v4.19.13 snapshot.
diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
new file mode 100644
index 0000000..503086f
--- /dev/null
+++ b/fs/pstore/Kconfig
@@ -0,0 +1,155 @@
+config PSTORE
+ tristate "Persistent store support"
+ select CRYPTO if PSTORE_COMPRESS
+ default n
+ help
+ This option enables generic access to platform level
+ persistent storage via "pstore" filesystem that can
+ be mounted as /dev/pstore. Only useful if you have
+ a platform level driver that registers with pstore to
+ provide the data, so you probably should just go say "Y"
+ (or "M") to a platform specific persistent store driver
+ (e.g. ACPI_APEI on X86) which will select this for you.
+ If you don't have a platform persistent store driver,
+ say N.
+
+config PSTORE_DEFLATE_COMPRESS
+ tristate "DEFLATE (ZLIB) compression"
+ default y
+ depends on PSTORE
+ select CRYPTO_DEFLATE
+ help
+ This option enables DEFLATE (also known as ZLIB) compression
+ algorithm support.
+
+config PSTORE_LZO_COMPRESS
+ tristate "LZO compression"
+ depends on PSTORE
+ select CRYPTO_LZO
+ help
+ This option enables LZO compression algorithm support.
+
+config PSTORE_LZ4_COMPRESS
+ tristate "LZ4 compression"
+ depends on PSTORE
+ select CRYPTO_LZ4
+ help
+ This option enables LZ4 compression algorithm support.
+
+config PSTORE_LZ4HC_COMPRESS
+ tristate "LZ4HC compression"
+ depends on PSTORE
+ select CRYPTO_LZ4HC
+ help
+ This option enables LZ4HC (high compression) mode algorithm.
+
+config PSTORE_842_COMPRESS
+ bool "842 compression"
+ depends on PSTORE
+ select CRYPTO_842
+ help
+ This option enables 842 compression algorithm support.
+
+config PSTORE_ZSTD_COMPRESS
+ bool "zstd compression"
+ depends on PSTORE
+ select CRYPTO_ZSTD
+ help
+ This option enables zstd compression algorithm support.
+
+config PSTORE_COMPRESS
+ def_bool y
+ depends on PSTORE
+ depends on PSTORE_DEFLATE_COMPRESS || PSTORE_LZO_COMPRESS || \
+ PSTORE_LZ4_COMPRESS || PSTORE_LZ4HC_COMPRESS || \
+ PSTORE_842_COMPRESS || PSTORE_ZSTD_COMPRESS
+
+choice
+ prompt "Default pstore compression algorithm"
+ depends on PSTORE_COMPRESS
+ help
+ This option chooses the default active compression algorithm.
+ This change be changed at boot with "pstore.compress=..." on
+ the kernel command line.
+
+ Currently, pstore has support for 6 compression algorithms:
+ deflate, lzo, lz4, lz4hc, 842 and zstd.
+
+ The default compression algorithm is deflate.
+
+ config PSTORE_DEFLATE_COMPRESS_DEFAULT
+ bool "deflate" if PSTORE_DEFLATE_COMPRESS
+
+ config PSTORE_LZO_COMPRESS_DEFAULT
+ bool "lzo" if PSTORE_LZO_COMPRESS
+
+ config PSTORE_LZ4_COMPRESS_DEFAULT
+ bool "lz4" if PSTORE_LZ4_COMPRESS
+
+ config PSTORE_LZ4HC_COMPRESS_DEFAULT
+ bool "lz4hc" if PSTORE_LZ4HC_COMPRESS
+
+ config PSTORE_842_COMPRESS_DEFAULT
+ bool "842" if PSTORE_842_COMPRESS
+
+ config PSTORE_ZSTD_COMPRESS_DEFAULT
+ bool "zstd" if PSTORE_ZSTD_COMPRESS
+
+endchoice
+
+config PSTORE_COMPRESS_DEFAULT
+ string
+ depends on PSTORE_COMPRESS
+ default "deflate" if PSTORE_DEFLATE_COMPRESS_DEFAULT
+ default "lzo" if PSTORE_LZO_COMPRESS_DEFAULT
+ default "lz4" if PSTORE_LZ4_COMPRESS_DEFAULT
+ default "lz4hc" if PSTORE_LZ4HC_COMPRESS_DEFAULT
+ default "842" if PSTORE_842_COMPRESS_DEFAULT
+ default "zstd" if PSTORE_ZSTD_COMPRESS_DEFAULT
+
+config PSTORE_CONSOLE
+ bool "Log kernel console messages"
+ depends on PSTORE
+ help
+ When the option is enabled, pstore will log all kernel
+ messages, even if no oops or panic happened.
+
+config PSTORE_PMSG
+ bool "Log user space messages"
+ depends on PSTORE
+ help
+ When the option is enabled, pstore will export a character
+ interface /dev/pmsg0 to log user space messages. On reboot
+ data can be retrieved from /sys/fs/pstore/pmsg-ramoops-[ID].
+
+ If unsure, say N.
+
+config PSTORE_FTRACE
+ bool "Persistent function tracer"
+ depends on PSTORE
+ depends on FUNCTION_TRACER
+ depends on DEBUG_FS
+ help
+ With this option kernel traces function calls into a persistent
+ ram buffer that can be decoded and dumped after reboot through
+ pstore filesystem. It can be used to determine what function
+ was last called before a reset or panic.
+
+ If unsure, say N.
+
+config PSTORE_RAM
+ tristate "Log panic/oops to a RAM buffer"
+ depends on PSTORE
+ depends on HAS_IOMEM
+ depends on HAVE_MEMBLOCK
+ select REED_SOLOMON
+ select REED_SOLOMON_ENC8
+ select REED_SOLOMON_DEC8
+ help
+ This enables panic and oops messages to be logged to a circular
+ buffer in RAM where it can be read back at some later point.
+
+ Note that for historical reasons, the module will be named
+ "ramoops.ko".
+
+ For more information, see Documentation/admin-guide/ramoops.rst.
diff --git a/fs/pstore/Makefile b/fs/pstore/Makefile
new file mode 100644
index 0000000..967b589
--- /dev/null
+++ b/fs/pstore/Makefile
@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux pstorefs routines.
+#
+
+obj-$(CONFIG_PSTORE) += pstore.o
+
+pstore-objs += inode.o platform.o
+pstore-$(CONFIG_PSTORE_FTRACE) += ftrace.o
+
+pstore-$(CONFIG_PSTORE_PMSG) += pmsg.o
+
+ramoops-objs += ram.o ram_core.o
+obj-$(CONFIG_PSTORE_RAM) += ramoops.o
diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c
new file mode 100644
index 0000000..06aab07
--- /dev/null
+++ b/fs/pstore/ftrace.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright 2012 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <linux/irqflags.h>
+#include <linux/percpu.h>
+#include <linux/smp.h>
+#include <linux/atomic.h>
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/ftrace.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/err.h>
+#include <linux/cache.h>
+#include <asm/barrier.h>
+#include "internal.h"
+
+/* This doesn't need to be atomic: speed is chosen over correctness here. */
+static u64 pstore_ftrace_stamp;
+
+static void notrace pstore_ftrace_call(unsigned long ip,
+ unsigned long parent_ip,
+ struct ftrace_ops *op,
+ struct pt_regs *regs)
+{
+ unsigned long flags;
+ struct pstore_ftrace_record rec = {};
+ struct pstore_record record = {
+ .type = PSTORE_TYPE_FTRACE,
+ .buf = (char *)&rec,
+ .size = sizeof(rec),
+ .psi = psinfo,
+ };
+
+ if (unlikely(oops_in_progress))
+ return;
+
+ local_irq_save(flags);
+
+ rec.ip = ip;
+ rec.parent_ip = parent_ip;
+ pstore_ftrace_write_timestamp(&rec, pstore_ftrace_stamp++);
+ pstore_ftrace_encode_cpu(&rec, raw_smp_processor_id());
+ psinfo->write(&record);
+
+ local_irq_restore(flags);
+}
+
+static struct ftrace_ops pstore_ftrace_ops __read_mostly = {
+ .func = pstore_ftrace_call,
+};
+
+static DEFINE_MUTEX(pstore_ftrace_lock);
+static bool pstore_ftrace_enabled;
+
+static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ u8 on;
+ ssize_t ret;
+
+ ret = kstrtou8_from_user(buf, count, 2, &on);
+ if (ret)
+ return ret;
+
+ mutex_lock(&pstore_ftrace_lock);
+
+ if (!on ^ pstore_ftrace_enabled)
+ goto out;
+
+ if (on) {
+ ftrace_ops_set_global_filter(&pstore_ftrace_ops);
+ ret = register_ftrace_function(&pstore_ftrace_ops);
+ } else {
+ ret = unregister_ftrace_function(&pstore_ftrace_ops);
+ }
+
+ if (ret) {
+ pr_err("%s: unable to %sregister ftrace ops: %zd\n",
+ __func__, on ? "" : "un", ret);
+ goto err;
+ }
+
+ pstore_ftrace_enabled = on;
+out:
+ ret = count;
+err:
+ mutex_unlock(&pstore_ftrace_lock);
+
+ return ret;
+}
+
+static ssize_t pstore_ftrace_knob_read(struct file *f, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char val[] = { '0' + pstore_ftrace_enabled, '\n' };
+
+ return simple_read_from_buffer(buf, count, ppos, val, sizeof(val));
+}
+
+static const struct file_operations pstore_knob_fops = {
+ .open = simple_open,
+ .read = pstore_ftrace_knob_read,
+ .write = pstore_ftrace_knob_write,
+};
+
+static struct dentry *pstore_ftrace_dir;
+
+void pstore_register_ftrace(void)
+{
+ struct dentry *file;
+
+ if (!psinfo->write)
+ return;
+
+ pstore_ftrace_dir = debugfs_create_dir("pstore", NULL);
+ if (!pstore_ftrace_dir) {
+ pr_err("%s: unable to create pstore directory\n", __func__);
+ return;
+ }
+
+ file = debugfs_create_file("record_ftrace", 0600, pstore_ftrace_dir,
+ NULL, &pstore_knob_fops);
+ if (!file) {
+ pr_err("%s: unable to create record_ftrace file\n", __func__);
+ goto err_file;
+ }
+
+ return;
+err_file:
+ debugfs_remove(pstore_ftrace_dir);
+}
+
+void pstore_unregister_ftrace(void)
+{
+ mutex_lock(&pstore_ftrace_lock);
+ if (pstore_ftrace_enabled) {
+ unregister_ftrace_function(&pstore_ftrace_ops);
+ pstore_ftrace_enabled = 0;
+ }
+ mutex_unlock(&pstore_ftrace_lock);
+
+ debugfs_remove_recursive(pstore_ftrace_dir);
+}
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
new file mode 100644
index 0000000..5fcb845
--- /dev/null
+++ b/fs/pstore/inode.c
@@ -0,0 +1,513 @@
+/*
+ * Persistent Storage - ramfs parts.
