1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
  4 */
  5#include <linux/memregion.h>
  6#include <linux/cpumask.h>
  7#include <linux/module.h>
  8#include <linux/device.h>
  9#include <linux/nd.h>
 10#include "nd-core.h"
 11#include "nd.h"
 12
 13static int nd_region_probe(struct device *dev)
 14{
 15	int err, rc;
 16	static unsigned long once;
 17	struct nd_region_data *ndrd;
 18	struct nd_region *nd_region = to_nd_region(dev);
 19	struct range range = {
 20		.start = nd_region->ndr_start,
 21		.end = nd_region->ndr_start + nd_region->ndr_size - 1,
 22	};
 23
 24	if (nd_region->num_lanes > num_online_cpus()
 25			&& nd_region->num_lanes < num_possible_cpus()
 26			&& !test_and_set_bit(0, &once)) {
 27		dev_dbg(dev, "online cpus (%d) < concurrent i/o lanes (%d) < possible cpus (%d)\n",
 28				num_online_cpus(), nd_region->num_lanes,
 29				num_possible_cpus());
 30		dev_dbg(dev, "setting nr_cpus=%d may yield better libnvdimm device performance\n",
 31				nd_region->num_lanes);
 32	}
 33
 34	rc = nd_region_activate(nd_region);
 35	if (rc)
 36		return rc;
 37
 38	if (devm_init_badblocks(dev, &nd_region->bb))
 39		return -ENODEV;
 40	nd_region->bb_state =
 41		sysfs_get_dirent(nd_region->dev.kobj.sd, "badblocks");
 42	if (!nd_region->bb_state)
 43		dev_warn(dev, "'badblocks' notification disabled\n");
 44	nvdimm_badblocks_populate(nd_region, &nd_region->bb, &range);
 45
 46	rc = nd_region_register_namespaces(nd_region, &err);
 47	if (rc < 0)
 48		return rc;
 49
 50	ndrd = dev_get_drvdata(dev);
 51	ndrd->ns_active = rc;
 52	ndrd->ns_count = rc + err;
 53
 54	if (rc && err && rc == err)
 55		return -ENODEV;
 56
 57	nd_region->btt_seed = nd_btt_create(nd_region);
 58	nd_region->pfn_seed = nd_pfn_create(nd_region);
 59	nd_region->dax_seed = nd_dax_create(nd_region);
 60	if (err == 0)
 61		return 0;
 62
 63	/*
 64	 * Given multiple namespaces per region, we do not want to
 65	 * disable all the successfully registered peer namespaces upon
 66	 * a single registration failure.  If userspace is missing a
 67	 * namespace that it expects it can disable/re-enable the region
 68	 * to retry discovery after correcting the failure.
 69	 * <regionX>/namespaces returns the current
 70	 * "<async-registered>/<total>" namespace count.
 71	 */
 72	dev_err(dev, "failed to register %d namespace%s, continuing...\n",
 73			err, err == 1 ? "" : "s");
 74	return 0;
 75}
 76
 77static int child_unregister(struct device *dev, void *data)
 78{
 79	nd_device_unregister(dev, ND_SYNC);
 80	return 0;
 81}
 82
 83static void nd_region_remove(struct device *dev)
 84{
 85	struct nd_region *nd_region = to_nd_region(dev);
 86
 87	device_for_each_child(dev, NULL, child_unregister);
 88
 89	/* flush attribute readers and disable */
 90	nvdimm_bus_lock(dev);
 91	nd_region->ns_seed = NULL;
 92	nd_region->btt_seed = NULL;
 93	nd_region->pfn_seed = NULL;
 94	nd_region->dax_seed = NULL;
 95	dev_set_drvdata(dev, NULL);
 96	nvdimm_bus_unlock(dev);
 97
 98	/*
 99	 * Note, this assumes device_lock() context to not race
100	 * nd_region_notify()
101	 */
102	sysfs_put(nd_region->bb_state);
103	nd_region->bb_state = NULL;
104
105	/*
106	 * Try to flush caches here since a disabled region may be subject to
107	 * secure erase while disabled, and previous dirty data should not be
108	 * written back to a new instance of the region. This only matters on
109	 * bare metal where security commands are available, so silent failure
110	 * here is ok.
111	 */
112	if (cpu_cache_has_invalidate_memregion())
113		cpu_cache_invalidate_memregion(IORES_DESC_PERSISTENT_MEMORY);
114}
115
116static int child_notify(struct device *dev, void *data)
117{
118	nd_device_notify(dev, *(enum nvdimm_event *) data);
119	return 0;
120}
121
122static void nd_region_notify(struct device *dev, enum nvdimm_event event)
123{
124	if (event == NVDIMM_REVALIDATE_POISON) {
125		struct nd_region *nd_region = to_nd_region(dev);
126
127		if (is_memory(&nd_region->dev)) {
128			struct range range = {
129				.start = nd_region->ndr_start,
130				.end = nd_region->ndr_start +
131					nd_region->ndr_size - 1,
132			};
133
134			nvdimm_badblocks_populate(nd_region,
135					&nd_region->bb, &range);
136			if (nd_region->bb_state)
137				sysfs_notify_dirent(nd_region->bb_state);
138		}
139	}
140	device_for_each_child(dev, &event, child_notify);
141}
142
143static struct nd_device_driver nd_region_driver = {
144	.probe = nd_region_probe,
145	.remove = nd_region_remove,
146	.notify = nd_region_notify,
147	.drv = {
148		.name = "nd_region",
149	},
150	.type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM,
151};
152
153int __init nd_region_init(void)
154{
155	return nd_driver_register(&nd_region_driver);
156}
157
158void nd_region_exit(void)
159{
160	driver_unregister(&nd_region_driver.drv);
161}
162
163MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM);