treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <[email protected]>

Author: GustavoARSilva

arch/alpha/kernel/module.c

@@ -212,7 +212,7 @@ apply_relocate_add(Elf64_Shdr *sechdrs, const char *strtab,
 			    STO_ALPHA_STD_GPLOAD)
 				/* Omit the prologue. */
 				value += 8;
-			/* FALLTHRU */
+			fallthrough;
 		case R_ALPHA_BRADDR:
 			value -= (u64)location + 4;
 			if (value & 3)

arch/alpha/kernel/signal.c

@@ -453,7 +453,7 @@ syscall_restart(unsigned long r0, unsigned long r19,
 			regs->r0 = EINTR;
 			break;
 		}
-		/* fallthrough */
+		fallthrough;
 	case ERESTARTNOINTR:
 		regs->r0 = r0;	/* reset v0 and a3 and replay syscall */
 		regs->r19 = r19;

arch/alpha/kernel/traps.c

@@ -883,7 +883,7 @@ do_entUnaUser(void __user * va, unsigned long opcode,
 
 	case 0x26: /* sts */
 		fake_reg = s_reg_to_mem(alpha_read_fp_reg(reg));
-		/* FALLTHRU */
+		fallthrough;
 
 	case 0x2c: /* stl */
 		__asm__ __volatile__(
@@ -911,7 +911,7 @@ do_entUnaUser(void __user * va, unsigned long opcode,
 
 	case 0x27: /* stt */
 		fake_reg = alpha_read_fp_reg(reg);
-		/* FALLTHRU */
+		fallthrough;
 
 	case 0x2d: /* stq */
 		__asm__ __volatile__(

arch/arc/kernel/disasm.c

@@ -339,7 +339,7 @@ void __kprobes disasm_instr(unsigned long addr, struct disasm_state *state,
 
 	case op_LDWX_S:	/* LDWX_S c, [b, u6] */
 		state->x = 1;
-		/* intentional fall-through */
+		fallthrough;
 
 	case op_LDW_S:	/* LDW_S c, [b, u6] */
 		state->zz = 2;

arch/arc/kernel/signal.c

@@ -321,7 +321,7 @@ static void arc_restart_syscall(struct k_sigaction *ka, struct pt_regs *regs)
 			regs->r0 = -EINTR;
 			break;
 		}
-		/* fallthrough */
+		fallthrough;
 
 	case -ERESTARTNOINTR:
 		/*

arch/arc/kernel/unwind.c

@@ -572,7 +572,7 @@ static unsigned long read_pointer(const u8 **pLoc, const void *end,
 #else
 		BUILD_BUG_ON(sizeof(u32) != sizeof(value));
 #endif
-		/* Fall through */
+		fallthrough;
 	case DW_EH_PE_native:
 		if (end < (const void *)(ptr.pul + 1))
 			return 0;
@@ -827,15 +827,15 @@ static int processCFI(const u8 *start, const u8 *end, unsigned long targetLoc,
 			case DW_CFA_def_cfa:
 				state->cfa.reg = get_uleb128(&ptr.p8, end);
 				unw_debug("cfa_def_cfa: r%lu ", state->cfa.reg);
-				/* fall through */
+				fallthrough;
 			case DW_CFA_def_cfa_offset:
 				state->cfa.offs = get_uleb128(&ptr.p8, end);
 				unw_debug("cfa_def_cfa_offset: 0x%lx ",
 					  state->cfa.offs);
 				break;
 			case DW_CFA_def_cfa_sf:
 				state->cfa.reg = get_uleb128(&ptr.p8, end);
-				/* fall through */
+				fallthrough;
 			case DW_CFA_def_cfa_offset_sf:
 				state->cfa.offs = get_sleb128(&ptr.p8, end)
 				    * state->dataAlign;