+ *
+ * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
+ *
+ * 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
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/fsnotify.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/time.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/string.h>
+#include <linux/mount.h>
+#include <linux/seq_file.h>
+#include <linux/ramfs.h>
+#include <linux/parser.h>
+#include <linux/sched.h>
+#include <linux/magic.h>
+#include <linux/pstore.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+
+#include "internal.h"
+
+#define PSTORE_NAMELEN 64
+
+static DEFINE_SPINLOCK(allpstore_lock);
+static LIST_HEAD(allpstore);
+
+struct pstore_private {
+ struct list_head list;
+ struct pstore_record *record;
+ size_t total_size;
+};
+
+struct pstore_ftrace_seq_data {
+ const void *ptr;
+ size_t off;
+ size_t size;
+};
+
+#define REC_SIZE sizeof(struct pstore_ftrace_record)
+
+static void free_pstore_private(struct pstore_private *private)
+{
+ if (!private)
+ return;
+ if (private->record) {
+ kfree(private->record->buf);
+ kfree(private->record);
+ }
+ kfree(private);
+}
+
+static void *pstore_ftrace_seq_start(struct seq_file *s, loff_t *pos)
+{
+ struct pstore_private *ps = s->private;
+ struct pstore_ftrace_seq_data *data;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return NULL;
+
+ data->off = ps->total_size % REC_SIZE;
+ data->off += *pos * REC_SIZE;
+ if (data->off + REC_SIZE > ps->total_size) {
+ kfree(data);
+ return NULL;
+ }
+
+ return data;
+
+}
+
+static void pstore_ftrace_seq_stop(struct seq_file *s, void *v)
+{
+ kfree(v);
+}
+
+static void *pstore_ftrace_seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+ struct pstore_private *ps = s->private;
+ struct pstore_ftrace_seq_data *data = v;
+
+ data->off += REC_SIZE;
+ if (data->off + REC_SIZE > ps->total_size)
+ return NULL;
+
+ (*pos)++;
+ return data;
+}
+
+static int pstore_ftrace_seq_show(struct seq_file *s, void *v)
+{
+ struct pstore_private *ps = s->private;
+ struct pstore_ftrace_seq_data *data = v;
+ struct pstore_ftrace_record *rec;
+
+ rec = (struct pstore_ftrace_record *)(ps->record->buf + data->off);
+
+ seq_printf(s, "CPU:%d ts:%llu %08lx %08lx %pf <- %pF\n",
+ pstore_ftrace_decode_cpu(rec),
+ pstore_ftrace_read_timestamp(rec),
+ rec->ip, rec->parent_ip, (void *)rec->ip,
+ (void *)rec->parent_ip);
+
+ return 0;
+}
+
+static const struct seq_operations pstore_ftrace_seq_ops = {
+ .start = pstore_ftrace_seq_start,
+ .next = pstore_ftrace_seq_next,
+ .stop = pstore_ftrace_seq_stop,
+ .show = pstore_ftrace_seq_show,
+};
+
+static ssize_t pstore_file_read(struct file *file, char __user *userbuf,
+ size_t count, loff_t *ppos)
+{
+ struct seq_file *sf = file->private_data;
+ struct pstore_private *ps = sf->private;
+
+ if (ps->record->type == PSTORE_TYPE_FTRACE)
+ return seq_read(file, userbuf, count, ppos);
+ return simple_read_from_buffer(userbuf, count, ppos,
+ ps->record->buf, ps->total_size);
+}
+
+static int pstore_file_open(struct inode *inode, struct file *file)
+{
+ struct pstore_private *ps = inode->i_private;
+ struct seq_file *sf;
+ int err;
+ const struct seq_operations *sops = NULL;
+
+ if (ps->record->type == PSTORE_TYPE_FTRACE)
+ sops = &pstore_ftrace_seq_ops;
+
+ err = seq_open(file, sops);
+ if (err < 0)
+ return err;
+
+ sf = file->private_data;
+ sf->private = ps;
+
+ return 0;
+}
+
+static loff_t pstore_file_llseek(struct file *file, loff_t off, int whence)
+{
+ struct seq_file *sf = file->private_data;
+
+ if (sf->op)
+ return seq_lseek(file, off, whence);
+ return default_llseek(file, off, whence);
+}
+
+static const struct file_operations pstore_file_operations = {
+ .open = pstore_file_open,
+ .read = pstore_file_read,
+ .llseek = pstore_file_llseek,
+ .release = seq_release,
+};
+
+/*
+ * When a file is unlinked from our file system we call the
+ * platform driver to erase the record from persistent store.
+ */
+static int pstore_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct pstore_private *p = d_inode(dentry)->i_private;
+ struct pstore_record *record = p->record;
+
+ if (!record->psi->erase)
+ return -EPERM;
+
+ mutex_lock(&record->psi->read_mutex);
+ record->psi->erase(record);
+ mutex_unlock(&record->psi->read_mutex);
+
+ return simple_unlink(dir, dentry);
+}
+
+static void pstore_evict_inode(struct inode *inode)
+{
+ struct pstore_private *p = inode->i_private;
+ unsigned long flags;
+
+ clear_inode(inode);
+ if (p) {
+ spin_lock_irqsave(&allpstore_lock, flags);
+ list_del(&p->list);
+ spin_unlock_irqrestore(&allpstore_lock, flags);
+ free_pstore_private(p);
+ }
+}
+
+static const struct inode_operations pstore_dir_inode_operations = {
+ .lookup = simple_lookup,
+ .unlink = pstore_unlink,
+};
+
+static struct inode *pstore_get_inode(struct super_block *sb)
+{
+ struct inode *inode = new_inode(sb);
+ if (inode) {
+ inode->i_ino = get_next_ino();
+ inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+ }
+ return inode;
+}
+
+enum {
+ Opt_kmsg_bytes, Opt_err
+};
+
+static const match_table_t tokens = {
+ {Opt_kmsg_bytes, "kmsg_bytes=%u"},
+ {Opt_err, NULL}
+};
+
+static void parse_options(char *options)
+{
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+ int option;
+
+ if (!options)
+ return;
+
+ while ((p = strsep(&options, ",")) != NULL) {
+ int token;
+
+ if (!*p)
+ continue;
+
+ token = match_token(p, tokens, args);
+ switch (token) {
+ case Opt_kmsg_bytes:
+ if (!match_int(&args[0], &option))
+ pstore_set_kmsg_bytes(option);
+ break;
+ }
+ }
+}
+
+/*
+ * Display the mount options in /proc/mounts.
+ */
+static int pstore_show_options(struct seq_file *m, struct dentry *root)
+{
+ if (kmsg_bytes != PSTORE_DEFAULT_KMSG_BYTES)
+ seq_printf(m, ",kmsg_bytes=%lu", kmsg_bytes);
+ return 0;
+}
+
+static int pstore_remount(struct super_block *sb, int *flags, char *data)
+{
+ sync_filesystem(sb);
+ parse_options(data);
+
+ return 0;
+}
+
+static const struct super_operations pstore_ops = {
+ .statfs = simple_statfs,
+ .drop_inode = generic_delete_inode,
+ .evict_inode = pstore_evict_inode,
+ .remount_fs = pstore_remount,
+ .show_options = pstore_show_options,
+};
+
+static struct super_block *pstore_sb;
+
+bool pstore_is_mounted(void)
+{
+ return pstore_sb != NULL;
+}
+
+/*
+ * Make a regular file in the root directory of our file system.
+ * Load it up with "size" bytes of data from "buf".
+ * Set the mtime & ctime to the date that this record was originally stored.
+ */
+int pstore_mkfile(struct dentry *root, struct pstore_record *record)
+{
+ struct dentry *dentry;
+ struct inode *inode;
+ int rc = 0;
+ char name[PSTORE_NAMELEN];
+ struct pstore_private *private, *pos;
+ unsigned long flags;
+ size_t size = record->size + record->ecc_notice_size;
+
+ WARN_ON(!inode_is_locked(d_inode(root)));
+
+ spin_lock_irqsave(&allpstore_lock, flags);
+ list_for_each_entry(pos, &allpstore, list) {
+ if (pos->record->type == record->type &&
+ pos->record->id == record->id &&
+ pos->record->psi == record->psi) {
+ rc = -EEXIST;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&allpstore_lock, flags);
+ if (rc)
+ return rc;
+
+ rc = -ENOMEM;
+ inode = pstore_get_inode(root->d_sb);
+ if (!inode)
+ goto fail;
+ inode->i_mode = S_IFREG | 0444;
+ inode->i_fop = &pstore_file_operations;
+ private = kzalloc(sizeof(*private), GFP_KERNEL);
+ if (!private)
+ goto fail_alloc;
+ private->record = record;
+
+ switch (record->type) {
+ case PSTORE_TYPE_DMESG:
+ scnprintf(name, sizeof(name), "dmesg-%s-%llu%s",
+ record->psi->name, record->id,
+ record->compressed ? ".enc.z" : "");
+ break;
+ case PSTORE_TYPE_CONSOLE:
+ scnprintf(name, sizeof(name), "console-%s-%llu",
+ record->psi->name, record->id);
+ break;
+ case PSTORE_TYPE_FTRACE:
+ scnprintf(name, sizeof(name), "ftrace-%s-%llu",
+ record->psi->name, record->id);
+ break;
+ case PSTORE_TYPE_MCE:
+ scnprintf(name, sizeof(name), "mce-%s-%llu",
+ record->psi->name, record->id);
+ break;
+ case PSTORE_TYPE_PPC_RTAS:
+ scnprintf(name, sizeof(name), "rtas-%s-%llu",
+ record->psi->name, record->id);
+ break;
+ case PSTORE_TYPE_PPC_OF:
+ scnprintf(name, sizeof(name), "powerpc-ofw-%s-%llu",
+ record->psi->name, record->id);
+ break;
+ case PSTORE_TYPE_PPC_COMMON:
+ scnprintf(name, sizeof(name), "powerpc-common-%s-%llu",
+ record->psi->name, record->id);
+ break;
+ case PSTORE_TYPE_PMSG:
+ scnprintf(name, sizeof(name), "pmsg-%s-%llu",
+ record->psi->name, record->id);
+ break;
+ case PSTORE_TYPE_PPC_OPAL:
+ scnprintf(name, sizeof(name), "powerpc-opal-%s-%llu",
+ record->psi->name, record->id);
+ break;
+ case PSTORE_TYPE_UNKNOWN:
+ scnprintf(name, sizeof(name), "unknown-%s-%llu",
+ record->psi->name, record->id);
+ break;
+ default:
+ scnprintf(name, sizeof(name), "type%d-%s-%llu",
+ record->type, record->psi->name, record->id);
+ break;
+ }
+
+ dentry = d_alloc_name(root, name);
+ if (!dentry)
+ goto fail_private;
+
+ inode->i_size = private->total_size = size;
+
+ inode->i_private = private;
+
+ if (record->time.tv_sec)
+ inode->i_mtime = inode->i_ctime = record->time;
+
+ d_add(dentry, inode);
+
+ spin_lock_irqsave(&allpstore_lock, flags);
+ list_add(&private->list, &allpstore);
+ spin_unlock_irqrestore(&allpstore_lock, flags);
+
+ return 0;
+
+fail_private:
+ free_pstore_private(private);
+fail_alloc:
+ iput(inode);
+
+fail:
+ return rc;
+}
+
+/*
+ * Read all the records from the persistent store. Create
+ * files in our filesystem. Don't warn about -EEXIST errors
+ * when we are re-scanning the backing store looking to add new
+ * error records.
