libnvdimm, nfit: dimm/memory-devices

Enable nvdimm devices to be registered on a nvdimm_bus.  The kernel
assigned device id for nvdimm devicesis dynamic.  If userspace needs a
more static identifier it should consult a provider-specific attribute.
In the case where NFIT is the provider, the 'nmemX/nfit/handle' or
'nmemX/nfit/serial' attributes may be used for this purpose.

Cc: Neil Brown <neilb@suse.de>
Cc: <linux-acpi@vger.kernel.org>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/acpi/nfit.c

@@ -381,6 +381,165 @@ static const struct attribute_group *acpi_nfit_attribute_groups[] = {
  NULL,
 };
 
+static struct acpi_nfit_memory_map *to_nfit_memdev(struct device *dev)
+{
+ struct nvdimm *nvdimm = to_nvdimm(dev);
+ struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
+
+ return __to_nfit_memdev(nfit_mem);
+}
+
+static struct acpi_nfit_control_region *to_nfit_dcr(struct device *dev)
+{
+ struct nvdimm *nvdimm = to_nvdimm(dev);
+ struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
+
+ return nfit_mem->dcr;
+}
+
+static ssize_t handle_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct acpi_nfit_memory_map *memdev = to_nfit_memdev(dev);
+
+ return sprintf(buf, "%#x\n", memdev->device_handle);
+}
+static DEVICE_ATTR_RO(handle);
+
+static ssize_t phys_id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct acpi_nfit_memory_map *memdev = to_nfit_memdev(dev);
+
+ return sprintf(buf, "%#x\n", memdev->physical_id);
+}
+static DEVICE_ATTR_RO(phys_id);
+
+static ssize_t vendor_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
+
+ return sprintf(buf, "%#x\n", dcr->vendor_id);
+}
+static DEVICE_ATTR_RO(vendor);
+
+static ssize_t rev_id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
+
+ return sprintf(buf, "%#x\n", dcr->revision_id);
+}
+static DEVICE_ATTR_RO(rev_id);
+
+static ssize_t device_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
+
+ return sprintf(buf, "%#x\n", dcr->device_id);
+}
+static DEVICE_ATTR_RO(device);
+
+static ssize_t format_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
+
+ return sprintf(buf, "%#x\n", dcr->code);
+}
+static DEVICE_ATTR_RO(format);
+
+static ssize_t serial_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct acpi_nfit_control_region *dcr = to_nfit_dcr(dev);
+
+ return sprintf(buf, "%#x\n", dcr->serial_number);
+}
+static DEVICE_ATTR_RO(serial);
+
+static struct attribute *acpi_nfit_dimm_attributes[] = {
+ &dev_attr_handle.attr,
+ &dev_attr_phys_id.attr,
+ &dev_attr_vendor.attr,
+ &dev_attr_device.attr,
+ &dev_attr_format.attr,
+ &dev_attr_serial.attr,
+ &dev_attr_rev_id.attr,
+ NULL,
+};
+
+static umode_t acpi_nfit_dimm_attr_visible(struct kobject *kobj,
+ struct attribute *a, int n)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+
+ if (to_nfit_dcr(dev))
+ return a->mode;
+ else
+ return 0;
+}
+
+static struct attribute_group acpi_nfit_dimm_attribute_group = {
+ .name = "nfit",
+ .attrs = acpi_nfit_dimm_attributes,
+ .is_visible = acpi_nfit_dimm_attr_visible,
+};
+
+static const struct attribute_group *acpi_nfit_dimm_attribute_groups[] = {
+ &acpi_nfit_dimm_attribute_group,
+ NULL,
+};
+
+static struct nvdimm *acpi_nfit_dimm_by_handle(struct acpi_nfit_desc *acpi_desc,
+ u32 device_handle)
+{
+ struct nfit_mem *nfit_mem;
+
+ list_for_each_entry(nfit_mem, &acpi_desc->dimms, list)
+ if (__to_nfit_memdev(nfit_mem)->device_handle == device_handle)
+ return nfit_mem->nvdimm;
+
+ return NULL;
+}
+
+static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
+{
+ struct nfit_mem *nfit_mem;
+
+ list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
+ struct nvdimm *nvdimm;
+ unsigned long flags = 0;
+ u32 device_handle;
+
+ device_handle = __to_nfit_memdev(nfit_mem)->device_handle;
+ nvdimm = acpi_nfit_dimm_by_handle(acpi_desc, device_handle);
+ if (nvdimm) {
+ /*
+ * If for some reason we find multiple DCRs the
+ * first one wins
+ */
+ dev_err(acpi_desc->dev, "duplicate DCR detected: %s\n",
+ nvdimm_name(nvdimm));
+ continue;
+ }
+
+ if (nfit_mem->bdw && nfit_mem->memdev_pmem)
+ flags |= NDD_ALIASING;
+
+ nvdimm = nvdimm_create(acpi_desc->nvdimm_bus, nfit_mem,
+ acpi_nfit_dimm_attribute_groups, flags);
+ if (!nvdimm)
+ return -ENOMEM;
+
+ nfit_mem->nvdimm = nvdimm;
+ }
+
+ return 0;
+}
+
 static int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, acpi_size sz)
 {
  struct device *dev = acpi_desc->dev;
@@ -408,7 +567,7 @@ static int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, acpi_size sz)
  if (nfit_mem_init(acpi_desc) != 0)
  return -ENOMEM;
 
