Only store the arm64 ID registers in the cpu_desc

There is no need to store a pointer to the CPU implementer and part
strings. Switch to load them directly into the sbuf used to print them
on boot.

While here print the machine ID register when we fail to determine the
implementer or part we are booting on.

Reviewed by:	markj, kib
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31346

sys/arm64/arm64/identcpu.c

@@ -47,6 +47,7 @@ __FBSDID("$FreeBSD$");
 #include <machine/md_var.h>
 #include <machine/undefined.h>
 
+static void print_cpu_midr(struct sbuf *sb, u_int cpu);
 static void print_cpu_features(u_int cpu);
 #ifdef COMPAT_FREEBSD32
 static u_long parse_cpu_features_hwcap32(void);
@@ -116,13 +117,6 @@ uint64_t __cpu_affinity[MAXCPU];
 static u_int cpu_aff_levels;
 
 struct cpu_desc {
-	u_int		cpu_impl;
-	u_int		cpu_part_num;
-	u_int		cpu_variant;
-	u_int		cpu_revision;
-	const char	*cpu_impl_name;
-	const char	*cpu_part_name;
-
 	uint64_t	mpidr;
 	uint64_t	id_aa64afr0;
 	uint64_t	id_aa64afr1;
@@ -169,7 +163,7 @@ struct cpu_parts {
 	u_int		part_id;
 	const char	*part_name;
 };
-#define	CPU_PART_NONE	{ 0, "Unknown Processor" }
+#define	CPU_PART_NONE	{ 0, NULL }
 
 struct cpu_implementers {
 	u_int			impl_id;
@@ -180,7 +174,7 @@ struct cpu_implementers {
 	 */
 	const struct cpu_parts	*cpu_parts;
 };
-#define	CPU_IMPLEMENTER_NONE	{ 0, "Unknown Implementer", cpu_parts_none }
+#define	CPU_IMPLEMENTER_NONE	{ 0, NULL, NULL }
 
 /*
  * Per-implementer table of (PartNum, CPU Name) pairs.
@@ -1435,7 +1429,6 @@ static struct mrs_user_reg user_regs[] = {
 
 	USER_REG(ID_AA64PFR0_EL1, id_aa64pfr0),
 	USER_REG(ID_AA64PFR1_EL1, id_aa64pfr1),
-
 #ifdef COMPAT_FREEBSD32
 	USER_REG(ID_ISAR5_EL1, id_isar5),
 
@@ -1754,10 +1747,17 @@ SYSINIT(identify_cpu, SI_SUB_CPU, SI_ORDER_ANY, identify_cpu_sysinit, NULL);
 static void
 cpu_features_sysinit(void *dummy __unused)
 {
+	struct sbuf sb;
 	u_int cpu;
 
 	CPU_FOREACH(cpu)
 		print_cpu_features(cpu);
+
+	/* Fill in cpu_model for the hw.model sysctl */
+	sbuf_new(&sb, cpu_model, sizeof(cpu_model), SBUF_FIXEDLEN);
+	print_cpu_midr(&sb, 0);
+	sbuf_finish(&sb);
+	sbuf_delete(&sb);
 }
 /* Log features before APs are released and start printing to the dmesg. */
 SYSINIT(cpu_features, SI_SUB_SMP - 1, SI_ORDER_ANY, cpu_features_sysinit, NULL);
@@ -1879,15 +1879,64 @@ print_id_register(struct sbuf *sb, const char *reg_name, uint64_t reg,
 	print_register(sb, reg_name, reg, print_id_fields, fields);
 }
 