arch/arm/kernel/hw_breakpoint.c

@@ -547,7 +547,7 @@ static int arch_build_bp_info(struct perf_event *bp,
 		if ((hw->ctrl.type != ARM_BREAKPOINT_EXECUTE)
 			&& max_watchpoint_len >= 8)
 			break;
-		/* Else, fall through */
+		fallthrough;
 	default:
 		return -EINVAL;
 	}
@@ -612,12 +612,12 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
 		/* Allow halfword watchpoints and breakpoints. */
 		if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
 			break;
-		/* Else, fall through */
+		fallthrough;
 	case 3:
 		/* Allow single byte watchpoint. */
 		if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
 			break;
-		/* Else, fall through */
+		fallthrough;
 	default:
 		ret = -EINVAL;
 		goto out;
@@ -884,7 +884,7 @@ static int hw_breakpoint_pending(unsigned long addr, unsigned int fsr,
 		break;
 	case ARM_ENTRY_ASYNC_WATCHPOINT:
 		WARN(1, "Asynchronous watchpoint exception taken. Debugging results may be unreliable\n");
-		/* Fall through */
+		fallthrough;
 	case ARM_ENTRY_SYNC_WATCHPOINT:
 		watchpoint_handler(addr, fsr, regs);
 		break;
@@ -933,7 +933,7 @@ static bool core_has_os_save_restore(void)
 		ARM_DBG_READ(c1, c1, 4, oslsr);
 		if (oslsr & ARM_OSLSR_OSLM0)
 			return true;
-		/* Else, fall through */
+		fallthrough;
 	default:
 		return false;
 	}

arch/arm/kernel/signal.c

@@ -596,7 +596,7 @@ static int do_signal(struct pt_regs *regs, int syscall)
 		switch (retval) {
 		case -ERESTART_RESTARTBLOCK:
 			restart -= 2;
-			/* Fall through */
+			fallthrough;
 		case -ERESTARTNOHAND:
 		case -ERESTARTSYS:
 		case -ERESTARTNOINTR:

arch/arm/mach-ep93xx/crunch.c

@@ -49,7 +49,7 @@ static int crunch_do(struct notifier_block *self, unsigned long cmd, void *t)
 		 * FALLTHROUGH: Ensure we don't try to overwrite our newly
 		 * initialised state information on the first fault.
 		 */
-		/* Fall through */
+		fallthrough;
 
 	case THREAD_NOTIFY_EXIT:
 		crunch_task_release(thread);

arch/arm/mach-mmp/pm-mmp2.c

@@ -123,19 +123,19 @@ void mmp2_pm_enter_lowpower_mode(int state)
 	case POWER_MODE_SYS_SLEEP:
 		apcr |= MPMU_PCR_PJ_SLPEN;		/* set the SLPEN bit */
 		apcr |= MPMU_PCR_PJ_VCTCXOSD;		/* set VCTCXOSD */
-		/* fall through */
+		fallthrough;
 	case POWER_MODE_CHIP_SLEEP:
 		apcr |= MPMU_PCR_PJ_SLPEN;
-		/* fall through */
+		fallthrough;
 	case POWER_MODE_APPS_SLEEP:
 		apcr |= MPMU_PCR_PJ_APBSD;		/* set APBSD */
-		/* fall through */
+		fallthrough;
 	case POWER_MODE_APPS_IDLE:
 		apcr |= MPMU_PCR_PJ_AXISD;		/* set AXISDD bit */
 		apcr |= MPMU_PCR_PJ_DDRCORSD;		/* set DDRCORSD bit */
 		idle_cfg |= APMU_PJ_IDLE_CFG_PJ_PWRDWN;	/* PJ power down */
 		apcr |= MPMU_PCR_PJ_SPSD;
-		/* fall through */
+		fallthrough;
 	case POWER_MODE_CORE_EXTIDLE:
 		idle_cfg |= APMU_PJ_IDLE_CFG_PJ_IDLE;	/* set the IDLE bit */
 		idle_cfg &= ~APMU_PJ_IDLE_CFG_ISO_MODE_CNTRL_MASK;

arch/arm/mach-mmp/pm-pxa910.c

@@ -145,23 +145,23 @@ void pxa910_pm_enter_lowpower_mode(int state)
 	case POWER_MODE_UDR:
 		/* only shutdown APB in UDR */
 		apcr |= MPMU_APCR_STBYEN | MPMU_APCR_APBSD;
-		/* fall through */
+		fallthrough;
 	case POWER_MODE_SYS_SLEEP:
 		apcr |= MPMU_APCR_SLPEN;		/* set the SLPEN bit */
 		apcr |= MPMU_APCR_VCTCXOSD;		/* set VCTCXOSD */
-		/* fall through */
+		fallthrough;
 	case POWER_MODE_APPS_SLEEP:
 		apcr |= MPMU_APCR_DDRCORSD;		/* set DDRCORSD */
-		/* fall through */
+		fallthrough;
 	case POWER_MODE_APPS_IDLE:
 		apcr |= MPMU_APCR_AXISD;		/* set AXISDD bit */
-		/* fall through */
+		fallthrough;
 	case POWER_MODE_CORE_EXTIDLE:
 		idle_cfg |= APMU_MOH_IDLE_CFG_MOH_IDLE;
 		idle_cfg |= APMU_MOH_IDLE_CFG_MOH_PWRDWN;
 		idle_cfg |= APMU_MOH_IDLE_CFG_MOH_PWR_SW(3)
 			| APMU_MOH_IDLE_CFG_MOH_L2_PWR_SW(3);
-		/* fall through */
+		fallthrough;
 	case POWER_MODE_CORE_INTIDLE:
 		break;
 	}

