fs: Add pstore filesystem

pstore is a persistent storage filesystem used for RAMOOPS. It is used
to store console logs, panics, ftrace and other information in case of a
crash/panic/oops/reboot.

pstore is implemented for barebox as a read-only filesystem at the
moment. It may be extended later on. The idea is to provide a way to
extract essential data from the last running kernel.

Most of the code is copied from the kernel. However this is only a
lightweight implementation without real write support yet.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

2 files changed, 177 insertions, 0 deletions

diff --git a/include/linux/pstore.h b/include/linux/pstore.h
new file mode 100644
index 0000000000..a925e14397
--- /dev/null
+++ b/include/linux/pstore.h
@@ -0,0 +1,90 @@
+/*
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef _LINUX_PSTORE_H
+#define _LINUX_PSTORE_H
+
+#include <linux/time.h>
+#include <linux/types.h>
+#include <asm-generic/errno.h>
+
+/* types */
+enum pstore_type_id {
+	PSTORE_TYPE_DMESG	= 0,
+	PSTORE_TYPE_MCE		= 1,
+	PSTORE_TYPE_CONSOLE	= 2,
+	PSTORE_TYPE_FTRACE	= 3,
+	/* PPC64 partition types */
+	PSTORE_TYPE_PPC_RTAS	= 4,
+	PSTORE_TYPE_PPC_OF	= 5,
+	PSTORE_TYPE_PPC_COMMON	= 6,
+	PSTORE_TYPE_PMSG	= 7,
+	PSTORE_TYPE_UNKNOWN	= 255
+};
+
+enum kmsg_dump_reason {
+	KMSG_DUMP_UNDEF,
+};
+
+struct module;
+
+struct pstore_info {
+	struct module	*owner;
+	char		*name;
+	char		*buf;
+	size_t		bufsize;
+	int		flags;
+	int		(*open)(struct pstore_info *psi);
+	int		(*close)(struct pstore_info *psi);
+	ssize_t		(*read)(u64 *id, enum pstore_type_id *type,
+			int *count, char **buf, bool *compressed,
+			struct pstore_info *psi);
+	int		(*write)(enum pstore_type_id type,
+			enum kmsg_dump_reason reason, u64 *id,
+			unsigned int part, int count, bool compressed,
+			size_t size, struct pstore_info *psi);
+	int		(*write_buf)(enum pstore_type_id type,
+			enum kmsg_dump_reason reason, u64 *id,
+			unsigned int part, const char *buf, bool compressed,
+			size_t size, struct pstore_info *psi);
+	int		(*erase)(enum pstore_type_id type, u64 id,
+			int count, struct pstore_info *psi);
+	void		*data;
+};
+
+#define	PSTORE_FLAGS_FRAGILE	1
+
+#ifdef CONFIG_FS_PSTORE
+extern int pstore_register(struct pstore_info *);
+extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason);
+#else
+static inline int
+pstore_register(struct pstore_info *psi)
+{
+	return -ENODEV;
+}
+static inline bool
+pstore_cannot_block_path(enum kmsg_dump_reason reason)
+{
+	return false;
+}
+#endif
+
+#endif /*_LINUX_PSTORE_H*/
diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h
new file mode 100644
index 0000000000..5ef823a57b
--- /dev/null
+++ b/include/linux/pstore_ram.h
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
+ * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#ifndef __LINUX_PSTORE_RAM_H__
+#define __LINUX_PSTORE_RAM_H__
+
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/types.h>
+
+struct persistent_ram_buffer;
+struct rs_control;
+
+struct persistent_ram_ecc_info {
+	int block_size;
+	int ecc_size;
+	int symsize;
+	int poly;
+};
+
+struct persistent_ram_zone {
+	phys_addr_t paddr;
+	size_t size;
+	struct persistent_ram_buffer *buffer;
+	size_t buffer_size;
+	struct resource *res;
+
+	/* ECC correction */
+	char *par_buffer;
+	char *par_header;
+	struct rs_control *rs_decoder;
+	int corrected_bytes;
+	int bad_blocks;
+	struct persistent_ram_ecc_info ecc_info;
+
+	char *old_log;
+	size_t old_log_size;
+};
+
+struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
+			u32 sig, struct persistent_ram_ecc_info *ecc_info,
+			unsigned int memtype);
+void persistent_ram_free(struct persistent_ram_zone *prz);
+void persistent_ram_zap(struct persistent_ram_zone *prz);
+
+int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,
+	unsigned int count);
+
+void persistent_ram_save_old(struct persistent_ram_zone *prz);
+size_t persistent_ram_old_size(struct persistent_ram_zone *prz);
+void *persistent_ram_old(struct persistent_ram_zone *prz);
+void persistent_ram_free_old(struct persistent_ram_zone *prz);
+ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
+	char *str, size_t len);
+
+/*
+ * Ramoops platform data
+ * @mem_size	memory size for ramoops
+ * @mem_address	physical memory address to contain ramoops
+ */
+
+struct ramoops_platform_data {
+	unsigned long	mem_size;
+	unsigned long	mem_address;
+	unsigned int	mem_type;
+	unsigned long	record_size;
+	unsigned long	console_size;
+	unsigned long	ftrace_size;
+	unsigned long	pmsg_size;
+	int		dump_oops;
+	struct persistent_ram_ecc_info ecc_info;
+};
+
+#endif