blkoops is a sample for pstore/blk. It can only record oops, excluding
panics as no read/write apis for panic registered. It support settings
on Kconfg/device tree/module parameters. It can record oops log even
power failure if "PSTORE_BLKOOPS_PART_PATH" on Kconfig or
"partition-path" on dts or "part_path" on module parameter is valid.
Otherwise, it can only record data to ram buffer, which will be dropped
when reboot.
Signed-off-by: liaoweixiong <liaoweixiong@xxxxxxxxxxxxxxxxx>
---
MAINTAINERS | 2 +-
fs/pstore/Kconfig | 117 +++++++++++++++++++++++++
fs/pstore/Makefile | 2 +
fs/pstore/blkoops.c | 239 ++++++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 359 insertions(+), 1 deletion(-)
create mode 100644 fs/pstore/blkoops.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 91c70df..534c574 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12056,7 +12056,7 @@ F: drivers/acpi/apei/erst.c
F: Documentation/admin-guide/ramoops.rst
F: Documentation/devicetree/bindings/reserved-memory/ramoops.txt
F: Documentation/devicetree/bindings/pstore-block/
-K: \b(pstore|ramoops)
+K: \b(pstore|ramoops|blkoops)
PTP HARDWARE CLOCK SUPPORT
M: Richard Cochran <richardcochran@xxxxxxxxx>
diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
index a881c53..f0a1a49 100644
--- a/fs/pstore/Kconfig
+++ b/fs/pstore/Kconfig
@@ -159,3 +159,120 @@ config PSTORE_BLK
help
This enables panic and oops message to be logged to a block dev
where it can be read back at some later point.
+
+config PSTORE_BLKOOPS
+ tristate "pstore block with oops logger"
+ depends on PSTORE_BLK
+ help
+ This is a sample for pstore block with oops logger.
+
+ It CANNOT record panic log as no read/write apis for panic registered.
+
+ It CAN record oops log even power failure if
+ "PSTORE_BLKOOPS_PART_PATH" on Kconfig or "partition-path" on dts or
+ "part_path" on module parameter is valid.
+
+ Otherwise, it can only record data to ram buffer, which will be
+ dropped when reboot.
+
+ NOTE that, there are three ways to set parameters of blkoops and
+ prioritize according to configuration flexibility. That is
+ Kconfig < device tree < module parameters. It means that the value can
+ be overwritten by higher priority settings.
+ 1. Kconfig
+ It just sets a default value.
+ 2. device tree
+ It is set on device tree, which will overwrites value from Kconfig,
+ but can also be overwritten by module parameters.
+ 3. module parameters
+ It is the first priority. Take care of that blkoops will take lower
+ priority settings if higher priority one do not set.
+
+config PSTORE_BLKOOPS_DMESG_SIZE
+ int "dmesg_size in kbytes for blkoops"
+ depends on PSTORE_BLKOOPS
+ default 64
+ help
+ This just sets size of dmesg (dmesg_size) for pstore/blk. The value
+ must be a multiple of 4096.
+
+ NOTE that, there are three ways to set parameters of blkoops and
+ prioritize according to configuration flexibility. That is
+ Kconfig < device tree < module parameters. It means that the value can
+ be overwritten by higher priority settings.
+ 1. Kconfig
+ It just sets a default value.
+ 2. device tree
+ It is set on device tree, which will overwrites value from Kconfig,
+ but can also be overwritten by module parameters.
+ 3. module parameters
+ It is the first priority. Take care of that blkoops will take lower
+ priority settings if higher priority one do not set.
+
+config PSTORE_BLKOOPS_PMSG_SIZE
+ int "pmsg_size in kbytes for blkoops"
+ depends on PSTORE_BLKOOPS
+ default 64
+ help
+ This just sets size of pmsg (pmsg_size) for pstore/blk. The value must
+ be a multiple of 4096. Pmsg work only if "part_path" is set.
+
+ NOTE that, there are three ways to set parameters of blkoops and
+ prioritize according to configuration flexibility. That is
+ Kconfig < device tree < module parameters. It means that the value can
+ be overwritten by higher priority settings.
+ 1. Kconfig
+ It just sets a default value.
+ 2. device tree
+ It is set on device tree, which will overwrites value from Kconfig,
+ but can also be overwritten by module parameters.
+ 3. module parameters
+ It is the first priority. Take care of that blkoops will take lower
+ priority settings if higher priority one do not set.
