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authorJisheng Zhang <jszhang@kernel.org>2023-09-12 18:40:40 +0300
committerPalmer Dabbelt <palmer@rivosinc.com>2023-11-05 20:05:51 +0300
commitc20d36cc2a2073d4cdcda92bd7a1bb9b3b3b7c79 (patch)
tree27fdb74d2935c6f6d6f1166be5af4d9ecc1924e6 /arch/riscv
parent07863871dfb162965b21bb8c2e4861bdb0019da3 (diff)
downloadlinux-c20d36cc2a2073d4cdcda92bd7a1bb9b3b3b7c79.tar.xz
riscv: don't probe unaligned access speed if already done
If misaligned_access_speed percpu var isn't so called "HWPROBE MISALIGNED UNKNOWN", it means the probe has happened(this is possible for example, hotplug off then hotplug on one cpu), and the percpu var has been set, don't probe again in this case. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Fixes: 584ea6564bca ("RISC-V: Probe for unaligned access speed") Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230912154040.3306-1-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv')
-rw-r--r--arch/riscv/kernel/cpufeature.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 970a71422bee..6a01ded615cd 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -572,6 +572,10 @@ void check_unaligned_access(int cpu)
if (check_unaligned_access_emulated(cpu))
return;
+ /* We are already set since the last check */
+ if (per_cpu(misaligned_access_speed, cpu) != RISCV_HWPROBE_MISALIGNED_UNKNOWN)
+ return;
+
page = alloc_pages(GFP_NOWAIT, get_order(MISALIGNED_BUFFER_SIZE));
if (!page) {
pr_warn("Can't alloc pages to measure memcpy performance");