diff options
author | Dan Williams <dan.j.williams@intel.com> | 2021-06-15 16:18:11 -0700 |
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committer | Dan Williams <dan.j.williams@intel.com> | 2021-06-15 16:46:34 -0700 |
commit | 6af7139c979474a29a6ad642c9bf32d92e24c5bc (patch) | |
tree | 8e971a9c4b6f2475858c80d5d0902a92994e680d | |
parent | 87815ee9d0060a91bdf18266e42837a9adb5972e (diff) | |
download | linux-6af7139c979474a29a6ad642c9bf32d92e24c5bc.tar.bz2 |
cxl/core: Add cxl-bus driver infrastructure
Enable devices on the 'cxl' bus to be attached to drivers. The initial
user of this functionality is a driver for an 'nvdimm-bridge' device
that anchors a libnvdimm hierarchy attached to CXL persistent memory
resources. Other device types that will leverage this include:
cxl_port: map and use component register functionality (HDM Decoders)
cxl_nvdimm: translate CXL memory expander endpoints to libnvdimm
'nvdimm' objects
cxl_region: translate CXL interleave sets to libnvdimm 'region' objects
The pairing of devices to drivers is handled through the cxl_device_id()
matching to cxl_driver.id values. A cxl_device_id() of '0' indicates no
driver support.
In addition to ->match(), ->probe(), and ->remove() support for the
'cxl' bus introduce MODULE_ALIAS_CXL() to autoload modules containing
cxl-drivers. Drivers are added in follow-on changes.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/162379909190.2993820.6134168109678004186.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
-rw-r--r-- | drivers/cxl/core.c | 73 | ||||
-rw-r--r-- | drivers/cxl/cxl.h | 22 |
2 files changed, 95 insertions, 0 deletions
diff --git a/drivers/cxl/core.c b/drivers/cxl/core.c index c613dc795498..68d6afea363b 100644 --- a/drivers/cxl/core.c +++ b/drivers/cxl/core.c @@ -767,8 +767,81 @@ int cxl_map_device_regs(struct pci_dev *pdev, } EXPORT_SYMBOL_GPL(cxl_map_device_regs); +/** + * __cxl_driver_register - register a driver for the cxl bus + * @cxl_drv: cxl driver structure to attach + * @owner: owning module/driver + * @modname: KBUILD_MODNAME for parent driver + */ +int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner, + const char *modname) +{ + if (!cxl_drv->probe) { + pr_debug("%s ->probe() must be specified\n", modname); + return -EINVAL; + } + + if (!cxl_drv->name) { + pr_debug("%s ->name must be specified\n", modname); + return -EINVAL; + } + + if (!cxl_drv->id) { + pr_debug("%s ->id must be specified\n", modname); + return -EINVAL; + } + + cxl_drv->drv.bus = &cxl_bus_type; + cxl_drv->drv.owner = owner; + cxl_drv->drv.mod_name = modname; + cxl_drv->drv.name = cxl_drv->name; + + return driver_register(&cxl_drv->drv); +} +EXPORT_SYMBOL_GPL(__cxl_driver_register); + +void cxl_driver_unregister(struct cxl_driver *cxl_drv) +{ + driver_unregister(&cxl_drv->drv); +} +EXPORT_SYMBOL_GPL(cxl_driver_unregister); + +static int cxl_device_id(struct device *dev) +{ + return 0; +} + +static int cxl_bus_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + return add_uevent_var(env, "MODALIAS=" CXL_MODALIAS_FMT, + cxl_device_id(dev)); +} + +static int cxl_bus_match(struct device *dev, struct device_driver *drv) +{ + return cxl_device_id(dev) == to_cxl_drv(drv)->id; +} + +static int cxl_bus_probe(struct device *dev) +{ + return to_cxl_drv(dev->driver)->probe(dev); +} + +static int cxl_bus_remove(struct device *dev) +{ + struct cxl_driver *cxl_drv = to_cxl_drv(dev->driver); + + if (cxl_drv->remove) + cxl_drv->remove(dev); + return 0; +} + struct bus_type cxl_bus_type = { .name = "cxl", + .uevent = cxl_bus_uevent, + .match = cxl_bus_match, + .probe = cxl_bus_probe, + .remove = cxl_bus_remove, }; EXPORT_SYMBOL_GPL(cxl_bus_type); diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 97a273ae3947..a6f8e7097ea2 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -268,4 +268,26 @@ devm_cxl_add_passthrough_decoder(struct device *host, struct cxl_port *port) } extern struct bus_type cxl_bus_type; + +struct cxl_driver { + const char *name; + int (*probe)(struct device *dev); + void (*remove)(struct device *dev); + struct device_driver drv; + int id; +}; + +static inline struct cxl_driver *to_cxl_drv(struct device_driver *drv) +{ + return container_of(drv, struct cxl_driver, drv); +} + +int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner, + const char *modname); +#define cxl_driver_register(x) __cxl_driver_register(x, THIS_MODULE, KBUILD_MODNAME) +void cxl_driver_unregister(struct cxl_driver *cxl_drv); + +#define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*") +#define CXL_MODALIAS_FMT "cxl:t%d" + #endif /* __CXL_H__ */ |