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>

1 files changed, 26 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__ */