Check for GISB arbitration errors through a chained notifier
when a process dies or a kernel panic occurs. This allows a
meaningful diagnostic message to occur along with other
diagnostic information.
Notably writes to a bad GISB address on an ARM64 architecture
kernel cause unrecoverable SError aborts and this allows the
cause of the abort to be seen.
Signed-off-by: Doug Berger <opendmb@xxxxxxxxx>
---
drivers/bus/brcmstb_gisb.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/drivers/bus/brcmstb_gisb.c b/drivers/bus/brcmstb_gisb.c
index 500b6bb5c739..774729002b8c 100644
--- a/drivers/bus/brcmstb_gisb.c
+++ b/drivers/bus/brcmstb_gisb.c
@@ -24,6 +24,8 @@
#include <linux/of.h>
#include <linux/bitops.h>
#include <linux/pm.h>
+#include <linux/kernel.h>
+#include <linux/kdebug.h>
#ifdef CONFIG_ARM
#include <asm/bug.h>
@@ -290,6 +292,25 @@ static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id)
return IRQ_HANDLED;
}
+/*
+ * Dump out gisb errors on die or panic.
+ */
+static int dump_gisb_error(struct notifier_block *self, unsigned long v,
+ void *p)
+{
+ struct brcmstb_gisb_arb_device *gdev;
+
+ /* iterate over each GISB arb registered handlers */
+ list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next)
+ brcmstb_gisb_arb_decode_addr(gdev, "async abort");
+
+ return 0;
+}
+
+static struct notifier_block gisb_error_notifier = {
+ .notifier_call = dump_gisb_error,
+};
+
static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
gisb_arb_get_timeout, gisb_arb_set_timeout);
@@ -408,6 +429,12 @@ static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
board_be_handler = brcmstb_bus_error_handler;
#endif
+ if (list_is_singular(&brcmstb_gisb_arb_device_list)) {
+ register_die_notifier(&gisb_error_notifier);
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &gisb_error_notifier);
+ }
+
dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n",
gdev->base, timeout_irq, tea_irq);
--
2.12.0
--
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