Re: [PATCH RFC 06/18] accel/qda: Add memory manager for CB devices

[Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>]

On 2/24/2026 4:20 AM, Dmitry Baryshkov wrote:
> On Tue, Feb 24, 2026 at 12:39:00AM +0530, Ekansh Gupta wrote:
>> Introduce a per-device memory manager for the QDA driver that tracks
>> IOMMU-capable compute context-bank (CB) devices. Each CB device is
>> represented by a qda_iommu_device and registered with a central
>> qda_memory_manager instance owned by qda_dev.
>>
>> The memory manager maintains an xarray of devices and assigns a
>> unique ID to each CB. It also provides basic lifetime management
> Sounds like IDR.
I was planning to stick with xarray accross QDA as IDR gives checkpatch warnings.
>
>> and a workqueue for deferred device removal. qda_cb_setup_device()
> What is deferred device removal? Why do you need it?
This is not needed, I was trying some experiment in my initial design(CB aggregation),
but it's not needed now, I'll remove this.
>
>> now allocates a qda_iommu_device for each CB and registers it with
>> the memory manager after DMA configuration succeeds.
>>
>> qda_init_device() is extended to allocate and initialize the memory
>> manager, while qda_deinit_device() will tear it down in later
>> patches. This prepares the QDA driver for fine-grained memory and
>> IOMMU domain management tied to individual CB devices.
>>
>> Signed-off-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>
>> ---
>>  drivers/accel/qda/Makefile             |   1 +
>>  drivers/accel/qda/qda_cb.c             |  32 +++++++
>>  drivers/accel/qda/qda_drv.c            |  46 ++++++++++
>>  drivers/accel/qda/qda_drv.h            |   3 +
>>  drivers/accel/qda/qda_memory_manager.c | 152 +++++++++++++++++++++++++++++++++
>>  drivers/accel/qda/qda_memory_manager.h | 101 ++++++++++++++++++++++
>>  6 files changed, 335 insertions(+)
>>