Panic callback handlers allows coresight device drivers to sync relevant trace data and trace metadata to reserved memory regions so that they can be retrieved later in the subsequent boot or in the crashdump kernel.
Signed-off-by: Linu Cherian lcherian@marvell.com --- drivers/hwtracing/coresight/coresight-core.c | 31 ++++++++++++++++++++ include/linux/coresight.h | 11 +++++++ 2 files changed, 42 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index d3bf82c0de1d..677c171d1e1d 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -19,6 +19,7 @@ #include <linux/of_platform.h> #include <linux/delay.h> #include <linux/pm_runtime.h> +#include <linux/panic_notifier.h>
#include "coresight-etm-perf.h" #include "coresight-priv.h" @@ -1765,6 +1766,31 @@ struct bus_type coresight_bustype = { .name = "coresight", };
+int coresight_panic_sync(struct device *dev, void *data) +{ + + struct coresight_device *csdev = container_of(dev, struct coresight_device, dev); + + /* Run through panic sync handlers for all enabled devices */ + if (csdev->enable && panic_ops(csdev)) + panic_ops(csdev)->sync(csdev); + + return 0; +} + +static int coresight_panic_cb(struct notifier_block *self, + unsigned long v, void *p) +{ + bus_for_each_dev(&coresight_bustype, NULL, NULL, + coresight_panic_sync); + + return 0; +} + +static struct notifier_block coresight_notifier = { + .notifier_call = coresight_panic_cb, +}; + static int __init coresight_init(void) { int ret; @@ -1777,6 +1803,11 @@ static int __init coresight_init(void) if (ret) goto exit_bus_unregister;
+ + /* Register function to be called for panic */ + ret = atomic_notifier_chain_register(&panic_notifier_list, + &coresight_notifier); + /* initialise the coresight syscfg API */ ret = cscfg_init(); if (!ret) diff --git a/include/linux/coresight.h b/include/linux/coresight.h index f19a47b9bb5a..8831df24733a 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -277,6 +277,7 @@ static struct coresight_dev_list (var) = { \ #define link_ops(csdev) csdev->ops->link_ops #define helper_ops(csdev) csdev->ops->helper_ops #define ect_ops(csdev) csdev->ops->ect_ops +#define panic_ops(csdev) csdev->ops->panic_ops
/** * struct coresight_ops_sink - basic operations for a sink @@ -351,12 +352,22 @@ struct coresight_ops_ect { int (*disable)(struct coresight_device *csdev); };
+/** + * struct coresight_ops_panic - Generic device ops for panic handing + * + * @sync : Sync the device register state/trace data + */ +struct coresight_ops_panic { + int (*sync)(struct coresight_device *csdev); +}; + struct coresight_ops { const struct coresight_ops_sink *sink_ops; const struct coresight_ops_link *link_ops; const struct coresight_ops_source *source_ops; const struct coresight_ops_helper *helper_ops; const struct coresight_ops_ect *ect_ops; + const struct coresight_ops_panic *panic_ops; };
#if IS_ENABLED(CONFIG_CORESIGHT)