acpi, nfit: Collect shutdown status

Some NVDIMMs, in addition to providing an indication of whether the
previous shutdown was clean, also provide a running count of lifetime
dirty-shutdown events for the device. In anticipation of this
functionality appearing on more devices arrange for the nfit driver to
retrieve / cache this data at DIMM discovery time, and export it via
sysfs.

Reviewed-by: Keith Busch <[e-mail]>
Signed-off-by: Dan Williams <[e-mail]>

drivers/acpi/nfit/core.c

···
 #include <asm/cacheflush.h>
 #include <acpi/nfit.h>
 #include "nfit.h"
+#include "intel.h"
 
 /*
  * For readq() and writeq() on 32-bit builds, the hi-lo, lo-hi order is
···
 static ssize_t flags_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
-	u16 flags = to_nfit_memdev(dev)->flags;
+	struct nvdimm *nvdimm = to_nvdimm(dev);
+	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
+	u16 flags = __to_nfit_memdev(nfit_mem)->flags;
+
+	if (test_bit(NFIT_MEM_DIRTY, &nfit_mem->flags))
+		flags |= ACPI_NFIT_MEM_FLUSH_FAILED;
 
 	return sprintf(buf, "%s%s%s%s%s%s%s\n",
 		flags & ACPI_NFIT_MEM_SAVE_FAILED ? "save_fail " : "",
···
 }
 static DEVICE_ATTR_RO(id);
 
+static ssize_t dirty_shutdown_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nvdimm *nvdimm = to_nvdimm(dev);
+	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
+
+	return sprintf(buf, "%d\n", nfit_mem->dirty_shutdown);
+}
+static DEVICE_ATTR_RO(dirty_shutdown);
+
 static struct attribute *acpi_nfit_dimm_attributes[] = {
 	&dev_attr_handle.attr,
 	&dev_attr_phys_id.attr,
···
 	&dev_attr_id.attr,
 	&dev_attr_family.attr,
 	&dev_attr_dsm_mask.attr,
+	&dev_attr_dirty_shutdown.attr,
 	NULL,
 };
 
···
 {
 	struct device *dev = container_of(kobj, struct device, kobj);
 	struct nvdimm *nvdimm = to_nvdimm(dev);
+	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
 
 	if (!to_nfit_dcr(dev)) {
 		/* Without a dcr only the memdev attributes can be surfaced */
···
 
 	if (a == &dev_attr_format1.attr && num_nvdimm_formats(nvdimm) <= 1)
 		return 0;
+
+	if (!test_bit(NFIT_MEM_DIRTY_COUNT, &nfit_mem->flags)
+			&& a == &dev_attr_dirty_shutdown.attr)
+		return 0;
+
 	return a->mode;
 }
 
···
 	if (ACPI_SUCCESS(status))
 		return true;
 	return false;
+}
+
+static void nfit_intel_shutdown_status(struct nfit_mem *nfit_mem)
+{
+	struct nd_intel_smart smart = { 0 };
+	union acpi_object in_buf = {
+		.type = ACPI_TYPE_BUFFER,
+		.buffer.pointer = (char *) &smart,
+		.buffer.length = sizeof(smart),
+	};
+	union acpi_object in_obj = {
+		.type = ACPI_TYPE_PACKAGE,
+		.package.count = 1,
+		.package.elements = &in_buf,
+	};
+	const u8 func = ND_INTEL_SMART;
+	const guid_t *guid = to_nfit_uuid(nfit_mem->family);
+	u8 revid = nfit_dsm_revid(nfit_mem->family, func);
+	struct acpi_device *adev = nfit_mem->adev;
+	acpi_handle handle = adev->handle;
+	union acpi_object *out_obj;
+
+	if ((nfit_mem->dsm_mask & (1 << func)) == 0)
+		return;
+
+	out_obj = acpi_evaluate_dsm(handle, guid, revid, func, &in_obj);
+	if (!out_obj)
+		return;
+
+	if (smart.flags & ND_INTEL_SMART_SHUTDOWN_VALID) {
+		if (smart.shutdown_state)
+			set_bit(NFIT_MEM_DIRTY, &nfit_mem->flags);
+	}
+
+	if (smart.flags & ND_INTEL_SMART_SHUTDOWN_COUNT_VALID) {
+		set_bit(NFIT_MEM_DIRTY_COUNT, &nfit_mem->flags);
+		nfit_mem->dirty_shutdown = smart.shutdown_count;
+	}
+	ACPI_FREE(out_obj);
+}
+
+static void populate_shutdown_status(struct nfit_mem *nfit_mem)
+{
+	/*
+	 * For DIMMs that provide a dynamic facility to retrieve a
+	 * dirty-shutdown status and/or a dirty-shutdown count, cache
+	 * these values in nfit_mem.
+	 */
+	if (nfit_mem->family == NVDIMM_FAMILY_INTEL)
+		nfit_intel_shutdown_status(nfit_mem);
 }
 
