These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / drivers / nvdimm / region.c

diff --git a/kernel/drivers/nvdimm/region.c b/kernel/drivers/nvdimm/region.c
new file mode 100644 (file)
index 0000000..7da63ea
--- /dev/null
+++ b/kernel/drivers/nvdimm/region.c
@@ -0,0 +1,116 @@
+/*
+ * 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);
+       nd_region->pfn_seed = nd_pfn_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;
+       nd_region->pfn_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);