+ */
+void pstore_get_records(int quiet)
+{
+ struct pstore_info *psi = psinfo;
+ struct dentry *root;
+
+ if (!psi || !pstore_sb)
+ return;
+
+ root = pstore_sb->s_root;
+
+ inode_lock(d_inode(root));
+ pstore_get_backend_records(psi, root, quiet);
+ inode_unlock(d_inode(root));
+}
+
+static int pstore_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct inode *inode;
+
+ pstore_sb = sb;
+
+ sb->s_maxbytes = MAX_LFS_FILESIZE;
+ sb->s_blocksize = PAGE_SIZE;
+ sb->s_blocksize_bits = PAGE_SHIFT;
+ sb->s_magic = PSTOREFS_MAGIC;
+ sb->s_op = &pstore_ops;
+ sb->s_time_gran = 1;
+
+ parse_options(data);
+
+ inode = pstore_get_inode(sb);
+ if (inode) {
+ inode->i_mode = S_IFDIR | 0750;
+ inode->i_op = &pstore_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+ inc_nlink(inode);
+ }
+ sb->s_root = d_make_root(inode);
+ if (!sb->s_root)
+ return -ENOMEM;
+
+ pstore_get_records(0);
+
+ return 0;
+}
+
+static struct dentry *pstore_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return mount_single(fs_type, flags, data, pstore_fill_super);
+}
+
+static void pstore_kill_sb(struct super_block *sb)
+{
+ kill_litter_super(sb);
+ pstore_sb = NULL;
+}
+
+static struct file_system_type pstore_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "pstore",
+ .mount = pstore_mount,
+ .kill_sb = pstore_kill_sb,
+};
+
+static int __init init_pstore_fs(void)
+{
+ int err;
+
+ pstore_choose_compression();
+
+ /* Create a convenient mount point for people to access pstore */
+ err = sysfs_create_mount_point(fs_kobj, "pstore");
+ if (err)
+ goto out;
+
+ err = register_filesystem(&pstore_fs_type);
+ if (err < 0)
+ sysfs_remove_mount_point(fs_kobj, "pstore");
+
+out:
+ return err;
+}
+module_init(init_pstore_fs)
+
+static void __exit exit_pstore_fs(void)
+{
+ unregister_filesystem(&pstore_fs_type);
+ sysfs_remove_mount_point(fs_kobj, "pstore");
+}
+module_exit(exit_pstore_fs)
+
+MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>");
+MODULE_LICENSE("GPL");
diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
new file mode 100644
index 0000000..fb767e2
--- /dev/null
+++ b/fs/pstore/internal.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PSTORE_INTERNAL_H__
+#define __PSTORE_INTERNAL_H__
+
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/pstore.h>
+
+#define PSTORE_DEFAULT_KMSG_BYTES 10240
+extern unsigned long kmsg_bytes;
+
+#ifdef CONFIG_PSTORE_FTRACE
+extern void pstore_register_ftrace(void);
+extern void pstore_unregister_ftrace(void);
+#else
+static inline void pstore_register_ftrace(void) {}
+static inline void pstore_unregister_ftrace(void) {}
+#endif
+
+#ifdef CONFIG_PSTORE_PMSG
+extern void pstore_register_pmsg(void);
+extern void pstore_unregister_pmsg(void);
+#else
+static inline void pstore_register_pmsg(void) {}
+static inline void pstore_unregister_pmsg(void) {}
+#endif
+
+extern struct pstore_info *psinfo;
+
+extern void pstore_set_kmsg_bytes(int);
+extern void pstore_get_records(int);
+extern void pstore_get_backend_records(struct pstore_info *psi,
+ struct dentry *root, int quiet);
+extern int pstore_mkfile(struct dentry *root,
+ struct pstore_record *record);
+extern bool pstore_is_mounted(void);
+extern void pstore_record_init(struct pstore_record *record,
+ struct pstore_info *psi);
+
+/* Called during module_init() */
+extern void __init pstore_choose_compression(void);
+
+#endif
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
new file mode 100644
index 0000000..15e99d5
--- /dev/null
+++ b/fs/pstore/platform.c
@@ -0,0 +1,787 @@
+/*
+ * Persistent Storage - platform driver interface parts.
+ *
+ * Copyright (C) 2007-2008 Google, Inc.
+ * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
+ *
+ * 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
+ */
+
+#define pr_fmt(fmt) "pstore: " fmt
+
+#include <linux/atomic.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kmsg_dump.h>
+#include <linux/console.h>
+#include <linux/module.h>
+#include <linux/pstore.h>
+#if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS)
+#include <linux/lzo.h>
+#endif
+#if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS)
+#include <linux/lz4.h>
+#endif
+#if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS)
+#include <linux/zstd.h>
+#endif
+#include <linux/crypto.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/jiffies.h>
+#include <linux/workqueue.h>
+
+#include "internal.h"
+
+/*
+ * We defer making "oops" entries appear in pstore - see
+ * whether the system is actually still running well enough
+ * to let someone see the entry
+ */
+static int pstore_update_ms = -1;
+module_param_named(update_ms, pstore_update_ms, int, 0600);
+MODULE_PARM_DESC(update_ms, "milliseconds before pstore updates its content "
+ "(default is -1, which means runtime updates are disabled; "
+ "enabling this option is not safe, it may lead to further "
+ "corruption on Oopses)");
+
+static int pstore_new_entry;
+
+static void pstore_timefunc(struct timer_list *);
+static DEFINE_TIMER(pstore_timer, pstore_timefunc);
+
+static void pstore_dowork(struct work_struct *);
+static DECLARE_WORK(pstore_work, pstore_dowork);
+
+/*
+ * pstore_lock just protects "psinfo" during
+ * calls to pstore_register()
+ */
+static DEFINE_SPINLOCK(pstore_lock);
+struct pstore_info *psinfo;
+
+static char *backend;
+static char *compress =
+#ifdef CONFIG_PSTORE_COMPRESS_DEFAULT
+ CONFIG_PSTORE_COMPRESS_DEFAULT;
+#else
+ NULL;
+#endif
+
+/* Compression parameters */
+static struct crypto_comp *tfm;
+
+struct pstore_zbackend {
+ int (*zbufsize)(size_t size);
+ const char *name;
+};
+
+static char *big_oops_buf;
+static size_t big_oops_buf_sz;
+
+/* How much of the console log to snapshot */
+unsigned long kmsg_bytes = PSTORE_DEFAULT_KMSG_BYTES;
+
+void pstore_set_kmsg_bytes(int bytes)
+{
+ kmsg_bytes = bytes;
+}
+
+/* Tag each group of saved records with a sequence number */
+static int oopscount;
+
+static const char *get_reason_str(enum kmsg_dump_reason reason)
+{
+ switch (reason) {
+ case KMSG_DUMP_PANIC:
+ return "Panic";
+ case KMSG_DUMP_OOPS:
+ return "Oops";
+ case KMSG_DUMP_EMERG:
+ return "Emergency";
+ case KMSG_DUMP_RESTART:
+ return "Restart";
+ case KMSG_DUMP_HALT:
+ return "Halt";
+ case KMSG_DUMP_POWEROFF:
+ return "Poweroff";
+ default:
+ return "Unknown";
+ }
+}
+
+bool pstore_cannot_block_path(enum kmsg_dump_reason reason)
+{
+ /*
+ * In case of NMI path, pstore shouldn't be blocked
+ * regardless of reason.
+ */
+ if (in_nmi())
+ return true;
+
+ switch (reason) {
+ /* In panic case, other cpus are stopped by smp_send_stop(). */
+ case KMSG_DUMP_PANIC:
+ /* Emergency restart shouldn't be blocked by spin lock. */
+ case KMSG_DUMP_EMERG:
+ return true;
+ default:
+ return false;
+ }
+}
+EXPORT_SYMBOL_GPL(pstore_cannot_block_path);
+
+#if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS)
+static int zbufsize_deflate(size_t size)
+{
+ size_t cmpr;
+
+ switch (size) {
+ /* buffer range for efivars */
+ case 1000 ... 2000:
+ cmpr = 56;
+ break;
+ case 2001 ... 3000:
+ cmpr = 54;
+ break;
+ case 3001 ... 3999:
+ cmpr = 52;
+ break;
+ /* buffer range for nvram, erst */
+ case 4000 ... 10000:
+ cmpr = 45;
+ break;
+ default:
+ cmpr = 60;
+ break;
+ }
+
+ return (size * 100) / cmpr;
+}
+#endif
+
+#if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS)
+static int zbufsize_lzo(size_t size)
+{
+ return lzo1x_worst_compress(size);
+}
+#endif
+
+#if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS)
+static int zbufsize_lz4(size_t size)
+{
+ return LZ4_compressBound(size);
+}
+#endif
+
+#if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS)
+static int zbufsize_842(size_t size)
+{
+ return size;
+}
+#endif
+
+#if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS)
+static int zbufsize_zstd(size_t size)
+{
+ return ZSTD_compressBound(size);
+}
+#endif
+
+static const struct pstore_zbackend *zbackend __ro_after_init;
+
+static const struct pstore_zbackend zbackends[] = {
+#if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS)
+ {
+ .zbufsize = zbufsize_deflate,
+ .name = "deflate",
+ },
+#endif
+#if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS)
+ {
+ .zbufsize = zbufsize_lzo,
+ .name = "lzo",
+ },
+#endif
+#if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS)
+ {
+ .zbufsize = zbufsize_lz4,
+ .name = "lz4",
+ },
+#endif
+#if IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS)
+ {
+ .zbufsize = zbufsize_lz4,
+ .name = "lz4hc",
+ },
+#endif
+#if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS)
+ {
+ .zbufsize = zbufsize_842,
+ .name = "842",
+ },
+#endif
+#if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS)
+ {
+ .zbufsize = zbufsize_zstd,
+ .name = "zstd",
+ },
+#endif
+ { }
+};
+
+static int pstore_compress(const void *in, void *out,
+ unsigned int inlen, unsigned int outlen)
+{
+ int ret;
+
+ ret = crypto_comp_compress(tfm, in, inlen, out, &outlen);
+ if (ret) {
+ pr_err("crypto_comp_compress failed, ret = %d!\n", ret);
+ return ret;
+ }
+
+ return outlen;
+}
+
+static int pstore_decompress(void *in, void *out,
+ unsigned int inlen, unsigned int outlen)
+{
+ int ret;
+
+ ret = crypto_comp_decompress(tfm, in, inlen, out, &outlen);
+ if (ret) {
+ pr_err("crypto_comp_decompress failed, ret = %d!\n", ret);
+ return ret;
+ }
+
+ return outlen;
+}
+
+static void allocate_buf_for_compression(void)
+{
+ if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend)
+ return;
+
+ if (!crypto_has_comp(zbackend->name, 0, 0)) {
+ pr_err("No %s compression\n", zbackend->name);
+ return;
+ }
+
+ big_oops_buf_sz = zbackend->zbufsize(psinfo->bufsize);
+ if (big_oops_buf_sz <= 0)
+ return;
+
+ big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
+ if (!big_oops_buf) {
+ pr_err("allocate compression buffer error!\n");
+ return;
+ }
+
+ tfm = crypto_alloc_comp(zbackend->name, 0, 0);
+ if (IS_ERR_OR_NULL(tfm)) {
+ kfree(big_oops_buf);
+ big_oops_buf = NULL;
+ pr_err("crypto_alloc_comp() failed!\n");
+ return;
+ }
+}
+
+static void free_buf_for_compression(void)
+{
+ if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && !IS_ERR_OR_NULL(tfm))
+ crypto_free_comp(tfm);
+ kfree(big_oops_buf);
+ big_oops_buf = NULL;
+ big_oops_buf_sz = 0;
+}
+
+/*
+ * Called when compression fails, since the printk buffer
+ * would be fetched for compression calling it again when
+ * compression fails would have moved the iterator of
+ * printk buffer which results in fetching old contents.
+ * Copy the recent messages from big_oops_buf to psinfo->buf
+ */
+static size_t copy_kmsg_to_buffer(int hsize, size_t len)
+{
+ size_t total_len;
+ size_t diff;
+
+ total_len = hsize + len;
+
+ if (total_len > psinfo->bufsize) {
+ diff = total_len - psinfo->bufsize + hsize;
+ memcpy(psinfo->buf, big_oops_buf, hsize);
+ memcpy(psinfo->buf + hsize, big_oops_buf + diff,
+ psinfo->bufsize - hsize);
+ total_len = psinfo->bufsize;
+ } else
+ memcpy(psinfo->buf, big_oops_buf, total_len);
+
+ return total_len;
+}
+
+void pstore_record_init(struct pstore_record *record,
+ struct pstore_info *psinfo)
+{
+ memset(record, 0, sizeof(*record));
+
+ record->psi = psinfo;
+
+ /* Report zeroed timestamp if called before timekeeping has resumed. */
+ record->time = ns_to_timespec64(ktime_get_real_fast_ns());
+}
+
+/*
+ * callback from kmsg_dump. (s2,l2) has the most recently
+ * written bytes, older bytes are in (s1,l1). Save as much
+ * as we can from the end of the buffer.
