[PATCH 6/9] riscv: Fix set up of vector cpu hotplug callback

From: Andrew Jones
Date: Fri Feb 07 2025 - 11:21:04 EST


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")
Signed-off-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
---
arch/riscv/kernel/unaligned_access_speed.c | 31 +++++++++++-----------
1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/arch/riscv/kernel/unaligned_access_speed.c b/arch/riscv/kernel/unaligned_access_speed.c
index c9d3237649bb..d9d4ca1fadc7 100644
--- 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;
}
--
2.48.1