sparc64: Migrate hvcons irq to panicked cpu

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>
(cherry picked from commit 7dd4fcf5b70694dc961eb6b954673e4fc9730dbd)

Signed-off-by: Vijay Kumar <vijay.ac.kumar@oracle.com>
Orabug: 24297427

diff --git a/arch/sparc/include/asm/setup.h b/arch/sparc/include/asm/setup.h
index 29d64b1758ed2a0ceb795a07c10205e6f923e6c6..478bf6bb4598b345dd7f590beee86f43893e7645 100644 (file)
--- 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;

diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
index e846288e2a3b8e880dd8214f136b8e3a24698646..d4b08210bcd70ba330053d4a8e617ea71a5cc616 100644 (file)
--- a/arch/sparc/kernel/smp_64.c
+++ b/arch/sparc/kernel/smp_64.c
@@ -1544,8 +1544,12 @@ 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;
 
                        set_cpu_online(cpu, false);

diff --git a/drivers/tty/serial/sunhv.c b/drivers/tty/serial/sunhv.c
index 0fedd8bf5ee30e93221045cb6d544b315810754f..6e84e857a0b7df8f7427b928b462e6bf2a95e6cf 100644 (file)
--- a/drivers/tty/serial/sunhv.c
+++ b/drivers/tty/serial/sunhv.c
@@ -418,6 +418,12 @@ 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