+ */
+static void pstore_dump(struct kmsg_dumper *dumper,
+ enum kmsg_dump_reason reason)
+{
+ unsigned long total = 0;
+ const char *why;
+ unsigned int part = 1;
+ unsigned long flags = 0;
+ int is_locked;
+ int ret;
+
+ why = get_reason_str(reason);
+
+ if (pstore_cannot_block_path(reason)) {
+ is_locked = spin_trylock_irqsave(&psinfo->buf_lock, flags);
+ if (!is_locked) {
+ pr_err("pstore dump routine blocked in %s path, may corrupt error record\n"
+ , in_nmi() ? "NMI" : why);
+ return;
+ }
+ } else {
+ spin_lock_irqsave(&psinfo->buf_lock, flags);
+ is_locked = 1;
+ }
+ oopscount++;
+ while (total < kmsg_bytes) {
+ char *dst;
+ size_t dst_size;
+ int header_size;
+ int zipped_len = -1;
+ size_t dump_size;
+ struct pstore_record record;
+
+ pstore_record_init(&record, psinfo);
+ record.type = PSTORE_TYPE_DMESG;
+ record.count = oopscount;
+ record.reason = reason;
+ record.part = part;
+ record.buf = psinfo->buf;
+
+ if (big_oops_buf && is_locked) {
+ dst = big_oops_buf;
+ dst_size = big_oops_buf_sz;
+ } else {
+ dst = psinfo->buf;
+ dst_size = psinfo->bufsize;
+ }
+
+ /* Write dump header. */
+ header_size = snprintf(dst, dst_size, "%s#%d Part%u\n", why,
+ oopscount, part);
+ dst_size -= header_size;
+
+ /* Write dump contents. */
+ if (!kmsg_dump_get_buffer(dumper, true, dst + header_size,
+ dst_size, &dump_size))
+ break;
+
+ if (big_oops_buf && is_locked) {
+ zipped_len = pstore_compress(dst, psinfo->buf,
+ header_size + dump_size,
+ psinfo->bufsize);
+
+ if (zipped_len > 0) {
+ record.compressed = true;
+ record.size = zipped_len;
+ } else {
+ record.size = copy_kmsg_to_buffer(header_size,
+ dump_size);
+ }
+ } else {
+ record.size = header_size + dump_size;
+ }
+
+ ret = psinfo->write(&record);
+ if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted())
+ pstore_new_entry = 1;
+
+ total += record.size;
+ part++;
+ }
+ if (is_locked)
+ spin_unlock_irqrestore(&psinfo->buf_lock, flags);
+}
+
+static struct kmsg_dumper pstore_dumper = {
+ .dump = pstore_dump,
+};
+
+/*
+ * Register with kmsg_dump to save last part of console log on panic.
+ */
+static void pstore_register_kmsg(void)
+{
+ kmsg_dump_register(&pstore_dumper);
+}
+
+static void pstore_unregister_kmsg(void)
+{
+ kmsg_dump_unregister(&pstore_dumper);
+}
+
+#ifdef CONFIG_PSTORE_CONSOLE
+static void pstore_console_write(struct console *con, const char *s, unsigned c)
+{
+ const char *e = s + c;
+
+ while (s < e) {
+ struct pstore_record record;
+ unsigned long flags;
+
+ pstore_record_init(&record, psinfo);
+ record.type = PSTORE_TYPE_CONSOLE;
+
+ if (c > psinfo->bufsize)
+ c = psinfo->bufsize;
+
+ if (oops_in_progress) {
+ if (!spin_trylock_irqsave(&psinfo->buf_lock, flags))
+ break;
+ } else {
+ spin_lock_irqsave(&psinfo->buf_lock, flags);
+ }
+ record.buf = (char *)s;
+ record.size = c;
+ psinfo->write(&record);
+ spin_unlock_irqrestore(&psinfo->buf_lock, flags);
+ s += c;
+ c = e - s;
+ }
+}
+
+static struct console pstore_console = {
+ .name = "pstore",
+ .write = pstore_console_write,
+ .flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME,
+ .index = -1,
+};
+
+static void pstore_register_console(void)
+{
+ register_console(&pstore_console);
+}
+
+static void pstore_unregister_console(void)
+{
+ unregister_console(&pstore_console);
+}
+#else
+static void pstore_register_console(void) {}
+static void pstore_unregister_console(void) {}
+#endif
+
+static int pstore_write_user_compat(struct pstore_record *record,
+ const char __user *buf)
+{
+ int ret = 0;
+
+ if (record->buf)
+ return -EINVAL;
+
+ record->buf = memdup_user(buf, record->size);
+ if (IS_ERR(record->buf)) {
+ ret = PTR_ERR(record->buf);
+ goto out;
+ }
+
+ ret = record->psi->write(record);
+
+ kfree(record->buf);
+out:
+ record->buf = NULL;
+
+ return unlikely(ret < 0) ? ret : record->size;
+}
+
+/*
+ * platform specific persistent storage driver registers with
+ * us here. If pstore is already mounted, call the platform
+ * read function right away to populate the file system. If not
+ * then the pstore mount code will call us later to fill out
+ * the file system.
+ */
+int pstore_register(struct pstore_info *psi)
+{
+ struct module *owner = psi->owner;
+
+ if (backend && strcmp(backend, psi->name)) {
+ pr_warn("ignoring unexpected backend '%s'\n", psi->name);
+ return -EPERM;
+ }
+
+ /* Sanity check flags. */
+ if (!psi->flags) {
+ pr_warn("backend '%s' must support at least one frontend\n",
+ psi->name);
+ return -EINVAL;
+ }
+
+ /* Check for required functions. */
+ if (!psi->read || !psi->write) {
+ pr_warn("backend '%s' must implement read() and write()\n",
+ psi->name);
+ return -EINVAL;
+ }
+
+ spin_lock(&pstore_lock);
+ if (psinfo) {
+ pr_warn("backend '%s' already loaded: ignoring '%s'\n",
+ psinfo->name, psi->name);
+ spin_unlock(&pstore_lock);
+ return -EBUSY;
+ }
+
+ if (!psi->write_user)
+ psi->write_user = pstore_write_user_compat;
+ psinfo = psi;
+ mutex_init(&psinfo->read_mutex);
+ spin_unlock(&pstore_lock);
+
+ if (owner && !try_module_get(owner)) {
+ psinfo = NULL;
+ return -EINVAL;
+ }
+
+ allocate_buf_for_compression();
+
+ if (pstore_is_mounted())
+ pstore_get_records(0);
+
+ if (psi->flags & PSTORE_FLAGS_DMESG)
+ pstore_register_kmsg();
+ if (psi->flags & PSTORE_FLAGS_CONSOLE)
+ pstore_register_console();
+ if (psi->flags & PSTORE_FLAGS_FTRACE)
+ pstore_register_ftrace();
+ if (psi->flags & PSTORE_FLAGS_PMSG)
+ pstore_register_pmsg();
+
+ /* Start watching for new records, if desired. */
+ if (pstore_update_ms >= 0) {
+ pstore_timer.expires = jiffies +
+ msecs_to_jiffies(pstore_update_ms);
+ add_timer(&pstore_timer);
+ }
+
+ /*
+ * Update the module parameter backend, so it is visible
+ * through /sys/module/pstore/parameters/backend
+ */
+ backend = psi->name;
+
+ pr_info("Registered %s as persistent store backend\n", psi->name);
+
+ module_put(owner);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pstore_register);
+
+void pstore_unregister(struct pstore_info *psi)
+{
+ /* Stop timer and make sure all work has finished. */
+ pstore_update_ms = -1;
+ del_timer_sync(&pstore_timer);
+ flush_work(&pstore_work);
+
+ if (psi->flags & PSTORE_FLAGS_PMSG)
+ pstore_unregister_pmsg();
+ if (psi->flags & PSTORE_FLAGS_FTRACE)
+ pstore_unregister_ftrace();
+ if (psi->flags & PSTORE_FLAGS_CONSOLE)
+ pstore_unregister_console();
+ if (psi->flags & PSTORE_FLAGS_DMESG)
+ pstore_unregister_kmsg();
+
+ free_buf_for_compression();
+
+ psinfo = NULL;
+ backend = NULL;
+}
+EXPORT_SYMBOL_GPL(pstore_unregister);
+
+static void decompress_record(struct pstore_record *record)
+{
+ int unzipped_len;
+ char *decompressed;
+
+ if (!record->compressed)
+ return;
+
+ /* Only PSTORE_TYPE_DMESG support compression. */
+ if (record->type != PSTORE_TYPE_DMESG) {
+ pr_warn("ignored compressed record type %d\n", record->type);
+ return;
+ }
+
+ /* No compression method has created the common buffer. */
+ if (!big_oops_buf) {
+ pr_warn("no decompression buffer allocated\n");
+ return;
+ }
+
+ unzipped_len = pstore_decompress(record->buf, big_oops_buf,
+ record->size, big_oops_buf_sz);
+ if (unzipped_len <= 0) {
+ pr_err("decompression failed: %d\n", unzipped_len);
+ return;
+ }
+
+ /* Build new buffer for decompressed contents. */
+ decompressed = kmalloc(unzipped_len + record->ecc_notice_size,
+ GFP_KERNEL);
+ if (!decompressed) {
+ pr_err("decompression ran out of memory\n");
+ return;
+ }
+ memcpy(decompressed, big_oops_buf, unzipped_len);
+
+ /* Append ECC notice to decompressed buffer. */
+ memcpy(decompressed + unzipped_len, record->buf + record->size,
+ record->ecc_notice_size);
+
+ /* Swap out compresed contents with decompressed contents. */
+ kfree(record->buf);
+ record->buf = decompressed;
+ record->size = unzipped_len;
+ record->compressed = false;
+}
+
+/*
+ * Read all the records from one persistent store backend. Create
+ * files in our filesystem. Don't warn about -EEXIST errors
+ * when we are re-scanning the backing store looking to add new
+ * error records.
+ */
+void pstore_get_backend_records(struct pstore_info *psi,
+ struct dentry *root, int quiet)
+{
+ int failed = 0;
+ unsigned int stop_loop = 65536;
+
+ if (!psi || !root)
+ return;
+
+ mutex_lock(&psi->read_mutex);
+ if (psi->open && psi->open(psi))
+ goto out;
+
+ /*
+ * Backend callback read() allocates record.buf. decompress_record()
+ * may reallocate record.buf. On success, pstore_mkfile() will keep
+ * the record.buf, so free it only on failure.
+ */
+ for (; stop_loop; stop_loop--) {
+ struct pstore_record *record;
+ int rc;
+
+ record = kzalloc(sizeof(*record), GFP_KERNEL);
+ if (!record) {
+ pr_err("out of memory creating record\n");
+ break;
+ }
+ pstore_record_init(record, psi);
+
+ record->size = psi->read(record);
+
+ /* No more records left in backend? */
+ if (record->size <= 0) {
+ kfree(record);
+ break;
+ }
+
+ decompress_record(record);
+ rc = pstore_mkfile(root, record);
+ if (rc) {
+ /* pstore_mkfile() did not take record, so free it. */
+ kfree(record->buf);
+ kfree(record);
+ if (rc != -EEXIST || !quiet)
+ failed++;
+ }
+ }
+ if (psi->close)
+ psi->close(psi);
+out:
+ mutex_unlock(&psi->read_mutex);
+
+ if (failed)
+ pr_warn("failed to create %d record(s) from '%s'\n",
+ failed, psi->name);
+ if (!stop_loop)
+ pr_err("looping? Too many records seen from '%s'\n",
+ psi->name);
+}
+
+static void pstore_dowork(struct work_struct *work)
+{
+ pstore_get_records(1);
+}
+
+static void pstore_timefunc(struct timer_list *unused)
+{
+ if (pstore_new_entry) {
+ pstore_new_entry = 0;
+ schedule_work(&pstore_work);
+ }
+
+ if (pstore_update_ms >= 0)
+ mod_timer(&pstore_timer,
+ jiffies + msecs_to_jiffies(pstore_update_ms));
+}
+
+void __init pstore_choose_compression(void)
+{
+ const struct pstore_zbackend *step;
+
+ if (!compress)
+ return;
+
+ for (step = zbackends; step->name; step++) {
+ if (!strcmp(compress, step->name)) {
+ zbackend = step;
+ pr_info("using %s compression\n", zbackend->name);
+ return;
+ }
+ }
+}
+
+module_param(compress, charp, 0444);
+MODULE_PARM_DESC(compress, "Pstore compression to use");
+
+module_param(backend, charp, 0444);
+MODULE_PARM_DESC(backend, "Pstore backend to use");
diff --git a/fs/pstore/pmsg.c b/fs/pstore/pmsg.c
new file mode 100644
index 0000000..24db02d
--- /dev/null
+++ b/fs/pstore/pmsg.c
@@ -0,0 +1,102 @@
+/*
+ * Copyright 2014 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.
