libnvdimm: control (ioctl) messages for nvdimm_bus and nvdimm devices

Most discovery/configuration of the nvdimm-subsystem is done via sysfs
attributes.  However, some nvdimm_bus instances, particularly the
ACPI.NFIT bus, define a small set of messages that can be passed to the
platform.  For convenience we derive the initial libnvdimm-ioctl command
formats directly from the NFIT DSM Interface Example formats.

    ND_CMD_SMART: media health and diagnostics
    ND_CMD_GET_CONFIG_SIZE: size of the label space
    ND_CMD_GET_CONFIG_DATA: read label space
    ND_CMD_SET_CONFIG_DATA: write label space
    ND_CMD_VENDOR: vendor-specific command passthrough
    ND_CMD_ARS_CAP: report address-range-scrubbing capabilities
    ND_CMD_ARS_START: initiate scrubbing
    ND_CMD_ARS_STATUS: report on scrubbing state
    ND_CMD_SMART_THRESHOLD: configure alarm thresholds for smart events

If a platform later defines different commands than this set it is
straightforward to extend support to those formats.

Most of the commands target a specific dimm.  However, the
address-range-scrubbing commands target the bus.  The 'commands'
attribute in sysfs of an nvdimm_bus, or nvdimm, enumerate the supported
commands for that object.

Cc: <linux-acpi@vger.kernel.org>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reported-by: Nicholas Moulin <nicholas.w.moulin@linux.intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

3 files changed, 205 insertions, 1 deletions

diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 07787f0dd7de..a39235819af3 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -14,13 +14,22 @@
  */
 #ifndef __LIBNVDIMM_H__
 #define __LIBNVDIMM_H__
+#include <linux/sizes.h>
+#include <linux/types.h>
 
 enum {
 	/* when a dimm supports both PMEM and BLK access a label is required */
 	NDD_ALIASING = 1 << 0,
+
+	/* need to set a limit somewhere, but yes, this is likely overkill */
+	ND_IOCTL_MAX_BUFLEN = SZ_4M,
+	ND_CMD_MAX_ELEM = 4,
+	ND_CMD_MAX_ENVELOPE = 16,
+	ND_CMD_ARS_STATUS_MAX = SZ_4K,
 };
 
 extern struct attribute_group nvdimm_bus_attribute_group;
+extern struct attribute_group nvdimm_attribute_group;
 
 struct nvdimm;
 struct nvdimm_bus_descriptor;
@@ -35,6 +44,14 @@ struct nvdimm_bus_descriptor {
 	ndctl_fn ndctl;
 };
 
