Re: [PATCH v3 2/4] misc: fastrpc: Rename phys to dma_addr for clarity

[Kumari Pallavi <kumari.pallavi@oss.qualcomm.com>]

On 11/14/2025 5:45 PM, Dmitry Baryshkov wrote:
>> Update all references of buf->phys and map->phys to buf->dma_addr and
>> map->dma_addr to accurately represent that these fields store DMA
>> addresses, not physical addresses. This change improves code clarity
>> and aligns with kernel conventions for dma_addr_t usage.
> Why do you mention dma_addr_t here?
> 

I mentioned dma_addr_t in the commit message because of the earlier 
feedback highlighted about the confusing use of phys for fields that 
actually store an IOVA-like address ('phys' with something more fitting 
for an IOVA or DMA address).

https://lore.kernel.org/all/969bdb49-0682-4345-98f7-523404bb4213@app.fastmail.com/

>> Signed-off-by: Kumari Pallavi<kumari.pallavi@oss.qualcomm.com>
>> ---
>>   drivers/misc/fastrpc.c | 76 ++++++++++++++++++++++--------------------
>>   1 file changed, 40 insertions(+), 36 deletions(-)
>>
>> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
>> index ee652ef01534..d6a7960fe716 100644
>> --- a/drivers/misc/fastrpc.c
>> +++ b/drivers/misc/fastrpc.c
>> @@ -106,7 +106,7 @@
>>   #define miscdev_to_fdevice(d) container_of(d, struct fastrpc_device, miscdev)
>>   
>>   struct fastrpc_phy_page {
>> -	u64 addr;		/* physical address */
>> +	u64 addr;		/* physical or dma address */
> What is the difference here? Aren't all of them DMA addresses?

Yes, correct—both represent DMA addresses, just typed differently 
depending on whether it originate from a physical or DMA mapping context.

ACK, I will update this in the next patch series.

Thanks,
Pallavi