+ */
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include "internal.h"
+
+static DEFINE_MUTEX(pmsg_lock);
+
+static ssize_t write_pmsg(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct pstore_record record;
+ int ret;
+
+ if (!count)
+ return 0;
+
+ pstore_record_init(&record, psinfo);
+ record.type = PSTORE_TYPE_PMSG;
+ record.size = count;
+
+ /* check outside lock, page in any data. write_user also checks */
+ if (!access_ok(VERIFY_READ, buf, count))
+ return -EFAULT;
+
+ mutex_lock(&pmsg_lock);
+ ret = psinfo->write_user(&record, buf);
+ mutex_unlock(&pmsg_lock);
+ return ret ? ret : count;
+}
+
+static const struct file_operations pmsg_fops = {
+ .owner = THIS_MODULE,
+ .llseek = noop_llseek,
+ .write = write_pmsg,
+};
+
+static struct class *pmsg_class;
+static int pmsg_major;
+#define PMSG_NAME "pmsg"
+#undef pr_fmt
+#define pr_fmt(fmt) PMSG_NAME ": " fmt
+
+static char *pmsg_devnode(struct device *dev, umode_t *mode)
+{
+ if (mode)
+ *mode = 0220;
+ return NULL;
+}
+
+void pstore_register_pmsg(void)
+{
+ struct device *pmsg_device;
+
+ pmsg_major = register_chrdev(0, PMSG_NAME, &pmsg_fops);
+ if (pmsg_major < 0) {
+ pr_err("register_chrdev failed\n");
+ goto err;
+ }
+
+ pmsg_class = class_create(THIS_MODULE, PMSG_NAME);
+ if (IS_ERR(pmsg_class)) {
+ pr_err("device class file already in use\n");
+ goto err_class;
+ }
+ pmsg_class->devnode = pmsg_devnode;
+
+ pmsg_device = device_create(pmsg_class, NULL, MKDEV(pmsg_major, 0),
+ NULL, "%s%d", PMSG_NAME, 0);
+ if (IS_ERR(pmsg_device)) {
+ pr_err("failed to create device\n");
+ goto err_device;
+ }
+ return;
+
+err_device:
+ class_destroy(pmsg_class);
+err_class:
+ unregister_chrdev(pmsg_major, PMSG_NAME);
+err:
+ return;
+}
+
+void pstore_unregister_pmsg(void)
+{
+ device_destroy(pmsg_class, MKDEV(pmsg_major, 0));
+ class_destroy(pmsg_class);
+ unregister_chrdev(pmsg_major, PMSG_NAME);
+}
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
new file mode 100644
index 0000000..03cd593
--- /dev/null
+++ b/fs/pstore/ram.c
@@ -0,0 +1,973 @@
+/*
+ * RAM Oops/Panic logger
+ *
+ * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
+ * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/pstore.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/compiler.h>
+#include <linux/pstore_ram.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#define RAMOOPS_KERNMSG_HDR "===="
+#define MIN_MEM_SIZE 4096UL
+
+static ulong record_size = MIN_MEM_SIZE;
+module_param(record_size, ulong, 0400);
+MODULE_PARM_DESC(record_size,
+ "size of each dump done on oops/panic");
+
+static ulong ramoops_console_size = MIN_MEM_SIZE;
+module_param_named(console_size, ramoops_console_size, ulong, 0400);
+MODULE_PARM_DESC(console_size, "size of kernel console log");
+
+static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
+module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
+MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
+
+static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
+module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
+MODULE_PARM_DESC(pmsg_size, "size of user space message log");
+
+static unsigned long long mem_address;
+module_param_hw(mem_address, ullong, other, 0400);
+MODULE_PARM_DESC(mem_address,
+ "start of reserved RAM used to store oops/panic logs");
+
+static ulong mem_size;
+module_param(mem_size, ulong, 0400);
+MODULE_PARM_DESC(mem_size,
+ "size of reserved RAM used to store oops/panic logs");
+
+static unsigned int mem_type;
+module_param(mem_type, uint, 0600);
+MODULE_PARM_DESC(mem_type,
+ "set to 1 to try to use unbuffered memory (default 0)");
+
+static int dump_oops = 1;
+module_param(dump_oops, int, 0600);
+MODULE_PARM_DESC(dump_oops,
+ "set to 1 to dump oopses, 0 to only dump panics (default 1)");
+
+static int ramoops_ecc;
+module_param_named(ecc, ramoops_ecc, int, 0600);
+MODULE_PARM_DESC(ramoops_ecc,
+ "if non-zero, the option enables ECC support and specifies "
+ "ECC buffer size in bytes (1 is a special value, means 16 "
+ "bytes ECC)");
+
+struct ramoops_context {
+ struct persistent_ram_zone **dprzs; /* Oops dump zones */
+ struct persistent_ram_zone *cprz; /* Console zone */
+ struct persistent_ram_zone **fprzs; /* Ftrace zones */
+ struct persistent_ram_zone *mprz; /* PMSG zone */
+ phys_addr_t phys_addr;
+ unsigned long size;
+ unsigned int memtype;
+ size_t record_size;
+ size_t console_size;
+ size_t ftrace_size;
+ size_t pmsg_size;
+ int dump_oops;
+ u32 flags;
+ struct persistent_ram_ecc_info ecc_info;
+ unsigned int max_dump_cnt;
+ unsigned int dump_write_cnt;
+ /* _read_cnt need clear on ramoops_pstore_open */
+ unsigned int dump_read_cnt;
+ unsigned int console_read_cnt;
+ unsigned int max_ftrace_cnt;
+ unsigned int ftrace_read_cnt;
+ unsigned int pmsg_read_cnt;
+ struct pstore_info pstore;
+};
+
+static struct platform_device *dummy;
+static struct ramoops_platform_data *dummy_data;
+
+static int ramoops_pstore_open(struct pstore_info *psi)
+{
+ struct ramoops_context *cxt = psi->data;
+
+ cxt->dump_read_cnt = 0;
+ cxt->console_read_cnt = 0;
+ cxt->ftrace_read_cnt = 0;
+ cxt->pmsg_read_cnt = 0;
+ return 0;
+}
+
+static struct persistent_ram_zone *
+ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
+ u64 *id,
+ enum pstore_type_id *typep, enum pstore_type_id type,
+ bool update)
+{
+ struct persistent_ram_zone *prz;
+ int i = (*c)++;
+
+ /* Give up if we never existed or have hit the end. */
+ if (!przs || i >= max)
+ return NULL;
+
+ prz = przs[i];
+ if (!prz)
+ return NULL;
+
+ /* Update old/shadowed buffer. */
+ if (update)
+ persistent_ram_save_old(prz);
+
+ if (!persistent_ram_old_size(prz))
+ return NULL;
+
+ *typep = type;
+ *id = i;
+
+ return prz;
+}
+
+static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
+ bool *compressed)
+{
+ char data_type;
+ int header_length = 0;
+
+ if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
+ (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
+ &header_length) == 3) {
+ if (data_type == 'C')
+ *compressed = true;
+ else
+ *compressed = false;
+ } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
+ (time64_t *)&time->tv_sec, &time->tv_nsec,
+ &header_length) == 2) {
+ *compressed = false;
+ } else {
+ time->tv_sec = 0;
+ time->tv_nsec = 0;
+ *compressed = false;
+ }
+ return header_length;
+}
+
+static bool prz_ok(struct persistent_ram_zone *prz)
+{
+ return !!prz && !!(persistent_ram_old_size(prz) +
+ persistent_ram_ecc_string(prz, NULL, 0));
+}
+
+static ssize_t ftrace_log_combine(struct persistent_ram_zone *dest,
+ struct persistent_ram_zone *src)
+{
+ size_t dest_size, src_size, total, dest_off, src_off;
+ size_t dest_idx = 0, src_idx = 0, merged_idx = 0;
+ void *merged_buf;
+ struct pstore_ftrace_record *drec, *srec, *mrec;
+ size_t record_size = sizeof(struct pstore_ftrace_record);
+
+ dest_off = dest->old_log_size % record_size;
+ dest_size = dest->old_log_size - dest_off;
+
+ src_off = src->old_log_size % record_size;
+ src_size = src->old_log_size - src_off;
+
+ total = dest_size + src_size;
+ merged_buf = kmalloc(total, GFP_KERNEL);
+ if (!merged_buf)
+ return -ENOMEM;
+
+ drec = (struct pstore_ftrace_record *)(dest->old_log + dest_off);
+ srec = (struct pstore_ftrace_record *)(src->old_log + src_off);
+ mrec = (struct pstore_ftrace_record *)(merged_buf);
+
+ while (dest_size > 0 && src_size > 0) {
+ if (pstore_ftrace_read_timestamp(&drec[dest_idx]) <
+ pstore_ftrace_read_timestamp(&srec[src_idx])) {
+ mrec[merged_idx++] = drec[dest_idx++];
+ dest_size -= record_size;
+ } else {
+ mrec[merged_idx++] = srec[src_idx++];
+ src_size -= record_size;
+ }
+ }
+
+ while (dest_size > 0) {
+ mrec[merged_idx++] = drec[dest_idx++];
+ dest_size -= record_size;
+ }
+
+ while (src_size > 0) {
+ mrec[merged_idx++] = srec[src_idx++];
+ src_size -= record_size;
+ }
+
+ kfree(dest->old_log);
+ dest->old_log = merged_buf;
+ dest->old_log_size = total;
+
+ return 0;
+}
+
+static ssize_t ramoops_pstore_read(struct pstore_record *record)
+{
+ ssize_t size = 0;
+ struct ramoops_context *cxt = record->psi->data;
+ struct persistent_ram_zone *prz = NULL;
+ int header_length = 0;
+ bool free_prz = false;
+
+ /*
+ * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
+ * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
+ * valid time stamps, so it is initialized to zero.
+ */
+ record->time.tv_sec = 0;
+ record->time.tv_nsec = 0;
+ record->compressed = false;
+
+ /* Find the next valid persistent_ram_zone for DMESG */
+ while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
+ prz = ramoops_get_next_prz(cxt->dprzs, &cxt->dump_read_cnt,
+ cxt->max_dump_cnt, &record->id,
+ &record->type,
+ PSTORE_TYPE_DMESG, 1);
+ if (!prz_ok(prz))
+ continue;
+ header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
+ &record->time,
+ &record->compressed);
+ /* Clear and skip this DMESG record if it has no valid header */
+ if (!header_length) {
+ persistent_ram_free_old(prz);
+ persistent_ram_zap(prz);
+ prz = NULL;
+ }
+ }
+
+ if (!prz_ok(prz))
+ prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
+ 1, &record->id, &record->type,
+ PSTORE_TYPE_CONSOLE, 0);
+
+ if (!prz_ok(prz))
+ prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
+ 1, &record->id, &record->type,
+ PSTORE_TYPE_PMSG, 0);
+
+ /* ftrace is last since it may want to dynamically allocate memory. */
+ if (!prz_ok(prz)) {
+ if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)) {
+ prz = ramoops_get_next_prz(cxt->fprzs,
+ &cxt->ftrace_read_cnt, 1, &record->id,
+ &record->type, PSTORE_TYPE_FTRACE, 0);
+ } else {
+ /*
+ * Build a new dummy record which combines all the
+ * per-cpu records including metadata and ecc info.
