diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 20a0756f27ef..ce91682770cb 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -164,7 +164,7 @@ config XTENSA_FAKE_NMI
 	  If unsure, say N.
 
 config XTENSA_UNALIGNED_USER
-	bool "Unaligned memory access in use space"
+	bool "Unaligned memory access in user space"
 	help
 	  The Xtensa architecture currently does not handle unaligned
 	  memory accesses in hardware but through an exception handler.
@@ -451,7 +451,7 @@ config USE_OF
 	help
 	  Include support for flattened device tree machine descriptions.
 
-config BUILTIN_DTB
+config BUILTIN_DTB_SOURCE
 	string "DTB to build into the kernel image"
 	depends on OF
 
diff --git a/arch/xtensa/boot/dts/Makefile b/arch/xtensa/boot/dts/Makefile
index f8052ba5aea8..0b8d00cdae7c 100644
--- a/arch/xtensa/boot/dts/Makefile
+++ b/arch/xtensa/boot/dts/Makefile
@@ -7,9 +7,9 @@
 #
 #
 
-BUILTIN_DTB := $(patsubst "%",%,$(CONFIG_BUILTIN_DTB)).dtb.o
-ifneq ($(CONFIG_BUILTIN_DTB),"")
-obj-$(CONFIG_OF) += $(BUILTIN_DTB)
+BUILTIN_DTB_SOURCE := $(patsubst "%",%,$(CONFIG_BUILTIN_DTB_SOURCE)).dtb.o
+ifneq ($(CONFIG_BUILTIN_DTB_SOURCE),"")
+obj-$(CONFIG_OF) += $(BUILTIN_DTB_SOURCE)
 endif
 
