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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
commite5fd91f1ef340da553f7a79da9540c3db711c937 (patch)
treeb11842027dc6641da63f4bcc524f8678263304a3 /drivers/nvdimm/region.c
parent2a9b0348e685a63d97486f6749622b61e9e3292f (diff)
Linux-libre 4.2-gnu
Diffstat (limited to 'drivers/nvdimm/region.c')
-rw-r--r--drivers/nvdimm/region.c114
1 files changed, 114 insertions, 0 deletions
diff --git a/drivers/nvdimm/region.c b/drivers/nvdimm/region.c
new file mode 100644
index 000000000..f28f78ccf
--- /dev/null
+++ b/drivers/nvdimm/region.c
@@ -0,0 +1,114 @@
+/*
+ * 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);