diff mbox series

[v7,6/7] kgdb: Expose default CPUs roundup fallback mechanism

Message ID 1604317487-14543-7-git-send-email-sumit.garg@linaro.org (mailing list archive)
State New, archived
Headers show
Series arm64: Add framework to turn an IPI as NMI | expand

Commit Message

Sumit Garg Nov. 2, 2020, 11:44 a.m. UTC
Add a new API kgdb_smp_call_nmi_hook() to expose default CPUs roundup
mechanism to a particular archichecture as a runtime fallback if it
detects to not support NMI roundup.

Currently such an architecture example is arm64 supporting pseudo NMIs
feature which is only available on platforms which have support for GICv3
or later version.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
---
 include/linux/kgdb.h      | 12 ++++++++++++
 kernel/debug/debug_core.c |  8 +++++++-
 2 files changed, 19 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index 0d6cf64..4190f13 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -200,6 +200,18 @@  kgdb_arch_handle_qxfer_pkt(char *remcom_in_buffer,
 extern void kgdb_call_nmi_hook(void *ignored);
 
 /**
+ *	kgdb_smp_call_nmi_hook - Provide default fallback mechanism to
+ *				 round-up CPUs
+ *
+ *	If you're using the default implementation of kgdb_roundup_cpus()
+ *	this function will be called.  And if an arch detects at runtime to
+ *	not support NMI based roundup then it can fallback to default
+ *	mechanism using this API.
+ */
+
+extern void kgdb_smp_call_nmi_hook(void);
+
+/**
  *	kgdb_roundup_cpus - Get other CPUs into a holding pattern
  *
  *	On SMP systems, we need to get the attention of the other CPUs
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 1e75a89..ae785d8 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -241,7 +241,7 @@  void __weak kgdb_call_nmi_hook(void *ignored)
 }
 NOKPROBE_SYMBOL(kgdb_call_nmi_hook);
 
-void __weak kgdb_roundup_cpus(void)
+void kgdb_smp_call_nmi_hook(void)
 {
 	call_single_data_t *csd;
 	int this_cpu = raw_smp_processor_id();
@@ -273,6 +273,12 @@  void __weak kgdb_roundup_cpus(void)
 			kgdb_info[cpu].rounding_up = false;
 	}
 }
+NOKPROBE_SYMBOL(kgdb_smp_call_nmi_hook);
+
+void __weak kgdb_roundup_cpus(void)
+{
+	kgdb_smp_call_nmi_hook();
+}
 NOKPROBE_SYMBOL(kgdb_roundup_cpus);
 
 #endif