Unlike the decoder enumeration for "root decoders" described by platform
firmware, standard decoders can be enumerated from the component
registers space once the base address has been identified (via PCI,
ACPI, or another mechanism).
Add common infrastructure for HDM (Host-managed-Device-Memory) Decoder
enumeration and share it between host-bridge, upstream switch port, and
cxl_test defined decoders.
The locking model for switch level decoders is to hold the port lock
over the enumeration. This facilitates moving the dport and decoder
enumeration to a 'port' driver. For now, the only enumerator of decoder
resources is the cxl_acpi root driver.
Co-developed-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/164374688404.395335.9239248252443123526.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The kbuild robot reports:
drivers/cxl/core/bus.c:516:1: warning: stack frame size (1032) exceeds
limit (1024) in function 'devm_cxl_add_decoder'
It is also the case the devm_cxl_add_decoder() is unwieldy to use for
all the different decoder types. Fix the stack usage by splitting the
creation into alloc and add steps. This also allows for context
specific construction before adding.
With the split the caller is responsible for registering a devm callback
to trigger device_unregister() for the decoder rather than it being
implicit in the decoder registration. I.e. the routine that calls alloc
is responsible for calling put_device() if the "add" operation fails.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Ben Widawsky <ben.widawsky@intel.com>
Link: https://lore.kernel.org/r/163225205828.3038145.6831131648369404859.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Now that the internals of mailbox operations are abstracted from the PCI
specifics a bulk of infrastructure can move to the core.
The CXL_PMEM driver intends to proxy LIBNVDIMM UAPI and driver requests
to the equivalent functionality provided by the CXL hardware mailbox
interface. In support of that intent move the mailbox implementation to
a shared location for the CXL_PCI driver native IOCTL path and CXL_PMEM
nvdimm command proxy path to share.
A unit test framework seeks to implement a unit test backend transport
for mailbox commands to communicate mocked up payloads. It can reuse all
of the mailbox infrastructure minus the PCI specifics, so that also gets
moved to the core.
Finally with the mailbox infrastructure and ioctl handling being
transport generic there is no longer any need to pass file
file_operations to devm_cxl_add_memdev(). That allows all the ioctl
boilerplate to move into the core for unit test reuse.
No functional change intended, just code movement.
Acked-by: Ben Widawsky <ben.widawsky@intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/163116435233.2460985.16197340449713287180.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The motivation for moving cxl_memdev allocation to the core (beyond
better file organization of sysfs attributes in core/ and drivers in
cxl/), is that device lifetime is longer than module lifetime. The cxl_pci
module should be free to come and go without needing to coordinate with
devices that need the text associated with cxl_memdev_release() to stay
resident. The move fixes a use after free bug when looping driver
load / unload with CONFIG_DEBUG_KOBJECT_RELEASE=y.
Another motivation for disconnecting cxl_memdev creation from cxl_pci is
to enable other drivers, like a unit test driver, to registers memdevs.
Fixes: b39cb1052a ("cxl/mem: Register CXL memX devices")
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/162792540495.368511.9748638751088219595.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Refactor the pmem / nvdimm-bridge functionality from core/bus.c to
core/pmem.c. Introduce drivers/core/core.h to communicate data
structures and helpers between the core bus and other functionality that
registers devices on the bus.
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/162792538899.368511.3881663908293411300.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Dan Williams