These changes are the raw update to linux-4.4.6-rt14. Kernel sources
[kvmfornfv.git] / kernel / drivers / nvdimm / btt_devs.c
diff --git a/kernel/drivers/nvdimm/btt_devs.c b/kernel/drivers/nvdimm/btt_devs.c
new file mode 100644 (file)
index 0000000..cb47751
--- /dev/null
@@ -0,0 +1,306 @@
+/*
+ * 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/blkdev.h>
+#include <linux/device.h>
+#include <linux/genhd.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include "nd-core.h"
+#include "btt.h"
+#include "nd.h"
+
+static void nd_btt_release(struct device *dev)
+{
+       struct nd_region *nd_region = to_nd_region(dev->parent);
+       struct nd_btt *nd_btt = to_nd_btt(dev);
+
+       dev_dbg(dev, "%s\n", __func__);
+       nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
+       ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
+       kfree(nd_btt->uuid);
+       kfree(nd_btt);
+}
+
+static struct device_type nd_btt_device_type = {
+       .name = "nd_btt",
+       .release = nd_btt_release,
+};
+
+bool is_nd_btt(struct device *dev)
+{
+       return dev->type == &nd_btt_device_type;
+}
+EXPORT_SYMBOL(is_nd_btt);
+
+struct nd_btt *to_nd_btt(struct device *dev)
+{
+       struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);
+
+       WARN_ON(!is_nd_btt(dev));
+       return nd_btt;
+}
+EXPORT_SYMBOL(to_nd_btt);
+
+static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
+       4096, 4104, 4160, 4224, 0 };
+
+static ssize_t sector_size_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct nd_btt *nd_btt = to_nd_btt(dev);
+
+       return nd_sector_size_show(nd_btt->lbasize, btt_lbasize_supported, buf);
+}
+
+static ssize_t sector_size_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t len)
+{
+       struct nd_btt *nd_btt = to_nd_btt(dev);
+       ssize_t rc;
+
+       device_lock(dev);
+       nvdimm_bus_lock(dev);
+       rc = nd_sector_size_store(dev, buf, &nd_btt->lbasize,
+                       btt_lbasize_supported);
+       dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
+                       rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+       nvdimm_bus_unlock(dev);
+       device_unlock(dev);
+
+       return rc ? rc : len;
+}
+static DEVICE_ATTR_RW(sector_size);
+
+static ssize_t uuid_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct nd_btt *nd_btt = to_nd_btt(dev);
+
+       if (nd_btt->uuid)
+               return sprintf(buf, "%pUb\n", nd_btt->uuid);
+       return sprintf(buf, "\n");
+}
+
+static ssize_t uuid_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t len)
+{
+       struct nd_btt *nd_btt = to_nd_btt(dev);
+       ssize_t rc;
+
+       device_lock(dev);
+       rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
+       dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
+                       rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+       device_unlock(dev);
+
+       return rc ? rc : len;
+}
+static DEVICE_ATTR_RW(uuid);
+
+static ssize_t namespace_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct nd_btt *nd_btt = to_nd_btt(dev);
+       ssize_t rc;
+
+       nvdimm_bus_lock(dev);
+       rc = sprintf(buf, "%s\n", nd_btt->ndns
+                       ? dev_name(&nd_btt->ndns->dev) : "");
+       nvdimm_bus_unlock(dev);
+       return rc;
+}
+
+static ssize_t namespace_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t len)
+{
+       struct nd_btt *nd_btt = to_nd_btt(dev);
+       ssize_t rc;
+
+       device_lock(dev);
+       nvdimm_bus_lock(dev);
+       rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
+       dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
+                       rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+       nvdimm_bus_unlock(dev);
+       device_unlock(dev);
+
+       return rc;
+}
+static DEVICE_ATTR_RW(namespace);
+
+static struct attribute *nd_btt_attributes[] = {
+       &dev_attr_sector_size.attr,
+       &dev_attr_namespace.attr,
+       &dev_attr_uuid.attr,
+       NULL,
+};
+
+static struct attribute_group nd_btt_attribute_group = {
+       .attrs = nd_btt_attributes,
+};
+
+static const struct attribute_group *nd_btt_attribute_groups[] = {
+       &nd_btt_attribute_group,
+       &nd_device_attribute_group,
+       &nd_numa_attribute_group,
+       NULL,
+};
+
+static struct device *__nd_btt_create(struct nd_region *nd_region,
+               unsigned long lbasize, u8 *uuid,
+               struct nd_namespace_common *ndns)
+{
