Re: [PATCH 4/6] zram: Add QPaCE zcomp backend

[Georgi Djakov]

On 10/1/2026 1:27 PM, Sergey Senozhatsky wrote:
> On (26/10/01 10:51), Krzysztof Kozlowski wrote:
>> On Wed, Sep 30, 2026 at 07:52:13AM -0700, Georgi Djakov wrote:
>>> Add a zcomp backend for the Qualcomm Page Compression Engine (QPaCE) so
>>> zram can expose qpace-lz4 as a selectable compression algorithm when the
>>> QPaCE driver is available.
>>>
>>> Compress and decompress operations are handled via the QPaCE urgent
>>> synchronous path: each request DMA-maps the source and destination
>>> buffers, issues a blocking hardware command, and returns the result size.
>>>
>>> Signed-off-by: Georgi Djakov <georgi.djakov@xxxxxxxxxxxxxxxx>
>>> ---
>>>  drivers/block/zram/Kconfig         |  11 +++
>>>  drivers/block/zram/Makefile        |   1 +
>>>  drivers/block/zram/backend_qpace.c | 134 +++++++++++++++++++++++++++++
>>
>> So entire qpace should go here, no? Why did you create this entire layer
>> of indirection, singleton management under drivers/soc?
> 
> qpace seems to be standalone/independent arch/soc specific, and can gain
> users outside of zram (fs compression, zswap, etc.).  zram's backends
> potentially can disappear all together, if we switch to acomp crypto API.

Are there any plans for switching back to the acomp crypto API? We moved away
from it some time ago and dropped all the crypto dependency in favor of the
custom comp backends, right?

Thanks,
Georgi