arch/arm/mach-omap2/id.c

@@ -396,7 +396,6 @@ void __init omap3xxx_check_revision(void)
 			cpu_rev = "3.1";
 			break;
 		case 7:
-		/* FALLTHROUGH */
 		default:
 			/* Use the latest known revision as default */
 			omap_revision = OMAP3430_REV_ES3_1_2;
@@ -416,7 +415,6 @@ void __init omap3xxx_check_revision(void)
 			cpu_rev = "1.0";
 			break;
 		case 1:
-		/* FALLTHROUGH */
 		default:
 			omap_revision = AM35XX_REV_ES1_1;
 			cpu_rev = "1.1";
@@ -435,7 +433,6 @@ void __init omap3xxx_check_revision(void)
 			cpu_rev = "1.1";
 			break;
 		case 2:
-		/* FALLTHROUGH */
 		default:
 			omap_revision = OMAP3630_REV_ES1_2;
 			cpu_rev = "1.2";
@@ -456,7 +453,6 @@ void __init omap3xxx_check_revision(void)
 			cpu_rev = "2.0";
 			break;
 		case 3:
-			/* FALLTHROUGH */
 		default:
 			omap_revision = TI8168_REV_ES2_1;
 			cpu_rev = "2.1";
@@ -473,7 +469,6 @@ void __init omap3xxx_check_revision(void)
 			cpu_rev = "2.0";
 			break;
 		case 2:
-		/* FALLTHROUGH */
 		default:
 			omap_revision = AM335X_REV_ES2_1;
 			cpu_rev = "2.1";
@@ -491,7 +486,6 @@ void __init omap3xxx_check_revision(void)
 			cpu_rev = "1.1";
 			break;
 		case 2:
-		/* FALLTHROUGH */
 		default:
 			omap_revision = AM437X_REV_ES1_2;
 			cpu_rev = "1.2";
@@ -502,7 +496,6 @@ void __init omap3xxx_check_revision(void)
 	case 0xb968:
 		switch (rev) {
 		case 0:
-		/* FALLTHROUGH */
 		case 1:
 			omap_revision = TI8148_REV_ES1_0;
 			cpu_rev = "1.0";
@@ -512,7 +505,6 @@ void __init omap3xxx_check_revision(void)
 			cpu_rev = "2.0";
 			break;
 		case 3:
-		/* FALLTHROUGH */
 		default:
 			omap_revision = TI8148_REV_ES2_1;
 			cpu_rev = "2.1";

arch/arm/mach-omap2/omap_device.c

@@ -240,7 +240,7 @@ static int _omap_device_notifier_call(struct notifier_block *nb,
 		if (pdev->dev.of_node)
 			omap_device_build_from_dt(pdev);
 		omap_auxdata_legacy_init(dev);
-		/* fall through */
+		fallthrough;
 	default:
 		od = to_omap_device(pdev);
 		if (od)

arch/arm/mach-orion5x/dns323-setup.c

@@ -624,7 +624,7 @@ static void __init dns323_init(void)
 		 dns323ab_leds[0].active_low = 1;
 		 gpio_request(DNS323_GPIO_LED_POWER1, "Power Led Enable");
 		 gpio_direction_output(DNS323_GPIO_LED_POWER1, 0);
-		/* Fall through */
+		fallthrough;
 	case DNS323_REV_B1:
 		i2c_register_board_info(0, dns323ab_i2c_devices,
 				ARRAY_SIZE(dns323ab_i2c_devices));

arch/arm/mach-rpc/riscpc.c

@@ -46,7 +46,7 @@ static int __init parse_tag_acorn(const struct tag *tag)
 	switch (tag->u.acorn.vram_pages) {
 	case 512:
 		vram_size += PAGE_SIZE * 256;
-		/* Fall through - ??? */
+		fallthrough;	/* ??? */
 	case 256:
 		vram_size += PAGE_SIZE * 256;
 	default:

arch/arm/mach-tegra/reset.c

@@ -70,7 +70,7 @@ static void __init tegra_cpu_reset_handler_enable(void)
 	switch (err) {
 	case -ENOSYS:
 		tegra_cpu_reset_handler_set(reset_address);
-		/* fall through */
+		fallthrough;
 	case 0:
 		is_enabled = true;
 		break;

