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

[Suman Anna <s-anna@ti.com>]

On 10/24/18 7:58 AM, Loic PALLARDY wrote:
> 
> 
>> -----Original Message-----
>> From: Suman Anna <s-anna@ti.com>
>> Sent: mercredi 24 octobre 2018 05:19
>> To: Loic PALLARDY <loic.pallardy@st.com>; bjorn.andersson@linaro.org;
>> ohad@wizery.com
>> Cc: linux-remoteproc@vger.kernel.org; linux-kernel@vger.kernel.org;
>> Arnaud POULIQUEN <arnaud.pouliquen@st.com>;
>> benjamin.gaignard@linaro.org
>> 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@ti.com>
>>>> Sent: mardi 23 octobre 2018 18:51
>>>> To: Loic PALLARDY <loic.pallardy@st.com>; bjorn.andersson@linaro.org;
>>>> ohad@wizery.com
>>>> Cc: linux-remoteproc@vger.kernel.org; linux-kernel@vger.kernel.org;
>>>> Arnaud POULIQUEN <arnaud.pouliquen@st.com>;
>>>> benjamin.gaignard@linaro.org
>>>> 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@st.com>
>>>>> Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
>>>>> ---
>>>>>  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

Yes, thanks.

regards
Suman

> Regards,
> Loic
>>
>> regards
>> Suman
>>
>>> Regards,
>>> Loic
>>>
>>>> regards
>>>> Suman
>>>>
>>>>>
>>>>>  	carveout->va = va;
>>>>>  	carveout->len = rsc->len;
>>>>>
>>>
>