RE: [PATCH v4 02/17] remoteproc: add rproc_va_to_pa function

[Loic PALLARDY]

Hi Suman,

> -----Original Message-----
> From: Suman Anna <s-anna@xxxxxx>
> Sent: mardi 23 octobre 2018 18:51
> To: Loic PALLARDY <loic.pallardy@xxxxxx>; bjorn.andersson@xxxxxxxxxx;
> ohad@xxxxxxxxxx
> Cc: linux-remoteproc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> Arnaud POULIQUEN <arnaud.pouliquen@xxxxxx>;
> benjamin.gaignard@xxxxxxxxxx
> Subject: Re: [PATCH v4 02/17] remoteproc: add rproc_va_to_pa function
> 
> Hi Loic, Bjorn,
> 
> On 7/27/18 8:14 AM, Loic Pallardy wrote:
> > This new function translates CPU virtual address in
> > CPU physical one according to virtual address location.
> >
> > Signed-off-by: Loic Pallardy <loic.pallardy@xxxxxx>
> > Acked-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> > ---
> >  drivers/remoteproc/remoteproc_core.c | 18 +++++++++++++++++-
> >  1 file changed, 17 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/remoteproc/remoteproc_core.c
> b/drivers/remoteproc/remoteproc_core.c
> > index 437fabf..8e5fe1e 100644
> > --- a/drivers/remoteproc/remoteproc_core.c
> > +++ b/drivers/remoteproc/remoteproc_core.c
> > @@ -140,6 +140,22 @@ static void rproc_disable_iommu(struct rproc
> *rproc)
> >  	iommu_domain_free(domain);
> >  }
> >
> > +static phys_addr_t rproc_va_to_pa(void *cpu_addr)
> > +{
> > +	/*
> > +	 * Return physical address according to virtual address location
> > +	 * - in vmalloc: if region ioremapped or defined as
> dma_alloc_coherent
> > +	 * - in kernel: if region allocated in generic dma memory pool
> > +	 */
> > +	if (is_vmalloc_addr(cpu_addr)) {
> > +		return page_to_phys(vmalloc_to_page(cpu_addr)) +
> > +				    offset_in_page(cpu_addr);
> > +	}
> > +
> > +	WARN_ON(!virt_addr_valid(cpu_addr));
> > +	return virt_to_phys(cpu_addr);
> > +}
> > +
> >  /**
> >   * rproc_da_to_va() - lookup the kernel virtual address for a remoteproc
> address
> >   * @rproc: handle of a remote processor
> > @@ -711,7 +727,7 @@ static int rproc_handle_carveout(struct rproc
> *rproc,
> >  	 * In this case, the device address and the physical address
> >  	 * are the same.
> >  	 */
> > -	rsc->pa = dma;
> > +	rsc->pa = (u32)rproc_va_to_pa(va);
> 
> While I agree with the direction here, we ought to add a check here
> warning users if some address bits are getting lost as a result of the
> typecast. Granted the issue may have been present previously with
> dma_addr_t as well, but most platforms were using 32-bit dma addresses,
> so this was kinda masked. There are ARMv7 platforms with LPAE enabled
> allowing physical addresses > 32-bits.
> 
> In anycase, we definitely have a need for a v2 for the fw_rsc_carveout
> structure to deal with 64-bit addresses.
> 

Agree with you.
Assumption for this series was to keep resource table as it is. Resource table improvement is planned in a second step.
Regards,
Loic

> regards
> Suman
> 
> >
> >  	carveout->va = va;
> >  	carveout->len = rsc->len;
> >