- return 0;
+ return acpi_nfit_register_dimms(acpi_desc);
 }
 
 static int acpi_nfit_add(struct acpi_device *adev)

drivers/acpi/nfit.h

@@ -59,6 +59,7 @@ struct nfit_memdev {
 
 /* assembled tables for a given dimm/memory-device */
 struct nfit_mem {
+ struct nvdimm *nvdimm;
  struct acpi_nfit_memory_map *memdev_dcr;
  struct acpi_nfit_memory_map *memdev_pmem;
  struct acpi_nfit_control_region *dcr;

drivers/nvdimm/Makefile

@@ -2,3 +2,4 @@ obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o
 
 libnvdimm-y := core.o
 libnvdimm-y += bus.o
+libnvdimm-y += dimm_devs.o

drivers/nvdimm/bus.c

@@ -13,6 +13,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 #include <linux/uaccess.h>
 #include <linux/fcntl.h>
+#include <linux/async.h>
 #include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/io.h>
@@ -21,6 +22,10 @@
 static int nvdimm_bus_major;
 static struct class *nd_class;
 
+struct bus_type nvdimm_bus_type = {
+ .name = "nd",
+};
+
 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
 {
  dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
@@ -59,9 +64,13 @@ int __init nvdimm_bus_init(void)
 {
  int rc;
 
+ rc = bus_register(&nvdimm_bus_type);
+ if (rc)
+ return rc;
+
  rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
  if (rc < 0)
- return rc;
+ goto err_chrdev;
  nvdimm_bus_major = rc;
 
  nd_class = class_create(THIS_MODULE, "nd");
@@ -72,6 +81,8 @@ int __init nvdimm_bus_init(void)
 
  err_class:
  unregister_chrdev(nvdimm_bus_major, "ndctl");
+ err_chrdev:
+ bus_unregister(&nvdimm_bus_type);
 
  return rc;
 }
@@ -80,4 +91,5 @@ void __exit nvdimm_bus_exit(void)
 {
  class_destroy(nd_class);
  unregister_chrdev(nvdimm_bus_major, "ndctl");
+ bus_unregister(&nvdimm_bus_type);
 }

drivers/nvdimm/core.c

@@ -18,8 +18,8 @@
 #include <linux/slab.h>
 #include "nd-core.h"
 
-static LIST_HEAD(nvdimm_bus_list);
-static DEFINE_MUTEX(nvdimm_bus_list_mutex);
+LIST_HEAD(nvdimm_bus_list);
+DEFINE_MUTEX(nvdimm_bus_list_mutex);
 static DEFINE_IDA(nd_ida);
 
 static void nvdimm_bus_release(struct device *dev)
@@ -48,6 +48,19 @@ struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus)
 }
 EXPORT_SYMBOL_GPL(to_nd_desc);
 
+struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev)
+{
+ struct device *dev;
+
+ for (dev = nd_dev; dev; dev = dev->parent)
+ if (dev->release == nvdimm_bus_release)
+ break;
+ dev_WARN_ONCE(nd_dev, !dev, "invalid dev, not on nd bus\n");
+ if (dev)
+ return to_nvdimm_bus(dev);
+ return NULL;
+}
+
 static const char *nvdimm_bus_provider(struct nvdimm_bus *nvdimm_bus)
 {
  struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
@@ -121,6 +134,21 @@ struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
 }
 EXPORT_SYMBOL_GPL(nvdimm_bus_register);
 
+static int child_unregister(struct device *dev, void *data)
+{
+ /*
+ * the singular ndctl class device per bus needs to be
+ * "device_destroy"ed, so skip it here
+ *
+ * i.e. remove classless children
+ */
+ if (dev->class)
+ /* pass */;
+ else
+ device_unregister(dev);
+ return 0;
+}
+
 void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
 {
  if (!nvdimm_bus)
@@ -130,6 +158,7 @@ void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
  list_del_init(&nvdimm_bus->list);
  mutex_unlock(&nvdimm_bus_list_mutex);
 
+ device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
  nvdimm_bus_destroy_ndctl(nvdimm_bus);
 
  device_unregister(&nvdimm_bus->dev);

drivers/nvdimm/dimm_devs.c

@@ -0,0 +1,92 @@
+/*
+ * 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.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include "nd-core.h"
+
+static DEFINE_IDA(dimm_ida);
+
+static void nvdimm_release(struct device *dev)
+{
+ struct nvdimm *nvdimm = to_nvdimm(dev);
+
+ ida_simple_remove(&dimm_ida, nvdimm->id);
+ kfree(nvdimm);
+}
+
+static struct device_type nvdimm_device_type = {
+ .name = "nvdimm",
+ .release = nvdimm_release,
+};
+
+static bool is_nvdimm(struct device *dev)
+{
+ return dev->type == &nvdimm_device_type;
+}
+
+struct nvdimm *to_nvdimm(struct device *dev)
+{
+ struct nvdimm *nvdimm = container_of(dev, struct nvdimm, dev);
+
+ WARN_ON(!is_nvdimm(dev));
+ return nvdimm;
+}
+EXPORT_SYMBOL_GPL(to_nvdimm);
+
+const char *nvdimm_name(struct nvdimm *nvdimm)
+{
+ return dev_name(&nvdimm->dev);
+}
+EXPORT_SYMBOL_GPL(nvdimm_name);
+
+void *nvdimm_provider_data(struct nvdimm *nvdimm)
+{
+ return nvdimm->provider_data;
+}
+EXPORT_SYMBOL_GPL(nvdimm_provider_data);
+
+struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data,
+ const struct attribute_group **groups, unsigned long flags)
+{
+ struct nvdimm *nvdimm = kzalloc(sizeof(*nvdimm), GFP_KERNEL);
+ struct device *dev;
+
+ if (!nvdimm)
+ return NULL;
+
+ nvdimm->id = ida_simple_get(&dimm_ida, 0, 0, GFP_KERNEL);
+ if (nvdimm->id < 0) {
+ kfree(nvdimm);
+ return NULL;
+ }
+ nvdimm->provider_data = provider_data;
+ nvdimm->flags = flags;
+
+ dev = &nvdimm->dev;
+ dev_set_name(dev, "nmem%d", nvdimm->id);
+ dev->parent = &nvdimm_bus->dev;
+ dev->type = &nvdimm_device_type;
+ dev->bus = &nvdimm_bus_type;
+ dev->groups = groups;
+ if (device_register(dev) != 0) {
+ put_device(dev);
+ return NULL;
+ }
+
+ return nvdimm;
+}
+EXPORT_SYMBOL_GPL(nvdimm_create);