[cip-dev] [PATCH] net: davinci_cpdma: use dma_addr_t for DMA address

[cip-dev] [PATCH] net: davinci_cpdma: use dma_addr_t for DMA address

[Nobuhiro Iwamatsu]

From: Arnd Bergmann <arnd@arndb.de>

commit 84092996673211f16ef3b942a191d7952e9dfea9 upstream.

The davinci_cpdma mixes up physical addresses as seen from the CPU
and DMA addresses as seen from a DMA master, since it can operate
on both normal memory or an on-chip buffer. If dma_addr_t is
different from phys_addr_t, this means we get a compile-time warning
about the type mismatch:

ethernet/ti/davinci_cpdma.c: In function 'cpdma_desc_pool_create':
ethernet/ti/davinci_cpdma.c:182:48: error: passing argument 3 of 'dma_alloc_coherent' from incompatible pointer type [-Werror=incompatible-pointer-types]
   pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys,
In file included from ethernet/ti/davinci_cpdma.c:21:0:
dma-mapping.h:398:21: note: expected 'dma_addr_t * {aka long long unsigned int *}' but argument is of type 'phys_addr_t * {aka unsigned int *}'
 static inline void *dma_alloc_coherent(struct device *dev, size_t size,

This slightly restructures the code so the address we use for
mapping RAM into a DMA address is always a dma_addr_t, avoiding
the warning. The code is correct even if both types are 32-bit
because the DMA master in this device only supports 32-bit addressing
anyway, independent of the types that are used.

We still assign this value to pool->phys, and that is wrong if
the driver is ever used with an IOMMU, but that value appears to
be never used, so there is no problem really. I've added a couple
of comments about where we do things that are slightly violating
the API.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
---
 drivers/net/ethernet/ti/davinci_cpdma.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c
index 657b65bf5cac..18bf3a8fdc50 100644
--- a/drivers/net/ethernet/ti/davinci_cpdma.c
+++ b/drivers/net/ethernet/ti/davinci_cpdma.c
@@ -82,7 +82,7 @@ struct cpdma_desc {
 
 struct cpdma_desc_pool {
 	phys_addr_t		phys;
-	u32			hw_addr;
+	dma_addr_t		hw_addr;
 	void __iomem		*iomap;		/* ioremap map */
 	void			*cpumap;	/* dma_alloc map */
 	int			desc_size, mem_size;
@@ -152,7 +152,7 @@ struct cpdma_chan {
  * abstract out these details
  */
 static struct cpdma_desc_pool *
-cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr,
+cpdma_desc_pool_create(struct device *dev, u32 phys, dma_addr_t hw_addr,
 				int size, int align)
 {
 	int bitmap_size;
@@ -176,13 +176,13 @@ cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr,
 
 	if (phys) {
 		pool->phys  = phys;
-		pool->iomap = ioremap(phys, size);
+		pool->iomap = ioremap(phys, size); /* should be memremap? */
 		pool->hw_addr = hw_addr;
 	} else {
-		pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys,
+		pool->cpumap = dma_alloc_coherent(dev, size, &pool->hw_addr,
 						  GFP_KERNEL);
-		pool->iomap = pool->cpumap;
-		pool->hw_addr = pool->phys;
+		pool->iomap = (void __iomem __force *)pool->cpumap;
+		pool->phys = pool->hw_addr; /* assumes no IOMMU, don't use this value */
 	}
 
 	if (pool->iomap)
-- 
2.23.0

[cip-dev] [PATCH] net: davinci_cpdma: use dma_addr_t for DMA address

[nobuhiro1.iwamatsu at toshiba.co.jp]

Hi,

This patch is needed to fix following build error on linux-4.4.y-cip-rt:
  https://gitlab.com/cip-project/cip-kernel/linux-cip/-/jobs/297855132

This problem does not occur with 4.4.y-cip.
The following fixes have been added in RT and this will affect:
  https://git.kernel.org/pub/scm/linux/kernel/git/cip/linux-cip.git/tree/Makefile?h=linux-4.4.y-cip-rt#n826

