Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
index 0cfac48..fffac6d 100644
--- a/arch/riscv/kernel/irq.c
+++ b/arch/riscv/kernel/irq.c
@@ -8,28 +8,28 @@
 #include <linux/interrupt.h>
 #include <linux/irqchip.h>
 #include <linux/irqdomain.h>
+#include <linux/seq_file.h>
+#include <asm/smp.h>
 
 /*
  * Possible interrupt causes:
  */
-#define INTERRUPT_CAUSE_SOFTWARE    1
-#define INTERRUPT_CAUSE_TIMER       5
-#define INTERRUPT_CAUSE_EXTERNAL    9
+#define INTERRUPT_CAUSE_SOFTWARE	IRQ_S_SOFT
+#define INTERRUPT_CAUSE_TIMER		IRQ_S_TIMER
+#define INTERRUPT_CAUSE_EXTERNAL	IRQ_S_EXT
 
-/*
- * The high order bit of the trap cause register is always set for
- * interrupts, which allows us to differentiate them from exceptions
- * quickly.  The INTERRUPT_CAUSE_* macros don't contain that bit, so we
- * need to mask it off.
- */
-#define INTERRUPT_CAUSE_FLAG	(1UL << (__riscv_xlen - 1))
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+	show_ipi_stats(p, prec);
+	return 0;
+}
 
-asmlinkage void __irq_entry do_IRQ(struct pt_regs *regs, unsigned long cause)
+asmlinkage __visible void __irq_entry do_IRQ(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
 
 	irq_enter();
-	switch (cause & ~INTERRUPT_CAUSE_FLAG) {
+	switch (regs->scause & ~SCAUSE_IRQ_FLAG) {
 	case INTERRUPT_CAUSE_TIMER:
 		riscv_timer_interrupt();
 		break;
@@ -46,7 +46,8 @@
 		handle_arch_irq(regs);
 		break;
 	default:
-		panic("unexpected interrupt cause");
+		pr_alert("unexpected interrupt cause 0x%lx", regs->scause);
+		BUG();
 	}
 	irq_exit();