[PATCH] irqchip/gic-v3: mark expected switch fall-through

[Matteo Croce <mcroce@redhat.com>]

Mark switch cases where we are expecting to fall through,
fixes the following warnings:

drivers/irqchip/irq-gic-v3.c: In function ‘gic_cpu_sys_reg_init’:
./arch/arm64/include/asm/sysreg.h:853:2: warning: this statement may fall through [-Wimplicit-fallthrough=]
  asm volatile(__msr_s(r, "%x0") : : "rZ" (__val));  \
  ^~~
./arch/arm64/include/asm/arch_gicv3.h:20:29: note: in expansion of macro ‘write_sysreg_s’
 #define write_gicreg(v, r)  write_sysreg_s(v, SYS_ ## r)
                             ^~~~~~~~~~~~~~
drivers/irqchip/irq-gic-v3.c:773:4: note: in expansion of macro ‘write_gicreg’
    write_gicreg(0, ICC_AP0R2_EL1);
    ^~~~~~~~~~~~
drivers/irqchip/irq-gic-v3.c:774:3: note: here
   case 6:
   ^~~~

drivers/irqchip/irq-gic-v3.c:788:3: note: in expansion of macro ‘write_gicreg’
   write_gicreg(0, ICC_AP1R2_EL1);
   ^~~~~~~~~~~~
  CC      net/ipv4/af_inet.o
drivers/irqchip/irq-gic-v3.c:789:2: note: here
  case 6:
  ^~~~

./arch/arm64/include/asm/arch_gicv3.h:20:29: note: in expansion of macro ‘write_sysreg_s’
 #define write_gicreg(v, r)  write_sysreg_s(v, SYS_ ## r)
                             ^~~~~~~~~~~~~~
drivers/irqchip/irq-gic-v3.c:790:3: note: in expansion of macro ‘write_gicreg’
   write_gicreg(0, ICC_AP1R1_EL1);
   ^~~~~~~~~~~~
drivers/irqchip/irq-gic-v3.c:791:2: note: here
  case 5:
  ^~~~

Signed-off-by: Matteo Croce <mcroce@redhat.com>
---
 drivers/irqchip/irq-gic-v3.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 9bca4896fa6f..4a5d220698f6 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -771,8 +771,10 @@ static void gic_cpu_sys_reg_init(void)
 		case 7:
 			write_gicreg(0, ICC_AP0R3_EL1);
 			write_gicreg(0, ICC_AP0R2_EL1);
+			/* fallthrough */
 		case 6:
 			write_gicreg(0, ICC_AP0R1_EL1);
+			/* fallthrough */
 		case 5:
 		case 4:
 			write_gicreg(0, ICC_AP0R0_EL1);
@@ -786,8 +788,10 @@ static void gic_cpu_sys_reg_init(void)
 	case 7:
 		write_gicreg(0, ICC_AP1R3_EL1);
 		write_gicreg(0, ICC_AP1R2_EL1);
+		/* fallthrough */
 	case 6:
 		write_gicreg(0, ICC_AP1R1_EL1);
+		/* fallthrough */
 	case 5:
 	case 4:
 		write_gicreg(0, ICC_AP1R0_EL1);
-- 
2.21.0