Store mpidr as a 64-bit value on arm64

The mpidr register is 64 bit on arm64 and 32 bit on arm. Fix this by
extending the arm64 definition to include the top 32 bits.

To preserve KBI when MFCing split the value into two 32 bit values.
This will be cleaned up later only on main.

Reviewed by:	bz
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D36346

6 files changed, 24 insertions, 11 deletions

diff --git a/sys/arm/arm/pmu_acpi.c b/sys/arm/arm/pmu_acpi.c
index 2e031338f144..8812ac7b3af4 100644
--- a/sys/arm/arm/pmu_acpi.c
+++ b/sys/arm/arm/pmu_acpi.c
@@ -72,7 +72,7 @@ madt_handler(ACPI_SUBTABLE_HEADER *entry, void *arg)
 
 	for (i = 0; i < MAXCPU; i++) {
 		pcpu = pcpu_find(i);
-		if (pcpu != NULL && pcpu->pc_mpidr == intr->ArmMpidr) {
+		if (pcpu != NULL && PCPU_GET_MPIDR(pcpu) == intr->ArmMpidr) {
 			cpuid = i;
 			break;
 		}
diff --git a/sys/arm/arm/pmu_fdt.c b/sys/arm/arm/pmu_fdt.c
index 0b435375aa22..fef15e106a33 100644
--- a/sys/arm/arm/pmu_fdt.c
+++ b/sys/arm/arm/pmu_fdt.c
@@ -105,7 +105,7 @@ pmu_parse_affinity(device_t dev, struct pmu_softc *sc, struct pmu_intr *irq,
 
 	for (i = 0; i < MAXCPU; i++) {
 		pcpu = pcpu_find(i);
-		if (pcpu != NULL && pcpu->pc_mpidr == mpidr) {
+		if (pcpu != NULL && PCPU_GET_MPIDR(pcpu) == mpidr) {
 			irq->cpuid = i;
 			return (0);
 		}
diff --git a/sys/arm/include/pcpu.h b/sys/arm/include/pcpu.h
index 2353b1d06b17..ced701516c70 100644
--- a/sys/arm/include/pcpu.h
+++ b/sys/arm/include/pcpu.h
@@ -139,6 +139,8 @@ set_tls(void *tls)
 #define	PCPU_PTR(member)	(&get_pcpu()->pc_ ## member)
 #define	PCPU_SET(member,value)	(get_pcpu()->pc_ ## member = (value))
 
+#define	PCPU_GET_MPIDR(pc)	((pc)->pc_mpidr)
+
 void pcpu0_init(void);
 #endif	/* _KERNEL */
 
diff --git a/sys/arm64/arm64/machdep.c b/sys/arm64/arm64/machdep.c
index 5ce5d279e8e0..c47e16e6b2b6 100644
--- a/sys/arm64/arm64/machdep.c
+++ b/sys/arm64/arm64/machdep.c
@@ -300,7 +300,8 @@ cpu_pcpu_init(struct pcpu *pcpu, int cpuid, size_t size)
 {
 
 	pcpu->pc_acpi_id = 0xffffffff;
-	pcpu->pc_mpidr = 0xffffffff;
+	pcpu->pc_mpidr_low = 0xffffffff;
+	pcpu->pc_mpidr_high = 0xffffffff;
 }
 
 void
diff --git a/sys/arm64/arm64/mp_machdep.c b/sys/arm64/arm64/mp_machdep.c
index a6e2be300bae..d1fbb4c079d2 100644
--- a/sys/arm64/arm64/mp_machdep.c
+++ b/sys/arm64/arm64/mp_machdep.c
@@ -153,7 +153,7 @@ static bool
 is_boot_cpu(uint64_t target_cpu)
 {
 
-	return (cpuid_to_pcpu[0]->pc_mpidr == (target_cpu & CPU_AFF_MASK));
+	return (PCPU_GET_MPIDR(cpuid_to_pcpu[0]) == (target_cpu & CPU_AFF_MASK));
 }
 
 static void
@@ -207,7 +207,7 @@ init_secondary(uint64_t cpu)
 {
 	struct pcpu *pcpup;
 	pmap_t pmap0;
-	u_int mpidr;
+	uint64_t mpidr;
 
 	ptrauth_mp_start(cpu);
 
