new file mode 100644
@@ -0,0 +1,2 @@
+The libnvdimm sub-system implements a common sysfs interface for
+platform nvdimm resources. See Documentation/driver-api/nvdimm/.
new file mode 100644
@@ -0,0 +1,74 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==================================
+NVDIMM Runtime Firmware Activation
+==================================
+
+Some persistent memory devices run a firmware locally on the device /
+"DIMM" to perform tasks like media management, capacity provisioning,
+and health monitoring. The process of updating that firmware typically
+involves a reboot because it has implications for in-flight memory
+transactions. However, reboots are disruptive and at least the Intel
+persistent memory platform implementation, described by the Intel ACPI
+DSM specification [1], has added support for activating firmware at
+runtime.
+
+A native sysfs interface is implemented in libnvdimm to allow platform
+to advertise and control their local runtime firmware activation
+capability.
+
+The libnvdimm bus object, ndbusX, implements an ndbusX/firmware_activate
+attribute that shows the state of the firmware activation as one of 'idle',
+'armed', 'overflow', and 'busy'.
+
+- idle:
+ No devices are set / armed to activate firmware
+
+- armed:
+ At least one device is armed
+
+- busy:
+ In the busy state armed devices are in the process of transitioning
+ back to idle and completing an activation cycle.
+
+- overflow:
+ If the platform has a concept of incremental work needed to perform
+ the activation it could be the case that too many DIMMs are armed for
+ activation. In that scenario the potential for firmware activation to
+ timeout is indicated by the 'overflow' state.
+
+This property is optionally read-write if the platform implementation
+allows firmware-activation at run-time. Some activations may involve a
+memory controller quiesce that may trigger undefined behavior in devices
+actively performing DMA. On these platform firmware_activate is not
+writable and instead activation occurs over a suspend event.
+
+The libnvdimm memory-device / DIMM object, nmemX, implements
+nmemX/firmware_activate and nmemX/firmware_activate_result attributes to
+communicate the per-device firmware activation state. Similar to the
+ndbusX/firmware_activate attribute, the nmemX/firmware_activate
+attribute indicates 'idle', 'armed', or 'busy'. The state transitions
+from 'armed' to 'idle' when the system is prepared to activate firmware,
+firmware staged + state set to armed, and a system sleep state
+transition is triggered. After that activation event the
+nmemX/firmware_activate_result attribute reflects the state of the last
+activation as one of:
+
+- none:
+ No runtime activation triggered since the last time the device was reset
+
+- success:
+ The last runtime activation completed successfully.
+
+- fail:
+ The last runtime activation failed for device-specific reasons.
+
+- not_staged:
+ The last runtime activation failed due to a sequencing error of the
+ firmware image not being staged.
+
+- need_reset:
+ Runtime firmware activation failed, but the firmware can still be
+ activated via the legacy method of power-cycling the system.
+
+[1]: https://docs.pmem.io/persistent-memory/
@@ -378,15 +378,107 @@ static ssize_t wait_probe_show(struct device *dev,
}
static DEVICE_ATTR_RO(wait_probe);
+static ssize_t firmware_activate_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
+ struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
+ enum nvdimm_fwa_state state;
+
+ if (!nd_desc->fw_ops)
+ return -EOPNOTSUPP;
+
+ nvdimm_bus_lock(dev);
+ state = nd_desc->fw_ops->activate_state(nd_desc);
+ nvdimm_bus_unlock(dev);
+
+ switch (state) {
+ case NVDIMM_FWA_IDLE:
+ return sprintf(buf, "idle\n");
+ case NVDIMM_FWA_BUSY:
+ return sprintf(buf, "busy\n");
+ case NVDIMM_FWA_ARMED:
+ return sprintf(buf, "armed\n");
+ case NVDIMM_FWA_ARM_OVERFLOW:
+ return sprintf(buf, "overflow\n");
+ default:
+ return -ENXIO;
+ }
+}
+
+static ssize_t firmware_activate_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t len)
+{
+ struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
+ struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
+ enum nvdimm_fwa_state state;
+ ssize_t rc;
+
+ if (!nd_desc->fw_ops)
+ return -EOPNOTSUPP;
+
+ nvdimm_bus_lock(dev);
+ state = nd_desc->fw_ops->activate_state(nd_desc);
+
+ switch (state) {
+ case NVDIMM_FWA_BUSY:
+ rc = -EBUSY;
+ break;
+ case NVDIMM_FWA_ARMED:
+ case NVDIMM_FWA_ARM_OVERFLOW:
+ rc = nd_desc->fw_ops->activate(nd_desc);
+ break;
+ case NVDIMM_FWA_IDLE:
+ default:
+ rc = -ENXIO;
+ }
+ nvdimm_bus_unlock(dev);
+
+ if (rc == 0)
+ rc = len;
+ return rc;
+}
+
+static DEVICE_ATTR_ADMIN_RW(firmware_activate);
+
