acpi, nfit: Add function to look up nvdimm device and provide SMBIOS handle

EDAC driver needs to look up attributes of NVDIMMs provided in SMBIOS.

Provide a function that looks up an acpi_nfit_memory_map from a device
handle (node/socket/mc/channel/dimm) and returns the SMBIOS handle.
Also pass back the "flags" so we can see if the NVDIMM is OK.
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Aristeu Rozanski <aris@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Erik Schmauss <erik.schmauss@intel.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Cc: Robert Moore <robert.moore@intel.com>
Cc: devel@acpica.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
Link: http://lkml.kernel.org/r/20180312182430.10335-4-tony.luck@intel.comSigned-off-by: Borislav Petkov <bp@suse.de>

drivers/acpi/nfit/core.c

@@ -23,6 +23,7 @@
 #include <linux/io.h>
 #include <linux/nd.h>
 #include <asm/cacheflush.h>
+#include <acpi/nfit.h>
 #include "nfit.h"
 
 /*
@@ -690,6 +691,32 @@ static bool add_memdev(struct acpi_nfit_desc *acpi_desc,
 	return true;
 }
 
+int nfit_get_smbios_id(u32 device_handle, u16 *flags)
+{
+	struct acpi_nfit_memory_map *memdev;
+	struct acpi_nfit_desc *acpi_desc;
+	struct nfit_mem *nfit_mem;
+
+	mutex_lock(&acpi_desc_lock);
+	list_for_each_entry(acpi_desc, &acpi_descs, list) {
+		mutex_lock(&acpi_desc->init_mutex);
+		list_for_each_entry(nfit_mem, &acpi_desc->dimms, list) {
+			memdev = __to_nfit_memdev(nfit_mem);
+			if (memdev->device_handle == device_handle) {
+				mutex_unlock(&acpi_desc->init_mutex);
+				mutex_unlock(&acpi_desc_lock);
+				*flags = memdev->flags;
+				return memdev->physical_id;
+			}
+		}
+		mutex_unlock(&acpi_desc->init_mutex);
+	}
+	mutex_unlock(&acpi_desc_lock);
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(nfit_get_smbios_id);
+
 /*
  * An implementation may provide a truncated control region if no block windows
  * are defined.

include/acpi/nfit.h

+/*
+ * SPDX-License-Identifier: GPL-2.0
+ * Copyright (C) 2018 Intel Corporation
+ */
+
+#ifndef __ACPI_NFIT_H
+#define __ACPI_NFIT_H
+
+#if IS_ENABLED(CONFIG_ACPI_NFIT)
+int nfit_get_smbios_id(u32 device_handle, u16 *flags);
+#else
+static inline int nfit_get_smbios_id(u32 device_handle, u16 *flags)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+#endif /* __ACPI_NFIT_H */