+
+config PSTORE_BLKOOPS_PART_SIZE
+ int "part_size in kbytes for blkoops"
+ depends on PSTORE_BLKOOPS
+ default 1024
+ help
+ This just sets partition size (part_size) for pstore/blk. Pstore/blk
+ will allocate part_size memory to temporarily hold the data. It's the
+ size of partition on part_path. The value must be a multiple of 4096.
+
+ NOTE that, there are three ways to set parameters of blkoops and
+ prioritize according to configuration flexibility. That is
+ Kconfig < device tree < module parameters. It means that the value can
+ be overwritten by higher priority settings.
+ 1. Kconfig
+ It just sets a default value.
+ 2. device tree
+ It is set on device tree, which will overwrites value from Kconfig,
+ but can also be overwritten by module parameters.
+ 3. module parameters
+ It is the first priority. Take care of that blkoops will take lower
+ priority settings if higher priority one do not set.
+
+config PSTORE_BLKOOPS_PART_PATH
+ string "part_path for blkoops"
+ depends on PSTORE_BLKOOPS
+ default ""
+ help
+ This just sets partition path (part_path) for pstore/blk. Pstore/blk
+ will record data to this block partition to avoid losing data due to
+ power failure. So, If it is not set, pstore/blk will drop all data
+ when reboot.
+
+ The strings must begin with "/dev/".
+
+ NOTE that, there are three ways to set parameters of blkoops and
+ prioritize according to configuration flexibility. That is
+ Kconfig < device tree < module parameters. It means that the value can
+ be overwritten by higher priority settings.
+ 1. Kconfig
+ It just sets a default value.
+ 2. device tree
+ It is set on device tree, which will overwrites value from Kconfig,
+ but can also be overwritten by module parameters.
+ 3. module parameters
+ It is the first priority. Take care of that blkoops will take lower
+ priority settings if higher priority one do not set.
diff --git a/fs/pstore/Makefile b/fs/pstore/Makefile
index 0ee2fc8..24b3d48 100644
--- a/fs/pstore/Makefile
+++ b/fs/pstore/Makefile
@@ -15,3 +15,5 @@ obj-$(CONFIG_PSTORE_RAM) += ramoops.o
obj-$(CONFIG_PSTORE_BLK) += pstore_blk.o
pstore_blk-y += blkzone.o
+
+obj-$(CONFIG_PSTORE_BLKOOPS) += blkoops.o
diff --git a/fs/pstore/blkoops.c b/fs/pstore/blkoops.c
new file mode 100644
index 0000000..fd926a5
--- /dev/null
+++ b/fs/pstore/blkoops.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *
+ * blkoops.c: Block device Oops logger
+ *
+ * Copyright (C) 2019 liaoweixiong <liaoweixiong@xxxxxxxxxxxxxxxxxx>
+ *
+ * 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.
+ *
+ */
+#define MODNAME "blkoops"
+#define pr_fmt(fmt) MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/pstore_blk.h>
+
+static long dmesg_size = -1;
+module_param(dmesg_size, long, 0400);
+MODULE_PARM_DESC(dmesg_size, "demsg size in kbytes");
+
+static long part_size = -1;
+module_param(part_size, long, 0400);
+MODULE_PARM_DESC(part_size, "partition size in kbytes");
+
+#define PART_PATH_INVALID "INVALID"
+static char part_path[80] = {PART_PATH_INVALID};
+module_param_string(part_path, part_path, 80, 0400);
+MODULE_PARM_DESC(part_path, "path of partition in /dev for general read/write");
+
+struct blkz_info blkz_info = {
+ .owner = THIS_MODULE,
+ .name = "blkoops",
+ .dump_oops = true,
+};
+
+struct blkoops_info {
+ unsigned long dmesg_size;
+ unsigned long part_size;
+ const char *part_path;
+};
+struct blkoops_info blkoops_info = {
+ .dmesg_size = CONFIG_PSTORE_BLKOOPS_DMESG_SIZE * 1024,
+ .part_size = CONFIG_PSTORE_BLKOOPS_PART_SIZE * 1024,
+ .part_path = CONFIG_PSTORE_BLKOOPS_PART_PATH,
+};
+
+static struct platform_device *dummy;
+
+static int blkoops_parse_dt_size(struct device_node *np,
+ const char *propname, u32 *value)
+{
+ u32 val32 = 0;
+ int ret;
+
+ ret = of_property_read_u32(np, propname, &val32);
+ if (ret < 0) {
+ if (ret != -EINVAL)
