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230 lines
5.2 KiB
230 lines
5.2 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* Copyright(c) 2021 Intel Corporation. All rights reserved. */ |
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#include <linux/libnvdimm.h> |
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#include <linux/device.h> |
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#include <linux/module.h> |
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#include <linux/ndctl.h> |
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#include <linux/async.h> |
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#include <linux/slab.h> |
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#include "mem.h" |
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#include "cxl.h" |
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/* |
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* Ordered workqueue for cxl nvdimm device arrival and departure |
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* to coordinate bus rescans when a bridge arrives and trigger remove |
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* operations when the bridge is removed. |
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*/ |
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static struct workqueue_struct *cxl_pmem_wq; |
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static void unregister_nvdimm(void *nvdimm) |
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{ |
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nvdimm_delete(nvdimm); |
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} |
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static int match_nvdimm_bridge(struct device *dev, const void *data) |
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{ |
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return strcmp(dev_name(dev), "nvdimm-bridge") == 0; |
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} |
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static struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(void) |
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{ |
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struct device *dev; |
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dev = bus_find_device(&cxl_bus_type, NULL, NULL, match_nvdimm_bridge); |
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if (!dev) |
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return NULL; |
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return to_cxl_nvdimm_bridge(dev); |
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} |
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static int cxl_nvdimm_probe(struct device *dev) |
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{ |
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struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev); |
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struct cxl_nvdimm_bridge *cxl_nvb; |
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unsigned long flags = 0; |
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struct nvdimm *nvdimm; |
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int rc = -ENXIO; |
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cxl_nvb = cxl_find_nvdimm_bridge(); |
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if (!cxl_nvb) |
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return -ENXIO; |
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device_lock(&cxl_nvb->dev); |
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if (!cxl_nvb->nvdimm_bus) |
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goto out; |
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set_bit(NDD_LABELING, &flags); |
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nvdimm = nvdimm_create(cxl_nvb->nvdimm_bus, cxl_nvd, NULL, flags, 0, 0, |
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NULL); |
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if (!nvdimm) |
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goto out; |
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rc = devm_add_action_or_reset(dev, unregister_nvdimm, nvdimm); |
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out: |
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device_unlock(&cxl_nvb->dev); |
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put_device(&cxl_nvb->dev); |
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return rc; |
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} |
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static struct cxl_driver cxl_nvdimm_driver = { |
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.name = "cxl_nvdimm", |
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.probe = cxl_nvdimm_probe, |
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.id = CXL_DEVICE_NVDIMM, |
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}; |
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static int cxl_pmem_ctl(struct nvdimm_bus_descriptor *nd_desc, |
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struct nvdimm *nvdimm, unsigned int cmd, void *buf, |
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unsigned int buf_len, int *cmd_rc) |
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{ |
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return -ENOTTY; |
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} |
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static bool online_nvdimm_bus(struct cxl_nvdimm_bridge *cxl_nvb) |
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{ |
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if (cxl_nvb->nvdimm_bus) |
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return true; |
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cxl_nvb->nvdimm_bus = |
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nvdimm_bus_register(&cxl_nvb->dev, &cxl_nvb->nd_desc); |
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return cxl_nvb->nvdimm_bus != NULL; |
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} |
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static int cxl_nvdimm_release_driver(struct device *dev, void *data) |
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{ |
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if (!is_cxl_nvdimm(dev)) |
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return 0; |
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device_release_driver(dev); |
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return 0; |
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} |
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static void offline_nvdimm_bus(struct nvdimm_bus *nvdimm_bus) |
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{ |
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if (!nvdimm_bus) |
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return; |
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/* |
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* Set the state of cxl_nvdimm devices to unbound / idle before |
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* nvdimm_bus_unregister() rips the nvdimm objects out from |
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* underneath them. |
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*/ |
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bus_for_each_dev(&cxl_bus_type, NULL, NULL, cxl_nvdimm_release_driver); |
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nvdimm_bus_unregister(nvdimm_bus); |
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} |
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static void cxl_nvb_update_state(struct work_struct *work) |