 # for CONFIG_OF_ALL_DTBS test
diff --git a/arch/xtensa/configs/audio_kc705_defconfig b/arch/xtensa/configs/audio_kc705_defconfig
index 2bf964df37ba..f378e56f9ce6 100644
--- a/arch/xtensa/configs/audio_kc705_defconfig
+++ b/arch/xtensa/configs/audio_kc705_defconfig
@@ -34,7 +34,7 @@ CONFIG_XTENSA_PLATFORM_XTFPGA=y
 CONFIG_CMDLINE_BOOL=y
 CONFIG_CMDLINE="earlycon=uart8250,mmio32native,0xfd050020,115200n8 console=ttyS0,115200n8 ip=dhcp root=/dev/nfs rw debug memmap=0x38000000@0"
 CONFIG_USE_OF=y
-CONFIG_BUILTIN_DTB="kc705"
+CONFIG_BUILTIN_DTB_SOURCE="kc705"
 # CONFIG_COMPACTION is not set
 # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
 CONFIG_PM=y
diff --git a/arch/xtensa/configs/cadence_csp_defconfig b/arch/xtensa/configs/cadence_csp_defconfig
index 3221b7053fa3..62f32a902568 100644
--- a/arch/xtensa/configs/cadence_csp_defconfig
+++ b/arch/xtensa/configs/cadence_csp_defconfig
@@ -38,7 +38,7 @@ CONFIG_HIGHMEM=y
 # CONFIG_PCI is not set
 CONFIG_XTENSA_PLATFORM_XTFPGA=y
 CONFIG_USE_OF=y
-CONFIG_BUILTIN_DTB="csp"
+CONFIG_BUILTIN_DTB_SOURCE="csp"
 # CONFIG_COMPACTION is not set
 CONFIG_XTFPGA_LCD=y
 # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
diff --git a/arch/xtensa/configs/generic_kc705_defconfig b/arch/xtensa/configs/generic_kc705_defconfig
index 985fa8546e4e..8bebe07f1060 100644
--- a/arch/xtensa/configs/generic_kc705_defconfig
+++ b/arch/xtensa/configs/generic_kc705_defconfig
@@ -33,7 +33,7 @@ CONFIG_XTENSA_PLATFORM_XTFPGA=y
 CONFIG_CMDLINE_BOOL=y
 CONFIG_CMDLINE="earlycon=uart8250,mmio32native,0xfd050020,115200n8 console=ttyS0,115200n8 ip=dhcp root=/dev/nfs rw debug memmap=0x38000000@0"
 CONFIG_USE_OF=y
-CONFIG_BUILTIN_DTB="kc705"
+CONFIG_BUILTIN_DTB_SOURCE="kc705"
 # CONFIG_COMPACTION is not set
 # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
 CONFIG_NET=y
diff --git a/arch/xtensa/configs/nommu_kc705_defconfig b/arch/xtensa/configs/nommu_kc705_defconfig
index f3fc4f970ca8..933ab2adf434 100644
--- a/arch/xtensa/configs/nommu_kc705_defconfig
+++ b/arch/xtensa/configs/nommu_kc705_defconfig
@@ -39,7 +39,7 @@ CONFIG_XTENSA_PLATFORM_XTFPGA=y
 CONFIG_CMDLINE_BOOL=y
 CONFIG_CMDLINE="earlycon=uart8250,mmio32native,0x9d050020,115200n8 console=ttyS0,115200n8 ip=dhcp root=/dev/nfs rw debug memmap=256M@0x60000000"
 CONFIG_USE_OF=y
-CONFIG_BUILTIN_DTB="kc705_nommu"
+CONFIG_BUILTIN_DTB_SOURCE="kc705_nommu"
 CONFIG_BINFMT_FLAT=y
 CONFIG_NET=y
 CONFIG_PACKET=y
diff --git a/arch/xtensa/configs/smp_lx200_defconfig b/arch/xtensa/configs/smp_lx200_defconfig
index 11fed6c06a7c..e29c5b179a5b 100644
--- a/arch/xtensa/configs/smp_lx200_defconfig
+++ b/arch/xtensa/configs/smp_lx200_defconfig
@@ -33,11 +33,12 @@ CONFIG_SMP=y
 CONFIG_HOTPLUG_CPU=y
 # CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX is not set
 # CONFIG_PCI is not set
+CONFIG_VECTORS_OFFSET=0x00002000
 CONFIG_XTENSA_PLATFORM_XTFPGA=y
 CONFIG_CMDLINE_BOOL=y
 CONFIG_CMDLINE="earlycon=uart8250,mmio32native,0xfd050020,115200n8 console=ttyS0,115200n8 ip=dhcp root=/dev/nfs rw debug memmap=96M@0"
 CONFIG_USE_OF=y
-CONFIG_BUILTIN_DTB="lx200mx"
+CONFIG_BUILTIN_DTB_SOURCE="lx200mx"
 # CONFIG_COMPACTION is not set
 # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
 CONFIG_NET=y
diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S
index da08e75100ab..7f009719304e 100644
--- a/arch/xtensa/kernel/head.S
+++ b/arch/xtensa/kernel/head.S
@@ -276,12 +276,13 @@ should_never_return:
 
 	movi	a2, cpu_start_ccount
 1:
+	memw
 	l32i	a3, a2, 0
 	beqi	a3, 0, 1b
 	movi	a3, 0
 	s32i	a3, a2, 0
-	memw
 1:
+	memw
 	l32i	a3, a2, 0
 	beqi	a3, 0, 1b
 	wsr	a3, ccount
@@ -317,11 +318,13 @@ ENTRY(cpu_restart)
 	rsr	a0, prid
 	neg	a2, a0
 	movi	a3, cpu_start_id
+	memw
 	s32i	a2, a3, 0
 #if XCHAL_DCACHE_IS_WRITEBACK
 	dhwbi	a3, 0
 #endif
 1:
+	memw
 	l32i	a2, a3, 0
 	dhi	a3, 0
 	bne	a2, a0, 1b
diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c
index 932d64689bac..be1f280c322c 100644
--- a/arch/xtensa/kernel/smp.c
+++ b/arch/xtensa/kernel/smp.c
@@ -83,7 +83,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 {
 	unsigned i;
 
