Re: [PATCH v2] drivers: cma: fix addressing on PAE machines

[Michal Nazarewicz]

On Mon, Dec 03 2012, Vitaly Andrianov <vitalya@xxxxxx> wrote:
> This patch fixes a couple of bugs that otherwise impair CMA functionality on
> PAE machines:
>
>   - alignment must be a 64-bit type when running on systems with 64-bit
>     physical addresses.  If this is not the case, the limit calculation thunks
>     allocations down to an address range < 4G.
>
>   - The allocated range check is removed. On 32bit ARM kernel with LPAE
>     enabled the base may be allocated outside the fist 4GB of physical
>     memory (keystone SoC for example).
>
> Signed-off-by: Vitaly Andrianov <vitalya@xxxxxx>
> Signed-off-by: Cyril Chemparathy <cyril@xxxxxx>

Acked-by: Michal Nazarewicz <mina86@xxxxxxxxxx>

> diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
> index 9a14694..097dd44 100644
> --- a/drivers/base/dma-contiguous.c
> +++ b/drivers/base/dma-contiguous.c
> @@ -60,8 +60,8 @@ struct cma *dma_contiguous_default_area;
>   * Users, who want to set the size of global CMA area for their system
>   * should use cma= kernel parameter.
>   */
> -static const unsigned long size_bytes = CMA_SIZE_MBYTES * SZ_1M;
> -static long size_cmdline = -1;
> +static const phys_addr_t size_bytes = CMA_SIZE_MBYTES * SZ_1M;
> +static phys_addr_t size_cmdline = -1;
>  
>  static int __init early_cma(char *p)
>  {
> @@ -73,7 +73,7 @@ early_param("cma", early_cma);
>  
>  #ifdef CONFIG_CMA_SIZE_PERCENTAGE
>  
> -static unsigned long __init __maybe_unused cma_early_percent_memory(void)
> +static phys_addr_t __init __maybe_unused cma_early_percent_memory(void)
>  {
>  	struct memblock_region *reg;
>  	unsigned long total_pages = 0;
> @@ -91,7 +91,7 @@ static unsigned long __init __maybe_unused cma_early_percent_memory(void)
>  
>  #else
>  
> -static inline __maybe_unused unsigned long cma_early_percent_memory(void)
> +static inline __maybe_unused phys_addr_t cma_early_percent_memory(void)
>  {
>  	return 0;
>  }
> @@ -109,7 +109,7 @@ static inline __maybe_unused unsigned long cma_early_percent_memory(void)
>   */
>  void __init dma_contiguous_reserve(phys_addr_t limit)
>  {
> -	unsigned long selected_size = 0;
> +	phys_addr_t selected_size = 0;
>  
>  	pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit);
>  
> @@ -129,7 +129,7 @@ void __init dma_contiguous_reserve(phys_addr_t limit)
>  
>  	if (selected_size) {
>  		pr_debug("%s: reserving %ld MiB for global area\n", __func__,
> -			 selected_size / SZ_1M);
> +			 (unsigned long)selected_size / SZ_1M);
>  
>  		dma_declare_contiguous(NULL, selected_size, 0, limit);
>  	}
> @@ -230,11 +230,11 @@ core_initcall(cma_init_reserved_areas);
>   * called by board specific code when early allocator (memblock or bootmem)
>   * is still activate.
>   */
> -int __init dma_declare_contiguous(struct device *dev, unsigned long size,
> +int __init dma_declare_contiguous(struct device *dev, phys_addr_t size,
>  				  phys_addr_t base, phys_addr_t limit)
>  {
>  	struct cma_reserved *r = &cma_reserved[cma_reserved_count];
> -	unsigned long alignment;
> +	phys_addr_t alignment;
>  
>  	pr_debug("%s(size %lx, base %08lx, limit %08lx)\n", __func__,
>  		 (unsigned long)size, (unsigned long)base,
> @@ -271,10 +271,6 @@ int __init dma_declare_contiguous(struct device *dev, unsigned long size,
>  		if (!addr) {
>  			base = -ENOMEM;
>  			goto err;
> -		} else if (addr + size > ~(unsigned long)0) {
> -			memblock_free(addr, size);
> -			base = -EINVAL;
> -			goto err;
>  		} else {
>  			base = addr;
>  		}
> diff --git a/include/linux/dma-contiguous.h b/include/linux/dma-contiguous.h
> index 2f303e4..01b5c84 100644
> --- a/include/linux/dma-contiguous.h
> +++ b/include/linux/dma-contiguous.h
> @@ -68,7 +68,7 @@ struct device;
>  extern struct cma *dma_contiguous_default_area;
>  
>  void dma_contiguous_reserve(phys_addr_t addr_limit);
> -int dma_declare_contiguous(struct device *dev, unsigned long size,
> +int dma_declare_contiguous(struct device *dev, phys_addr_t size,
>  			   phys_addr_t base, phys_addr_t limit);
>  
>  struct page *dma_alloc_from_contiguous(struct device *dev, int count,
> @@ -83,7 +83,7 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages,
>  static inline void dma_contiguous_reserve(phys_addr_t limit) { }
>  
>  static inline
> -int dma_declare_contiguous(struct device *dev, unsigned long size,
> +int dma_declare_contiguous(struct device *dev, phys_addr_t size,
>  			   phys_addr_t base, phys_addr_t limit)
>  {
>  	return -ENOSYS;

-- 
Best regards,                                         _     _
.o. | Liege of Serenely Enlightened Majesty of      o' \,=./ `o
..o | Computer Science,  MichaÅ âmina86â Nazarewicz    (o o)
ooo +----<email/xmpp: mpn@xxxxxxxxxx>--------------ooO--(_)--Ooo--

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