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()
  ...

Makefile

@@ -797,12 +797,6 @@ KBUILD_CFLAGS += -Wno-gnu
 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
 # See modpost pattern 2
 KBUILD_CFLAGS += -mno-global-merge
-else
-
-# Warn about unmarked fall-throughs in switch statement.
-# Disabled for clang while comment to attribute conversion happens and
-# https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
-KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough,)
 endif
 
 # These warnings generated too much noise in a regular build.
@@ -983,6 +977,9 @@ NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
 # warn about C99 declaration after statement
 KBUILD_CFLAGS += -Wdeclaration-after-statement
 
+# Warn about unmarked fall-throughs in switch statement.
+KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=5,$(call cc-option,-Wimplicit-fallthrough,))
+
 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
 KBUILD_CFLAGS += -Wvla
 

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 */

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:

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:

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;
 	}

drivers/char/powernv-op-panel.c

@@ -75,6 +75,7 @@ static int __op_panel_update_display(void)
 				rc);
 			break;
 		}
+		break;
 	case OPAL_SUCCESS:
 		break;
 	default:

drivers/cpufreq/longhaul.c

@@ -942,8 +942,6 @@ static int __init longhaul_init(void)
 		return cpufreq_register_driver(&longhaul_driver);
 	case 10:
 		pr_err("Use acpi-cpufreq driver for VIA C7\n");
-	default:
-		;
 	}
 
 	return -ENODEV;

drivers/dma/ipu/ipu_idmac.c

@@ -618,6 +618,7 @@ static int ipu_enable_channel(struct idmac *idmac, struct idmac_channel *ichan)
 	case IDMAC_SDC_1:
 	case IDMAC_IC_7:
 		ipu_channel_set_priority(ipu, channel, true);
+		break;
 	default:
 		break;
 	}
@@ -978,6 +979,7 @@ static int ipu_init_channel(struct idmac *idmac, struct idmac_channel *ichan)
 	case IDMAC_SDC_0:
 	case IDMAC_SDC_1:
 		n_desc = 4;
+		break;
 	default:
 		break;
 	}

drivers/dma/mpc512x_dma.c

@@ -813,6 +813,7 @@ inline bool is_buswidth_valid(u8 buswidth, bool is_mpc8308)
 	case 16:
 		if (is_mpc8308)
 			return false;
+		break;
 	case 1:
 	case 2:
 	case 4:

drivers/dma/ti/k3-udma.c

@@ -4948,6 +4948,7 @@ static int setup_resources(struct udma_dev *ud)
 						       ud->tchan_cnt),
 			 ud->rchan_cnt - bitmap_weight(ud->rchan_map,
 						       ud->rchan_cnt));
+		break;
 	default:
 		break;
 	}

drivers/gpu/drm/i915/gem/i915_gem_shrinker.c

@@ -62,6 +62,7 @@ static void try_to_writeback(struct drm_i915_gem_object *obj,
 	switch (obj->mm.madv) {
 	case I915_MADV_DONTNEED:
 		i915_gem_object_truncate(obj);
+		return;
 	case __I915_MADV_PURGED:
 		return;
 	}

drivers/gpu/drm/msm/msm_gem.c

@@ -1169,7 +1169,7 @@ static int msm_gem_new_impl(struct drm_device *dev,
 	case MSM_BO_CACHED_COHERENT:
 		if (priv->has_cached_coherent)
 			break;
-		/* fallthrough */
+		fallthrough;
 	default:
 		DRM_DEV_ERROR(dev->dev, "invalid cache flag: %x\n",
 				(flags & MSM_BO_CACHE_MASK));

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

@@ -379,6 +379,7 @@ static void arm_smmu_cmdq_skip_err(struct arm_smmu_device *smmu)
 	switch (idx) {
 	case CMDQ_ERR_CERROR_ABT_IDX:
 		dev_err(smmu->dev, "retrying command fetch\n");
+		return;
 	case CMDQ_ERR_CERROR_NONE_IDX:
 		return;
 	case CMDQ_ERR_CERROR_ATC_INV_IDX:

drivers/mmc/host/jz4740_mmc.c

@@ -789,6 +789,8 @@ static irqreturn_t jz_mmc_irq_worker(int irq, void *devid)
 				break;
 			}
 		}
+		fallthrough;
+
 	case JZ4740_MMC_STATE_DONE:
 		break;
 	}

