pstore: new filesystem interface to platform persistent storage

Some platforms have a small amount of non-volatile storage that
can be used to store information useful to diagnose the cause of
a system crash.  This is the generic part of a file system interface
that presents information from the crash as a series of files in
/dev/pstore.  Once the information has been seen, the underlying
storage is freed by deleting the files.

Signed-off-by: Tony Luck <tony.luck@intel.com>

2 files changed, 61 insertions, 0 deletions

diff --git a/include/linux/magic.h b/include/linux/magic.h
index ff690d05f129..e87fd5ac3e5e 100644
--- a/include/linux/magic.h
+++ b/include/linux/magic.h
@@ -26,6 +26,7 @@
 #define ISOFS_SUPER_MAGIC	0x9660
 #define JFFS2_SUPER_MAGIC	0x72b6
 #define ANON_INODE_FS_MAGIC	0x09041934
+#define PSTOREFS_MAGIC		0x6165676C
 
 #define MINIX_SUPER_MAGIC	0x137F		/* original minix fs */
 #define MINIX_SUPER_MAGIC2	0x138F		/* minix fs, 30 char names */
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
new file mode 100644
index 000000000000..41977737bb7d
--- /dev/null
+++ b/include/linux/pstore.h
@@ -0,0 +1,60 @@
+/*
+ * Persistent Storage - pstore.h
+ *
+ * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
+ *
+ * This code is the generic layer to export data records from platform
+ * level persistent storage via a file system.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#ifndef _LINUX_PSTORE_H
+#define _LINUX_PSTORE_H
+
+/* types */
+enum pstore_type_id {
+	PSTORE_TYPE_DMESG	= 0,
+	PSTORE_TYPE_MCE		= 1,
+	PSTORE_TYPE_UNKNOWN	= 255
+};
+
+struct pstore_info {
+	struct module	*owner;
+	char		*name;
+	struct mutex	buf_mutex;	/* serialize access to 'buf' */
+	char		*buf;
+	size_t		bufsize;
+	size_t		(*read)(u64 *id, enum pstore_type_id *type,
+			struct timespec *time);
+	u64		(*write)(enum pstore_type_id type, size_t size);
+	int		(*erase)(u64 id);
+};
+
+#ifdef CONFIG_PSTORE
+extern int pstore_register(struct pstore_info *);
+extern int pstore_write(enum pstore_type_id type, char *buf, size_t size);
+#else
+static inline int
+pstore_register(struct pstore_info *psi)
+{
+	return -ENODEV;
+}
+static inline int
+pstore_write(enum pstore_type_id type, char *buf, size_t size)
+{
+	return -ENODEV;
+}
+#endif
+
+#endif /*_LINUX_PSTORE_H*/