[linux-2.6-block.git] / drivers / nvdimm / region.c

/*
 * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 */
#include <linux/cpumask.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/nd.h>
#include "nd.h"

static int nd_region_probe(struct device *dev)
{
	int err, rc;
	static unsigned long once;
	struct nd_region_namespaces *num_ns;
	struct nd_region *nd_region = to_nd_region(dev);

	if (nd_region->num_lanes > num_online_cpus()
			&& nd_region->num_lanes < num_possible_cpus()
			&& !test_and_set_bit(0, &once)) {
		dev_info(dev, "online cpus (%d) < concurrent i/o lanes (%d) < possible cpus (%d)\n",
				num_online_cpus(), nd_region->num_lanes,
				num_possible_cpus());
		dev_info(dev, "setting nr_cpus=%d may yield better libnvdimm device performance\n",
				nd_region->num_lanes);
	}

	rc = nd_blk_region_init(nd_region);
	if (rc)
		return rc;

	rc = nd_region_register_namespaces(nd_region, &err);
	num_ns = devm_kzalloc(dev, sizeof(*num_ns), GFP_KERNEL);
	if (!num_ns)
		return -ENOMEM;

	if (rc < 0)
		return rc;

	num_ns->active = rc;
	num_ns->count = rc + err;
	dev_set_drvdata(dev, num_ns);

	if (rc && err && rc == err)
		return -ENODEV;

	nd_region->btt_seed = nd_btt_create(nd_region);
	if (err == 0)
		return 0;

	/*
	 * Given multiple namespaces per region, we do not want to
	 * disable all the successfully registered peer namespaces upon
	 * a single registration failure.  If userspace is missing a
	 * namespace that it expects it can disable/re-enable the region
	 * to retry discovery after correcting the failure.
	 * <regionX>/namespaces returns the current
	 * "<async-registered>/<total>" namespace count.
	 */
	dev_err(dev, "failed to register %d namespace%s, continuing...\n",
			err, err == 1 ? "" : "s");
	return 0;
}

static int child_unregister(struct device *dev, void *data)
{
	nd_device_unregister(dev, ND_SYNC);
	return 0;
}

static int nd_region_remove(struct device *dev)
{
	struct nd_region *nd_region = to_nd_region(dev);

	/* flush attribute readers and disable */
	nvdimm_bus_lock(dev);
	nd_region->ns_seed = NULL;
	nd_region->btt_seed = NULL;
	dev_set_drvdata(dev, NULL);
	nvdimm_bus_unlock(dev);

	device_for_each_child(dev, NULL, child_unregister);
	return 0;
}

static struct nd_device_driver nd_region_driver = {
	.probe = nd_region_probe,
	.remove = nd_region_remove,
	.drv = {
		.name = "nd_region",
	},
	.type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM,
};

int __init nd_region_init(void)
{
	return nd_driver_register(&nd_region_driver);
}

void nd_region_exit(void)
{
	driver_unregister(&nd_region_driver.drv);
}

MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM);
MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_BLK);
Commit	Line	Data
3d88002e DW	1	/*
	2	* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of version 2 of the GNU General Public License as
	6	* published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful, but
	9	* WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	11	* General Public License for more details.
	12	*/
5212e11f	13	#include <linux/cpumask.h>
3d88002e DW	14	#include <linux/module.h>
	15	#include <linux/device.h>
	16	#include <linux/nd.h>
	17	#include "nd.h"
	18
	19	static int nd_region_probe(struct device *dev)
	20	{
047fc8a1	21	int err, rc;
5212e11f	22	static unsigned long once;
3d88002e DW	23	struct nd_region_namespaces *num_ns;
3d88002e DW	24	struct nd_region *nd_region = to_nd_region(dev);
3d88002e	25
5212e11f VV	26	if (nd_region->num_lanes > num_online_cpus()
	27	&& nd_region->num_lanes < num_possible_cpus()
	28	&& !test_and_set_bit(0, &once)) {
	29	dev_info(dev, "online cpus (%d) < concurrent i/o lanes (%d) < possible cpus (%d)\n",
	30	num_online_cpus(), nd_region->num_lanes,
	31	num_possible_cpus());
	32	dev_info(dev, "setting nr_cpus=%d may yield better libnvdimm device performance\n",
	33	nd_region->num_lanes);
	34	}
	35
047fc8a1 RZ	36	rc = nd_blk_region_init(nd_region);
	37	if (rc)
	38	return rc;
	39
	40	rc = nd_region_register_namespaces(nd_region, &err);
3d88002e DW	41	num_ns = devm_kzalloc(dev, sizeof(*num_ns), GFP_KERNEL);
	42	if (!num_ns)
	43	return -ENOMEM;
	44
	45	if (rc < 0)
	46	return rc;
	47
	48	num_ns->active = rc;
	49	num_ns->count = rc + err;
	50	dev_set_drvdata(dev, num_ns);
	51
8c2f7e86 DW	52	if (rc && err && rc == err)
	53	return -ENODEV;
	54
	55	nd_region->btt_seed = nd_btt_create(nd_region);
3d88002e DW	56	if (err == 0)
	57	return 0;
	58
3d88002e DW	59	/*
	60	* Given multiple namespaces per region, we do not want to
	61	* disable all the successfully registered peer namespaces upon
	62	* a single registration failure. If userspace is missing a
	63	* namespace that it expects it can disable/re-enable the region
	64	* to retry discovery after correcting the failure.
	65	* <regionX>/namespaces returns the current
	66	* "<async-registered>/<total>" namespace count.
	67	*/
	68	dev_err(dev, "failed to register %d namespace%s, continuing...\n",
	69	err, err == 1 ? "" : "s");
	70	return 0;
	71	}
	72
	73	static int child_unregister(struct device dev, void data)
	74	{
	75	nd_device_unregister(dev, ND_SYNC);
	76	return 0;
	77	}
	78
	79	static int nd_region_remove(struct device *dev)
	80	{
bf9bccc1 DW	81	struct nd_region *nd_region = to_nd_region(dev);
bf9bccc1 DW	82
3d88002e DW	83	/* flush attribute readers and disable */
3d88002e DW	84	nvdimm_bus_lock(dev);
bf9bccc1	85	nd_region->ns_seed = NULL;
8c2f7e86	86	nd_region->btt_seed = NULL;
3d88002e DW	87	dev_set_drvdata(dev, NULL);
	88	nvdimm_bus_unlock(dev);
	89
	90	device_for_each_child(dev, NULL, child_unregister);
	91	return 0;
	92	}
	93
	94	static struct nd_device_driver nd_region_driver = {
	95	.probe = nd_region_probe,
	96	.remove = nd_region_remove,
	97	.drv = {
	98	.name = "nd_region",
	99	},
	100	.type = ND_DRIVER_REGION_BLK \| ND_DRIVER_REGION_PMEM,
	101	};
	102
	103	int __init nd_region_init(void)
	104	{
	105	return nd_driver_register(&nd_region_driver);
	106	}
	107
	108	void nd_region_exit(void)
	109	{
	110	driver_unregister(&nd_region_driver.drv);
	111	}
	112
	113	MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM);
	114	MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_BLK);