drivers/mtd/chips/cfi_util.c

@@ -108,8 +108,8 @@ map_word cfi_build_cmd(u_long cmd, struct map_info *map, struct cfi_private *cfi
 #if BITS_PER_LONG >= 64
 	case 8:
 		onecmd |= (onecmd << (chip_mode * 32));
-#endif
 		fallthrough;
+#endif
 	case 4:
 		onecmd |= (onecmd << (chip_mode * 16));
 		fallthrough;
@@ -164,8 +164,8 @@ unsigned long cfi_merge_status(map_word val, struct map_info *map,
 #if BITS_PER_LONG >= 64
 	case 8:
 		res |= (onestat >> (chip_mode * 32));
-#endif
 		fallthrough;
+#endif
 	case 4:
 		res |= (onestat >> (chip_mode * 16));
 		fallthrough;

drivers/net/ethernet/netronome/nfp/flower/conntrack.c

@@ -1159,6 +1159,7 @@ int nfp_fl_ct_del_flow(struct nfp_fl_ct_map_entry *ct_map_ent)
 				       nfp_ct_map_params);
 		nfp_fl_ct_clean_flow_entry(ct_map_ent->ct_entry);
 		kfree(ct_map_ent);
+		break;
 	default:
 		break;
 	}

drivers/net/wireless/mediatek/mt76/mt7921/main.c

@@ -389,6 +389,7 @@ static int mt7921_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 	case WLAN_CIPHER_SUITE_WEP104:
 		if (!mvif->wep_sta)
 			return -EOPNOTSUPP;
+		break;
 	case WLAN_CIPHER_SUITE_TKIP:
 	case WLAN_CIPHER_SUITE_CCMP:
 	case WLAN_CIPHER_SUITE_CCMP_256:

drivers/pci/proc.c

@@ -230,8 +230,8 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,
 			break;
 		}
 		/* If arch decided it can't, fall through... */
-#endif /* HAVE_PCI_MMAP */
 		fallthrough;
+#endif /* HAVE_PCI_MMAP */
 	default:
 		ret = -EINVAL;
 		break;

drivers/power/supply/ab8500_fg.c

@@ -1728,6 +1728,7 @@ static void ab8500_fg_algorithm_calibrate(struct ab8500_fg *di)
 		break;
 	case AB8500_FG_CALIB_WAIT:
 		dev_dbg(di->dev, "Calibration WFI\n");
+		break;
 	default:
 		break;
 	}
@@ -2224,6 +2225,7 @@ static int ab8500_fg_get_ext_psy_data(struct device *dev, void *data)
 					queue_work(di->fg_wq, &di->fg_work);
 					break;
 				}
+				break;
 			default:
 				break;
 			}

drivers/power/supply/abx500_chargalg.c

@@ -1150,6 +1150,7 @@ static int abx500_chargalg_get_ext_psy_data(struct device *dev, void *data)
 				default:
 					break;
 				}
+				break;
 			default:
 				break;
 			}

drivers/s390/char/tape_char.c

@@ -371,8 +371,6 @@ __tapechar_ioctl(struct tape_device *device,
 			case MTSEEK:
 				if (device->required_tapemarks)
 					tape_std_terminate_write(device);
-			default:
-				;
 		}
 		rc = tape_mtop(device, op.mt_op, op.mt_count);
 

drivers/s390/net/ctcm_fsms.c

@@ -1454,6 +1454,7 @@ static void ctcmpc_chx_rx(fsm_instance *fi, int event, void *arg)
 				get_ccwdev_lock(ch->cdev), saveflags);
 		if (rc != 0)
 			ctcm_ccw_check_rc(ch, rc, "normal RX");
+		break;
 	default:
 		break;
 	}

drivers/s390/net/qeth_l3_main.c

@@ -434,6 +434,7 @@ static int qeth_l3_correct_routing_type(struct qeth_card *card,
 			if (qeth_is_ipafunc_supported(card, prot,
 						      IPA_OSA_MC_ROUTER))
 				return 0;
+			goto out_inval;
 		default:
 			goto out_inval;
 		}

drivers/scsi/libsas/sas_discover.c

@@ -461,7 +461,7 @@ static void sas_discover_domain(struct work_struct *work)
 		break;
 #else
 		pr_notice("ATA device seen but CONFIG_SCSI_SAS_ATA=N so cannot attach\n");
-		/* Fall through */
+		fallthrough;
 #endif
 		/* Fall through - only for the #else condition above. */
 	default:

drivers/usb/gadget/udc/fsl_qe_udc.c

@@ -586,6 +586,7 @@ static int qe_ep_init(struct qe_udc *udc,
 			case USB_SPEED_FULL:
 				if (max <= 1023)
 					break;
+				fallthrough;
 			default:
 				goto en_done;
 			}