+struct nd_cmd_desc {
+	int in_num;
+	int out_num;
+	u32 in_sizes[ND_CMD_MAX_ELEM];
+	int out_sizes[ND_CMD_MAX_ELEM];
+};
+
+struct nvdimm_bus;
 struct device;
 struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
 		struct nvdimm_bus_descriptor *nfit_desc);
@@ -45,5 +62,13 @@ struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus);
 const char *nvdimm_name(struct nvdimm *nvdimm);
 void *nvdimm_provider_data(struct nvdimm *nvdimm);
 struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data,
-		const struct attribute_group **groups, unsigned long flags);
+		const struct attribute_group **groups, unsigned long flags,
+		unsigned long *dsm_mask);
+const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd);
+const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd);
+u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
+		const struct nd_cmd_desc *desc, int idx, void *buf);
+u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
+		const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
+		const u32 *out_field);
 #endif /* __LIBNVDIMM_H__ */
diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
index 1a0006a76b00..200cc5ea2998 100644
--- a/include/uapi/linux/Kbuild
+++ b/include/uapi/linux/Kbuild
@@ -271,6 +271,7 @@ header-y += ncp_fs.h
 header-y += ncp.h
 header-y += ncp_mount.h
 header-y += ncp_no.h
+header-y += ndctl.h
 header-y += neighbour.h
 header-y += netconf.h
 header-y += netdevice.h
diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h
new file mode 100644
index 000000000000..ff13c23b26df
--- /dev/null
+++ b/include/uapi/linux/ndctl.h
@@ -0,0 +1,178 @@
+/*
+ * Copyright (c) 2014-2015, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 2.1, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+#ifndef __NDCTL_H__
+#define __NDCTL_H__
+
+#include <linux/types.h>
+
+struct nd_cmd_smart {
+	__u32 status;
+	__u8 data[128];
+} __packed;
+
+struct nd_cmd_smart_threshold {
+	__u32 status;
+	__u8 data[8];
+} __packed;
+
+struct nd_cmd_dimm_flags {
+	__u32 status;
+	__u32 flags;
+} __packed;
+
+struct nd_cmd_get_config_size {
+	__u32 status;
+	__u32 config_size;
+	__u32 max_xfer;
+} __packed;
+
+struct nd_cmd_get_config_data_hdr {
+	__u32 in_offset;
+	__u32 in_length;
+	__u32 status;
+	__u8 out_buf[0];
+} __packed;
+
+struct nd_cmd_set_config_hdr {
+	__u32 in_offset;
+	__u32 in_length;
+	__u8 in_buf[0];
+} __packed;
+
+struct nd_cmd_vendor_hdr {
+	__u32 opcode;
+	__u32 in_length;
+	__u8 in_buf[0];
+} __packed;
+
+struct nd_cmd_vendor_tail {
+	__u32 status;
+	__u32 out_length;
+	__u8 out_buf[0];
+} __packed;
+
+struct nd_cmd_ars_cap {
+	__u64 address;
+	__u64 length;
+	__u32 status;
+	__u32 max_ars_out;
+} __packed;
+
+struct nd_cmd_ars_start {
+	__u64 address;
+	__u64 length;
+	__u16 type;
+	__u8 reserved[6];
+	__u32 status;
+} __packed;
+
+struct nd_cmd_ars_status {
+	__u32 status;
+	__u32 out_length;
+	__u64 address;
+	__u64 length;
+	__u16 type;
+	__u32 num_records;
+	struct nd_ars_record {
+		__u32 handle;
+		__u32 flags;
+		__u64 err_address;
+		__u64 mask;
+	} __packed records[0];
+} __packed;
+
+enum {
+	ND_CMD_IMPLEMENTED = 0,
+
+	/* bus commands */
+	ND_CMD_ARS_CAP = 1,
+	ND_CMD_ARS_START = 2,
+	ND_CMD_ARS_STATUS = 3,
+
+	/* per-dimm commands */
+	ND_CMD_SMART = 1,
+	ND_CMD_SMART_THRESHOLD = 2,
+	ND_CMD_DIMM_FLAGS = 3,
+	ND_CMD_GET_CONFIG_SIZE = 4,
+	ND_CMD_GET_CONFIG_DATA = 5,
+	ND_CMD_SET_CONFIG_DATA = 6,
+	ND_CMD_VENDOR_EFFECT_LOG_SIZE = 7,
+	ND_CMD_VENDOR_EFFECT_LOG = 8,
+	ND_CMD_VENDOR = 9,
+};
+
+static inline const char *nvdimm_bus_cmd_name(unsigned cmd)
+{
+	static const char * const names[] = {
+		[ND_CMD_ARS_CAP] = "ars_cap",
+		[ND_CMD_ARS_START] = "ars_start",
+		[ND_CMD_ARS_STATUS] = "ars_status",
+	};
+
+	if (cmd < ARRAY_SIZE(names) && names[cmd])
+		return names[cmd];
+	return "unknown";
+}
+
+static inline const char *nvdimm_cmd_name(unsigned cmd)
+{
+	static const char * const names[] = {
+		[ND_CMD_SMART] = "smart",
+		[ND_CMD_SMART_THRESHOLD] = "smart_thresh",
+		[ND_CMD_DIMM_FLAGS] = "flags",
+		[ND_CMD_GET_CONFIG_SIZE] = "get_size",
+		[ND_CMD_GET_CONFIG_DATA] = "get_data",
+		[ND_CMD_SET_CONFIG_DATA] = "set_data",
+		[ND_CMD_VENDOR_EFFECT_LOG_SIZE] = "effect_size",
+		[ND_CMD_VENDOR_EFFECT_LOG] = "effect_log",
+		[ND_CMD_VENDOR] = "vendor",
+	};
+
+	if (cmd < ARRAY_SIZE(names) && names[cmd])
+		return names[cmd];
+	return "unknown";
+}
+
+#define ND_IOCTL 'N'
+
+#define ND_IOCTL_SMART			_IOWR(ND_IOCTL, ND_CMD_SMART,\
+					struct nd_cmd_smart)
+
+#define ND_IOCTL_SMART_THRESHOLD	_IOWR(ND_IOCTL, ND_CMD_SMART_THRESHOLD,\
+					struct nd_cmd_smart_threshold)
+
+#define ND_IOCTL_DIMM_FLAGS		_IOWR(ND_IOCTL, ND_CMD_DIMM_FLAGS,\
+					struct nd_cmd_dimm_flags)
+
+#define ND_IOCTL_GET_CONFIG_SIZE	_IOWR(ND_IOCTL, ND_CMD_GET_CONFIG_SIZE,\
+					struct nd_cmd_get_config_size)
+
+#define ND_IOCTL_GET_CONFIG_DATA	_IOWR(ND_IOCTL, ND_CMD_GET_CONFIG_DATA,\
+					struct nd_cmd_get_config_data_hdr)
+
+#define ND_IOCTL_SET_CONFIG_DATA	_IOWR(ND_IOCTL, ND_CMD_SET_CONFIG_DATA,\
+					struct nd_cmd_set_config_hdr)
+
+#define ND_IOCTL_VENDOR			_IOWR(ND_IOCTL, ND_CMD_VENDOR,\
+					struct nd_cmd_vendor_hdr)
+
+#define ND_IOCTL_ARS_CAP		_IOWR(ND_IOCTL, ND_CMD_ARS_CAP,\
+					struct nd_cmd_ars_cap)
+
+#define ND_IOCTL_ARS_START		_IOWR(ND_IOCTL, ND_CMD_ARS_START,\
+					struct nd_cmd_ars_start)
+
+#define ND_IOCTL_ARS_STATUS		_IOWR(ND_IOCTL, ND_CMD_ARS_STATUS,\
+					struct nd_cmd_ars_status)
+
+#endif /* __NDCTL_H__ */