+ pr_err("failed to parse property %s: %d\n",
+ propname, ret);
+ return ret;
+ }
+
+ if (val32 * 1024 > INT_MAX) {
+ pr_err("%s %u > INT_MAX\n", propname, val32);
+ return -EOVERFLOW;
+ }
+
+ *value = val32 * 1024;
+ return 0;
+}
+
+static int __init blkoops_parse_dt(struct blkoops_info *info,
+ struct device_node *np)
+{
+ int ret;
+ u32 value;
+
+ pr_info("using device tree\n");
+
+ ret = of_property_read_string(np, "partition-path",
+ &info->part_path);
+ if (ret < 0 && ret != -EINVAL) {
+ pr_err("failed to parse partition path : %d\n", ret);
+ return ret;
+ }
+
+#define parse_size(name, field) { \
+ ret = blkoops_parse_dt_size(np, name, &value); \
+ if (ret < 0 && ret != -EINVAL) \
+ return ret; \
+ else if (ret == 0) \
+ field = value; \
+ }
+
+ parse_size("partition-size", info->part_size);
+ parse_size("dmesg-size", info->dmesg_size);
+
+#undef parse_size
+ return 0;
+}
+
+static int blkoops_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *of_node = dev_of_node(dev);
+ struct blkoops_info *info = dev->platform_data;
+
+ if (of_node && !info) {
+ int err;
+
+ info = &blkoops_info;
+ err = blkoops_parse_dt(info, of_node);
+ if (err)
+ return err;
+ }
+
+ if (!strcmp(info->part_path, PART_PATH_INVALID) ||
+ strlen(info->part_path) == 0) {
+ pr_info("no path for block partition, use ram buffer only\n");
+ } else if (strncmp(info->part_path, "/dev/", 5) != 0) {
+ pr_err("invalid partition path %s, use ram buffer only\n",
+ info->part_path);
+ } else {
+ pr_debug("path for block partition: %s\n", info->part_path);
+ blkz_info.part_path = info->part_path;
+ }
+
+#define check_size(name, size) { \
+ if (info->name & (size - 1)) { \
+ pr_err(#name " must be a multiple of %d\n", \
+ (size)); \
+ return -EINVAL; \
+ } \
+ blkz_info.name = info->name; \
+ }
+
+ check_size(part_size, 4096);
+ check_size(dmesg_size, 4096);
+
+#undef check_size
+
+ /*
+ * Update the module parameter variables as well so they are visible
+ * through /sys/module/blkoops/parameters/
+ */
+ dmesg_size = blkz_info.dmesg_size;
+ part_size = blkz_info.part_size;
+ if (blkz_info.part_path)
+ strncpy(part_path, blkz_info.part_path, 80 - 1);
+ else
+ part_path[0] = '\0';
+ return blkz_register(&blkz_info);
+}
+
+static int blkoops_remove(struct platform_device *pdev)
+{
+ blkz_unregister(&blkz_info);
+ return 0;
+}
+
+static const struct of_device_id dt_match[] = {
+ { .compatible = MODNAME},
+ {}
+};
+
+static struct platform_driver blkoops_driver = {
+ .probe = blkoops_probe,
+ .remove = blkoops_remove,
+ .driver = {
+ .name = MODNAME,
+ .of_match_table = dt_match,
+ },
+};
+
+void blkoops_register_dummy(void)
+{
+ struct blkoops_info *info = &blkoops_info;
+ /*
+ * 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 (part_size < 0)
+ return;
+
+ pr_info("using module parameters\n");
+
+ info->part_size = (unsigned long)part_size * 1024;
+ if (strcmp(part_path, PART_PATH_INVALID))
+ info->part_path = (const char *)part_path;
+ if (dmesg_size >= 0)
+ info->dmesg_size = (unsigned long)dmesg_size * 1024;
+
+ dummy = platform_device_register_data(NULL, MODNAME, -1, info,
+ sizeof(*info));
+ if (IS_ERR(dummy)) {
+ pr_err("could not create platform device: %ld\n",
+ PTR_ERR(dummy));
+ dummy = NULL;
+ }
+}
+
+static int __init blkoops_init(void)
+{
+ int ret;
+
+ blkoops_register_dummy();
+ ret = platform_driver_register(&blkoops_driver);
+ if (ret != 0) {
+ platform_device_unregister(dummy);
+ dummy = NULL;
+ }
+ return ret;
+}
+module_init(blkoops_init);
+
+static void __exit blkoops_exit(void)
+{
+ platform_driver_unregister(&blkoops_driver);
+ platform_device_unregister(dummy);
+ dummy = NULL;
+}
+module_exit(blkoops_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("liaoweixiong <liaoweixiong@xxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Sample for Pstore BLK with Oops logger");
--
1.9.1
