf = &async->buf_page_list[i]; - if (s->async_dma_dir != DMA_NONE) + buf = &bm->page_list[i]; + if (bm->dma_dir != DMA_NONE) #ifdef CONFIG_HAS_DMA - buf->virt_addr = dma_alloc_coherent(dev->hw_dev, + buf->virt_addr = dma_alloc_coherent(bm->dma_hw_dev, PAGE_SIZE, &buf->dma_addr, GFP_KERNEL | @@ -108,6 +127,7 @@ static void __comedi_buf_alloc(struct comedi_device *dev, pages[i] = virt_to_page(buf->virt_addr); } + bm->n_pages = i; /* vmap the prealloc_buf if all the pages were allocated */ if (i == n_pages) @@ -117,6 +137,26 @@ static void __comedi_buf_alloc(struct comedi_device *dev, vfree(pages); } +void comedi_buf_map_get(struct comedi_buf_map *bm) +{ + if (bm) + kref_get(&bm->refcount); +} + +int comedi_buf_map_put(struct comedi_buf_map *bm) +{ + if (bm) + return kref_put(&bm->refcount, comedi_buf_map_kref_release); + return 1; +} + +bool comedi_buf_is_mmapped(struct comedi_async *async) +{ + struct comedi_buf_map *bm = async->buf_map; + + return bm && (atomic_read(&bm->refcount.refcount) > 1); +} + int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s, unsigned long new_size) { @@ -130,7 +170,7 @@ int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s, return 0; /* deallocate old buffer */ - __comedi_buf_free(dev, s, async->n_buf_pages); + __comedi_buf_free(dev, s); /* allocate new buffer */ if (new_size) { @@ -140,10 +180,9 @@ int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s, if (!async->prealloc_buf) { /* allocation failed */ - __comedi_buf_free(dev, s, n_pages); + __comedi_buf_free(dev, s); return -ENOMEM; } - async->n_buf_pages = n_pages; } async->prealloc_bufsz = new_size; diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 8cb9d956e8f2..58f2b27144ca 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -264,7 +264,7 @@ static int resize_async_buffer(struct comedi_device *dev, DPRINTK("subdevice is busy, cannot resize buffer\n"); return -EBUSY; } - if (async->mmap_count) { + if (comedi_buf_is_mmapped(async)) { DPRINTK("subdevice is mmapped, cannot resize buffer\n"); return -EBUSY; } @@ -647,7 +647,7 @@ static int is_device_busy(struct comedi_device *dev) s = &dev->subdevices[i]; if (s->busy) return 1; - if (s->async && s->async->mmap_count) + if (s->async && comedi_buf_is_mmapped(s->async)) return 1; } @@ -1899,28 +1899,18 @@ done: static void comedi_vm_open(struct vm_area_struct *area) { - struct comedi_async *async; - struct comedi_device *dev; + struct comedi_buf_map *bm; - async = area->vm_private_data; - dev = async->subdevice->device; - - mutex_lock(&dev->mutex); - async->mmap_count++; - mutex_unlock(&dev->mutex); + bm = area->vm_private_data; + comedi_buf_map_get(bm); } static void comedi_vm_close(struct vm_area_struct *area) { - struct comedi_async *async; - struct comedi_device *dev; + struct comedi_buf_map *bm; - async = area->vm_private_data; - dev = async->subdevice->device; - - mutex_lock(&dev->mutex); - async->mmap_count--; - mutex_unlock(&dev->mutex); + bm = area->vm_private_data; + comedi_buf_map_put(bm); } static struct vm_operations_struct comedi_vm_ops = { @@ -1934,6 +1924,7 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma) struct comedi_device *dev = file->private_data; struct comedi_subdevice *s; struct comedi_async *async; + struct comedi_buf_map *bm; unsigned long start = vma->vm_start; unsigned long size; int n_pages; @@ -1980,8 +1971,13 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma) } n_pages = size >> PAGE_SHIFT; + bm = async->buf_map; + if (!bm || n_pages > bm->n_pages) { + retval = -EINVAL; + goto done; + } for (i = 0; i < n_pages; ++i) { - struct comedi_buf_page *buf = &async->buf_page_list[i]; + struct comedi_buf_page *buf = &bm->page_list[i]; if (remap_pfn_range(vma, start, page_to_pfn(virt_to_page(buf->virt_addr)), @@ -1993,9 +1989,9 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma) } vma->vm_ops = &comedi_vm_ops; - vma->vm_private_data = async; + vma->vm_private_data = bm; - async->mmap_count++; + vma->vm_ops->open(vma); retval = 0; done: diff --git a/drivers/staging/comedi/comedi_internal.h b/drivers/staging/comedi/comedi_internal.h index 151693b11383..9a746570f161 100644 --- a/drivers/staging/comedi/comedi_internal.h +++ b/drivers/staging/comedi/comedi_internal.h @@ -16,6 +16,9 @@ void comedi_free_subdevice_minor(struct comedi_subdevice *s); int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s, unsigned long new_size); void comedi_buf_reset(struct comedi_async *async); +bool comedi_buf_is_mmapped(struct comedi_async *async); +void comedi_buf_map_get(struct comedi_buf_map *bm); +int comedi_buf_map_put(struct comedi_buf_map *bm); unsigned int comedi_buf_write_n_allocated(struct comedi_async *async); void comedi_device_cancel_all(struct comedi_device *dev); diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h index 4e7cd1443be6..a7b8937aa4a3 100644 --- a/drivers/staging/comedi/comedidev.h +++ b/drivers/staging/comedi/comedidev.h @@ -104,18 +104,22 @@ struct comedi_buf_page { dma_addr_t dma_addr; }; +struct comedi_buf_map { + struct device *dma_hw_dev; + struct comedi_buf_page *page_list; + unsigned int n_pages; + enum dma_data_direction dma_dir; + struct kref refcount; +}; + struct comedi_async { struct comedi_subdevice *subdevice; void *prealloc_buf; /* pre-allocated buffer */ unsigned int prealloc_bufsz; /* buffer size, in bytes */ - /* virtual and dma address of each page */ - struct comedi_buf_page *buf_page_list; - unsigned n_buf_pages; /* num elements in buf_page_list */ + struct comedi_buf_map *buf_map; /* map of buffer pages */ unsigned int max_bufsize; /* maximum buffer size, bytes */ - /* current number of mmaps of prealloc_buf */ - unsigned int mmap_count; /* byte count for writer (write completed) */ unsigned int buf_write_count; diff --git a/drivers/staging/comedi/drivers/mite.c b/drivers/staging/comedi/drivers/mite.c index 35cb4ace7970..1a2191699351 100644 --- a/drivers/staging/comedi/drivers/mite.c +++ b/drivers/staging/comedi/drivers/mite.c @@ -345,7 +345,7 @@ int mite_buf_change(struct mite_dma_descriptor_ring *ring, for (i = 0; i < n_links; i++) { ring->descriptors[i].count = cpu_to_le32(PAGE_SIZE); ring->descriptors[i].addr = - cpu_to_le32(async->buf_page_list[i].dma_addr); + cpu_to_le32(async->buf_map->page_list[i].dma_addr); ring->descriptors[i].next = cpu_to_le32(ring->descriptors_dma_addr + (i + 1) *