+ */
+ struct persistent_ram_zone *tmp_prz, *prz_next;
+
+ tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
+ GFP_KERNEL);
+ if (!tmp_prz)
+ return -ENOMEM;
+ free_prz = true;
+
+ while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
+ prz_next = ramoops_get_next_prz(cxt->fprzs,
+ &cxt->ftrace_read_cnt,
+ cxt->max_ftrace_cnt,
+ &record->id,
+ &record->type,
+ PSTORE_TYPE_FTRACE, 0);
+
+ if (!prz_ok(prz_next))
+ continue;
+
+ tmp_prz->ecc_info = prz_next->ecc_info;
+ tmp_prz->corrected_bytes +=
+ prz_next->corrected_bytes;
+ tmp_prz->bad_blocks += prz_next->bad_blocks;
+ size = ftrace_log_combine(tmp_prz, prz_next);
+ if (size)
+ goto out;
+ }
+ record->id = 0;
+ prz = tmp_prz;
+ }
+ }
+
+ if (!prz_ok(prz)) {
+ size = 0;
+ goto out;
+ }
+
+ size = persistent_ram_old_size(prz) - header_length;
+
+ /* ECC correction notice */
+ record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
+
+ record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
+ if (record->buf == NULL) {
+ size = -ENOMEM;
+ goto out;
+ }
+
+ memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
+ size);
+
+ persistent_ram_ecc_string(prz, record->buf + size,
+ record->ecc_notice_size + 1);
+
+out:
+ if (free_prz) {
+ kfree(prz->old_log);
+ kfree(prz);
+ }
+
+ return size;
+}
+
+static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
+ struct pstore_record *record)
+{
+ char *hdr;
+ size_t len;
+
+ hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
+ (time64_t)record->time.tv_sec,
+ record->time.tv_nsec / 1000,
+ record->compressed ? 'C' : 'D');
+ WARN_ON_ONCE(!hdr);
+ len = hdr ? strlen(hdr) : 0;
+ persistent_ram_write(prz, hdr, len);
+ kfree(hdr);
+
+ return len;
+}
+
+static int notrace ramoops_pstore_write(struct pstore_record *record)
+{
+ struct ramoops_context *cxt = record->psi->data;
+ struct persistent_ram_zone *prz;
+ size_t size, hlen;
+
+ if (record->type == PSTORE_TYPE_CONSOLE) {
+ if (!cxt->cprz)
+ return -ENOMEM;
+ persistent_ram_write(cxt->cprz, record->buf, record->size);
+ return 0;
+ } else if (record->type == PSTORE_TYPE_FTRACE) {
+ int zonenum;
+
+ if (!cxt->fprzs)
+ return -ENOMEM;
+ /*
+ * Choose zone by if we're using per-cpu buffers.
+ */
+ if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
+ zonenum = smp_processor_id();
+ else
+ zonenum = 0;
+
+ persistent_ram_write(cxt->fprzs[zonenum], record->buf,
+ record->size);
+ return 0;
+ } else if (record->type == PSTORE_TYPE_PMSG) {
+ pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
+ return -EINVAL;
+ }
+
+ if (record->type != PSTORE_TYPE_DMESG)
+ return -EINVAL;
+
+ /*
+ * Out of the various dmesg dump types, ramoops is currently designed
+ * to only store crash logs, rather than storing general kernel logs.
+ */
+ if (record->reason != KMSG_DUMP_OOPS &&
+ record->reason != KMSG_DUMP_PANIC)
+ return -EINVAL;
+
+ /* Skip Oopes when configured to do so. */
+ if (record->reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
+ return -EINVAL;
+
+ /*
+ * Explicitly only take the first part of any new crash.
+ * If our buffer is larger than kmsg_bytes, this can never happen,
+ * and if our buffer is smaller than kmsg_bytes, we don't want the
+ * report split across multiple records.
+ */
+ if (record->part != 1)
+ return -ENOSPC;
+
+ if (!cxt->dprzs)
+ return -ENOSPC;
+
+ prz = cxt->dprzs[cxt->dump_write_cnt];
+
+ /* Build header and append record contents. */
+ hlen = ramoops_write_kmsg_hdr(prz, record);
+ size = record->size;
+ if (size + hlen > prz->buffer_size)
+ size = prz->buffer_size - hlen;
+ persistent_ram_write(prz, record->buf, size);
+
+ cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
+
+ return 0;
+}
+
+static int notrace ramoops_pstore_write_user(struct pstore_record *record,
+ const char __user *buf)
+{
+ if (record->type == PSTORE_TYPE_PMSG) {
+ struct ramoops_context *cxt = record->psi->data;
+
+ if (!cxt->mprz)
+ return -ENOMEM;
+ return persistent_ram_write_user(cxt->mprz, buf, record->size);
+ }
+
+ return -EINVAL;
+}
+
+static int ramoops_pstore_erase(struct pstore_record *record)
+{
+ struct ramoops_context *cxt = record->psi->data;
+ struct persistent_ram_zone *prz;
+
+ switch (record->type) {
+ case PSTORE_TYPE_DMESG:
+ if (record->id >= cxt->max_dump_cnt)
+ return -EINVAL;
+ prz = cxt->dprzs[record->id];
+ break;
+ case PSTORE_TYPE_CONSOLE:
+ prz = cxt->cprz;
+ break;
+ case PSTORE_TYPE_FTRACE:
+ if (record->id >= cxt->max_ftrace_cnt)
+ return -EINVAL;
+ prz = cxt->fprzs[record->id];
+ break;
+ case PSTORE_TYPE_PMSG:
+ prz = cxt->mprz;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ persistent_ram_free_old(prz);
+ persistent_ram_zap(prz);
+
+ return 0;
+}
+
+static struct ramoops_context oops_cxt = {
+ .pstore = {
+ .owner = THIS_MODULE,
+ .name = "ramoops",
+ .open = ramoops_pstore_open,
+ .read = ramoops_pstore_read,
+ .write = ramoops_pstore_write,
+ .write_user = ramoops_pstore_write_user,
+ .erase = ramoops_pstore_erase,
+ },
+};
+
+static void ramoops_free_przs(struct ramoops_context *cxt)
+{
+ int i;
+
+ /* Free dump PRZs */
+ if (cxt->dprzs) {
+ for (i = 0; i < cxt->max_dump_cnt; i++)
+ persistent_ram_free(cxt->dprzs[i]);
+
+ kfree(cxt->dprzs);
+ cxt->max_dump_cnt = 0;
+ }
+
+ /* Free ftrace PRZs */
+ if (cxt->fprzs) {
+ for (i = 0; i < cxt->max_ftrace_cnt; i++)
+ persistent_ram_free(cxt->fprzs[i]);
+ kfree(cxt->fprzs);
+ cxt->max_ftrace_cnt = 0;
+ }
+}
+
+static int ramoops_init_przs(const char *name,
+ struct device *dev, struct ramoops_context *cxt,
+ struct persistent_ram_zone ***przs,
+ phys_addr_t *paddr, size_t mem_sz,
+ ssize_t record_size,
+ unsigned int *cnt, u32 sig, u32 flags)
+{
+ int err = -ENOMEM;
+ int i;
+ size_t zone_sz;
+ struct persistent_ram_zone **prz_ar;
+
+ /* Allocate nothing for 0 mem_sz or 0 record_size. */
+ if (mem_sz == 0 || record_size == 0) {
+ *cnt = 0;
+ return 0;
+ }
+
+ /*
+ * If we have a negative record size, calculate it based on
+ * mem_sz / *cnt. If we have a positive record size, calculate
+ * cnt from mem_sz / record_size.
+ */
+ if (record_size < 0) {
+ if (*cnt == 0)
+ return 0;
+ record_size = mem_sz / *cnt;
+ if (record_size == 0) {
+ dev_err(dev, "%s record size == 0 (%zu / %u)\n",
+ name, mem_sz, *cnt);
+ goto fail;
+ }
+ } else {
+ *cnt = mem_sz / record_size;
+ if (*cnt == 0) {
+ dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
+ name, mem_sz, record_size);
+ goto fail;
+ }
+ }
+
+ if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
+ dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
+ name,
+ mem_sz, (unsigned long long)*paddr,
+ cxt->size, (unsigned long long)cxt->phys_addr);
+ goto fail;
+ }
+
+ zone_sz = mem_sz / *cnt;
+ if (!zone_sz) {
+ dev_err(dev, "%s zone size == 0\n", name);
+ goto fail;
+ }
+
+ prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
+ if (!prz_ar)
+ goto fail;
+
+ for (i = 0; i < *cnt; i++) {
+ prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
+ &cxt->ecc_info,
+ cxt->memtype, flags);
+ if (IS_ERR(prz_ar[i])) {
+ err = PTR_ERR(prz_ar[i]);
+ dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
+ name, record_size,
+ (unsigned long long)*paddr, err);
+
+ while (i > 0) {
+ i--;
+ persistent_ram_free(prz_ar[i]);
+ }
+ kfree(prz_ar);
+ goto fail;
+ }
+ *paddr += zone_sz;
+ }
+
+ *przs = prz_ar;
+ return 0;
+
+fail:
+ *cnt = 0;
+ return err;
+}
+
+static int ramoops_init_prz(const char *name,
+ struct device *dev, struct ramoops_context *cxt,
+ struct persistent_ram_zone **prz,
+ phys_addr_t *paddr, size_t sz, u32 sig)
+{
+ if (!sz)
+ return 0;
+
+ if (*paddr + sz - cxt->phys_addr > cxt->size) {
+ dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
+ name, sz, (unsigned long long)*paddr,
+ cxt->size, (unsigned long long)cxt->phys_addr);
+ return -ENOMEM;
+ }
+
+ *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
+ cxt->memtype, 0);
+ if (IS_ERR(*prz)) {
+ int err = PTR_ERR(*prz);
+
+ dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
+ name, sz, (unsigned long long)*paddr, err);
+ return err;
+ }
+
+ persistent_ram_zap(*prz);
+
+ *paddr += sz;
+
+ return 0;
+}
+
+static int ramoops_parse_dt_size(struct platform_device *pdev,
+ const char *propname, u32 *value)
+{
+ u32 val32 = 0;
+ int ret;
+
+ ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
+ if (ret < 0 && ret != -EINVAL) {
+ dev_err(&pdev->dev, "failed to parse property %s: %d\n",
+ propname, ret);
+ return ret;
+ }
+
+ if (val32 > INT_MAX) {
+ dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
+ return -EOVERFLOW;
+ }
+
+ *value = val32;
+ return 0;
+}
+
+static int ramoops_parse_dt(struct platform_device *pdev,
+ struct ramoops_platform_data *pdata)
+{
+ struct device_node *of_node = pdev->dev.of_node;
+ struct resource *res;
+ u32 value;
+ int ret;
+
+ dev_dbg(&pdev->dev, "using Device Tree\n");
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev,
+ "failed to locate DT /reserved-memory resource\n");
+ return -EINVAL;
+ }
+
+ pdata->mem_size = resource_size(res);
+ pdata->mem_address = res->start;
+ pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
+ pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
+
+#define parse_size(name, field) { \
+ ret = ramoops_parse_dt_size(pdev, name, &value); \
+ if (ret < 0) \
+ return ret; \
+ field = value; \
+ }
+
+ parse_size("record-size", pdata->record_size);
+ parse_size("console-size", pdata->console_size);
+ parse_size("ftrace-size", pdata->ftrace_size);
+ parse_size("pmsg-size", pdata->pmsg_size);
+ parse_size("ecc-size", pdata->ecc_info.ecc_size);
+ parse_size("flags", pdata->flags);
+
+#undef parse_size
+
+ return 0;
+}
+
+static int ramoops_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ramoops_platform_data *pdata = dev->platform_data;
+ struct ramoops_context *cxt = &oops_cxt;
+ size_t dump_mem_sz;
+ phys_addr_t paddr;
+ int err = -EINVAL;
+
+ if (dev_of_node(dev) && !pdata) {
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata) {
+ pr_err("cannot allocate platform data buffer\n");
+ err = -ENOMEM;
+ goto fail_out;
+ }
+
+ err = ramoops_parse_dt(pdev, pdata);
+ if (err < 0)
+ goto fail_out;
+ }
+
+ /*
+ * Only a single ramoops area allowed at a time, so fail extra
+ * probes.