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{ |
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struct cxl_nvdimm_bridge *cxl_nvb = |
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container_of(work, typeof(*cxl_nvb), state_work); |
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struct nvdimm_bus *victim_bus = NULL; |
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bool release = false, rescan = false; |
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device_lock(&cxl_nvb->dev); |
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switch (cxl_nvb->state) { |
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case CXL_NVB_ONLINE: |
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if (!online_nvdimm_bus(cxl_nvb)) { |
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dev_err(&cxl_nvb->dev, |
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"failed to establish nvdimm bus\n"); |
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release = true; |
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} else |
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rescan = true; |
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break; |
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case CXL_NVB_OFFLINE: |
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case CXL_NVB_DEAD: |
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victim_bus = cxl_nvb->nvdimm_bus; |
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cxl_nvb->nvdimm_bus = NULL; |
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break; |
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default: |
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break; |
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} |
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device_unlock(&cxl_nvb->dev); |
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if (release) |
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device_release_driver(&cxl_nvb->dev); |
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if (rescan) { |
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int rc = bus_rescan_devices(&cxl_bus_type); |
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dev_dbg(&cxl_nvb->dev, "rescan: %d\n", rc); |
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} |
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offline_nvdimm_bus(victim_bus); |
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put_device(&cxl_nvb->dev); |
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} |
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static void cxl_nvdimm_bridge_remove(struct device *dev) |
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{ |
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struct cxl_nvdimm_bridge *cxl_nvb = to_cxl_nvdimm_bridge(dev); |
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if (cxl_nvb->state == CXL_NVB_ONLINE) |
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cxl_nvb->state = CXL_NVB_OFFLINE; |
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if (queue_work(cxl_pmem_wq, &cxl_nvb->state_work)) |
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get_device(&cxl_nvb->dev); |
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} |
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static int cxl_nvdimm_bridge_probe(struct device *dev) |
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{ |
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struct cxl_nvdimm_bridge *cxl_nvb = to_cxl_nvdimm_bridge(dev); |
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if (cxl_nvb->state == CXL_NVB_DEAD) |
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return -ENXIO; |
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if (cxl_nvb->state == CXL_NVB_NEW) { |
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cxl_nvb->nd_desc = (struct nvdimm_bus_descriptor) { |
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.provider_name = "CXL", |
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.module = THIS_MODULE, |
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.ndctl = cxl_pmem_ctl, |
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}; |
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INIT_WORK(&cxl_nvb->state_work, cxl_nvb_update_state); |
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} |
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cxl_nvb->state = CXL_NVB_ONLINE; |
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if (queue_work(cxl_pmem_wq, &cxl_nvb->state_work)) |
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get_device(&cxl_nvb->dev); |
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return 0; |
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} |
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static struct cxl_driver cxl_nvdimm_bridge_driver = { |
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.name = "cxl_nvdimm_bridge", |
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.probe = cxl_nvdimm_bridge_probe, |
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.remove = cxl_nvdimm_bridge_remove, |
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.id = CXL_DEVICE_NVDIMM_BRIDGE, |
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}; |
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static __init int cxl_pmem_init(void) |
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{ |
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int rc; |
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cxl_pmem_wq = alloc_ordered_workqueue("cxl_pmem", 0); |
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if (!cxl_pmem_wq) |
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return -ENXIO; |
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rc = cxl_driver_register(&cxl_nvdimm_bridge_driver); |
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if (rc) |
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goto err_bridge; |
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rc = cxl_driver_register(&cxl_nvdimm_driver); |
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if (rc) |
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goto err_nvdimm; |
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return 0; |
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err_nvdimm: |
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cxl_driver_unregister(&cxl_nvdimm_bridge_driver); |
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err_bridge: |
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destroy_workqueue(cxl_pmem_wq); |
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return rc; |
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} |
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static __exit void cxl_pmem_exit(void) |
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{ |
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cxl_driver_unregister(&cxl_nvdimm_driver); |
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cxl_driver_unregister(&cxl_nvdimm_bridge_driver); |
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destroy_workqueue(cxl_pmem_wq); |
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} |
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MODULE_LICENSE("GPL v2"); |
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module_init(cxl_pmem_init); |
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module_exit(cxl_pmem_exit); |
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MODULE_IMPORT_NS(CXL); |
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MODULE_ALIAS_CXL(CXL_DEVICE_NVDIMM_BRIDGE); |
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MODULE_ALIAS_CXL(CXL_DEVICE_NVDIMM);
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