/*
  * Called from the secondary holding pen, this is the secondary CPU entry point.

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 3b3f6b56e733039cad7ff5b8995db16a68f3c762..3f3712e47c94c62836fb89cd4bfb3595fbb41557 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c

@@ -83,7 +83,26 @@ enum ipi_msg_type {
 
 static int ipi_irq_base __ro_after_init;
 static int nr_ipi __ro_after_init = NR_IPI;
-static struct irq_desc *ipi_desc[MAX_IPI] __ro_after_init;
+
+struct ipi_descs {
+	struct irq_desc *descs[MAX_IPI];
+};
+
+static DEFINE_PER_CPU(struct ipi_descs, pcpu_ipi_desc);
+
+#define get_ipi_desc(__cpu, __ipi) (per_cpu_ptr(&pcpu_ipi_desc, __cpu)->descs[__ipi])
+
+static bool percpu_ipi_descs __ro_after_init;
+
+static int ipi_to_irq(int ipi, int cpu)
+{
+	return ipi_irq_base + (cpu * nr_ipi) + ipi;
+}
+
+static int irq_to_ipi(int irq)
+{
+	return (irq - ipi_irq_base) % nr_ipi;
+}
 
 static bool crash_stop;
 

@@ -844,7 +863,7 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 		seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i,
 			   prec >= 4 ? " " : "");
 		for_each_online_cpu(cpu)
-			seq_printf(p, "%10u ", irq_desc_kstat_cpu(ipi_desc[i], cpu));
+			seq_printf(p, "%10u ", irq_desc_kstat_cpu(get_ipi_desc(cpu, i), cpu));
 		seq_printf(p, "      %s\n", ipi_types[i]);
 	}
 

@@ -919,7 +938,13 @@ static void __noreturn ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs
 
 static void arm64_backtrace_ipi(cpumask_t *mask)
 {
-	__ipi_send_mask(ipi_desc[IPI_CPU_BACKTRACE], mask);
+	unsigned int cpu;
+
+	if (!percpu_ipi_descs)
+		__ipi_send_mask(get_ipi_desc(0, IPI_CPU_BACKTRACE), mask);
+	else
+		for_each_cpu(cpu, mask)
+			__ipi_send_single(get_ipi_desc(cpu, IPI_CPU_BACKTRACE), cpu);
 }
 
 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, int exclude_cpu)

@@ -944,7 +969,7 @@ void kgdb_roundup_cpus(void)
 		if (cpu == this_cpu)
 			continue;
 
-		__ipi_send_single(ipi_desc[IPI_KGDB_ROUNDUP], cpu);
+		__ipi_send_single(get_ipi_desc(cpu, IPI_KGDB_ROUNDUP), cpu);
 	}
 }
 #endif

@@ -1013,14 +1038,21 @@ static void do_handle_IPI(int ipinr)
 
 static irqreturn_t ipi_handler(int irq, void *data)
 {
-	do_handle_IPI(irq - ipi_irq_base);
+	do_handle_IPI(irq_to_ipi(irq));
 	return IRQ_HANDLED;
 }
 
 static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
 {
+	unsigned int cpu;
+
 	trace_ipi_raise(target, ipi_types[ipinr]);
-	__ipi_send_mask(ipi_desc[ipinr], target);
+
+	if (!percpu_ipi_descs)
+		__ipi_send_mask(get_ipi_desc(0, ipinr), target);
+	else
+		for_each_cpu(cpu, target)
+			__ipi_send_single(get_ipi_desc(cpu, ipinr), cpu);
 }
 
 static bool ipi_should_be_nmi(enum ipi_msg_type ipi)

@@ -1046,11 +1078,15 @@ static void ipi_setup(int cpu)
 		return;
 
 	for (i = 0; i < nr_ipi; i++) {
-		if (ipi_should_be_nmi(i)) {
-			prepare_percpu_nmi(ipi_irq_base + i);
-			enable_percpu_nmi(ipi_irq_base + i, 0);
+		if (!percpu_ipi_descs) {
+			if (ipi_should_be_nmi(i)) {
+				prepare_percpu_nmi(ipi_irq_base + i);
+				enable_percpu_nmi(ipi_irq_base + i, 0);
+			} else {
+				enable_percpu_irq(ipi_irq_base + i, 0);
+			}
 		} else {
-			enable_percpu_irq(ipi_irq_base + i, 0);
+			enable_irq(irq_desc_get_irq(get_ipi_desc(cpu, i)));
 		}
 	}
 }

@@ -1064,44 +1100,79 @@ static void ipi_teardown(int cpu)
 		return;
 
 	for (i = 0; i < nr_ipi; i++) {
-		if (ipi_should_be_nmi(i)) {
-			disable_percpu_nmi(ipi_irq_base + i);
-			teardown_percpu_nmi(ipi_irq_base + i);
+		if (!percpu_ipi_descs) {
+			if (ipi_should_be_nmi(i)) {
+				disable_percpu_nmi(ipi_irq_base + i);
+				teardown_percpu_nmi(ipi_irq_base + i);
+			} else {
+				disable_percpu_irq(ipi_irq_base + i);
+			}
 		} else {
-			disable_percpu_irq(ipi_irq_base + i);
+			disable_irq(irq_desc_get_irq(get_ipi_desc(cpu, i)));
 		}
 	}
 }
 #endif
 
-void __init set_smp_ipi_range(int ipi_base, int n)
+static void ipi_setup_ppi(int ipi)
+{
+	int err, irq, cpu;
+
+	irq = ipi_irq_base + ipi;
+
+	if (ipi_should_be_nmi(irq)) {
+		err = request_percpu_nmi(irq, ipi_handler, "IPI", &irq_stat);
+		WARN(err, "Could not request IRQ %d as NMI, err=%d\n", irq, err);
+	} else {
+		err = request_percpu_irq(irq, ipi_handler, "IPI", &irq_stat);
+		WARN(err, "Could not request IRQ %d as IRQ, err=%d\n", irq, err);
+	}
+
+	for_each_possible_cpu(cpu)
+		get_ipi_desc(cpu, ipi) = irq_to_desc(irq);
+
+	irq_set_status_flags(irq, IRQ_HIDDEN);
+}
+
+static void ipi_setup_lpi(int ipi, int ncpus)
+{
+	for (int cpu = 0; cpu < ncpus; cpu++) {
+		int err, irq;
+
+		irq = ipi_to_irq(ipi, cpu);
+
+		err = irq_force_affinity(irq, cpumask_of(cpu));
+
+		WARN(err, "Could not force affinity IRQ %d, err=%d\n", irq, err);
+
+		err = request_irq(irq, ipi_handler, IRQF_NO_AUTOEN, "IPI",
+				  &irq_stat);