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

[Loic PALLARDY]

> -----Original Message-----
> From: Suman Anna <s-anna@xxxxxx>
> Sent: mercredi 24 octobre 2018 05:19
> 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
> 
> On 10/23/18 2:51 PM, Loic PALLARDY wrote:
> > 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.
> 
> Perhaps, we should add a WARN_ON for the time being until we enhance
> the
> resource table for 64-bit platforms/addresses.

OK I will propose a patch to add WARN_ON on cast applied on resource table field
Regards,
Loic
> 
> regards
> Suman
> 
> > Regards,
> > Loic
> >
> >> regards
> >> Suman
> >>
> >>>
> >>>  	carveout->va = va;
> >>>  	carveout->len = rsc->len;
> >>>
> >