+ */
+ if (cxt->max_dump_cnt) {
+ pr_err("already initialized\n");
+ goto fail_out;
+ }
+
+ /* Make sure we didn't get bogus platform data pointer. */
+ if (!pdata) {
+ pr_err("NULL platform data\n");
+ goto fail_out;
+ }
+
+ if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
+ !pdata->ftrace_size && !pdata->pmsg_size)) {
+ pr_err("The memory size and the record/console size must be "
+ "non-zero\n");
+ goto fail_out;
+ }
+
+ if (pdata->record_size && !is_power_of_2(pdata->record_size))
+ pdata->record_size = rounddown_pow_of_two(pdata->record_size);
+ if (pdata->console_size && !is_power_of_2(pdata->console_size))
+ pdata->console_size = rounddown_pow_of_two(pdata->console_size);
+ if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
+ pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
+ if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
+ pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
+
+ cxt->size = pdata->mem_size;
+ cxt->phys_addr = pdata->mem_address;
+ cxt->memtype = pdata->mem_type;
+ cxt->record_size = pdata->record_size;
+ cxt->console_size = pdata->console_size;
+ cxt->ftrace_size = pdata->ftrace_size;
+ cxt->pmsg_size = pdata->pmsg_size;
+ cxt->dump_oops = pdata->dump_oops;
+ cxt->flags = pdata->flags;
+ cxt->ecc_info = pdata->ecc_info;
+
+ paddr = cxt->phys_addr;
+
+ dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
+ - cxt->pmsg_size;
+ err = ramoops_init_przs("dump", dev, cxt, &cxt->dprzs, &paddr,
+ dump_mem_sz, cxt->record_size,
+ &cxt->max_dump_cnt, 0, 0);
+ if (err)
+ goto fail_out;
+
+ err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
+ cxt->console_size, 0);
+ if (err)
+ goto fail_init_cprz;
+
+ cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
+ ? nr_cpu_ids
+ : 1;
+ err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
+ cxt->ftrace_size, -1,
+ &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
+ (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
+ ? PRZ_FLAG_NO_LOCK : 0);
+ if (err)
+ goto fail_init_fprz;
+
+ err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
+ cxt->pmsg_size, 0);
+ if (err)
+ goto fail_init_mprz;
+
+ cxt->pstore.data = cxt;
+ /*
+ * Since bufsize is only used for dmesg crash dumps, it
+ * must match the size of the dprz record (after PRZ header
+ * and ECC bytes have been accounted for).
+ */
+ cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
+ cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL);
+ if (!cxt->pstore.buf) {
+ pr_err("cannot allocate pstore crash dump buffer\n");
+ err = -ENOMEM;
+ goto fail_clear;
+ }
+ spin_lock_init(&cxt->pstore.buf_lock);
+
+ cxt->pstore.flags = PSTORE_FLAGS_DMESG;
+ if (cxt->console_size)
+ cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
+ if (cxt->ftrace_size)
+ cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
+ if (cxt->pmsg_size)
+ cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
+
+ err = pstore_register(&cxt->pstore);
+ if (err) {
+ pr_err("registering with pstore failed\n");
+ goto fail_buf;
+ }
+
+ /*
+ * Update the module parameter variables as well so they are visible
+ * through /sys/module/ramoops/parameters/
+ */
+ mem_size = pdata->mem_size;
+ mem_address = pdata->mem_address;
+ record_size = pdata->record_size;
+ dump_oops = pdata->dump_oops;
+ ramoops_console_size = pdata->console_size;
+ ramoops_pmsg_size = pdata->pmsg_size;
+ ramoops_ftrace_size = pdata->ftrace_size;
+
+ pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
+ cxt->size, (unsigned long long)cxt->phys_addr,
+ cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
+
+ return 0;
+
+fail_buf:
+ kfree(cxt->pstore.buf);
+fail_clear:
+ cxt->pstore.bufsize = 0;
+ persistent_ram_free(cxt->mprz);
+fail_init_mprz:
+fail_init_fprz:
+ persistent_ram_free(cxt->cprz);
+fail_init_cprz:
+ ramoops_free_przs(cxt);
+fail_out:
+ return err;
+}
+
+static int ramoops_remove(struct platform_device *pdev)
+{
+ struct ramoops_context *cxt = &oops_cxt;
+
+ pstore_unregister(&cxt->pstore);
+
+ kfree(cxt->pstore.buf);
+ cxt->pstore.bufsize = 0;
+
+ persistent_ram_free(cxt->mprz);
+ persistent_ram_free(cxt->cprz);
+ ramoops_free_przs(cxt);
+
+ return 0;
+}
+
+static const struct of_device_id dt_match[] = {
+ { .compatible = "ramoops" },
+ {}
+};
+
+static struct platform_driver ramoops_driver = {
+ .probe = ramoops_probe,
+ .remove = ramoops_remove,
+ .driver = {
+ .name = "ramoops",
+ .of_match_table = dt_match,
+ },
+};
+
+static inline void ramoops_unregister_dummy(void)
+{
+ platform_device_unregister(dummy);
+ dummy = NULL;
+
+ kfree(dummy_data);
+ dummy_data = NULL;
+}
+
+static void __init ramoops_register_dummy(void)
+{
+ /*
+ * Prepare a dummy platform data structure to carry the module
+ * parameters. If mem_size isn't set, then there are no module
+ * parameters, and we can skip this.
+ */
+ if (!mem_size)
+ return;
+
+ pr_info("using module parameters\n");
+
+ dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
+ if (!dummy_data) {
+ pr_info("could not allocate pdata\n");
+ return;
+ }
+
+ dummy_data->mem_size = mem_size;
+ dummy_data->mem_address = mem_address;
+ dummy_data->mem_type = mem_type;
+ dummy_data->record_size = record_size;
+ dummy_data->console_size = ramoops_console_size;
+ dummy_data->ftrace_size = ramoops_ftrace_size;
+ dummy_data->pmsg_size = ramoops_pmsg_size;
+ dummy_data->dump_oops = dump_oops;
+ dummy_data->flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
+
+ /*
+ * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
+ * (using 1 byte for ECC isn't much of use anyway).
+ */
+ dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
+
+ dummy = platform_device_register_data(NULL, "ramoops", -1,
+ dummy_data, sizeof(struct ramoops_platform_data));
+ if (IS_ERR(dummy)) {
+ pr_info("could not create platform device: %ld\n",
+ PTR_ERR(dummy));
+ dummy = NULL;
+ ramoops_unregister_dummy();
+ }
+}
+
+static int __init ramoops_init(void)
+{
+ int ret;
+
+ ramoops_register_dummy();
+ ret = platform_driver_register(&ramoops_driver);
+ if (ret != 0)
+ ramoops_unregister_dummy();
+
+ return ret;
+}
+late_initcall(ramoops_init);
+
+static void __exit ramoops_exit(void)
+{
+ platform_driver_unregister(&ramoops_driver);
+ ramoops_unregister_dummy();
+}
+module_exit(ramoops_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
+MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
new file mode 100644
index 0000000..0792595
--- /dev/null
+++ b/fs/pstore/ram_core.c
@@ -0,0 +1,576 @@
+/*
+ * Copyright (C) 2012 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.
+ *
+ */
+
+#define pr_fmt(fmt) "persistent_ram: " fmt
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/memblock.h>
+#include <linux/pstore_ram.h>
+#include <linux/rslib.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+#include <asm/page.h>
+
+struct persistent_ram_buffer {
+ uint32_t sig;
+ atomic_t start;
+ atomic_t size;
+ uint8_t data[0];
+};
+
+#define PERSISTENT_RAM_SIG (0x43474244) /* DBGC */
+
+static inline size_t buffer_size(struct persistent_ram_zone *prz)
+{
+ return atomic_read(&prz->buffer->size);
+}
+
+static inline size_t buffer_start(struct persistent_ram_zone *prz)
+{
+ return atomic_read(&prz->buffer->start);
+}
+
+/* increase and wrap the start pointer, returning the old value */
+static size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
+{
+ int old;
+ int new;
+ unsigned long flags = 0;
+
+ if (!(prz->flags & PRZ_FLAG_NO_LOCK))
+ raw_spin_lock_irqsave(&prz->buffer_lock, flags);
+
+ old = atomic_read(&prz->buffer->start);
+ new = old + a;
+ while (unlikely(new >= prz->buffer_size))
+ new -= prz->buffer_size;
+ atomic_set(&prz->buffer->start, new);
+
+ if (!(prz->flags & PRZ_FLAG_NO_LOCK))
+ raw_spin_unlock_irqrestore(&prz->buffer_lock, flags);
+
+ return old;
+}
+
+/* increase the size counter until it hits the max size */
+static void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
+{
+ size_t old;
+ size_t new;
+ unsigned long flags = 0;
+
+ if (!(prz->flags & PRZ_FLAG_NO_LOCK))
+ raw_spin_lock_irqsave(&prz->buffer_lock, flags);
+
+ old = atomic_read(&prz->buffer->size);
+ if (old == prz->buffer_size)
+ goto exit;
+
+ new = old + a;
+ if (new > prz->buffer_size)
+ new = prz->buffer_size;
+ atomic_set(&prz->buffer->size, new);
+
+exit:
+ if (!(prz->flags & PRZ_FLAG_NO_LOCK))
+ raw_spin_unlock_irqrestore(&prz->buffer_lock, flags);
+}
+
+static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
+ uint8_t *data, size_t len, uint8_t *ecc)
+{
+ int i;
+
+ /* Initialize the parity buffer */
+ memset(prz->ecc_info.par, 0,
+ prz->ecc_info.ecc_size * sizeof(prz->ecc_info.par[0]));
+ encode_rs8(prz->rs_decoder, data, len, prz->ecc_info.par, 0);
+ for (i = 0; i < prz->ecc_info.ecc_size; i++)
+ ecc[i] = prz->ecc_info.par[i];
+}
+
+static int persistent_ram_decode_rs8(struct persistent_ram_zone *prz,
+ void *data, size_t len, uint8_t *ecc)
+{
+ int i;
+
+ for (i = 0; i < prz->ecc_info.ecc_size; i++)
+ prz->ecc_info.par[i] = ecc[i];
+ return decode_rs8(prz->rs_decoder, data, prz->ecc_info.par, len,
+ NULL, 0, NULL, 0, NULL);
+}
+
+static void notrace persistent_ram_update_ecc(struct persistent_ram_zone *prz,
+ unsigned int start, unsigned int count)
+{
+ struct persistent_ram_buffer *buffer = prz->buffer;
+ uint8_t *buffer_end = buffer->data + prz->buffer_size;
+ uint8_t *block;
+ uint8_t *par;
+ int ecc_block_size = prz->ecc_info.block_size;
+ int ecc_size = prz->ecc_info.ecc_size;
+ int size = ecc_block_size;
+
+ if (!ecc_size)
+ return;
+
+ block = buffer->data + (start & ~(ecc_block_size - 1));
+ par = prz->par_buffer + (start / ecc_block_size) * ecc_size;
+
+ do {
+ if (block + ecc_block_size > buffer_end)
+ size = buffer_end - block;
+ persistent_ram_encode_rs8(prz, block, size, par);
+ block += ecc_block_size;
+ par += ecc_size;
+ } while (block < buffer->data + start + count);
+}
+
+static void persistent_ram_update_header_ecc(struct persistent_ram_zone *prz)
+{
+ struct persistent_ram_buffer *buffer = prz->buffer;
+
+ if (!prz->ecc_info.ecc_size)
+ return;
+
+ persistent_ram_encode_rs8(prz, (uint8_t *)buffer, sizeof(*buffer),
+ prz->par_header);
+}
+
+static void persistent_ram_ecc_old(struct persistent_ram_zone *prz)
+{
+ struct persistent_ram_buffer *buffer = prz->buffer;
+ uint8_t *block;
+ uint8_t *par;
+
+ if (!prz->ecc_info.ecc_size)
+ return;
+
+ block = buffer->data;
+ par = prz->par_buffer;
+ while (block < buffer->data + buffer_size(prz)) {
+ int numerr;
+ int size = prz->ecc_info.block_size;
+ if (block + size > buffer->data + prz->buffer_size)
+ size = buffer->data + prz->buffer_size - block;
+ numerr = persistent_ram_decode_rs8(prz, block, size, par);
+ if (numerr > 0) {
+ pr_devel("error in block %p, %d\n", block, numerr);
+ prz->corrected_bytes += numerr;
+ } else if (numerr < 0) {
+ pr_devel("uncorrectable error in block %p\n", block);
+ prz->bad_blocks++;
+ }
+ block += prz->ecc_info.block_size;
+ par += prz->ecc_info.ecc_size;
+ }
+}
+
+static int persistent_ram_init_ecc(struct persistent_ram_zone *prz,
+ struct persistent_ram_ecc_info *ecc_info)
+{
+ int numerr;
+ struct persistent_ram_buffer *buffer = prz->buffer;
+ int ecc_blocks;
+ size_t ecc_total;
+
+ if (!ecc_info || !ecc_info->ecc_size)
+ return 0;
+
+ prz->ecc_info.block_size = ecc_info->block_size ?: 128;
+ prz->ecc_info.ecc_size = ecc_info->ecc_size ?: 16;
+ prz->ecc_info.symsize = ecc_info->symsize ?: 8;
+ prz->ecc_info.poly = ecc_info->poly ?: 0x11d;
+
+ ecc_blocks = DIV_ROUND_UP(prz->buffer_size - prz->ecc_info.ecc_size,
+ prz->ecc_info.block_size +
+ prz->ecc_info.ecc_size);
+ ecc_total = (ecc_blocks + 1) * prz->ecc_info.ecc_size;
+ if (ecc_total >= prz->buffer_size) {
+ pr_err("%s: invalid ecc_size %u (total %zu, buffer size %zu)\n",
+ __func__, prz->ecc_info.ecc_size,
+ ecc_total, prz->buffer_size);
+ return -EINVAL;
+ }
+
+ prz->buffer_size -= ecc_total;
+ prz->par_buffer = buffer->data + prz->buffer_size;
+ prz->par_header = prz->par_buffer +
+ ecc_blocks * prz->ecc_info.ecc_size;
+
+ /*
+ * first consecutive root is 0
+ * primitive element to generate roots = 1
+ */
+ prz->rs_decoder = init_rs(prz->ecc_info.symsize, prz->ecc_info.poly,
+ 0, 1, prz->ecc_info.ecc_size);
+ if (prz->rs_decoder == NULL) {
+ pr_info("init_rs failed\n");
+ return -EINVAL;
+ }
+
+ /* allocate workspace instead of using stack VLA */
+ prz->ecc_info.par = kmalloc_array(prz->ecc_info.ecc_size,
+ sizeof(*prz->ecc_info.par),
+ GFP_KERNEL);
+ if (!prz->ecc_info.par) {
+ pr_err("cannot allocate ECC parity workspace\n");
+ return -ENOMEM;
+ }
+
+ prz->corrected_bytes = 0;
+ prz->bad_blocks = 0;
+
+ numerr = persistent_ram_decode_rs8(prz, buffer, sizeof(*buffer),
+ prz->par_header);
+ if (numerr > 0) {
+ pr_info("error in header, %d\n", numerr);
+ prz->corrected_bytes += numerr;
+ } else if (numerr < 0) {
+ pr_info("uncorrectable error in header\n");
+ prz->bad_blocks++;
+ }
+
+ return 0;
+}
+
+ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
+ char *str, size_t len)
+{
+ ssize_t ret;
+
+ if (!prz->ecc_info.ecc_size)
+ return 0;
+
+ if (prz->corrected_bytes || prz->bad_blocks)
+ ret = snprintf(str, len, ""
+ "\n%d Corrected bytes, %d unrecoverable blocks\n",
+ prz->corrected_bytes, prz->bad_blocks);
+ else
+ ret = snprintf(str, len, "\nNo errors detected\n");
+
+ return ret;
+}
+
+static void notrace persistent_ram_update(struct persistent_ram_zone *prz,
+ const void *s, unsigned int start, unsigned int count)
+{
+ struct persistent_ram_buffer *buffer = prz->buffer;
+ memcpy_toio(buffer->data + start, s, count);
+ persistent_ram_update_ecc(prz, start, count);
+}
+
+static int notrace persistent_ram_update_user(struct persistent_ram_zone *prz,
+ const void __user *s, unsigned int start, unsigned int count)
+{
+ struct persistent_ram_buffer *buffer = prz->buffer;
+ int ret = unlikely(__copy_from_user(buffer->data + start, s, count)) ?