Best regards,
  Nobuhiro

> -----Original Message-----
> From: cip-dev-bounces at lists.cip-project.org
> [mailto:cip-dev-bounces at lists.cip-project.org] On Behalf Of Nobuhiro
> Iwamatsu
> Sent: Wednesday, September 18, 2019 5:01 PM
> To: cip-dev at lists.cip-project.org
> Subject: [cip-dev] [PATCH] net: davinci_cpdma: use dma_addr_t for DMA
> address
> 
> From: Arnd Bergmann <arnd@arndb.de>
> 
> commit 84092996673211f16ef3b942a191d7952e9dfea9 upstream.
> 
> The davinci_cpdma mixes up physical addresses as seen from the CPU and
> DMA addresses as seen from a DMA master, since it can operate on both
> normal memory or an on-chip buffer. If dma_addr_t is different from
> phys_addr_t, this means we get a compile-time warning about the type
> mismatch:
> 
> ethernet/ti/davinci_cpdma.c: In function 'cpdma_desc_pool_create':
> ethernet/ti/davinci_cpdma.c:182:48: error: passing argument 3 of
> 'dma_alloc_coherent' from incompatible pointer type
> [-Werror=incompatible-pointer-types]
>    pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys, In file
> included from ethernet/ti/davinci_cpdma.c:21:0:
> dma-mapping.h:398:21: note: expected 'dma_addr_t * {aka long long
> unsigned int *}' but argument is of type 'phys_addr_t * {aka unsigned
> int *}'
>  static inline void *dma_alloc_coherent(struct device *dev, size_t size,
> 
> This slightly restructures the code so the address we use for mapping
> RAM into a DMA address is always a dma_addr_t, avoiding the warning. The
> code is correct even if both types are 32-bit because the DMA master in
> this device only supports 32-bit addressing anyway, independent of the
> types that are used.
> 
> We still assign this value to pool->phys, and that is wrong if the driver
> is ever used with an IOMMU, but that value appears to be never used, so
> there is no problem really. I've added a couple of comments about where
> we do things that are slightly violating the API.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: David S. Miller <davem@davemloft.net>
> Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
> ---
>  drivers/net/ethernet/ti/davinci_cpdma.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c
> b/drivers/net/ethernet/ti/davinci_cpdma.c
> index 657b65bf5cac..18bf3a8fdc50 100644
> --- a/drivers/net/ethernet/ti/davinci_cpdma.c
> +++ b/drivers/net/ethernet/ti/davinci_cpdma.c
> @@ -82,7 +82,7 @@ struct cpdma_desc {
> 
>  struct cpdma_desc_pool {
>  	phys_addr_t		phys;
> -	u32			hw_addr;
> +	dma_addr_t		hw_addr;
>  	void __iomem		*iomap;		/* ioremap map */
>  	void			*cpumap;	/* dma_alloc map */
>  	int			desc_size, mem_size;
> @@ -152,7 +152,7 @@ struct cpdma_chan {
>   * abstract out these details
>   */
>  static struct cpdma_desc_pool *
> -cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr,
> +cpdma_desc_pool_create(struct device *dev, u32 phys, dma_addr_t
> +hw_addr,
>  				int size, int align)
>  {
>  	int bitmap_size;
> @@ -176,13 +176,13 @@ cpdma_desc_pool_create(struct device *dev, u32 phys,
> u32 hw_addr,
> 
>  	if (phys) {
>  		pool->phys  = phys;
> -		pool->iomap = ioremap(phys, size);
> +		pool->iomap = ioremap(phys, size); /* should be
> memremap? */
>  		pool->hw_addr = hw_addr;
>  	} else {
> -		pool->cpumap = dma_alloc_coherent(dev, size,
> &pool->phys,
> +		pool->cpumap = dma_alloc_coherent(dev, size,
> &pool->hw_addr,
>  						  GFP_KERNEL);
> -		pool->iomap = pool->cpumap;
> -		pool->hw_addr = pool->phys;
> +		pool->iomap = (void __iomem __force *)pool->cpumap;
> +		pool->phys = pool->hw_addr; /* assumes no IOMMU, don't
> use this value
> +*/
>  	}
> 
>  	if (pool->iomap)
> --
> 2.23.0
> 
> _______________________________________________
> cip-dev mailing list
> cip-dev at lists.cip-project.org
> https://lists.cip-project.org/mailman/listinfo/cip-dev

[cip-dev] [PATCH] net: davinci_cpdma: use dma_addr_t for DMA address

[Pavel Machek]

Hi!

