8c2f7e8658
NVDIMM namespaces, in addition to accepting "struct bio" based requests, also have the capability to perform byte-aligned accesses. By default only the bio/block interface is used. However, if another driver can make effective use of the byte-aligned capability it can claim namespace interface and use the byte-aligned ->rw_bytes() interface. The BTT driver is the initial first consumer of this mechanism to allow adding atomic sector update semantics to a pmem or blk namespace. This patch is the sysfs infrastructure to allow configuring a BTT instance for a namespace. Enabling that BTT and performing i/o is in a subsequent patch. Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
99 lines
2.5 KiB
C
99 lines
2.5 KiB
C
/*
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* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/nd.h>
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#include "nd.h"
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static int nd_region_probe(struct device *dev)
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{
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int err;
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struct nd_region_namespaces *num_ns;
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struct nd_region *nd_region = to_nd_region(dev);
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int rc = nd_region_register_namespaces(nd_region, &err);
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num_ns = devm_kzalloc(dev, sizeof(*num_ns), GFP_KERNEL);
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if (!num_ns)
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return -ENOMEM;
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if (rc < 0)
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return rc;
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num_ns->active = rc;
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num_ns->count = rc + err;
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dev_set_drvdata(dev, num_ns);
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if (rc && err && rc == err)
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return -ENODEV;
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nd_region->btt_seed = nd_btt_create(nd_region);
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if (err == 0)
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return 0;
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/*
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* Given multiple namespaces per region, we do not want to
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* disable all the successfully registered peer namespaces upon
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* a single registration failure. If userspace is missing a
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* namespace that it expects it can disable/re-enable the region
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* to retry discovery after correcting the failure.
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* <regionX>/namespaces returns the current
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* "<async-registered>/<total>" namespace count.
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*/
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dev_err(dev, "failed to register %d namespace%s, continuing...\n",
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err, err == 1 ? "" : "s");
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return 0;
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}
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static int child_unregister(struct device *dev, void *data)
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{
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nd_device_unregister(dev, ND_SYNC);
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return 0;
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}
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static int nd_region_remove(struct device *dev)
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{
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struct nd_region *nd_region = to_nd_region(dev);
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/* flush attribute readers and disable */
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nvdimm_bus_lock(dev);
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nd_region->ns_seed = NULL;
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nd_region->btt_seed = NULL;
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dev_set_drvdata(dev, NULL);
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nvdimm_bus_unlock(dev);
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device_for_each_child(dev, NULL, child_unregister);
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return 0;
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}
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static struct nd_device_driver nd_region_driver = {
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.probe = nd_region_probe,
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.remove = nd_region_remove,
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.drv = {
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.name = "nd_region",
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},
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.type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM,
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};
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int __init nd_region_init(void)
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{
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return nd_driver_register(&nd_region_driver);
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}
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void nd_region_exit(void)
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{
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driver_unregister(&nd_region_driver.drv);
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}
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MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM);
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MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_BLK);
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