+       struct nd_btt *nd_btt;
+       struct device *dev;
+
+       nd_btt = kzalloc(sizeof(*nd_btt), GFP_KERNEL);
+       if (!nd_btt)
+               return NULL;
+
+       nd_btt->id = ida_simple_get(&nd_region->btt_ida, 0, 0, GFP_KERNEL);
+       if (nd_btt->id < 0) {
+               kfree(nd_btt);
+               return NULL;
+       }
+
+       nd_btt->lbasize = lbasize;
+       if (uuid)
+               uuid = kmemdup(uuid, 16, GFP_KERNEL);
+       nd_btt->uuid = uuid;
+       dev = &nd_btt->dev;
+       dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
+       dev->parent = &nd_region->dev;
+       dev->type = &nd_btt_device_type;
+       dev->groups = nd_btt_attribute_groups;
+       device_initialize(&nd_btt->dev);
+       if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
+               dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
+                               __func__, dev_name(ndns->claim));
+               put_device(dev);
+               return NULL;
+       }
+       return dev;
+}
+
+struct device *nd_btt_create(struct nd_region *nd_region)
+{
+       struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);
+
+       if (dev)
+               __nd_device_register(dev);
+       return dev;
+}
+
+static bool uuid_is_null(u8 *uuid)
+{
+       static const u8 null_uuid[16];
+
+       return (memcmp(uuid, null_uuid, 16) == 0);
+}
+
+/**
+ * nd_btt_arena_is_valid - check if the metadata layout is valid
+ * @nd_btt:    device with BTT geometry and backing device info
+ * @super:     pointer to the arena's info block being tested
+ *
+ * Check consistency of the btt info block with itself by validating
+ * the checksum, and with the parent namespace by verifying the
+ * parent_uuid contained in the info block with the one supplied in.
+ *
+ * Returns:
+ * false for an invalid info block, true for a valid one
+ */
+bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
+{
+       const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
+       u64 checksum;
+
+       if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
+               return false;
+
+       if (!uuid_is_null(super->parent_uuid))
+               if (memcmp(super->parent_uuid, parent_uuid, 16) != 0)
+                       return false;
+
+       checksum = le64_to_cpu(super->checksum);
+       super->checksum = 0;
+       if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
+               return false;
+       super->checksum = cpu_to_le64(checksum);
+
+       /* TODO: figure out action for this */
+       if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
+               dev_info(&nd_btt->dev, "Found arena with an error flag\n");
+
+       return true;
+}
+EXPORT_SYMBOL(nd_btt_arena_is_valid);
+
+static int __nd_btt_probe(struct nd_btt *nd_btt,
+               struct nd_namespace_common *ndns, struct btt_sb *btt_sb)
+{
+       if (!btt_sb || !ndns || !nd_btt)
+               return -ENODEV;
+
+       if (nvdimm_read_bytes(ndns, SZ_4K, btt_sb, sizeof(*btt_sb)))
+               return -ENXIO;
+
+       if (nvdimm_namespace_capacity(ndns) < SZ_16M)
+               return -ENXIO;
+
+       if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
+               return -ENODEV;
+
+       nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
+       nd_btt->uuid = kmemdup(btt_sb->uuid, 16, GFP_KERNEL);
+       if (!nd_btt->uuid)
+               return -ENOMEM;
+
+       __nd_device_register(&nd_btt->dev);
+
+       return 0;
+}
+
+int nd_btt_probe(struct nd_namespace_common *ndns, void *drvdata)
+{
+       int rc;
+       struct device *dev;
+       struct btt_sb *btt_sb;
+       struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
+
+       if (ndns->force_raw)
+               return -ENODEV;
+
+       nvdimm_bus_lock(&ndns->dev);
+       dev = __nd_btt_create(nd_region, 0, NULL, ndns);
+       nvdimm_bus_unlock(&ndns->dev);
+       if (!dev)
+               return -ENOMEM;
+       dev_set_drvdata(dev, drvdata);
+       btt_sb = kzalloc(sizeof(*btt_sb), GFP_KERNEL);
+       rc = __nd_btt_probe(to_nd_btt(dev), ndns, btt_sb);
+       kfree(btt_sb);
+       dev_dbg(&ndns->dev, "%s: btt: %s\n", __func__,
+                       rc == 0 ? dev_name(dev) : "<none>");
+       if (rc < 0) {
+               struct nd_btt *nd_btt = to_nd_btt(dev);
+
+               __nd_detach_ndns(dev, &nd_btt->ndns);
+               put_device(dev);
+       }
+
+       return rc;
+}
+EXPORT_SYMBOL(nd_btt_probe);