Read the CPU 0 arm64 ID registers early in initarm

We also update the kernel view early in the boot. This will allow the
use of the common kernel view in ifunc resolvers.

Sponsored by:	Innovate UK

4 files changed, 13 insertions, 14 deletions

diff --git a/sys/arm64/arm64/identcpu.c b/sys/arm64/arm64/identcpu.c
index 6220e7f365ae..356e434bd677 100644
--- a/sys/arm64/arm64/identcpu.c
+++ b/sys/arm64/arm64/identcpu.c
@@ -992,7 +992,7 @@ update_lower_register(uint64_t val, uint64_t new_val, u_int shift,
 	return (val);
 }
 
-static void
+void
 update_special_regs(u_int cpu)
 {
 	struct mrs_field *fields;
@@ -1072,7 +1072,8 @@ identify_cpu_sysinit(void *dummy __unused)
 			elf_hwcap = hwcap;
 		else
 			elf_hwcap &= hwcap;
-		update_special_regs(cpu);
+		if (cpu != 0)
+			update_special_regs(cpu);
 
 		if (CTR_DIC_VAL(cpu_desc[cpu].ctr) == 0)
 			dic = false;
@@ -1457,24 +1458,16 @@ identify_cache(uint64_t ctr)
 }
 
 void
-identify_cpu(void)
+identify_cpu(u_int cpu)
 {
 	u_int midr;
 	u_int impl_id;
 	u_int part_id;
-	u_int cpu;
 	size_t i;
 	const struct cpu_parts *cpu_partsp = NULL;
 
-	cpu = PCPU_GET(cpuid);
 	midr = get_midr();
 
-	/*
-	 * Store midr to pcpu to allow fast reading
-	 * from EL0, EL1 and assembly code.
-	 */
-	PCPU_SET(midr, midr);
-
 	impl_id = CPU_IMPL(midr);
 	for (i = 0; i < nitems(cpu_implementers); i++) {
 		if (impl_id == cpu_implementers[i].impl_id ||
diff --git a/sys/arm64/arm64/machdep.c b/sys/arm64/arm64/machdep.c
index fa698c7dbdaa..9c6788eece8e 100644
--- a/sys/arm64/arm64/machdep.c
+++ b/sys/arm64/arm64/machdep.c
@@ -172,7 +172,6 @@ cpu_startup(void *dummy)
 {
 
 	undef_init();
-	identify_cpu();
 	install_cpu_errata();
 
 	vm_ksubmap_init(&kmi);
@@ -1138,6 +1137,9 @@ initarm(struct arm64_bootparams *abp)
 	if (kmdp == NULL)
 		kmdp = preload_search_by_type("elf64 kernel");
 
+	identify_cpu(0);
+	update_special_regs(0);
+
 	link_elf_ireloc(kmdp);
 	try_load_dtb(kmdp);
 
@@ -1181,6 +1183,7 @@ initarm(struct arm64_bootparams *abp)
 	    "msr tpidr_el1, %0" :: "r"(pcpup));
 
 	PCPU_SET(curthread, &thread0);
+	PCPU_SET(midr, get_midr());
 
 	/* Do basic tuning, hz etc */
 	init_param1();
diff --git a/sys/arm64/arm64/mp_machdep.c b/sys/arm64/arm64/mp_machdep.c
index b90873c65054..d3dea3597106 100644
--- a/sys/arm64/arm64/mp_machdep.c
+++ b/sys/arm64/arm64/mp_machdep.c
@@ -220,7 +220,7 @@ init_secondary(uint64_t cpu)
 	 * We need this before signalling the CPU is ready to
 	 * let the boot CPU use the results.
 	 */
-	identify_cpu();
+	identify_cpu(cpu);
 
 	/* Ensure the stores in identify_cpu have completed */
 	atomic_thread_fence_acq_rel();
@@ -230,6 +230,8 @@ init_secondary(uint64_t cpu)
 	while (!atomic_load_int(&aps_ready))
 		__asm __volatile("wfe");
 
+	pcpup->pc_midr = get_midr();
+
 	/* Initialize curthread */
 	KASSERT(PCPU_GET(idlethread) != NULL, ("no idle thread"));
 	pcpup->pc_curthread = pcpup->pc_idlethread;
diff --git a/sys/arm64/include/cpu.h b/sys/arm64/include/cpu.h
index 7cd7461e528c..fcc97149fb8c 100644
--- a/sys/arm64/include/cpu.h
+++ b/sys/arm64/include/cpu.h
@@ -167,11 +167,12 @@ void	cpu_halt(void) __dead2;
 void	cpu_reset(void) __dead2;
 void	fork_trampoline(void);
 void	identify_cache(uint64_t);
-void	identify_cpu(void);
+void	identify_cpu(u_int);
 void	install_cpu_errata(void);
 void	swi_vm(void *v);
 
 /* Functions to read the sanitised view of the special registers */
+void	update_special_regs(u_int);
 bool	extract_user_id_field(u_int, u_int, uint8_t *);
 bool	get_kernel_reg(u_int, uint64_t *);