Re: [PATCH 1/3] crypto: marvell/cesa - replace dma_to_phys with dma_map_single

[okaya]

On 2016-03-17 18:54, Russell King - ARM Linux wrote:
> On Thu, Mar 17, 2016 at 06:02:15PM -0400, Sinan Kaya wrote:
> > Getting ready to remove dma_to_phys API. Drivers should not be
> > using this API for DMA operations. Instead, they should go
> > through the dma_map or dma_alloc APIs.
> >
> > Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
> > ---
> >  drivers/crypto/marvell/cesa.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/crypto/marvell/cesa.c 
> > b/drivers/crypto/marvell/cesa.c
> > index c0656e7..52ddfa4 100644
> > --- a/drivers/crypto/marvell/cesa.c
> > +++ b/drivers/crypto/marvell/cesa.c
> > @@ -350,8 +350,8 @@ 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_single(cesa->dev, engine->sram,
> > +					  DMA_TO_DEVICE);
>
> Documentation/DMA-API.txt
>
> dma_addr_t
> dma_map_single(struct device *dev, void *cpu_addr, size_t size,
>                       enum dma_data_direction direction)
>
> Notes:  Not all memory regions in a machine can be mapped by this API.
> Further, contiguous kernel virtual space may not be contiguous as
> physical memory.  Since this API does not provide any scatter/gather
> capability, it will fail if the user tries to map a non-physically
> contiguous piece of memory.  For this reason, memory to be mapped by
> this API should be obtained from sources which guarantee it to be
> physically contiguous (like kmalloc).
>
> Specifically, ioremapped memory will *not* work as you expect with
> dma_map_single().


What is the correct way? I don't want to write engine->sram_dma = sram