diff options
| author | Ben Widawsky <ben.widawsky@intel.com> | 2022-02-04 18:18:31 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2022-02-09 09:57:32 +0300 |
| commit | 8dd2bc0f8e02d39bd80851ca787bcbdb7d495e69 (patch) | |
| tree | 827f38afbf5d9584f967a51c3d454de09a47b3ff /drivers/cxl/cxl.h | |
| parent | 2703c16c75aea142c3079ec34ae2262c0557ef7f (diff) | |
| download | linux-8dd2bc0f8e02d39bd80851ca787bcbdb7d495e69.tar.xz | |
cxl/mem: Add the cxl_mem driver
At this point the subsystem can enumerate all CXL ports (CXL.mem decode
resources in upstream switch ports and host bridges) in a system. The
last mile is connecting those ports to endpoints.
The cxl_mem driver connects an endpoint device to the platform CXL.mem
protoctol decode-topology. At ->probe() time it walks its
device-topology-ancestry and adds a CXL Port object at every Upstream
Port hop until it gets to CXL root. The CXL root object is only present
after a platform firmware driver registers platform CXL resources. For
ACPI based platform this is managed by the ACPI0017 device and the
cxl_acpi driver.
The ports are registered such that disabling a given port automatically
unregisters all descendant ports, and the chain can only be registered
after the root is established.
Given ACPI device scanning may run asynchronously compared to PCI device
scanning the root driver is tasked with rescanning the bus after the
root successfully probes.
Conversely if any ports in a chain between the root and an endpoint
becomes disconnected it subsequently triggers the endpoint to
unregister. Given lock depenedencies the endpoint unregistration happens
in a workqueue asynchronously. If userspace cares about synchronizing
delayed work after port events the /sys/bus/cxl/flush attribute is
available for that purpose.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
[djbw: clarify changelog, rework hotplug support]
Link: https://lore.kernel.org/r/164398782997.903003.9725273241627693186.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl/cxl.h')
| -rw-r--r-- | drivers/cxl/cxl.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index de4fbe7cbf42..f5e5b4ac8228 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -328,6 +328,9 @@ struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport, struct cxl_port *parent_port); struct cxl_port *find_cxl_root(struct device *dev); int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd); +int cxl_bus_rescan(void); +struct cxl_port *cxl_mem_find_port(struct cxl_memdev *cxlmd); +bool schedule_cxl_memdev_detach(struct cxl_memdev *cxlmd); struct cxl_dport *devm_cxl_add_dport(struct cxl_port *port, struct device *dport, int port_id, @@ -345,6 +348,8 @@ struct cxl_decoder *cxl_switch_decoder_alloc(struct cxl_port *port, int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map); int cxl_decoder_add_locked(struct cxl_decoder *cxld, int *target_map); int cxl_decoder_autoremove(struct device *host, struct cxl_decoder *cxld); +int cxl_endpoint_autoremove(struct cxl_memdev *cxlmd, struct cxl_port *endpoint); + struct cxl_hdm; struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port); int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm); @@ -377,6 +382,7 @@ void cxl_driver_unregister(struct cxl_driver *cxl_drv); #define CXL_DEVICE_NVDIMM 2 #define CXL_DEVICE_PORT 3 #define CXL_DEVICE_ROOT 4 +#define CXL_DEVICE_MEMORY_EXPANDER 5 #define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*") #define CXL_MODALIAS_FMT "cxl:t%d" |