linux/drivers/cxl
Dan Williams f6b8ab32e3 cxl/memdev: Make mailbox functionality optional
In support of the Linux CXL core scaling for a wider set of CXL devices,
allow for the creation of memdevs with some memory device capabilities
disabled. Specifically, allow for CXL devices outside of those claiming
to be compliant with the generic CXL memory device class code, like
vendor specific Type-2/3 devices that host CXL.mem. This implies, allow
for the creation of memdevs that only support component-registers, not
necessarily memory-device-registers (like mailbox registers). A memdev
derived from a CXL endpoint that does not support generic class code
expectations is tagged "CXL_DEVTYPE_DEVMEM", while a memdev derived from a
class-code compliant endpoint is tagged "CXL_DEVTYPE_CLASSMEM".

The primary assumption of a CXL_DEVTYPE_DEVMEM memdev is that it
optionally may not host a mailbox. Disable the command passthrough ioctl
for memdevs that are not CXL_DEVTYPE_CLASSMEM, and return empty strings
from memdev attributes associated with data retrieved via the
class-device-standard IDENTIFY command. Note that empty strings were
chosen over attribute visibility to maintain compatibility with shipping
versions of cxl-cli that expect those attributes to always be present.
Once cxl-cli has dropped that requirement this workaround can be
deprecated.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168679260782.3436160.7587293613945445365.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2023-06-25 14:31:08 -07:00
..
core cxl/memdev: Make mailbox functionality optional 2023-06-25 14:31:08 -07:00
acpi.c Merge branch 'for-6.3/cxl-ram-region' into cxl/next 2023-02-10 18:11:01 -08:00
cxl.h cxl/regs: Clarify when a 'struct cxl_register_map' is input vs output 2023-06-25 14:31:08 -07:00
cxlmem.h cxl/memdev: Make mailbox functionality optional 2023-06-25 14:31:08 -07:00
cxlpci.h cxl: Wait Memory_Info_Valid before access memory related info 2023-05-18 16:42:41 -07:00
Kconfig Merge branch 'for-6.3/cxl-ram-region' into cxl/next 2023-02-10 18:11:01 -08:00
Makefile cxl/pmem: Introduce nvdimm_security_ops with ->get_flags() operation 2022-11-30 16:30:47 -08:00
mem.c cxl/mbox: Move mailbox related driver state to its own data structure 2023-06-25 14:31:08 -07:00
pci.c cxl/mbox: Move mailbox related driver state to its own data structure 2023-06-25 14:31:08 -07:00
pmem.c cxl/mbox: Move mailbox related driver state to its own data structure 2023-06-25 14:31:08 -07:00
port.c cxl: Move cxl_await_media_ready() to before capacity info retrieval 2023-05-18 16:43:45 -07:00
security.c cxl/mbox: Move mailbox related driver state to its own data structure 2023-06-25 14:31:08 -07:00