On 20/05/2025 19:08, Charlie Jenkins wrote:
On Tue, May 20, 2025 at 10:19:47AM +0200, Clément Léger wrote:
On 20/05/2025 01:32, Charlie Jenkins wrote:
On Thu, May 15, 2025 at 10:22:10AM +0200, Clément Léger wrote:
Split the code that check for the uniformity of misaligned accesses performance on all cpus from check_unaligned_access_emulated_all_cpus() to its own function which will be used for delegation check. No functional changes intended.
Signed-off-by: Clément Léger cleger@rivosinc.com Reviewed-by: Andrew Jones ajones@ventanamicro.com
arch/riscv/kernel/traps_misaligned.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c index e551ba17f557..287ec37021c8 100644 --- a/arch/riscv/kernel/traps_misaligned.c +++ b/arch/riscv/kernel/traps_misaligned.c @@ -647,6 +647,18 @@ bool __init check_vector_unaligned_access_emulated_all_cpus(void) } #endif +static bool all_cpus_unaligned_scalar_access_emulated(void) +{
- int cpu;
- for_each_online_cpu(cpu)
if (per_cpu(misaligned_access_speed, cpu) !=misaligned_access_speed is only defined when CONFIG_RISCV_SCALAR_MISALIGNED. This function should return false when !CONFIG_RISCV_SCALAR_MISALIGNED and only use this logic otherwise.
Hi Charlie,
misaligned_access_speed is defined in unaligned_access_speed.c which is compiled based on CONFIG_RISCV_MISALIGNED (ditto for trap_misaligned.c)
obj-$(CONFIG_RISCV_MISALIGNED) += unaligned_access_speed.o
However, the declaration for it in the header cpu-feature.h however is under a CONFIG_RISCV_SCALAR_MISALIGNED ifdef. So either the declaration or the definition is wrong but the ifdefery soup makes it quite difficult to understand what's going on.
I would suggest to move the DECLARE_PER_CPU under CONFIG_RISCV_MISALIGNED so that it reduces ifdef in traps_misaligned as well.
Here is the patch I am using locally for testing purposes, but if there is a way to reduce the number of ifdefs that is probably the better way to go:
Hi Charlie,
I have another way to do so which indeed reduces the number of ifdef/duplicated functions. I'll submit that.
Thanks,
Clément
From 18f9a056d3b597934c931abdf72fb6e775ccb714 Mon Sep 17 00:00:00 2001 From: Charlie Jenkins charlie@rivosinc.com Date: Mon, 19 May 2025 16:35:51 -0700 Subject: [PATCH] fixup! riscv: misaligned: move emulated access uniformity check in a function
arch/riscv/kernel/traps_misaligned.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c index f3ab84bc4632..1449c6a4ac21 100644 --- a/arch/riscv/kernel/traps_misaligned.c +++ b/arch/riscv/kernel/traps_misaligned.c @@ -647,6 +647,10 @@ bool __init check_vector_unaligned_access_emulated_all_cpus(void) } #endif +#ifdef CONFIG_RISCV_SCALAR_MISALIGNED
+static bool unaligned_ctl __read_mostly;
static bool all_cpus_unaligned_scalar_access_emulated(void) { int cpu; @@ -659,10 +663,6 @@ static bool all_cpus_unaligned_scalar_access_emulated(void) return true; } -#ifdef CONFIG_RISCV_SCALAR_MISALIGNED
-static bool unaligned_ctl __read_mostly;
static void check_unaligned_access_emulated(void *arg __always_unused) { int cpu = smp_processor_id(); @@ -716,6 +716,10 @@ bool unaligned_ctl_available(void) return unaligned_ctl; } #else +static bool all_cpus_unaligned_scalar_access_emulated(void) +{
- return false;
+} bool __init check_unaligned_access_emulated_all_cpus(void) { return false;