riscv: Fix set up of vector cpu hotplug callback

Whether or not we have RISCV_PROBE_VECTOR_UNALIGNED_ACCESS we need to
set up a cpu hotplug callback to check if we have vector at all,
since, when we don't have vector, we need to set
vector_misaligned_access to unsupported rather than leave it the
default of unknown.

Fixes: e7c9d66 ("RISC-V: Report vector unaligned access speed hwprobe")
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20250304120014.143628-16-ajones@ventanamicro.com
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>

Author: jones-drew

arch/riscv/kernel/unaligned_access_speed.c

@@ -356,34 +356,37 @@ static void check_vector_unaligned_access(struct work_struct *work __always_unus
 	per_cpu(vector_misaligned_access, cpu) = speed;
 }
 
+/* Measure unaligned access speed on all CPUs present at boot in parallel. */
+static int __init vec_check_unaligned_access_speed_all_cpus(void *unused __always_unused)
+{
+	schedule_on_each_cpu(check_vector_unaligned_access);
+
+	return 0;
+}
+#else /* CONFIG_RISCV_PROBE_VECTOR_UNALIGNED_ACCESS */
+static int __init vec_check_unaligned_access_speed_all_cpus(void *unused __always_unused)
+{
+	return 0;
+}
+#endif
+
 static int riscv_online_cpu_vec(unsigned int cpu)
 {
 	if (!has_vector()) {
 		per_cpu(vector_misaligned_access, cpu) = RISCV_HWPROBE_MISALIGNED_VECTOR_UNSUPPORTED;
 		return 0;
 	}
 
+#ifdef CONFIG_RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
 	if (per_cpu(vector_misaligned_access, cpu) != RISCV_HWPROBE_MISALIGNED_VECTOR_UNKNOWN)
 		return 0;
 
 	check_vector_unaligned_access_emulated(NULL);
 	check_vector_unaligned_access(NULL);
-	return 0;
-}
-
-/* Measure unaligned access speed on all CPUs present at boot in parallel. */
-static int __init vec_check_unaligned_access_speed_all_cpus(void *unused __always_unused)
-{
-	schedule_on_each_cpu(check_vector_unaligned_access);
+#endif
 
 	return 0;
 }
-#else /* CONFIG_RISCV_PROBE_VECTOR_UNALIGNED_ACCESS */
-static int __init vec_check_unaligned_access_speed_all_cpus(void *unused __always_unused)
-{
-	return 0;
-}
-#endif
 
 static int __init check_unaligned_access_all_cpus(void)
 {
@@ -409,10 +412,8 @@ static int __init check_unaligned_access_all_cpus(void)
 	cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "riscv:online",
 				  riscv_online_cpu, riscv_offline_cpu);
 #endif
-#ifdef CONFIG_RISCV_PROBE_VECTOR_UNALIGNED_ACCESS
 	cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "riscv:online",
 				  riscv_online_cpu_vec, NULL);
-#endif
 
 	return 0;
 }