arch/arm/mm/alignment.c

@@ -694,7 +694,7 @@ thumb2arm(u16 tinstr)
 			return subset[(L<<1) | ((tinstr & (1<<8)) >> 8)] |
 			    (tinstr & 255);		/* register_list */
 		}
-		/* Else, fall through - for illegal instruction case */
+		fallthrough;	/* for illegal instruction case */
 
 	default:
 		return BAD_INSTR;
@@ -750,7 +750,7 @@ do_alignment_t32_to_handler(u32 *pinstr, struct pt_regs *regs,
 	case 0xe8e0:
 	case 0xe9e0:
 		poffset->un = (tinst2 & 0xff) << 2;
-		/* Fall through */
+		fallthrough;
 
 	case 0xe940:
 	case 0xe9c0:

arch/arm/mm/proc-v7-bugs.c

@@ -71,7 +71,7 @@ static void cpu_v7_spectre_init(void)
 		/* Other ARM CPUs require no workaround */
 		if (read_cpuid_implementor() == ARM_CPU_IMP_ARM)
 			break;
-		/* fallthrough */
+		fallthrough;
 		/* Cortex A57/A72 require firmware workaround */
 	case ARM_CPU_PART_CORTEX_A57:
 	case ARM_CPU_PART_CORTEX_A72: {

arch/arm/plat-omap/dma.c

@@ -309,14 +309,14 @@ void omap_set_dma_src_burst_mode(int lch, enum omap_dma_burst_mode burst_mode)
 		 * not supported by current hardware on OMAP1
 		 * w |= (0x03 << 7);
 		 */
-		/* fall through */
+		fallthrough;
 	case OMAP_DMA_DATA_BURST_16:
 		if (dma_omap2plus()) {
 			burst = 0x3;
 			break;
 		}
 		/* OMAP1 don't support burst 16 */
-		/* fall through */
+		fallthrough;
 	default:
 		BUG();
 	}
@@ -393,7 +393,7 @@ void omap_set_dma_dest_burst_mode(int lch, enum omap_dma_burst_mode burst_mode)
 			break;
 		}
 		/* OMAP1 don't support burst 16 */
-		/* fall through */
+		fallthrough;
 	default:
 		printk(KERN_ERR "Invalid DMA burst mode\n");
 		BUG();

arch/arm/probes/decode.c

@@ -307,7 +307,7 @@ static bool __kprobes decode_regs(probes_opcode_t *pinsn, u32 regs, bool modify)
 		case REG_TYPE_NOPCWB:
 			if (!is_writeback(insn))
 				break; /* No writeback, so any register is OK */
-			/* fall through... */
+			fallthrough;
 		case REG_TYPE_NOPC:
 		case REG_TYPE_NOPCX:
 			/* Reject PC (R15) */

arch/arm/probes/kprobes/core.c

@@ -280,7 +280,7 @@ void __kprobes kprobe_handler(struct pt_regs *regs)
 				/* A nested probe was hit in FIQ, it is a BUG */
 				pr_warn("Unrecoverable kprobe detected.\n");
 				dump_kprobe(p);
-				/* fall through */
+				fallthrough;
 			default:
 				/* impossible cases */
 				BUG();

arch/arm64/kernel/acpi.c

@@ -322,7 +322,7 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
 			 */
 			if (memblock_is_map_memory(phys))
 				return (void __iomem *)__phys_to_virt(phys);
-			/* fall through */
+			fallthrough;
 
 		default:
 			if (region->attribute & EFI_MEMORY_WB)

arch/arm64/kernel/cpufeature.c

@@ -686,7 +686,7 @@ static s64 arm64_ftr_safe_value(const struct arm64_ftr_bits *ftrp, s64 new,
 	case FTR_HIGHER_OR_ZERO_SAFE:
 		if (!cur || !new)
 			break;
-		/* Fallthrough */
+		fallthrough;
 	case FTR_HIGHER_SAFE:
 		ret = new > cur ? new : cur;
 		break;

arch/arm64/kernel/cpuinfo.c

@@ -327,7 +327,7 @@ static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
 		set_bit(ICACHEF_VPIPT, &__icache_flags);
 		break;
 	default:
-		/* Fallthrough */
+		fallthrough;
 	case ICACHE_POLICY_VIPT:
 		/* Assume aliasing */
 		set_bit(ICACHEF_ALIASING, &__icache_flags);