Re: [PATCH v2 6/7] misc: bcm-vk: add Broadcom VK driver

[Dan Carpenter]

On Fri, Apr 17, 2020 at 02:49:11PM -0700, Scott Branden wrote:
> > > +static int bcm_vk_dma_alloc(struct device *dev,
> > > +			    struct bcm_vk_dma *dma,
> > > +			    int direction,
> > > +			    struct _vk_data *vkdata)
> > > +{
> > > +	dma_addr_t addr, sg_addr;
> > > +	int err;
> > > +	int i;
> > > +	int offset;
> > > +	uint32_t size;
> > > +	uint32_t remaining_size;
> > > +	uint32_t transfer_size;
> > > +	uint64_t data;
> > > +	unsigned long first, last;
> > > +	struct _vk_data *sgdata;
> > > +
> > > +	/* Get 64-bit user address */
> > > +	data = get_unaligned(&(vkdata->address));
> > Extra parens.
> removed
> > 
> > > +
> > > +	/* offset into first page */
> > > +	offset = offset_in_page(data);
> > > +
> > > +	/* Calculate number of pages */
> > > +	first = (data & PAGE_MASK) >> PAGE_SHIFT;
> > > +	last  = ((data + vkdata->size - 1) & PAGE_MASK) >> PAGE_SHIFT;
> > > +	dma->nr_pages = last - first + 1;
> > > +
> > > +	/* Allocate DMA pages */
> > > +	dma->pages = kmalloc_array(dma->nr_pages,
> > > +				   sizeof(struct page *),
> > > +				   GFP_KERNEL);
> > > +	if (dma->pages == NULL)
> > > +		return -ENOMEM;
> > > +
> > > +	dev_dbg(dev, "Alloc DMA Pages [0x%llx+0x%x => %d pages]\n",
> > > +		data, vkdata->size, dma->nr_pages);
> > > +
> > > +	dma->direction = direction;
> > > +
> > > +	/* Get user pages into memory */
> > > +	err = get_user_pages_fast(data & PAGE_MASK,
> > > +				  dma->nr_pages,
> > > +				  direction == DMA_FROM_DEVICE,
> > > +				  dma->pages);
> > > +	if (err != dma->nr_pages) {
> > > +		dma->nr_pages = (err >= 0) ? err : 0;
> > > +		dev_err(dev, "get_user_pages_fast, err=%d [%d]\n",
> > > +			err, dma->nr_pages);
> > > +		return err < 0 ? err : -EINVAL;
> > > +	}
> > > +
> > > +	/* Max size of sg list is 1 per mapped page + fields at start */
> > > +	dma->sglen = (dma->nr_pages * sizeof(*sgdata)) +
> > > +		     (sizeof(uint32_t) * SGLIST_VKDATA_START);
> > > +
> > > +	/* Allocate sglist */
> > > +	dma->sglist = dma_alloc_coherent(dev,
> > > +					 dma->sglen,
> > > +					 &dma->handle,
> > > +					 GFP_KERNEL);
> > 
> > 	dma->sglist = dma_alloc_coherent(dev, dma->sglen, &dma->handle,
> > 					 GFP_KERNEL);
> done
> > 
> > 
> > 
> > > +	if (!dma->sglist)
> > > +		return -ENOMEM;
> > No cleanup?
> what needs to be cleaned up?

dma->pages should be freed probably?  And a put_user_pages_fast()?

regards,
dan carpenter