That indeed seems to fix the failure. Tree now
compiles, so I pushed the result.

Thanks for the patch!

Best regards,
								Pavel

> From: Arnd Bergmann <arnd@arndb.de>
> 
> commit 84092996673211f16ef3b942a191d7952e9dfea9 upstream.
> 
> The davinci_cpdma mixes up physical addresses as seen from the CPU
> and DMA addresses as seen from a DMA master, since it can operate
> on both normal memory or an on-chip buffer. If dma_addr_t is
> different from phys_addr_t, this means we get a compile-time warning
> about the type mismatch:
> 
> ethernet/ti/davinci_cpdma.c: In function 'cpdma_desc_pool_create':
> ethernet/ti/davinci_cpdma.c:182:48: error: passing argument 3 of 'dma_alloc_coherent' from incompatible pointer type [-Werror=incompatible-pointer-types]
>    pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys,
> In file included from ethernet/ti/davinci_cpdma.c:21:0:
> dma-mapping.h:398:21: note: expected 'dma_addr_t * {aka long long unsigned int *}' but argument is of type 'phys_addr_t * {aka unsigned int *}'
>  static inline void *dma_alloc_coherent(struct device *dev, size_t size,
> 
> This slightly restructures the code so the address we use for
> mapping RAM into a DMA address is always a dma_addr_t, avoiding
> the warning. The code is correct even if both types are 32-bit
> because the DMA master in this device only supports 32-bit addressing
> anyway, independent of the types that are used.
> 
> We still assign this value to pool->phys, and that is wrong if
> the driver is ever used with an IOMMU, but that value appears to
> be never used, so there is no problem really. I've added a couple
> of comments about where we do things that are slightly violating
> the API.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: David S. Miller <davem@davemloft.net>
> Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
> ---
>  drivers/net/ethernet/ti/davinci_cpdma.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c
> index 657b65bf5cac..18bf3a8fdc50 100644
> --- a/drivers/net/ethernet/ti/davinci_cpdma.c
> +++ b/drivers/net/ethernet/ti/davinci_cpdma.c
> @@ -82,7 +82,7 @@ struct cpdma_desc {
>  
>  struct cpdma_desc_pool {
>  	phys_addr_t		phys;
> -	u32			hw_addr;
> +	dma_addr_t		hw_addr;
>  	void __iomem		*iomap;		/* ioremap map */
>  	void			*cpumap;	/* dma_alloc map */
>  	int			desc_size, mem_size;
> @@ -152,7 +152,7 @@ struct cpdma_chan {
>   * abstract out these details
>   */
>  static struct cpdma_desc_pool *
> -cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr,
> +cpdma_desc_pool_create(struct device *dev, u32 phys, dma_addr_t hw_addr,
>  				int size, int align)
>  {
>  	int bitmap_size;
> @@ -176,13 +176,13 @@ cpdma_desc_pool_create(struct device *dev, u32 phys, u32 hw_addr,
>  
>  	if (phys) {
>  		pool->phys  = phys;
> -		pool->iomap = ioremap(phys, size);
> +		pool->iomap = ioremap(phys, size); /* should be memremap? */
>  		pool->hw_addr = hw_addr;
>  	} else {
> -		pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys,
> +		pool->cpumap = dma_alloc_coherent(dev, size, &pool->hw_addr,
>  						  GFP_KERNEL);
> -		pool->iomap = pool->cpumap;
> -		pool->hw_addr = pool->phys;
> +		pool->iomap = (void __iomem __force *)pool->cpumap;
> +		pool->phys = pool->hw_addr; /* assumes no IOMMU, don't use this value */
>  	}
>  
>  	if (pool->iomap)

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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