Patch "sparc64: Migrate hvcons irq to panicked cpu" has been added to the 4.9-stable tree

Patch "sparc64: Migrate hvcons irq to panicked cpu" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    sparc64: Migrate hvcons irq to panicked cpu

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     sparc64-migrate-hvcons-irq-to-panicked-cpu.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Thu Oct 19 15:04:02 CEST 2017
From: Vijay Kumar <vijay.ac.kumar@oracle.com>
Date: Wed, 1 Feb 2017 11:34:38 -0800
Subject: sparc64: Migrate hvcons irq to panicked cpu

From: Vijay Kumar <vijay.ac.kumar@oracle.com>


[ Upstream commit 7dd4fcf5b70694dc961eb6b954673e4fc9730dbd ]

On panic, all other CPUs are stopped except the one which had
hit panic. To keep console alive, we need to migrate hvcons irq
to panicked CPU.

Signed-off-by: Vijay Kumar <vijay.ac.kumar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/sparc/include/asm/setup.h |    5 ++++-
 arch/sparc/kernel/smp_64.c     |    6 +++++-
 drivers/tty/serial/sunhv.c     |    6 ++++++
 3 files changed, 15 insertions(+), 2 deletions(-)

--- a/arch/sparc/include/asm/setup.h
+++ b/arch/sparc/include/asm/setup.h
@@ -59,8 +59,11 @@ extern atomic_t dcpage_flushes;
 extern atomic_t dcpage_flushes_xcall;
 
 extern int sysctl_tsb_ratio;
-#endif
 
+#ifdef CONFIG_SERIAL_SUNHV
+void sunhv_migrate_hvcons_irq(int cpu);
+#endif
+#endif
 void sun_do_break(void);
 extern int stop_a_enabled;
 extern int scons_pwroff;
--- a/arch/sparc/kernel/smp_64.c
+++ b/arch/sparc/kernel/smp_64.c
@@ -1465,8 +1465,12 @@ void smp_send_stop(void)
 	int cpu;
 
 	if (tlb_type == hypervisor) {
+		int this_cpu = smp_processor_id();
+#ifdef CONFIG_SERIAL_SUNHV
+		sunhv_migrate_hvcons_irq(this_cpu);
+#endif
 		for_each_online_cpu(cpu) {
-			if (cpu == smp_processor_id())
+			if (cpu == this_cpu)
 				continue;
 #ifdef CONFIG_SUN_LDOMS
 			if (ldom_domaining_enabled) {
--- a/drivers/tty/serial/sunhv.c
+++ b/drivers/tty/serial/sunhv.c
@@ -398,6 +398,12 @@ static struct uart_driver sunhv_reg = {
 
 static struct uart_port *sunhv_port;
 
+void sunhv_migrate_hvcons_irq(int cpu)
+{
+	/* Migrate hvcons irq to param cpu */
+	irq_force_affinity(sunhv_port->irq, cpumask_of(cpu));
+}
+
 /* Copy 's' into the con_write_page, decoding "\n" into
  * "\r\n" along the way.  We have to return two lengths
  * because the caller needs to know how much to advance


Patches currently in stable-queue which might be from vijay.ac.kumar@oracle.com are

queue-4.9/sparc64-migrate-hvcons-irq-to-panicked-cpu.patch