-	for (i = 0; i < max_cpus; ++i)
+	for_each_possible_cpu(i)
 		set_cpu_present(i, true);
 }
 
@@ -96,6 +96,11 @@ void __init smp_init_cpus(void)
 	pr_info("%s: Core Count = %d\n", __func__, ncpus);
 	pr_info("%s: Core Id = %d\n", __func__, core_id);
 
+	if (ncpus > NR_CPUS) {
+		ncpus = NR_CPUS;
+		pr_info("%s: limiting core count by %d\n", __func__, ncpus);
+	}
+
 	for (i = 0; i < ncpus; ++i)
 		set_cpu_possible(i, true);
 }
@@ -195,9 +200,11 @@ static int boot_secondary(unsigned int cpu, struct task_struct *ts)
 	int i;
 
 #ifdef CONFIG_HOTPLUG_CPU
-	cpu_start_id = cpu;
-	system_flush_invalidate_dcache_range(
-			(unsigned long)&cpu_start_id, sizeof(cpu_start_id));
+	WRITE_ONCE(cpu_start_id, cpu);
+	/* Pairs with the third memw in the cpu_restart */
+	mb();
+	system_flush_invalidate_dcache_range((unsigned long)&cpu_start_id,
+					     sizeof(cpu_start_id));
 #endif
 	smp_call_function_single(0, mx_cpu_start, (void *)cpu, 1);
 
@@ -206,18 +213,21 @@ static int boot_secondary(unsigned int cpu, struct task_struct *ts)
 			ccount = get_ccount();
 		while (!ccount);
 
-		cpu_start_ccount = ccount;
+		WRITE_ONCE(cpu_start_ccount, ccount);
 
-		while (time_before(jiffies, timeout)) {
+		do {
+			/*
+			 * Pairs with the first two memws in the
+			 * .Lboot_secondary.
+			 */
 			mb();
-			if (!cpu_start_ccount)
-				break;
-		}
+			ccount = READ_ONCE(cpu_start_ccount);
+		} while (ccount && time_before(jiffies, timeout));
 
-		if (cpu_start_ccount) {
+		if (ccount) {
 			smp_call_function_single(0, mx_cpu_stop,
-					(void *)cpu, 1);
-			cpu_start_ccount = 0;
+						 (void *)cpu, 1);
+			WRITE_ONCE(cpu_start_ccount, 0);
 			return -EIO;
 		}
 	}
@@ -237,6 +247,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
 	pr_debug("%s: Calling wakeup_secondary(cpu:%d, idle:%p, sp: %08lx)\n",
 			__func__, cpu, idle, start_info.stack);
 
+	init_completion(&cpu_running);
 	ret = boot_secondary(cpu, idle);
 	if (ret == 0) {
 		wait_for_completion_timeout(&cpu_running,
@@ -298,8 +309,10 @@ void __cpu_die(unsigned int cpu)
 	unsigned long timeout = jiffies + msecs_to_jiffies(1000);
 	while (time_before(jiffies, timeout)) {
 		system_invalidate_dcache_range((unsigned long)&cpu_start_id,
-				sizeof(cpu_start_id));
-		if (cpu_start_id == -cpu) {
+					       sizeof(cpu_start_id));
+		/* Pairs with the second memw in the cpu_restart */
+		mb();
+		if (READ_ONCE(cpu_start_id) == -cpu) {
 			platform_cpu_kill(cpu);
 			return;
 		}
diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c
index fd524a54d2ab..378186b5eb40 100644
--- a/arch/xtensa/kernel/time.c
+++ b/arch/xtensa/kernel/time.c
@@ -89,7 +89,7 @@ static int ccount_timer_shutdown(struct clock_event_device *evt)
 		container_of(evt, struct ccount_timer, evt);
 
