2018-01-10 15:15:43

by Robin Murphy

[permalink] [raw]
Subject: [PATCH] crypto: marvell/cesa - Fix DMA API misuse

phys_to_dma() is an internal helper for certain DMA API implementations,
and is not appropriate for drivers to use. It appears that what the CESA
driver really wants to be using is dma_map_resource() - admittedly that
didn't exist when the offending code was first merged, but it does now.

Signed-off-by: Robin Murphy <[email protected]>
---

Found by inspection and compile-tested only

drivers/crypto/marvell/cesa.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/crypto/marvell/cesa.c b/drivers/crypto/marvell/cesa.c
index 293832488cc9..f81fa4a3e66b 100644
--- a/drivers/crypto/marvell/cesa.c
+++ b/drivers/crypto/marvell/cesa.c
@@ -15,6 +15,7 @@
*/

#include <linux/delay.h>
+#include <linux/dma-mapping.h>
#include <linux/genalloc.h>
#include <linux/interrupt.h>
#include <linux/io.h>
@@ -409,8 +410,11 @@ static int mv_cesa_get_sram(struct platform_device *pdev, int idx)
if (IS_ERR(engine->sram))
return PTR_ERR(engine->sram);

- engine->sram_dma = phys_to_dma(cesa->dev,
- (phys_addr_t)res->start);
+ engine->sram_dma = dma_map_resource(cesa->dev, res->start,
+ cesa->sram_size,
+ DMA_BIDIRECTIONAL, 0);
+ if (dma_mapping_error(cesa->dev, engine->sram_dma))
+ return -ENOMEM;

return 0;
}
@@ -420,11 +424,12 @@ static void mv_cesa_put_sram(struct platform_device *pdev, int idx)
struct mv_cesa_dev *cesa = platform_get_drvdata(pdev);
struct mv_cesa_engine *engine = &cesa->engines[idx];

- if (!engine->pool)
- return;
-
- gen_pool_free(engine->pool, (unsigned long)engine->sram,
- cesa->sram_size);
+ if (engine->pool)
+ gen_pool_free(engine->pool, (unsigned long)engine->sram,
+ cesa->sram_size);
+ else
+ dma_unmap_resource(cesa->dev, engine->sram_dma,
+ cesa->sram_size, DMA_BIDIRECTIONAL, 0);
}

static int mv_cesa_probe(struct platform_device *pdev)
--
2.13.4.dirty


2018-01-10 15:25:34

by Boris Brezillon

[permalink] [raw]
Subject: Re: [PATCH] crypto: marvell/cesa - Fix DMA API misuse

On Wed, 10 Jan 2018 15:15:43 +0000
Robin Murphy <[email protected]> wrote:

> phys_to_dma() is an internal helper for certain DMA API implementations,
> and is not appropriate for drivers to use. It appears that what the CESA
> driver really wants to be using is dma_map_resource() - admittedly that
> didn't exist when the offending code was first merged, but it does now.
>
> Signed-off-by: Robin Murphy <[email protected]>

Acked-by: Boris Brezillon <[email protected]>

> ---
>
> Found by inspection and compile-tested only
>
> drivers/crypto/marvell/cesa.c | 19 ++++++++++++-------
> 1 file changed, 12 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/crypto/marvell/cesa.c b/drivers/crypto/marvell/cesa.c
> index 293832488cc9..f81fa4a3e66b 100644
> --- a/drivers/crypto/marvell/cesa.c
> +++ b/drivers/crypto/marvell/cesa.c
> @@ -15,6 +15,7 @@
> */
>
> #include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> #include <linux/genalloc.h>
> #include <linux/interrupt.h>
> #include <linux/io.h>
> @@ -409,8 +410,11 @@ static int mv_cesa_get_sram(struct platform_device *pdev, int idx)
> if (IS_ERR(engine->sram))
> return PTR_ERR(engine->sram);
>
> - engine->sram_dma = phys_to_dma(cesa->dev,
> - (phys_addr_t)res->start);
> + engine->sram_dma = dma_map_resource(cesa->dev, res->start,
> + cesa->sram_size,
> + DMA_BIDIRECTIONAL, 0);
> + if (dma_mapping_error(cesa->dev, engine->sram_dma))
> + return -ENOMEM;
>
> return 0;
> }
> @@ -420,11 +424,12 @@ static void mv_cesa_put_sram(struct platform_device *pdev, int idx)
> struct mv_cesa_dev *cesa = platform_get_drvdata(pdev);
> struct mv_cesa_engine *engine = &cesa->engines[idx];
>
> - if (!engine->pool)
> - return;
> -
> - gen_pool_free(engine->pool, (unsigned long)engine->sram,
> - cesa->sram_size);
> + if (engine->pool)
> + gen_pool_free(engine->pool, (unsigned long)engine->sram,
> + cesa->sram_size);
> + else
> + dma_unmap_resource(cesa->dev, engine->sram_dma,
> + cesa->sram_size, DMA_BIDIRECTIONAL, 0);
> }
>
> static int mv_cesa_probe(struct platform_device *pdev)

2018-01-10 15:48:17

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH] crypto: marvell/cesa - Fix DMA API misuse

On Wed, Jan 10, 2018 at 04:25:22PM +0100, Boris Brezillon wrote:
> On Wed, 10 Jan 2018 15:15:43 +0000
> Robin Murphy <[email protected]> wrote:
>
> > phys_to_dma() is an internal helper for certain DMA API implementations,
> > and is not appropriate for drivers to use. It appears that what the CESA
> > driver really wants to be using is dma_map_resource() - admittedly that
> > didn't exist when the offending code was first merged, but it does now.
> >
> > Signed-off-by: Robin Murphy <[email protected]>
>
> Acked-by: Boris Brezillon <[email protected]>

Thanks. Robin, Boris: do you want me to pick this up in the
dma-mapping tree and move it before the dma-direct.h introduction?

2018-01-10 16:23:20

by Boris Brezillon

[permalink] [raw]
Subject: Re: [PATCH] crypto: marvell/cesa - Fix DMA API misuse

Hi Christoph,

On Wed, 10 Jan 2018 16:48:17 +0100
Christoph Hellwig <[email protected]> wrote:

> On Wed, Jan 10, 2018 at 04:25:22PM +0100, Boris Brezillon wrote:
> > On Wed, 10 Jan 2018 15:15:43 +0000
> > Robin Murphy <[email protected]> wrote:
> >
> > > phys_to_dma() is an internal helper for certain DMA API implementations,
> > > and is not appropriate for drivers to use. It appears that what the CESA
> > > driver really wants to be using is dma_map_resource() - admittedly that
> > > didn't exist when the offending code was first merged, but it does now.
> > >
> > > Signed-off-by: Robin Murphy <[email protected]>
> >
> > Acked-by: Boris Brezillon <[email protected]>
>
> Thanks. Robin, Boris: do you want me to pick this up in the
> dma-mapping tree and move it before the dma-direct.h introduction?

You should probably sync with Herbert, I'm just the maintainer of this
driver, not the crypto subsystem.

Regards,

Boris

2018-01-18 12:03:14

by Herbert Xu

[permalink] [raw]
Subject: Re: [PATCH] crypto: marvell/cesa - Fix DMA API misuse

On Wed, Jan 10, 2018 at 03:15:43PM +0000, Robin Murphy wrote:
> phys_to_dma() is an internal helper for certain DMA API implementations,
> and is not appropriate for drivers to use. It appears that what the CESA
> driver really wants to be using is dma_map_resource() - admittedly that
> didn't exist when the offending code was first merged, but it does now.
>
> Signed-off-by: Robin Murphy <[email protected]>

Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt