Re: [PATCH v3 1/2] dmaengine: idxd: Expose DSA3.0 capabilities through sysfs

[Vinod Koul <vkoul@kernel.org>]

On 21-08-25, 16:51, Yi Sun wrote:
> Introduce sysfs interfaces for 3 new Data Streaming Accelerator (DSA)
> capability registers (dsacap0-2) to enable userspace awareness of hardware
> features in DSA version 3 and later devices.
> 
> Userspace components (e.g. configure libraries, workload Apps) require this
> information to:
> 1. Select optimal data transfer strategies based on SGL capabilities
> 2. Enable hardware-specific optimizations for floating-point operations
> 3. Configure memory operations with proper numerical handling
> 4. Verify compute operation compatibility before submitting jobs
> 
> The output format is <dsacap2>,<dsacap1>,<dsacap0>, where each DSA
> capability value is a 64-bit hexadecimal number, separated by commas.
> The ordering follows the DSA 3.0 specification layout:
>  Offset:    0x190    0x188    0x180
>  Reg:       dsacap2  dsacap1  dsacap0
> 
> Example:
> cat /sys/bus/dsa/devices/dsa0/dsacaps
>  000000000000f18d,0014000e000007aa,00fa01ff01ff03ff

sysfs are supposed to be single values only, should we rather do per
capability? Also in future if you have more than three...? what happens
then?

-- 
~Vinod