Re: SDXI on AMD EPYC (in relation to Nathan’s SDXI dmaengine patchset)

[Nathan Lynch <nathan.lynch@amd.com>]

Karim Manaouil <kmanaouil.dev@gmail.com> writes:
>
> I have a dual-socket AMD EPYC 9004 in the lab (I pasted /proc/cpuinfo at
> the end) and I wanted to see if I can get the SDXI series from Nathan [2]
> to work on them, as this will open the door for me to experiment more on
> AMD hardware.
>
> I don't know if these CPUs are equipped with these accelerators or not.
> lspci is showing these devices (four on each NUMA node):
>
> # lspci | grep SDXI
> 06:00.1 System peripheral: Advanced Micro Devices, Inc. [AMD] SDXI
> 21:00.1 System peripheral: Advanced Micro Devices, Inc. [AMD] SDXI
> 41:00.1 System peripheral: Advanced Micro Devices, Inc. [AMD] SDXI
> 64:00.1 System peripheral: Advanced Micro Devices, Inc. [AMD] SDXI
> 81:00.1 System peripheral: Advanced Micro Devices, Inc. [AMD] SDXI
> a3:00.1 System peripheral: Advanced Micro Devices, Inc. [AMD] SDXI
> c1:00.1 System peripheral: Advanced Micro Devices, Inc. [AMD] SDXI
> e1:00.1 System peripheral: Advanced Micro Devices, Inc. [AMD] SDXI
>
> All of them have these PCI specs
>
> vendor=0x1022
> device=0x14dc
> class=0x088000
> subsystem_vendor=0x1458
> subsystem_device=0x1000
> BARs= 	BAR0/1 512 KiB prefetchable
> 	BAR2/3 512 KiB prefetchable
>
> Class 0x088000 is:
> base class    0x08  System peripheral
> subclass      0x80  Other system peripheral
>
> However, the PCI device class does not actually match the class from
> Nathan's patchset [2]:
>
> +#define PCI_CLASS_ACCELERATOR_SDXI		0x120100
>
> +static const struct pci_device_id sdxi_id_table[] = {
> +	{ PCI_DEVICE_CLASS(PCI_CLASS_ACCELERATOR_SDXI, 0xffffff) },
> +	{ }
> +};
>
> So these functions appear to be exposed as generic system peripherals
> (base class 0x08, subclass 0x80) rather than as SDXI processing
> accelerators (base class 0x12, subclass 0x01).
>
> Do you know whether these AMD 1022:14dc on this platform are actually
> SDXI accelerators?

Afraid I don't have any information about these devices. The driver
isn't intended to support them.