diff options
| author | Clément Léger <cleger@rivosinc.com> | 2025-05-23 12:19:24 +0200 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@dabbelt.com> | 2025-06-04 15:11:04 -0700 |
| commit | 9f9f6fdd1dc6791bcfe251160a96a446199f85ce (patch) | |
| tree | 1f62941a6ebec2225e96d5d5f7dbeabfec1275fc | |
| parent | cf5a8abc6560f989a880bec3647c614e638a0c9f (diff) | |
riscv: misaligned: use on_each_cpu() for scalar misaligned access probing
schedule_on_each_cpu() was used without any good reason while documented
as very slow. This call was in the boot path, so better use
on_each_cpu() for scalar misaligned checking. Vector misaligned check
still needs to use schedule_on_each_cpu() since it requires irqs to be
enabled but that's less of a problem since this code is ran in a kthread.
Add a comment to explicit that.
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Tested-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20250523101932.1594077-8-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
| -rw-r--r-- | arch/riscv/kernel/traps_misaligned.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c index 592b1a28e897..34b4a4e9dfca 100644 --- a/arch/riscv/kernel/traps_misaligned.c +++ b/arch/riscv/kernel/traps_misaligned.c @@ -627,6 +627,10 @@ bool __init check_vector_unaligned_access_emulated_all_cpus(void) { int cpu; + /* + * While being documented as very slow, schedule_on_each_cpu() is used since + * kernel_vector_begin() expects irqs to be enabled or it will panic() + */ schedule_on_each_cpu(check_vector_unaligned_access_emulated); for_each_online_cpu(cpu) @@ -647,7 +651,7 @@ bool __init check_vector_unaligned_access_emulated_all_cpus(void) static bool unaligned_ctl __read_mostly; -static void check_unaligned_access_emulated(struct work_struct *work __always_unused) +static void check_unaligned_access_emulated(void *arg __always_unused) { int cpu = smp_processor_id(); long *mas_ptr = per_cpu_ptr(&misaligned_access_speed, cpu); @@ -688,7 +692,7 @@ bool __init check_unaligned_access_emulated_all_cpus(void) * accesses emulated since tasks requesting such control can run on any * CPU. */ - schedule_on_each_cpu(check_unaligned_access_emulated); + on_each_cpu(check_unaligned_access_emulated, NULL, 1); for_each_online_cpu(cpu) if (per_cpu(misaligned_access_speed, cpu) |