+static umode_t nvdimm_bus_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+ struct device *dev = container_of(kobj, typeof(*dev), kobj);
+ struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
+ struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
+
+ if (a == &dev_attr_firmware_activate.attr) {
+ enum nvdimm_fwa_capability cap;
+
+ if (!nd_desc->fw_ops)
+ return 0;
+
+ nvdimm_bus_lock(dev);
+ cap = nd_desc->fw_ops->capability(nd_desc);
+ nvdimm_bus_unlock(dev);
+
+ if (cap < NVDIMM_FWA_CAP_QUIESCE)
+ return 0;
+ /* Force suspend flow for activate */
+ if (cap == NVDIMM_FWA_CAP_QUIESCE)
+ return 0400;
+ /* Live activation permitted */
+ return 0600;
+ }
+ return a->mode;
+}
+
static struct attribute *nvdimm_bus_attributes[] = {
&dev_attr_commands.attr,
&dev_attr_wait_probe.attr,
&dev_attr_provider.attr,
+ &dev_attr_firmware_activate.attr,
NULL,
};
static const struct attribute_group nvdimm_bus_attribute_group = {
.attrs = nvdimm_bus_attributes,
+ .is_visible = nvdimm_bus_visible,
};
const struct attribute_group *nvdimm_bus_attribute_groups[] = {
@@ -406,6 +406,88 @@ static ssize_t security_store(struct device *dev,
}
static DEVICE_ATTR_RW(security);
+static ssize_t firmware_activate_result_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct nvdimm *nvdimm = to_nvdimm(dev);
+ enum nvdimm_fwa_result result;
+
+ if (!nvdimm->fw_ops)
+ return -EOPNOTSUPP;
+
+ nvdimm_bus_lock(dev);
+ result = nvdimm->fw_ops->activate_result(nvdimm);
+ nvdimm_bus_unlock(dev);
+
+ switch (result) {
+ case NVDIMM_FWA_RESULT_NONE:
+ return sprintf(buf, "none\n");
+ case NVDIMM_FWA_RESULT_SUCCESS:
+ return sprintf(buf, "success\n");
+ case NVDIMM_FWA_RESULT_FAIL:
+ return sprintf(buf, "fail\n");
+ case NVDIMM_FWA_RESULT_NOTSTAGED:
+ return sprintf(buf, "not_staged\n");
+ case NVDIMM_FWA_RESULT_NEEDRESET:
+ return sprintf(buf, "need_reset\n");
+ default:
+ return -ENXIO;
+ }
+}
+static DEVICE_ATTR_ADMIN_RO(firmware_activate_result);
+
+static ssize_t firmware_activate_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct nvdimm *nvdimm = to_nvdimm(dev);
+ enum nvdimm_fwa_state state;
+
+ if (!nvdimm->fw_ops)
+ return -EOPNOTSUPP;
+
+ nvdimm_bus_lock(dev);
+ state = nvdimm->fw_ops->activate_state(nvdimm);
+ nvdimm_bus_unlock(dev);
+
+ switch (state) {
+ case NVDIMM_FWA_IDLE:
+ return sprintf(buf, "idle\n");
+ case NVDIMM_FWA_BUSY:
+ return sprintf(buf, "busy\n");
+ case NVDIMM_FWA_ARMED:
+ return sprintf(buf, "armed\n");
+ default:
+ return -ENXIO;
+ }
+}
+
+static ssize_t firmware_activate_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t len)
+{
+ struct nvdimm *nvdimm = to_nvdimm(dev);
+ enum nvdimm_fwa_trigger arg;
+ int rc;
+
+ if (!nvdimm->fw_ops)
+ return -EOPNOTSUPP;
+
+ if (sysfs_streq(buf, "arm"))
+ arg = NVDIMM_FWA_ARM;
+ else if (sysfs_streq(buf, "disarm"))
+ arg = NVDIMM_FWA_DISARM;
+ else
+ return -EINVAL;
+
+ nvdimm_bus_lock(dev);
+ rc = nvdimm->fw_ops->arm(nvdimm, arg);
+ nvdimm_bus_unlock(dev);
+
+ if (rc < 0)
+ return rc;
+ return len;
+}
+static DEVICE_ATTR_ADMIN_RW(firmware_activate);
+
static struct attribute *nvdimm_attributes[] = {
&dev_attr_state.attr,
&dev_attr_flags.attr,
@@ -413,6 +495,8 @@ static struct attribute *nvdimm_attributes[] = {
&dev_attr_available_slots.attr,
&dev_attr_security.attr,
&dev_attr_frozen.attr,
+ &dev_attr_firmware_activate.attr,
+ &dev_attr_firmware_activate_result.attr,
NULL,
};
@@ -421,6 +505,17 @@ static umode_t nvdimm_visible(struct kobject *kobj, struct attribute *a, int n)
struct device *dev = container_of(kobj, typeof(*dev), kobj);
struct nvdimm *nvdimm = to_nvdimm(dev);
+ if (a == &dev_attr_firmware_activate.attr) {
+ struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
+ struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
+
+ if (!nd_desc->fw_ops)
+ return 0;
+ if (!nvdimm->fw_ops)
+ return 0;
+ return a->mode;
+ }
+
if (a != &dev_attr_security.attr && a != &dev_attr_frozen.attr)
return a->mode;
if (!nvdimm->sec.flags)
@@ -45,6 +45,7 @@ struct nvdimm {
struct kernfs_node *overwrite_state;
} sec;
struct delayed_work dwork;
+ const struct nvdimm_fw_ops *fw_ops;
};
static inline unsigned long nvdimm_security_flags(
@@ -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,
Abstract the platform specific mechanics for 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'. Cc: Jonathan Corbet <corbet@lwn.net> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- Documentation/ABI/testing/sysfs-bus-nvdimm | 2 .../driver-api/nvdimm/firmware-activate.rst | 74 ++++++++++++++++ drivers/nvdimm/core.c | 92 +++++++++++++++++++ drivers/nvdimm/dimm_devs.c | 95 ++++++++++++++++++++ drivers/nvdimm/nd-core.h | 1 include/linux/libnvdimm.h | 44 +++++++++ 6 files changed, 308 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-nvdimm create mode 100644 Documentation/driver-api/nvdimm/firmware-activate.rst