@@ -218,10 +218,10 @@ init_secondary(uint64_t cpu)
 	 */
 	mpidr = READ_SPECIALREG(mpidr_el1) & CPU_AFF_MASK;
 	if (cpu >= MAXCPU || cpuid_to_pcpu[cpu] == NULL ||
-	    cpuid_to_pcpu[cpu]->pc_mpidr != mpidr) {
+	    PCPU_GET_MPIDR(cpuid_to_pcpu[cpu]) != mpidr) {
 		for (cpu = 0; cpu < mp_maxid; cpu++)
 			if (cpuid_to_pcpu[cpu] != NULL &&
-			    cpuid_to_pcpu[cpu]->pc_mpidr == mpidr)
+			    PCPU_GET_MPIDR(cpuid_to_pcpu[cpu]) == mpidr)
 				break;
 		if ( cpu >= MAXCPU)
 			panic("MPIDR for this CPU is not in pcpu table");
@@ -517,7 +517,8 @@ start_cpu(u_int cpuid, uint64_t target_cpu, int domain)
 
 	pcpup = (struct pcpu *)pcpu_mem;
 	pcpu_init(pcpup, cpuid, sizeof(struct pcpu));
-	pcpup->pc_mpidr = target_cpu & CPU_AFF_MASK;
+	pcpup->pc_mpidr_low = target_cpu & CPU_AFF_MASK;
+	pcpup->pc_mpidr_high = (target_cpu & CPU_AFF_MASK) >> 32;
 
 	dpcpu[cpuid - 1] = (void *)(pcpup + 1);
 	dpcpu_init(dpcpu[cpuid - 1], cpuid);
@@ -688,11 +689,15 @@ cpu_init_fdt(void)
 void
 cpu_mp_start(void)
 {
+	uint64_t mpidr;
+
 	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
 
 	/* CPU 0 is always boot CPU. */
 	CPU_SET(0, &all_cpus);
-	cpuid_to_pcpu[0]->pc_mpidr = READ_SPECIALREG(mpidr_el1) & CPU_AFF_MASK;
+	mpidr = READ_SPECIALREG(mpidr_el1) & CPU_AFF_MASK;
+	cpuid_to_pcpu[0]->pc_mpidr_low = mpidr;
+	cpuid_to_pcpu[0]->pc_mpidr_high = mpidr >> 32;
 
 	switch(arm64_bus_method) {
 #ifdef DEV_ACPI
diff --git a/sys/arm64/include/pcpu.h b/sys/arm64/include/pcpu.h
index b93f3b2e4816..8d60b4ef6356 100644
--- a/sys/arm64/include/pcpu.h
+++ b/sys/arm64/include/pcpu.h
@@ -48,8 +48,10 @@ struct debug_monitor_state;
 	struct pmap *pc_curpmap;					\
 	struct pmap *pc_curvmpmap;					\
 	u_int	pc_bcast_tlbi_workaround;				\
-	u_int	pc_mpidr;	/* stored MPIDR value */		\
-	char __pad[201]
+	/* Store as two u_int values to preserve KBI */			\
+	u_int	pc_mpidr_low;	/* lower MPIDR 32 bits */		\
+	u_int	pc_mpidr_high;	/* upper MPIDR 32 bits */		\
+	char __pad[197]
 
 #ifdef _KERNEL
 
@@ -83,6 +85,9 @@ get_curthread(void)
 #define	PCPU_PTR(member)	(&pcpup->pc_ ## member)
 #define	PCPU_SET(member,value)	(pcpup->pc_ ## member = (value))
 
+#define	PCPU_GET_MPIDR(pc)	\
+    ((((uint64_t)((pc)->pc_mpidr_high)) << 32) | ((pc)->pc_mpidr_low))
+
 #endif	/* _KERNEL */
 
 #endif	/* !_MACHINE_PCPU_H_ */