Messages in this thread | | | Subject | Re: [PATCH v3 5/9] xen/gntdev: Allow mappings for DMA buffers | From | Boris Ostrovsky <> | Date | Tue, 12 Jun 2018 21:26:49 -0400 |
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On 06/12/2018 09:41 AM, Oleksandr Andrushchenko wrote:
> > static void gntdev_print_maps(struct gntdev_priv *priv, > @@ -121,8 +146,27 @@ static void gntdev_free_map(struct grant_map *map) > if (map == NULL) > return; > > +#ifdef CONFIG_XEN_GRANT_DMA_ALLOC > + if (map->dma_vaddr) { > + struct gnttab_dma_alloc_args args; > + > + args.dev = map->dma_dev; > + args.coherent = map->dma_flags & GNTDEV_DMA_FLAG_COHERENT;
args.coherent = !!(map->dma_flags & GNTDEV_DMA_FLAG_COHERENT);
> + args.nr_pages = map->count; > + args.pages = map->pages; > + args.frames = map->frames; > + args.vaddr = map->dma_vaddr; > + args.dev_bus_addr = map->dma_bus_addr; > + > + gnttab_dma_free_pages(&args); > + } else > +#endif > if (map->pages) > gnttab_free_pages(map->count, map->pages); > + > +#ifdef CONFIG_XEN_GRANT_DMA_ALLOC > + kfree(map->frames); > +#endif > kfree(map->pages); > kfree(map->grants); > kfree(map->map_ops); > @@ -132,7 +176,8 @@ static void gntdev_free_map(struct grant_map *map) > kfree(map); > } > > -static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count) > +static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count, > + int dma_flags) > { > struct grant_map *add; > int i; > @@ -155,6 +200,37 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count) > NULL == add->pages) > goto err; > > +#ifdef CONFIG_XEN_GRANT_DMA_ALLOC > + add->dma_flags = dma_flags; > + > + /* > + * Check if this mapping is requested to be backed > + * by a DMA buffer. > + */ > + if (dma_flags & (GNTDEV_DMA_FLAG_WC | GNTDEV_DMA_FLAG_COHERENT)) { > + struct gnttab_dma_alloc_args args; > + > + add->frames = kcalloc(count, sizeof(add->frames[0]), > + GFP_KERNEL); > + if (!add->frames) > + goto err; > + > + /* Remember the device, so we can free DMA memory. */ > + add->dma_dev = priv->dma_dev; > + > + args.dev = priv->dma_dev; > + args.coherent = dma_flags & GNTDEV_DMA_FLAG_COHERENT;
And again here.
> + args.nr_pages = count; > + args.pages = add->pages; > + args.frames = add->frames; > + > + if (gnttab_dma_alloc_pages(&args)) > + goto err; > + > + add->dma_vaddr = args.vaddr; > + add->dma_bus_addr = args.dev_bus_addr; > + } else > +#endif > if (gnttab_alloc_pages(count, add->pages)) > goto err; > > @@ -325,6 +401,14 @@ static int map_grant_pages(struct grant_map *map) > map->unmap_ops[i].handle = map->map_ops[i].handle; > if (use_ptemod) > map->kunmap_ops[i].handle = map->kmap_ops[i].handle; > +#ifdef CONFIG_XEN_GRANT_DMA_ALLOC > + else if (map->dma_vaddr) { > + unsigned long mfn;
This should be called bfn now.
> + > + mfn = pfn_to_bfn(page_to_pfn(map->pages[i])); > + map->unmap_ops[i].dev_bus_addr = __pfn_to_phys(mfn); > + } > +#endif > } > return err; > } > @@ -548,6 +632,17 @@ static int gntdev_open(struct inode *inode, struct file *flip) > } > > flip->private_data = priv; > +#ifdef CONFIG_XEN_GRANT_DMA_ALLOC > + priv->dma_dev = gntdev_miscdev.this_device; > + > + /* > + * The device is not spawn from a device tree, so arch_setup_dma_ops > + * is not called, thus leaving the device with dummy DMA ops. > + * Fix this call of_dma_configure() with a NULL node to set
"Fix this by calling ..." I think.
> + * default DMA ops. > + */ > + of_dma_configure(priv->dma_dev, NULL); > +#endif > pr_debug("priv %p\n", priv); > > return 0;
With those fixed,
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
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