+static void
+print_cpu_midr(struct sbuf *sb, u_int cpu)
+{
+	const struct cpu_parts *cpu_partsp;
+	const char *cpu_impl_name;
+	const char *cpu_part_name;
+	u_int midr;
+	u_int impl_id;
+	u_int part_id;
+
+	midr = pcpu_find(cpu)->pc_midr;
+
+	cpu_impl_name = NULL;
+	cpu_partsp = NULL;
+	impl_id = CPU_IMPL(midr);
+	for (int i = 0; cpu_implementers[i].impl_name != NULL; i++) {
+		if (impl_id == cpu_implementers[i].impl_id) {
+			cpu_impl_name = cpu_implementers[i].impl_name;
+			cpu_partsp = cpu_implementers[i].cpu_parts;
+			break;
+		}
+	}
+	/* Unknown implementer, so unknown part */
+	if (cpu_impl_name == NULL) {
+		sbuf_printf(sb, "Unknown Implementer (midr: %08x)", midr);
+		return;
+	}
+
+	KASSERT(cpu_partsp != NULL, ("%s: No parts table for implementer %s",
+	    __func__, cpu_impl_name));
+
+	cpu_part_name = NULL;
+	part_id = CPU_PART(midr);
+	for (int i = 0; cpu_partsp[i].part_name != NULL; i++) {
+		if (part_id == cpu_partsp[i].part_id) {
+			cpu_part_name = cpu_partsp[i].part_name;
+			break;
+		}
+	}
+	/* Known Implementer, Unknown part */
+	if (cpu_part_name == NULL) {
+		sbuf_printf(sb, "%s Unknown CPU r%dp%d (midr: %08x)",
+		    cpu_impl_name, CPU_VAR(midr), CPU_REV(midr), midr);
+		return;
+	}
+
+	sbuf_printf(sb, "%s %s r%dp%d", cpu_impl_name,
+	    cpu_part_name, CPU_VAR(midr), CPU_REV(midr));
+}
+
 static void
 print_cpu_features(u_int cpu)
 {
 	struct sbuf *sb;
 
 	sb = sbuf_new_auto();
-	sbuf_printf(sb, "CPU%3d: %s %s r%dp%d", cpu,
-	    cpu_desc[cpu].cpu_impl_name, cpu_desc[cpu].cpu_part_name,
-	    cpu_desc[cpu].cpu_variant, cpu_desc[cpu].cpu_revision);
+	sbuf_printf(sb, "CPU%3u: ", cpu);
+	print_cpu_midr(sb, cpu);
 
 	sbuf_cat(sb, " affinity:");
 	switch(cpu_aff_levels) {
@@ -2058,43 +2107,6 @@ identify_cache(uint64_t ctr)
 void
 identify_cpu(u_int cpu)
 {
-	u_int midr;
-	u_int impl_id;
-	u_int part_id;
-	size_t i;
-	const struct cpu_parts *cpu_partsp = NULL;
-
-	midr = get_midr();
-
-	impl_id = CPU_IMPL(midr);
-	for (i = 0; i < nitems(cpu_implementers); i++) {
-		if (impl_id == cpu_implementers[i].impl_id ||
-		    cpu_implementers[i].impl_id == 0) {
-			cpu_desc[cpu].cpu_impl = impl_id;
-			cpu_desc[cpu].cpu_impl_name =
-			    cpu_implementers[i].impl_name;
-			cpu_partsp = cpu_implementers[i].cpu_parts;
-			break;
-		}
-	}
-
-	part_id = CPU_PART(midr);
-	for (i = 0; &cpu_partsp[i] != NULL; i++) {
-		if (part_id == cpu_partsp[i].part_id ||
-		    cpu_partsp[i].part_id == 0) {
-			cpu_desc[cpu].cpu_part_num = part_id;
-			cpu_desc[cpu].cpu_part_name = cpu_partsp[i].part_name;
-			break;
-		}
-	}
-
-	cpu_desc[cpu].cpu_revision = CPU_REV(midr);
-	cpu_desc[cpu].cpu_variant = CPU_VAR(midr);
-
-	snprintf(cpu_model, sizeof(cpu_model), "%s %s r%dp%d",
-	    cpu_desc[cpu].cpu_impl_name, cpu_desc[cpu].cpu_part_name,
-	    cpu_desc[cpu].cpu_variant, cpu_desc[cpu].cpu_revision);
-
 	/* Save affinity for current CPU */
 	cpu_desc[cpu].mpidr = get_mpidr();
 	CPU_AFFINITY(cpu) = cpu_desc[cpu].mpidr & CPU_AFF_MASK;