Merge tag 'v4.9.220' into 4.9-2.3.x-imx

This is the 4.9.220 stable release

Conflicts:
	arch/arm/Kconfig.debug
	arch/arm/boot/dts/imx7s.dtsi
	arch/arm/mach-imx/common.h
	arch/arm/mach-imx/cpuidle-imx6q.c
	arch/arm/mach-imx/cpuidle-imx6sx.c
	arch/arm/mach-imx/suspend-imx6.S
	block/blk-core.c
	drivers/crypto/caam/caamalg.c
	drivers/crypto/mxs-dcp.c
	drivers/dma/imx-sdma.c
	drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
	drivers/input/keyboard/imx_keypad.c
	drivers/input/keyboard/snvs_pwrkey.c
	drivers/mmc/host/sdhci.c
	drivers/net/can/flexcan.c
	drivers/net/ethernet/freescale/fec_main.c
	drivers/net/phy/phy_device.c
	drivers/net/wireless/ath/ath10k/pci.c
	drivers/tty/serial/imx.c
	drivers/usb/dwc3/gadget.c
	drivers/usb/host/xhci.c
	include/linux/blkdev.h
	include/linux/cpu.h
	include/linux/platform_data/dma-imx-sdma.h
	kernel/cpu.c
	net/wireless/util.c
	sound/soc/fsl/Kconfig
	sound/soc/fsl/fsl_esai.c
	sound/soc/fsl/fsl_sai.c
	sound/soc/fsl/imx-sgtl5000.c

1 files changed, 27 insertions, 19 deletions

diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 2863ad306692..33ba47c44816 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -181,6 +181,12 @@ asmlinkage __visible void smp_reboot_interrupt(void)
 	irq_exit();
 }
 
+static int register_stop_handler(void)
+{
+	return register_nmi_handler(NMI_LOCAL, smp_stop_nmi_callback,
+				    NMI_FLAG_FIRST, "smp_stop");
+}
+
 static void native_stop_other_cpus(int wait)
 {
 	unsigned long flags;
@@ -214,39 +220,41 @@ static void native_stop_other_cpus(int wait)
 		apic->send_IPI_allbutself(REBOOT_VECTOR);
 
 		/*
-		 * Don't wait longer than a second if the caller
-		 * didn't ask us to wait.
+		 * Don't wait longer than a second for IPI completion. The
+		 * wait request is not checked here because that would
+		 * prevent an NMI shutdown attempt in case that not all
+		 * CPUs reach shutdown state.
 		 */
 		timeout = USEC_PER_SEC;
-		while (num_online_cpus() > 1 && (wait || timeout--))
+		while (num_online_cpus() > 1 && timeout--)
 			udelay(1);
 	}
-	
-	/* if the REBOOT_VECTOR didn't work, try with the NMI */
-	if ((num_online_cpus() > 1) && (!smp_no_nmi_ipi))  {
-		if (register_nmi_handler(NMI_LOCAL, smp_stop_nmi_callback,
-					 NMI_FLAG_FIRST, "smp_stop"))
-			/* Note: we ignore failures here */
-			/* Hope the REBOOT_IRQ is good enough */
-			goto finish;
-
-		/* sync above data before sending IRQ */
-		wmb();
 
-		pr_emerg("Shutting down cpus with NMI\n");
+	/* if the REBOOT_VECTOR didn't work, try with the NMI */
+	if (num_online_cpus() > 1) {
+		/*
+		 * If NMI IPI is enabled, try to register the stop handler
+		 * and send the IPI. In any case try to wait for the other
+		 * CPUs to stop.
+		 */
+		if (!smp_no_nmi_ipi && !register_stop_handler()) {
+			/* Sync above data before sending IRQ */
+			wmb();
 
-		apic->send_IPI_allbutself(NMI_VECTOR);
+			pr_emerg("Shutting down cpus with NMI\n");
 
+			apic->send_IPI_allbutself(NMI_VECTOR);
+		}
 		/*
-		 * Don't wait longer than a 10 ms if the caller
-		 * didn't ask us to wait.
+		 * Don't wait longer than 10 ms if the caller didn't
+		 * reqeust it. If wait is true, the machine hangs here if
+		 * one or more CPUs do not reach shutdown state.
 		 */
 		timeout = USEC_PER_MSEC * 10;
 		while (num_online_cpus() > 1 && (wait || timeout--))
 			udelay(1);
 	}
 
-finish:
 	local_irq_save(flags);
 	disable_local_APIC();
 	mcheck_cpu_clear(this_cpu_ptr(&cpu_info));