On Wed, May 21 2014, Gioh Kim <gioh.kim@xxxxxxx> wrote:
> Date: Tue, 20 May 2014 14:16:20 +0900
> Subject: [PATCH] arm: dma-mapping: add checking cma area initialized
>
> If CMA is turned on and CMA size is set to zero, kernel should
> behave as if CMA was not enabled at compile time.
> Every dma allocation should check existence of cma area
> before requesting memory.
>
> Signed-off-by: Gioh Kim <gioh.kim@xxxxxxx>
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Some minor comments. Also, I'd love for someone more experienced with
ARM to take a look at this as well.
> ---
> arch/arm/mm/dma-mapping.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index 18e98df..61f7b93 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -379,7 +379,7 @@ static int __init atomic_pool_init(void)
> unsigned long *bitmap;
> struct page *page;
> struct page **pages;
> - void *ptr;
> + void *ptr = NULL;
This is unnecessary any more.
> int bitmap_size = BITS_TO_LONGS(nr_pages) * sizeof(long);
>
> bitmap = kzalloc(bitmap_size, GFP_KERNEL);
> @@ -390,12 +390,13 @@ static int __init atomic_pool_init(void)
> if (!pages)
> goto no_pages;
>
> - if (IS_ENABLED(CONFIG_DMA_CMA))
> + if (IS_ENABLED(CONFIG_DMA_CMA) && dma_contiguous_default_area)
+ if (dev_get_cma_area(NULL))
dev_get_cma_area returns NULL if !IS_ENABLED(CONFIG_DMA_CMA) so there's
no need to check it explicitly. And with NULL argument,
deg_get_cma_area returns the default area.
> ptr = __alloc_from_contiguous(NULL, pool->size, prot, &page,
> atomic_pool_init);
> else
> ptr = __alloc_remap_buffer(NULL, pool->size, gfp, prot, &page,
> atomic_pool_init);
> +
> if (ptr) {
> int i;
>
> @@ -669,6 +670,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
> u64 mask = get_coherent_dma_mask(dev);
> struct page *page = NULL;
> void *addr;
> + struct cma *cma = dev_get_cma_area(dev);
>
> #ifdef CONFIG_DMA_API_DEBUG
> u64 limit = (mask + 1) & ~mask;
> @@ -701,7 +703,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
> addr = __alloc_simple_buffer(dev, size, gfp, &page);
> else if (!(gfp & __GFP_WAIT))
> addr = __alloc_from_pool(size, &page);
> - else if (!IS_ENABLED(CONFIG_DMA_CMA))
> + else if (!IS_ENABLED(CONFIG_DMA_CMA) || !cma)
Like above, just do:
+ else if (!dev_get_cma_area(dev))
This will also allow to drop the “cma” variable above.
> addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller);
> else
> addr = __alloc_from_contiguous(dev, size, prot, &page, caller);
> @@ -780,6 +782,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
> bool is_coherent)
> {
> struct page *page = pfn_to_page(dma_to_pfn(dev, handle));
> + struct cma *cma = dev_get_cma_area(dev);
>
> if (dma_release_from_coherent(dev, get_order(size), cpu_addr))
> return;
> @@ -790,7 +793,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
> __dma_free_buffer(page, size);
> } else if (__free_from_pool(cpu_addr, size)) {
> return;
> - } else if (!IS_ENABLED(CONFIG_DMA_CMA)) {
> + } else if (!IS_ENABLED(CONFIG_DMA_CMA) || !cma) {
Ditto.
> __dma_free_remap(cpu_addr, size);
> __dma_free_buffer(page, size);
> } else {
> @@ -798,6 +801,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
> * Non-atomic allocations cannot be freed with IRQs disabled
> */
> WARN_ON(irqs_disabled());
> +
Unrelated change.
> __free_from_contiguous(dev, page, cpu_addr, size);
> }
> }
> --
> 1.7.9.5
--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michał “mina86” Nazarewicz (o o)
ooo +--<mpn@xxxxxxxxxx>--<xmpp:mina86@xxxxxxxxxx>--ooO--(_)--Ooo--
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