Re: [PATCH v3] cxl: Rename mem to pci

[Ben Widawsky <ben.widawsky@intel.com>]

On 21-05-26 10:44:13, Ben Widawsky wrote:
> As the driver has undergone development, it's become clear that the
> majority [entirety?] of the current functionality in mem.c is actually a
> layer encapsulating functionality exposed through PCI based
> interactions. This layer can be used either in isolation or to provide
> functionality for higher level functionality.
> 
> CXL capabilities exist in a parallel domain to PCIe. CXL devices are
> enumerable and controllable via "legacy" PCIe mechanisms; however, their
> CXL capabilities are a superset of PCIe. For example, a CXL device may
> be connected to a non-CXL capable PCIe root port, and therefore will not
> be able to participate in CXL.mem or CXL.cache operations, but can still
> be accessed through PCIe mechanisms for CXL.io operations.
> 
> To properly represent the PCI nature of this driver, and in preparation for
> introducing a new driver for the CXL.mem / HDM decoder (Host-managed Device
> Memory) capabilities of a CXL memory expander, rename mem.c to pci.c so that
> mem.c is available for this new driver.
> 
> The result of the change is that there is a clear layering distinction
> in the driver, and a systems administrator may load only the cxl_pci
> module and gain access to such operations as, firmware update, offline
> provisioning of devices, and error collection. In addition to freeing up
> the file name for another purpose, there are two primary reasons this is
> useful,
>     1. Acting upon devices which don't have full CXL capabilities. This
>        may happen for instance if the CXL device is connected in a CXL
>        unaware part of the platform topology.
>     2. Userspace-first provisioning for devices without kernel driver
>        interference. This may be useful when provisioning a new device
>        in a specific manner that might otherwise be blocked or prevented
>        by the real CXL mem driver.
> 
> Reviewed-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>

[snip]

I forgot to put the reasoning for v3...

I accidentally left acpi.o in the Makefile. The only diff from v2 is acpi.o is
dropped.

Ben