 	if (timer->irq_enabled) {
-		disable_irq(evt->irq);
+		disable_irq_nosync(evt->irq);
 		timer->irq_enabled = 0;
 	}
 	return 0;
diff --git a/drivers/irqchip/irq-xtensa-mx.c b/drivers/irqchip/irq-xtensa-mx.c
index 5385f5768345..27933338f7b3 100644
--- a/drivers/irqchip/irq-xtensa-mx.c
+++ b/drivers/irqchip/irq-xtensa-mx.c
@@ -71,14 +71,17 @@ static void xtensa_mx_irq_mask(struct irq_data *d)
 	unsigned int mask = 1u << d->hwirq;
 
 	if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
-				XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
-		set_er(1u << (xtensa_get_ext_irq_no(d->hwirq) -
-					HW_IRQ_MX_BASE), MIENG);
-	} else {
-		mask = __this_cpu_read(cached_irq_mask) & ~mask;
-		__this_cpu_write(cached_irq_mask, mask);
-		xtensa_set_sr(mask, intenable);
+		    XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
+		unsigned int ext_irq = xtensa_get_ext_irq_no(d->hwirq);
+
+		if (ext_irq >= HW_IRQ_MX_BASE) {
+			set_er(1u << (ext_irq - HW_IRQ_MX_BASE), MIENG);
+			return;
+		}
 	}
+	mask = __this_cpu_read(cached_irq_mask) & ~mask;
+	__this_cpu_write(cached_irq_mask, mask);
+	xtensa_set_sr(mask, intenable);
 }
 
 static void xtensa_mx_irq_unmask(struct irq_data *d)
@@ -86,14 +89,17 @@ static void xtensa_mx_irq_unmask(struct irq_data *d)
 	unsigned int mask = 1u << d->hwirq;
 
 	if (mask & (XCHAL_INTTYPE_MASK_EXTERN_EDGE |
-				XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
-		set_er(1u << (xtensa_get_ext_irq_no(d->hwirq) -
-					HW_IRQ_MX_BASE), MIENGSET);
-	} else {
-		mask |= __this_cpu_read(cached_irq_mask);
-		__this_cpu_write(cached_irq_mask, mask);
-		xtensa_set_sr(mask, intenable);
+		    XCHAL_INTTYPE_MASK_EXTERN_LEVEL)) {
+		unsigned int ext_irq = xtensa_get_ext_irq_no(d->hwirq);
+
+		if (ext_irq >= HW_IRQ_MX_BASE) {
+			set_er(1u << (ext_irq - HW_IRQ_MX_BASE), MIENGSET);
+			return;
+		}
 	}
+	mask |= __this_cpu_read(cached_irq_mask);
+	__this_cpu_write(cached_irq_mask, mask);
+	xtensa_set_sr(mask, intenable);
 }
 
 static void xtensa_mx_irq_enable(struct irq_data *d)
@@ -113,7 +119,11 @@ static void xtensa_mx_irq_ack(struct irq_data *d)
 
 static int xtensa_mx_irq_retrigger(struct irq_data *d)
 {
-	xtensa_set_sr(1 << d->hwirq, intset);
+	unsigned int mask = 1u << d->hwirq;
+
+	if (WARN_ON(mask & ~XCHAL_INTTYPE_MASK_SOFTWARE))
+		return 0;
+	xtensa_set_sr(mask, intset);
 	return 1;
 }
 
diff --git a/drivers/irqchip/irq-xtensa-pic.c b/drivers/irqchip/irq-xtensa-pic.c
index c200234dd2c9..ab12328be5ee 100644
--- a/drivers/irqchip/irq-xtensa-pic.c
+++ b/drivers/irqchip/irq-xtensa-pic.c
@@ -70,7 +70,11 @@ static void xtensa_irq_ack(struct irq_data *d)
 
 static int xtensa_irq_retrigger(struct irq_data *d)
 {
-	xtensa_set_sr(1 << d->hwirq, intset);
+	unsigned int mask = 1u << d->hwirq;
+
+	if (WARN_ON(mask & ~XCHAL_INTTYPE_MASK_SOFTWARE))
+		return 0;
+	xtensa_set_sr(mask, intset);
 	return 1;
 }