 static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
···
 		dev_dbg(dev, "%s: has _LSW\n", dev_name(&adev_dimm->dev));
 		set_bit(NFIT_MEM_LSW, &nfit_mem->flags);
 	}
+
+	populate_shutdown_status(nfit_mem);
 
 	return 0;
 }

drivers/acpi/nfit/intel.h

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright(c) 2018 Intel Corporation. All rights reserved.
+ * Intel specific definitions for NVDIMM Firmware Interface Table - NFIT
+ */
+#ifndef _NFIT_INTEL_H_
+#define _NFIT_INTEL_H_
+
+#define ND_INTEL_SMART 1
+
+#define ND_INTEL_SMART_SHUTDOWN_COUNT_VALID     (1 << 5)
+#define ND_INTEL_SMART_SHUTDOWN_VALID           (1 << 10)
+
+struct nd_intel_smart {
+	u32 status;
+	union {
+		struct {
+			u32 flags;
+			u8 reserved0[4];
+			u8 health;
+			u8 spares;
+			u8 life_used;
+			u8 alarm_flags;
+			u16 media_temperature;
+			u16 ctrl_temperature;
+			u32 shutdown_count;
+			u8 ait_status;
+			u16 pmic_temperature;
+			u8 reserved1[8];
+			u8 shutdown_state;
+			u32 vendor_size;
+			u8 vendor_data[92];
+		} __packed;
+		u8 data[128];
+	};
+} __packed;
+
+#endif

drivers/acpi/nfit/nfit.h

···
 enum nfit_mem_flags {
 	NFIT_MEM_LSR,
 	NFIT_MEM_LSW,
+	NFIT_MEM_DIRTY,
+	NFIT_MEM_DIRTY_COUNT,
 };
 
 /* assembled tables for a given dimm/memory-device */
···
 	struct resource *flush_wpq;
 	unsigned long dsm_mask;
 	unsigned long flags;
+	u32 dirty_shutdown;
 	int family;
 };
 

tools/testing/nvdimm/test/nfit.c

···
 #include <linux/list.h>
 #include <linux/slab.h>
 #include <nd-core.h>
+#include <intel.h>
 #include <nfit.h>
 #include <nd.h>
 #include "nfit_test.h"

tools/testing/nvdimm/test/nfit_test.h

···
 #define ND_INTEL_SMART_INJECT_FATAL		(1 << 2)
 #define ND_INTEL_SMART_INJECT_SHUTDOWN		(1 << 3)
 
-struct nd_intel_smart {
-	__u32 status;
-	union {
-		struct {
-			__u32 flags;
-			__u8 reserved0[4];
-			__u8 health;
-			__u8 spares;
-			__u8 life_used;
-			__u8 alarm_flags;
-			__u16 media_temperature;
-			__u16 ctrl_temperature;
-			__u32 shutdown_count;
-			__u8 ait_status;
-			__u16 pmic_temperature;
-			__u8 reserved1[8];
-			__u8 shutdown_state;
-			__u32 vendor_size;
-			__u8 vendor_data[92];
-		} __packed;
-		__u8 data[128];
-	};
-} __packed;
-
 struct nd_intel_smart_threshold {
 	__u32 status;
 	union {