diff options
author | Dan Williams <dan.j.williams@intel.com> | 2021-06-16 02:36:31 +0300 |
---|---|---|
committer | Dan Williams <dan.j.williams@intel.com> | 2021-06-16 02:47:34 +0300 |
commit | 21083f51521fb0f60dbac591f175c3ed48435af4 (patch) | |
tree | f9b813ffc5cd6d524b55a1888bb5c2d136c5fe76 /drivers/cxl/pmem.c | |
parent | 2bbafda405c04cfed1b57b761d13ada3154c0f89 (diff) | |
download | linux-21083f51521fb0f60dbac591f175c3ed48435af4.tar.xz |
cxl/pmem: Register 'pmem' / cxl_nvdimm devices
While a memX device on /sys/bus/cxl represents a CXL memory expander
control interface, a pmemX device represents the persistent memory
sub-functionality. It bridges the CXL subystem to the libnvdimm nmemX
control interface.
With this skeleton ndctl can now see persistent memory devices on a
"CXL" bus. Later patches add support for translating libnvdimm native
commands to CXL commands.
# ndctl list -BDiu -b CXL
{
"provider":"CXL",
"dev":"ndbus1",
"dimms":[
{
"dev":"nmem1",
"state":"disabled"
},
{
"dev":"nmem0",
"state":"disabled"
}
]
}
Given nvdimm_bus_unregister() removes all devices on an ndbus0 the
cxl_pmem infrastructure needs to arrange ->remove() to be triggered on
cxl_nvdimm devices to keep their enabled state synchronized with the
registration state of their corresponding device on the nvdimm_bus. In
other words, always arrange for cxl_nvdimm_driver.remove() to unregister
nvdimms from an nvdimm_bus ahead of the bus being unregistered.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/162380012696.3039556.4293801691038740850.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl/pmem.c')
-rw-r--r-- | drivers/cxl/pmem.c | 108 |
1 files changed, 99 insertions, 9 deletions
diff --git a/drivers/cxl/pmem.c b/drivers/cxl/pmem.c index 8365839856dc..0088e41dd2f3 100644 --- a/drivers/cxl/pmem.c +++ b/drivers/cxl/pmem.c @@ -3,7 +3,10 @@ #include <linux/libnvdimm.h> #include <linux/device.h> #include <linux/module.h> +#include <linux/ndctl.h> +#include <linux/async.h> #include <linux/slab.h> +#include "mem.h" #include "cxl.h" /* @@ -13,6 +16,62 @@ */ static struct workqueue_struct *cxl_pmem_wq; +static void unregister_nvdimm(void *nvdimm) +{ + nvdimm_delete(nvdimm); +} + +static int match_nvdimm_bridge(struct device *dev, const void *data) +{ + return strcmp(dev_name(dev), "nvdimm-bridge") == 0; +} + +static struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(void) +{ + struct device *dev; + + dev = bus_find_device(&cxl_bus_type, NULL, NULL, match_nvdimm_bridge); + if (!dev) + return NULL; + return to_cxl_nvdimm_bridge(dev); +} + +static int cxl_nvdimm_probe(struct device *dev) +{ + struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev); + struct cxl_nvdimm_bridge *cxl_nvb; + unsigned long flags = 0; + struct nvdimm *nvdimm; + int rc = -ENXIO; + + cxl_nvb = cxl_find_nvdimm_bridge(); + if (!cxl_nvb) + return -ENXIO; + + device_lock(&cxl_nvb->dev); + if (!cxl_nvb->nvdimm_bus) + goto out; + + set_bit(NDD_LABELING, &flags); + nvdimm = nvdimm_create(cxl_nvb->nvdimm_bus, cxl_nvd, NULL, flags, 0, 0, + NULL); + if (!nvdimm) + goto out; + + rc = devm_add_action_or_reset(dev, unregister_nvdimm, nvdimm); +out: + device_unlock(&cxl_nvb->dev); + put_device(&cxl_nvb->dev); + + return rc; +} + +static struct cxl_driver cxl_nvdimm_driver = { + .name = "cxl_nvdimm", + .probe = cxl_nvdimm_probe, + .id = CXL_DEVICE_NVDIMM, +}; + static int cxl_pmem_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm, unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc) @@ -29,19 +88,34 @@ static bool online_nvdimm_bus(struct cxl_nvdimm_bridge *cxl_nvb) return cxl_nvb->nvdimm_bus != NULL; } -static void offline_nvdimm_bus(struct cxl_nvdimm_bridge *cxl_nvb) +static int cxl_nvdimm_release_driver(struct device *dev, void *data) { - if (!cxl_nvb->nvdimm_bus) + if (!is_cxl_nvdimm(dev)) + return 0; + device_release_driver(dev); + return 0; +} + +static void offline_nvdimm_bus(struct nvdimm_bus *nvdimm_bus) +{ + if (!nvdimm_bus) return; - nvdimm_bus_unregister(cxl_nvb->nvdimm_bus); - cxl_nvb->nvdimm_bus = NULL; + + /* + * Set the state of cxl_nvdimm devices to unbound / idle before + * nvdimm_bus_unregister() rips the nvdimm objects out from + * underneath them. + */ + bus_for_each_dev(&cxl_bus_type, NULL, NULL, cxl_nvdimm_release_driver); + nvdimm_bus_unregister(nvdimm_bus); } static void cxl_nvb_update_state(struct work_struct *work) { struct cxl_nvdimm_bridge *cxl_nvb = container_of(work, typeof(*cxl_nvb), state_work); - bool release = false; + struct nvdimm_bus *victim_bus = NULL; + bool release = false, rescan = false; device_lock(&cxl_nvb->dev); switch (cxl_nvb->state) { @@ -50,11 +124,13 @@ static void cxl_nvb_update_state(struct work_struct *work) dev_err(&cxl_nvb->dev, "failed to establish nvdimm bus\n"); release = true; - } + } else + rescan = true; break; case CXL_NVB_OFFLINE: case CXL_NVB_DEAD: - offline_nvdimm_bus(cxl_nvb); + victim_bus = cxl_nvb->nvdimm_bus; + cxl_nvb->nvdimm_bus = NULL; break; default: break; @@ -63,6 +139,12 @@ static void cxl_nvb_update_state(struct work_struct *work) if (release) device_release_driver(&cxl_nvb->dev); + if (rescan) { + int rc = bus_rescan_devices(&cxl_bus_type); + + dev_dbg(&cxl_nvb->dev, "rescan: %d\n", rc); + } + offline_nvdimm_bus(victim_bus); put_device(&cxl_nvb->dev); } @@ -118,17 +200,24 @@ static __init int cxl_pmem_init(void) rc = cxl_driver_register(&cxl_nvdimm_bridge_driver); if (rc) - goto err; + goto err_bridge; + + rc = cxl_driver_register(&cxl_nvdimm_driver); + if (rc) + goto err_nvdimm; return 0; -err: +err_nvdimm: + cxl_driver_unregister(&cxl_nvdimm_bridge_driver); +err_bridge: destroy_workqueue(cxl_pmem_wq); return rc; } static __exit void cxl_pmem_exit(void) { + cxl_driver_unregister(&cxl_nvdimm_driver); cxl_driver_unregister(&cxl_nvdimm_bridge_driver); destroy_workqueue(cxl_pmem_wq); } @@ -138,3 +227,4 @@ module_init(cxl_pmem_init); module_exit(cxl_pmem_exit); MODULE_IMPORT_NS(CXL); MODULE_ALIAS_CXL(CXL_DEVICE_NVDIMM_BRIDGE); +MODULE_ALIAS_CXL(CXL_DEVICE_NVDIMM); |