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: e7c9d66e313b ("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>

diff --git a/arch/riscv/kernel/unaligned_access_speed.c b/arch/riscv/kernel/unaligned_access_speed.c
index c9d3237..d9d4ca1 100644 (file)
--- a/arch/riscv/kernel/unaligned_access_speed.c
+++ b/arch/riscv/kernel/unaligned_access_speed.c
@@ -356,6 +356,20 @@ 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()) {
@@ -363,27 +377,16 @@ static int riscv_online_cpu_vec(unsigned int cpu)
                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;
 }