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authorMarco Stornelli <marco.stornelli@gmail.com>2010-05-26 14:43:54 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-27 09:12:50 -0700
commit56d611a04fb2db77334e06274de4daed92e2c626 (patch)
tree49ee40b22419ba36ffc6d94d9b66649b6d42ea52 /drivers/char/ramoops.c
parenta747c5abc329611220f16df0bb4cf0ca4a7fdf0c (diff)
downloadop-kernel-dev-56d611a04fb2db77334e06274de4daed92e2c626.zip
op-kernel-dev-56d611a04fb2db77334e06274de4daed92e2c626.tar.gz
char drivers: RAM oops/panic logger
Ramoops, like mtdoops, can log oops/panic information but in RAM. It can be used with persistent RAM for systems without flash support. In addition, for this systems, with this driver, it's no more needed add to the kernel the mtd subsystem with advantage in footprint. It can be used in a very easy way with persistent RAM for systems without flash support. For these systems, with this driver, it is no longer required to cinlude mtd subsystem with an advantage in footprint. In addition, you can save flash space and store this information only in RAM. Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com> Cc: Simon Kagstrom <simon.kagstrom@netinsight.net> Cc: David Woodhouse <David.Woodhouse@intel.com> Cc; Anders Grafstrom <anders.grafstrom@netinsight.net> Cc: Yuasa Yoichi <yuasa@linux-mips.org> Cc: Jamie Lokier <jamie@shareable.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/char/ramoops.c')
-rw-r--r--drivers/char/ramoops.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/char/ramoops.c b/drivers/char/ramoops.c
new file mode 100644
index 0000000..74f00b5
--- /dev/null
+++ b/drivers/char/ramoops.c
@@ -0,0 +1,162 @@
+/*
+ * RAM Oops/Panic logger
+ *
+ * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/kmsg_dump.h>
+#include <linux/time.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+
+#define RAMOOPS_KERNMSG_HDR "===="
+#define RAMOOPS_HEADER_SIZE (5 + sizeof(struct timeval))
+
+#define RECORD_SIZE 4096
+
+static ulong mem_address;
+module_param(mem_address, ulong, 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 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 struct ramoops_context {
+ struct kmsg_dumper dump;
+ void *virt_addr;
+ phys_addr_t phys_addr;
+ unsigned long size;
+ int count;
+ int max_count;
+} oops_cxt;
+
+static void ramoops_do_dump(struct kmsg_dumper *dumper,
+ enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
+ const char *s2, unsigned long l2)
+{
+ struct ramoops_context *cxt = container_of(dumper,
+ struct ramoops_context, dump);
+ unsigned long s1_start, s2_start;
+ unsigned long l1_cpy, l2_cpy;
+ int res;
+ char *buf;
+ struct timeval timestamp;
+
+ /* Only dump oopses if dump_oops is set */
+ if (reason == KMSG_DUMP_OOPS && !dump_oops)
+ return;
+
+ buf = (char *)(cxt->virt_addr + (cxt->count * RECORD_SIZE));
+ memset(buf, '\0', RECORD_SIZE);
+ res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
+ buf += res;
+ do_gettimeofday(&timestamp);
+ res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
+ buf += res;
+
+ l2_cpy = min(l2, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE));
+ l1_cpy = min(l1, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE) - l2_cpy);
+
+ s2_start = l2 - l2_cpy;
+ s1_start = l1 - l1_cpy;
+
+ memcpy(buf, s1 + s1_start, l1_cpy);
+ memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
+
+ cxt->count = (cxt->count + 1) % cxt->max_count;
+}
+
+static int __init ramoops_init(void)
+{
+ struct ramoops_context *cxt = &oops_cxt;
+ int err = -EINVAL;
+
+ if (!mem_size) {
+ printk(KERN_ERR "ramoops: invalid size specification");
+ goto fail3;
+ }
+
+ rounddown_pow_of_two(mem_size);
+
+ if (mem_size < RECORD_SIZE) {
+ printk(KERN_ERR "ramoops: size too small");
+ goto fail3;
+ }
+
+ cxt->max_count = mem_size / RECORD_SIZE;
+ cxt->count = 0;
+ cxt->size = mem_size;
+ cxt->phys_addr = mem_address;
+
+ if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
+ printk(KERN_ERR "ramoops: request mem region failed");
+ err = -EINVAL;
+ goto fail3;
+ }
+
+ cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size);
+ if (!cxt->virt_addr) {
+ printk(KERN_ERR "ramoops: ioremap failed");
+ goto fail2;
+ }
+
+ cxt->dump.dump = ramoops_do_dump;
+ err = kmsg_dump_register(&cxt->dump);
+ if (err) {
+ printk(KERN_ERR "ramoops: registering kmsg dumper failed");
+ goto fail1;
+ }
+
+ return 0;
+
+fail1:
+ iounmap(cxt->virt_addr);
+fail2:
+ release_mem_region(cxt->phys_addr, cxt->size);
+fail3:
+ return err;
+}
+
+static void __exit ramoops_exit(void)
+{
+ struct ramoops_context *cxt = &oops_cxt;
+
+ if (kmsg_dump_unregister(&cxt->dump) < 0)
+ printk(KERN_WARNING "ramoops: could not unregister kmsg_dumper");
+
+ iounmap(cxt->virt_addr);
+ release_mem_region(cxt->phys_addr, cxt->size);
+}
+
+
+module_init(ramoops_init);
+module_exit(ramoops_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
+MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");
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