Merge tag 'Wimplicit-fallthrough-clang-5.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux

Pull fallthrough fixes from Gustavo Silva:
 "This fixes many fall-through warnings when building with Clang and
  -Wimplicit-fallthrough, and also enables -Wimplicit-fallthrough for
  Clang, globally.

  It's also important to notice that since we have adopted the use of
  the pseudo-keyword macro fallthrough, we also want to avoid having
  more /* fall through */ comments being introduced. Contrary to GCC,
  Clang doesn't recognize any comments as implicit fall-through markings
  when the -Wimplicit-fallthrough option is enabled.

  So, in order to avoid having more comments being introduced, we use
  the option -Wimplicit-fallthrough=5 for GCC, which similar to Clang,
  will cause a warning in case a code comment is intended to be used as
  a fall-through marking. The patch for Makefile also enforces this.

  We had almost 4,000 of these issues for Clang in the beginning, and
  there might be a couple more out there when building some
  architectures with certain configurations. However, with the recent
  fixes I think we are in good shape and it is now possible to enable
  the warning for Clang"

* tag 'Wimplicit-fallthrough-clang-5.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (27 commits)
  Makefile: Enable -Wimplicit-fallthrough for Clang
  powerpc/smp: Fix fall-through warning for Clang
  dmaengine: mpc512x: Fix fall-through warning for Clang
  usb: gadget: fsl_qe_udc: Fix fall-through warning for Clang
  powerpc/powernv: Fix fall-through warning for Clang
  MIPS: Fix unreachable code issue
  MIPS: Fix fall-through warnings for Clang
  ASoC: Mediatek: MT8183: Fix fall-through warning for Clang
  power: supply: Fix fall-through warnings for Clang
  dmaengine: ti: k3-udma: Fix fall-through warning for Clang
  s390: Fix fall-through warnings for Clang
  dmaengine: ipu: Fix fall-through warning for Clang
  iommu/arm-smmu-v3: Fix fall-through warning for Clang
  mmc: jz4740: Fix fall-through warning for Clang
  PCI: Fix fall-through warning for Clang
  scsi: libsas: Fix fall-through warning for Clang
  video: fbdev: Fix fall-through warning for Clang
  math-emu: Fix fall-through warning
  cpufreq: Fix fall-through warning for Clang
  drm/msm: Fix fall-through warning in msm_gem_new_impl()
  ...

4 files changed, 5 insertions, 1 deletions

diff --git a/arch/mips/include/asm/fpu.h b/arch/mips/include/asm/fpu.h
index 08f9dd6903b7..86310d6e1035 100644
--- a/arch/mips/include/asm/fpu.h
+++ b/arch/mips/include/asm/fpu.h
@@ -76,7 +76,7 @@ static inline int __enable_fpu(enum fpu_mode mode)
 		/* we only have a 32-bit FPU */
 		return SIGFPE;
 #endif
-		fallthrough;
+		/* fallthrough */
 	case FPU_32BIT:
 		if (cpu_has_fre) {
 			/* clear FRE */
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index cd4afcdf3725..9adad24c2e65 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -1383,6 +1383,7 @@ static void build_r4000_tlb_refill_handler(void)
 	switch (boot_cpu_type()) {
 	default:
 		if (sizeof(long) == 4) {
+		fallthrough;
 	case CPU_LOONGSON2EF:
 		/* Loongson2 ebase is different than r4k, we have more space */
 			if ((p - tlb_handler) > 64)
@@ -2169,6 +2170,7 @@ static void build_r4000_tlb_load_handler(void)
 		default:
 			if (cpu_has_mips_r2_exec_hazard) {
 				uasm_i_ehb(&p);
+			fallthrough;
 
 		case CPU_CAVIUM_OCTEON:
 		case CPU_CAVIUM_OCTEON_PLUS:
diff --git a/arch/powerpc/platforms/powermac/smp.c b/arch/powerpc/platforms/powermac/smp.c
index bdfea6d6ab69..3256a316e884 100644
--- a/arch/powerpc/platforms/powermac/smp.c
+++ b/arch/powerpc/platforms/powermac/smp.c
@@ -146,6 +146,7 @@ static inline void psurge_clr_ipi(int cpu)
 		switch(psurge_type) {
 		case PSURGE_DUAL:
 			out_8(psurge_sec_intr, ~0);
+			break;
 		case PSURGE_NONE:
 			break;
 		default:
diff --git a/arch/s390/kernel/uprobes.c b/arch/s390/kernel/uprobes.c
index bbf8622bbf5d..bd3ef121c379 100644
--- a/arch/s390/kernel/uprobes.c
+++ b/arch/s390/kernel/uprobes.c
@@ -126,6 +126,7 @@ int arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val,
 	case DIE_SSTEP:
 		if (uprobe_post_sstep_notifier(regs))
 			return NOTIFY_STOP;
+		break;
 	default:
 		break;
 	}