On Wed, Jul 02, 2014 at 11:03:38AM -0700, Laura Abbott wrote:
[...]
> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
[...]
> +static struct gen_pool *atomic_pool;
> +
> +#define DEFAULT_DMA_COHERENT_POOL_SIZE  SZ_256K
> +static size_t atomic_pool_size = DEFAULT_DMA_COHERENT_POOL_SIZE;

There doesn't seem to be much use for this since it can't be overridden
via init_dma_coherent_pool_size like on ARM.

> +static int __free_from_pool(void *start, size_t size)
> +{
> +     if (!__in_atomic_pool(start, size))
> +             return 0;
> +
> +     gen_pool_free(atomic_pool, (unsigned long)start, size);
> +
> +     return 1;
> +}
> +
> +

There's a gratuituous blank line here.

>  static void *__dma_alloc_coherent(struct device *dev, size_t size,
>                                 dma_addr_t *dma_handle, gfp_t flags,
>                                 struct dma_attrs *attrs)
> @@ -53,7 +103,8 @@ static void *__dma_alloc_coherent(struct device *dev, 
> size_t size,
>       if (IS_ENABLED(CONFIG_ZONE_DMA) &&
>           dev->coherent_dma_mask <= DMA_BIT_MASK(32))
>               flags |= GFP_DMA;
> -     if (IS_ENABLED(CONFIG_DMA_CMA)) {
> +
> +     if (!(flags & __GFP_WAIT) && IS_ENABLED(CONFIG_DMA_CMA)) {

I think the diff would be more readable here if this wasn't introducing
a blank linke and kept the IS_ENABLED() first.

>               struct page *page;
>  
>               size = PAGE_ALIGN(size);
> @@ -73,50 +124,56 @@ static void __dma_free_coherent(struct device *dev, 
> size_t size,
>                               void *vaddr, dma_addr_t dma_handle,
>                               struct dma_attrs *attrs)
>  {
> +     bool freed;
> +     phys_addr_t paddr = dma_to_phys(dev, dma_handle);
> +
>       if (dev == NULL) {
>               WARN_ONCE(1, "Use an actual device structure for DMA 
> allocation\n");
>               return;
>       }
>  
> -     if (IS_ENABLED(CONFIG_DMA_CMA)) {
> -             phys_addr_t paddr = dma_to_phys(dev, dma_handle);
>  
> -             dma_release_from_contiguous(dev,

The above leaves an unnecessary blank line in place.

>       ptr = __dma_alloc_coherent(dev, size, dma_handle, flags, attrs);
>       if (!ptr)
>               goto no_mem;
> -     map = kmalloc(sizeof(struct page *) << order, flags & ~GFP_DMA);
> -     if (!map)
> -             goto no_map;
>  
>       /* remove any dirty cache lines on the kernel alias */
>       __dma_flush_range(ptr, ptr + size);
>  
> +

Adds an unnecessary blank line.

> @@ -332,6 +391,67 @@ static struct notifier_block amba_bus_nb = {
>  
>  extern int swiotlb_late_init_with_default_size(size_t default_size);
>  
> +static int __init atomic_pool_init(void)
> +{
> +     pgprot_t prot = __pgprot(PROT_NORMAL_NC);
> +     unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
> +     struct page *page;
> +     void *addr;
> +
> +

There's another gratuituous blank line here...

> +     if (dev_get_cma_area(NULL))
> +             page = dma_alloc_from_contiguous(NULL, nr_pages,
> +                                     get_order(atomic_pool_size));
> +     else
> +             page = alloc_pages(GFP_KERNEL, get_order(atomic_pool_size));
> +
> +

and here.

> +     if (page) {
> +             int ret;
> +
> +             atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
> +             if (!atomic_pool)
> +                     goto free_page;
> +
> +             addr = dma_common_contiguous_remap(page, atomic_pool_size,
> +                                     VM_USERMAP, prot, atomic_pool_init);
> +
> +             if (!addr)
> +                     goto destroy_genpool;
> +
> +             memset(addr, 0, atomic_pool_size);
> +             __dma_flush_range(addr, addr + atomic_pool_size);
> +
> +             ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
> +                                     page_to_phys(page),
> +                                     atomic_pool_size, -1);
> +             if (ret)
> +                     goto remove_mapping;
> +
> +             gen_pool_set_algo(atomic_pool,
> +                               gen_pool_first_fit_order_align, NULL);
> +
> +             pr_info("DMA: preallocated %zd KiB pool for atomic 
> allocations\n",

I think this should be "%zu" because atomic_pool_size is a size_t, not a
ssize_t.

> +                     atomic_pool_size / 1024);
> +             return 0;
> +     }
> +     goto out;
> +
> +remove_mapping:
> +     dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
> +destroy_genpool:
> +     gen_pool_destroy(atomic_pool);
> +     atomic_pool == NULL;

This probably doesn't belong here.

> +free_page:
> +     if (!dma_release_from_contiguous(NULL, page, nr_pages))
> +             __free_pages(page, get_order(atomic_pool_size));

You use get_order(atomic_pool_size) a lot, perhaps it should be a
temporary variable?

> +out:
> +     pr_err("DMA: failed to allocate %zx KiB pool for atomic coherent 
> allocation\n",
> +             atomic_pool_size / 1024);

Print in decimal rather than hexadecimal?

Thierry

Attachment: pgpgvjYdVFSbo.pgp
Description: PGP signature

Reply via email to