PM, libnvdimm: Add runtime firmware activation support

Abstract platform specific mechanics for nvdimm firmware activation
behind a handful of generic ops. At the bus level ->activate_state()
indicates the unified state (idle, busy, armed) of all DIMMs on the bus,
and ->capability() indicates the system state expectations for activate.
At the DIMM level ->activate_state() indicates the per-DIMM state,
->activate_result() indicates the outcome of the last activation
attempt, and ->arm() attempts to transition the DIMM from 'idle' to
'armed'.

A new hibernate_quiet_exec() facility is added to support firmware
activation in an OS defined system quiesce state. It leverages the fact
that the hibernate-freeze state wants to assert that a memory
hibernation snapshot can be taken. This is in contrast to a platform
firmware defined quiesce state that may forcefully quiet the memory
controller independent of whether an individual device-driver properly
supports hibernate-freeze.

The libnvdimm sysfs interface is extended to support detection of a
firmware activate capability. The mechanism supports enumeration and
triggering of firmware activate, optionally in the
hibernate_quiet_exec() context.

[rafael: hibernate_quiet_exec() proposal]
[vishal: fix up sparse warning, grammar in Documentation/]

Cc: Pavel Machek <pavel@ucw.cz>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Co-developed-by: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>

2 files changed, 50 insertions, 0 deletions

diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index ad9898ece7d3..15dbcb718316 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -86,6 +86,7 @@ struct nvdimm_bus_descriptor {
 	int (*flush_probe)(struct nvdimm_bus_descriptor *nd_desc);
 	int (*clear_to_send)(struct nvdimm_bus_descriptor *nd_desc,
 			struct nvdimm *nvdimm, unsigned int cmd, void *data);
+	const struct nvdimm_bus_fw_ops *fw_ops;
 };
 
 struct nd_cmd_desc {
@@ -200,6 +201,49 @@ struct nvdimm_security_ops {
 	int (*query_overwrite)(struct nvdimm *nvdimm);
 };
 
+enum nvdimm_fwa_state {
+	NVDIMM_FWA_INVALID,
+	NVDIMM_FWA_IDLE,
+	NVDIMM_FWA_ARMED,
+	NVDIMM_FWA_BUSY,
+	NVDIMM_FWA_ARM_OVERFLOW,
+};
+
+enum nvdimm_fwa_trigger {
+	NVDIMM_FWA_ARM,
+	NVDIMM_FWA_DISARM,
+};
+
+enum nvdimm_fwa_capability {
+	NVDIMM_FWA_CAP_INVALID,
+	NVDIMM_FWA_CAP_NONE,
+	NVDIMM_FWA_CAP_QUIESCE,
+	NVDIMM_FWA_CAP_LIVE,
+};
+
+enum nvdimm_fwa_result {
+	NVDIMM_FWA_RESULT_INVALID,
+	NVDIMM_FWA_RESULT_NONE,
+	NVDIMM_FWA_RESULT_SUCCESS,
+	NVDIMM_FWA_RESULT_NOTSTAGED,
+	NVDIMM_FWA_RESULT_NEEDRESET,
+	NVDIMM_FWA_RESULT_FAIL,
+};
+
+struct nvdimm_bus_fw_ops {
+	enum nvdimm_fwa_state (*activate_state)
+		(struct nvdimm_bus_descriptor *nd_desc);
+	enum nvdimm_fwa_capability (*capability)
+		(struct nvdimm_bus_descriptor *nd_desc);
+	int (*activate)(struct nvdimm_bus_descriptor *nd_desc);
+};
+
+struct nvdimm_fw_ops {
+	enum nvdimm_fwa_state (*activate_state)(struct nvdimm *nvdimm);
+	enum nvdimm_fwa_result (*activate_result)(struct nvdimm *nvdimm);
+	int (*arm)(struct nvdimm *nvdimm, enum nvdimm_fwa_trigger arg);
+};
+
 void badrange_init(struct badrange *badrange);
 int badrange_add(struct badrange *badrange, u64 addr, u64 length);
 void badrange_forget(struct badrange *badrange, phys_addr_t start,
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index b960098acfb0..cb9afad82a90 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -453,6 +453,8 @@ extern bool hibernation_available(void);
 asmlinkage int swsusp_save(void);
 extern struct pbe *restore_pblist;
 int pfn_is_nosave(unsigned long pfn);
+
+int hibernate_quiet_exec(int (*func)(void *data), void *data);
 #else /* CONFIG_HIBERNATION */
 static inline void register_nosave_region(unsigned long b, unsigned long e) {}
 static inline void register_nosave_region_late(unsigned long b, unsigned long e) {}
@@ -464,6 +466,10 @@ static inline void hibernation_set_ops(const struct platform_hibernation_ops *op
 static inline int hibernate(void) { return -ENOSYS; }
 static inline bool system_entering_hibernation(void) { return false; }
 static inline bool hibernation_available(void) { return false; }
+
+static inline int hibernate_quiet_exec(int (*func)(void *data), void *data) {
+	return -ENOTSUPP;
+}
 #endif /* CONFIG_HIBERNATION */
 
 #ifdef CONFIG_HIBERNATION_SNAPSHOT_DEV