ACPI: NFIT: Add runtime firmware activate support

Plumb the platform specific backend for the generic libnvdimm firmware
activate interface. Register dimm level operations to arm/disarm
activation, and register bus level operations to report the dynamic
platform-quiesce time relative to the number of dimms armed for firmware
activation.

A new nfit-specific bus attribute "firmware_activate_noidle" is added to
allow the activation to switch between platform enforced, and OS
opportunistic device quiesce. In other words, let the hibernate cycle
handle in-flight device-dma rather than the platform attempting to
increase PCI-E timeouts and the like.

Cc: Dave Jiang <[email protected]>
Cc: Ira Weiny <[email protected]>
Cc: Vishal Verma <[email protected]>
Signed-off-by: Dan Williams <[email protected]>
Signed-off-by: Vishal Verma <[email protected]>

Author: djbw

Documentation/ABI/testing/sysfs-bus-nfit

@@ -202,6 +202,25 @@ Description:
 		functions. See the section named 'NVDIMM Root Device _DSMs' in
 		the ACPI specification.
 
+What:		/sys/bus/nd/devices/ndbusX/nfit/firmware_activate_noidle
+Date:		Apr, 2020
+KernelVersion:	v5.8
+Contact:	[email protected]
+Description:
+		(RW) The Intel platform implementation of firmware activate
+		support exposes an option let the platform force idle devices in
+		the system over the activation event, or trust that the OS will
+		do it. The safe default is to let the platform force idle
+		devices since the kernel is already in a suspend state, and on
+		the chance that a driver does not properly quiesce bus-mastering
+		after a suspend callback the platform will handle it.  However,
+		the activation might abort if, for example, platform firmware
+		determines that the activation time exceeds the max PCI-E
+		completion timeout. Since the platform does not know whether the
+		OS is running the activation from a suspend context it aborts,
+		but if the system owner trusts driver suspend callback to be
+		sufficient then 'firmware_activation_noidle' can be
+		enabled to bypass the activation abort.
 
 What:		/sys/bus/nd/devices/regionX/nfit/range_index
 Date:		Jun, 2015

drivers/acpi/nfit/core.c

@@ -1392,8 +1392,12 @@ static umode_t nfit_visible(struct kobject *kobj, struct attribute *a, int n)
 	struct device *dev = container_of(kobj, struct device, kobj);
 	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
 
-	if (a == &dev_attr_scrub.attr && !ars_supported(nvdimm_bus))
-		return 0;
+	if (a == &dev_attr_scrub.attr)
+		return ars_supported(nvdimm_bus) ? a->mode : 0;
+
+	if (a == &dev_attr_firmware_activate_noidle.attr)
+		return intel_fwa_supported(nvdimm_bus) ? a->mode : 0;
+
 	return a->mode;
 }
 
@@ -1402,6 +1406,7 @@ static struct attribute *acpi_nfit_attributes[] = {
 	&dev_attr_scrub.attr,
 	&dev_attr_hw_error_scrub.attr,
 	&dev_attr_bus_dsm_mask.attr,
+	&dev_attr_firmware_activate_noidle.attr,
 	NULL,
 };
 
@@ -2019,6 +2024,26 @@ static const struct nvdimm_security_ops *acpi_nfit_get_security_ops(int family)
 	}
 }
 
+static const struct nvdimm_fw_ops *acpi_nfit_get_fw_ops(
+		struct nfit_mem *nfit_mem)
+{
+	unsigned long mask;
+	struct acpi_nfit_desc *acpi_desc = nfit_mem->acpi_desc;
+	struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
+
+	if (!nd_desc->fw_ops)
+		return NULL;
+
+	if (nfit_mem->family != NVDIMM_FAMILY_INTEL)
+		return NULL;
+
+	mask = nfit_mem->dsm_mask & NVDIMM_INTEL_FW_ACTIVATE_CMDMASK;
+	if (mask != NVDIMM_INTEL_FW_ACTIVATE_CMDMASK)
+		return NULL;
+
+	return intel_fw_ops;
+}
+
 static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
 {
 	struct nfit_mem *nfit_mem;
@@ -2095,7 +2120,8 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
 				acpi_nfit_dimm_attribute_groups,
 				flags, cmd_mask, flush ? flush->hint_count : 0,
 				nfit_mem->flush_wpq, &nfit_mem->id[0],
-				acpi_nfit_get_security_ops(nfit_mem->family));
+				acpi_nfit_get_security_ops(nfit_mem->family),
+				acpi_nfit_get_fw_ops(nfit_mem));
 		if (!nvdimm)
 			return -ENOMEM;
 
@@ -2170,8 +2196,10 @@ static void acpi_nfit_init_dsms(struct acpi_nfit_desc *acpi_desc)
 	if (acpi_desc->bus_cmd_force_en) {
 		nd_desc->cmd_mask = acpi_desc->bus_cmd_force_en;
 		mask = &nd_desc->bus_family_mask;
-		if (acpi_desc->family_dsm_mask[NVDIMM_BUS_FAMILY_INTEL])
+		if (acpi_desc->family_dsm_mask[NVDIMM_BUS_FAMILY_INTEL]) {
 			set_bit(NVDIMM_BUS_FAMILY_INTEL, mask);
+			nd_desc->fw_ops = intel_bus_fw_ops;
+		}
 	}
 
 	adev = to_acpi_dev(acpi_desc);
@@ -2202,6 +2230,11 @@ static void acpi_nfit_init_dsms(struct acpi_nfit_desc *acpi_desc)
 	for_each_set_bit(i, &dsm_mask, BITS_PER_LONG)
 		if (acpi_check_dsm(adev->handle, guid, 1, 1ULL << i))
 			set_bit(i, mask);
+
+	if (*mask == dsm_mask) {
+		set_bit(NVDIMM_BUS_FAMILY_INTEL, &nd_desc->bus_family_mask);
+		nd_desc->fw_ops = intel_bus_fw_ops;
+	}
 }
 
 static ssize_t range_index_show(struct device *dev,