+ -EFAULT : 0;
+ persistent_ram_update_ecc(prz, start, count);
+ return ret;
+}
+
+void persistent_ram_save_old(struct persistent_ram_zone *prz)
+{
+ struct persistent_ram_buffer *buffer = prz->buffer;
+ size_t size = buffer_size(prz);
+ size_t start = buffer_start(prz);
+
+ if (!size)
+ return;
+
+ if (!prz->old_log) {
+ persistent_ram_ecc_old(prz);
+ prz->old_log = kmalloc(size, GFP_KERNEL);
+ }
+ if (!prz->old_log) {
+ pr_err("failed to allocate buffer\n");
+ return;
+ }
+
+ prz->old_log_size = size;
+ memcpy_fromio(prz->old_log, &buffer->data[start], size - start);
+ memcpy_fromio(prz->old_log + size - start, &buffer->data[0], start);
+}
+
+int notrace persistent_ram_write(struct persistent_ram_zone *prz,
+ const void *s, unsigned int count)
+{
+ int rem;
+ int c = count;
+ size_t start;
+
+ if (unlikely(c > prz->buffer_size)) {
+ s += c - prz->buffer_size;
+ c = prz->buffer_size;
+ }
+
+ buffer_size_add(prz, c);
+
+ start = buffer_start_add(prz, c);
+
+ rem = prz->buffer_size - start;
+ if (unlikely(rem < c)) {
+ persistent_ram_update(prz, s, start, rem);
+ s += rem;
+ c -= rem;
+ start = 0;
+ }
+ persistent_ram_update(prz, s, start, c);
+
+ persistent_ram_update_header_ecc(prz);
+
+ return count;
+}
+
+int notrace persistent_ram_write_user(struct persistent_ram_zone *prz,
+ const void __user *s, unsigned int count)
+{
+ int rem, ret = 0, c = count;
+ size_t start;
+
+ if (unlikely(!access_ok(VERIFY_READ, s, count)))
+ return -EFAULT;
+ if (unlikely(c > prz->buffer_size)) {
+ s += c - prz->buffer_size;
+ c = prz->buffer_size;
+ }
+
+ buffer_size_add(prz, c);
+
+ start = buffer_start_add(prz, c);
+
+ rem = prz->buffer_size - start;
+ if (unlikely(rem < c)) {
+ ret = persistent_ram_update_user(prz, s, start, rem);
+ s += rem;
+ c -= rem;
+ start = 0;
+ }
+ if (likely(!ret))
+ ret = persistent_ram_update_user(prz, s, start, c);
+
+ persistent_ram_update_header_ecc(prz);
+
+ return unlikely(ret) ? ret : count;
+}
+
+size_t persistent_ram_old_size(struct persistent_ram_zone *prz)
+{
+ return prz->old_log_size;
+}
+
+void *persistent_ram_old(struct persistent_ram_zone *prz)
+{
+ return prz->old_log;
+}
+
+void persistent_ram_free_old(struct persistent_ram_zone *prz)
+{
+ kfree(prz->old_log);
+ prz->old_log = NULL;
+ prz->old_log_size = 0;
+}
+
+void persistent_ram_zap(struct persistent_ram_zone *prz)
+{
+ atomic_set(&prz->buffer->start, 0);
+ atomic_set(&prz->buffer->size, 0);
+ persistent_ram_update_header_ecc(prz);
+}
+
+static void *persistent_ram_vmap(phys_addr_t start, size_t size,
+ unsigned int memtype)
+{
+ struct page **pages;
+ phys_addr_t page_start;
+ unsigned int page_count;
+ pgprot_t prot;
+ unsigned int i;
+ void *vaddr;
+
+ page_start = start - offset_in_page(start);
+ page_count = DIV_ROUND_UP(size + offset_in_page(start), PAGE_SIZE);
+
+ if (memtype)
+ prot = pgprot_noncached(PAGE_KERNEL);
+ else
+ prot = pgprot_writecombine(PAGE_KERNEL);
+
+ pages = kmalloc_array(page_count, sizeof(struct page *), GFP_KERNEL);
+ if (!pages) {
+ pr_err("%s: Failed to allocate array for %u pages\n",
+ __func__, page_count);
+ return NULL;
+ }
+
+ for (i = 0; i < page_count; i++) {
+ phys_addr_t addr = page_start + i * PAGE_SIZE;
+ pages[i] = pfn_to_page(addr >> PAGE_SHIFT);
+ }
+ vaddr = vmap(pages, page_count, VM_MAP, prot);
+ kfree(pages);
+
+ /*
+ * Since vmap() uses page granularity, we must add the offset
+ * into the page here, to get the byte granularity address
+ * into the mapping to represent the actual "start" location.
+ */
+ return vaddr + offset_in_page(start);
+}
+
+static void *persistent_ram_iomap(phys_addr_t start, size_t size,
+ unsigned int memtype)
+{
+ void *va;
+
+ if (!request_mem_region(start, size, "persistent_ram")) {
+ pr_err("request mem region (0x%llx@0x%llx) failed\n",
+ (unsigned long long)size, (unsigned long long)start);
+ return NULL;
+ }
+
+ if (memtype)
+ va = ioremap(start, size);
+ else
+ va = ioremap_wc(start, size);
+
+ /*
+ * Since request_mem_region() and ioremap() are byte-granularity
+ * there is no need handle anything special like we do when the
+ * vmap() case in persistent_ram_vmap() above.
+ */
+ return va;
+}
+
+static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
+ struct persistent_ram_zone *prz, int memtype)
+{
+ prz->paddr = start;
+ prz->size = size;
+
+ if (pfn_valid(start >> PAGE_SHIFT))
+ prz->vaddr = persistent_ram_vmap(start, size, memtype);
+ else
+ prz->vaddr = persistent_ram_iomap(start, size, memtype);
+
+ if (!prz->vaddr) {
+ pr_err("%s: Failed to map 0x%llx pages at 0x%llx\n", __func__,
+ (unsigned long long)size, (unsigned long long)start);
+ return -ENOMEM;
+ }
+
+ prz->buffer = prz->vaddr;
+ prz->buffer_size = size - sizeof(struct persistent_ram_buffer);
+
+ return 0;
+}
+
+static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig,
+ struct persistent_ram_ecc_info *ecc_info)
+{
+ int ret;
+
+ ret = persistent_ram_init_ecc(prz, ecc_info);
+ if (ret)
+ return ret;
+
+ sig ^= PERSISTENT_RAM_SIG;
+
+ if (prz->buffer->sig == sig) {
+ if (buffer_size(prz) > prz->buffer_size ||
+ buffer_start(prz) > buffer_size(prz))
+ pr_info("found existing invalid buffer, size %zu, start %zu\n",
+ buffer_size(prz), buffer_start(prz));
+ else {
+ pr_debug("found existing buffer, size %zu, start %zu\n",
+ buffer_size(prz), buffer_start(prz));
+ persistent_ram_save_old(prz);
+ return 0;
+ }
+ } else {
+ pr_debug("no valid data in buffer (sig = 0x%08x)\n",
+ prz->buffer->sig);
+ }
+
+ /* Rewind missing or invalid memory area. */
+ prz->buffer->sig = sig;
+ persistent_ram_zap(prz);
+
+ return 0;
+}
+
+void persistent_ram_free(struct persistent_ram_zone *prz)
+{
+ if (!prz)
+ return;
+
+ if (prz->vaddr) {
+ if (pfn_valid(prz->paddr >> PAGE_SHIFT)) {
+ /* We must vunmap() at page-granularity. */
+ vunmap(prz->vaddr - offset_in_page(prz->paddr));
+ } else {
+ iounmap(prz->vaddr);
+ release_mem_region(prz->paddr, prz->size);
+ }
+ prz->vaddr = NULL;
+ }
+ if (prz->rs_decoder) {
+ free_rs(prz->rs_decoder);
+ prz->rs_decoder = NULL;
+ }
+ kfree(prz->ecc_info.par);
+ prz->ecc_info.par = NULL;
+
+ persistent_ram_free_old(prz);
+ kfree(prz);
+}
+
+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, u32 flags)
+{
+ struct persistent_ram_zone *prz;
+ int ret = -ENOMEM;
+
+ prz = kzalloc(sizeof(struct persistent_ram_zone), GFP_KERNEL);
+ if (!prz) {
+ pr_err("failed to allocate persistent ram zone\n");
+ goto err;
+ }
+
+ /* Initialize general buffer state. */
+ raw_spin_lock_init(&prz->buffer_lock);
+ prz->flags = flags;
+
+ ret = persistent_ram_buffer_map(start, size, prz, memtype);
+ if (ret)
+ goto err;
+
+ ret = persistent_ram_post_init(prz, sig, ecc_info);
+ if (ret)
+ goto err;
+
+ return prz;
+err:
+ persistent_ram_free(prz);
+ return ERR_PTR(ret);
+}