drivers/video/fbdev/xilinxfb.c

@@ -241,6 +241,8 @@ xilinx_fb_blank(int blank_mode, struct fb_info *fbi)
 	case FB_BLANK_POWERDOWN:
 		/* turn off panel */
 		xilinx_fb_out32(drvdata, REG_CTRL, 0);
+		break;
+
 	default:
 		break;
 	}

fs/fcntl.c

@@ -369,8 +369,8 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
 	/* 32-bit arches must use fcntl64() */
 	case F_OFD_SETLK:
 	case F_OFD_SETLKW:
-#endif
 		fallthrough;
+#endif
 	case F_SETLK:
 	case F_SETLKW:
 		if (copy_from_user(&flock, argp, sizeof(flock)))

fs/xfs/libxfs/xfs_attr.c

@@ -483,7 +483,7 @@ xfs_attr_set_iter(
 		if (error)
 			return error;
 
-		/* fallthrough */
+		fallthrough;
 	case XFS_DAS_RM_LBLK:
 		/* Set state in case xfs_attr_rmtval_remove returns -EAGAIN */
 		dac->dela_state = XFS_DAS_RM_LBLK;
@@ -496,7 +496,7 @@ xfs_attr_set_iter(
 			return -EAGAIN;
 		}
 
-		/* fallthrough */
+		fallthrough;
 	case XFS_DAS_RD_LEAF:
 		/*
 		 * This is the last step for leaf format. Read the block with
@@ -528,7 +528,7 @@ xfs_attr_set_iter(
 				return error;
 		}
 
-		/* fallthrough */
+		fallthrough;
 	case XFS_DAS_ALLOC_NODE:
 		/*
 		 * If there was an out-of-line value, allocate the blocks we
@@ -590,7 +590,7 @@ xfs_attr_set_iter(
 		if (error)
 			return error;
 
-		/* fallthrough */
+		fallthrough;
 	case XFS_DAS_RM_NBLK:
 		/* Set state in case xfs_attr_rmtval_remove returns -EAGAIN */
 		dac->dela_state = XFS_DAS_RM_NBLK;
@@ -603,7 +603,7 @@ xfs_attr_set_iter(
 			return -EAGAIN;
 		}
 
-		/* fallthrough */
+		fallthrough;
 	case XFS_DAS_CLR_FLAG:
 		/*
 		 * The last state for node format. Look up the old attr and
@@ -1406,7 +1406,7 @@ xfs_attr_remove_iter(
 			state = dac->da_state;
 		}
 
-		/* fallthrough */
+		fallthrough;
 	case XFS_DAS_RMTBLK:
 		dac->dela_state = XFS_DAS_RMTBLK;
 
@@ -1441,7 +1441,7 @@ xfs_attr_remove_iter(
 			return -EAGAIN;
 		}
 
-		/* fallthrough */
+		fallthrough;
 	case XFS_DAS_RM_NAME:
 		/*
 		 * If we came here fresh from a transaction roll, reattach all
@@ -1469,7 +1469,7 @@ xfs_attr_remove_iter(
 			return -EAGAIN;
 		}
 
-		/* fallthrough */
+		fallthrough;
 	case XFS_DAS_RM_SHRINK:
 		/*
 		 * If the result is small enough, push it all into the inode.

include/math-emu/op-common.h

@@ -338,7 +338,7 @@ do {									     \
 	FP_SET_EXCEPTION(FP_EX_INVALID | FP_EX_INVALID_ISI);		     \
 	break;								     \
       }									     \
-    /* FALLTHRU */							     \
+    fallthrough;							     \
 									     \
   case _FP_CLS_COMBINE(FP_CLS_INF,FP_CLS_NORMAL):			     \
   case _FP_CLS_COMBINE(FP_CLS_INF,FP_CLS_ZERO):				     \

kernel/debug/gdbstub.c

@@ -1045,8 +1045,8 @@ int gdb_serial_stub(struct kgdb_state *ks)
 				gdb_cmd_detachkill(ks);
 				return DBG_PASS_EVENT;
 			}
-#endif
 			fallthrough;
+#endif
 		case 'C': /* Exception passing */
 			tmp = gdb_cmd_exception_pass(ks);
 			if (tmp > 0)

sound/soc/mediatek/mt8183/mt8183-dai-adda.c

@@ -341,6 +341,7 @@ static int set_mtkaif_rx(struct mtk_base_afe *afe)
 	case MT8183_MTKAIF_PROTOCOL_1:
 		regmap_write(afe->regmap, AFE_AUD_PAD_TOP, 0x31);
 		regmap_write(afe->regmap, AFE_ADDA_MTKAIF_CFG0, 0x0);
+		break;
 	default:
 		break;
 	}