[PATCH v3 4/8] RISC-V: Check Zicclsm to set unaligned access speed

[Jesse Taube <jesse@rivosinc.com>]

Check for Zicclsm before checking for unaligned access speed. This will
greatly reduce the boot up time as finding the access speed is no longer
necessary.

Signed-off-by: Jesse Taube <jesse@rivosinc.com>
---
V2 -> V3:
 - New patch split from previous patch
---
 arch/riscv/kernel/unaligned_access_speed.c | 26 ++++++++++++++--------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/arch/riscv/kernel/unaligned_access_speed.c b/arch/riscv/kernel/unaligned_access_speed.c
index a9a6bcb02acf..329fd289b5c8 100644
--- a/arch/riscv/kernel/unaligned_access_speed.c
+++ b/arch/riscv/kernel/unaligned_access_speed.c
@@ -259,23 +259,31 @@ static int check_unaligned_access_speed_all_cpus(void)
 	kfree(bufs);
 	return 0;
 }
+#else /* CONFIG_RISCV_PROBE_UNALIGNED_ACCESS */
+static int check_unaligned_access_speed_all_cpus(void)
+{
+	return 0;
+}
+#endif
 
 static int check_unaligned_access_all_cpus(void)
 {
-	bool all_cpus_emulated = check_unaligned_access_emulated_all_cpus();
+	bool all_cpus_emulated;
+	int cpu;
+
+	if (riscv_has_extension_unlikely(RISCV_ISA_EXT_ZICCLSM)) {
+		for_each_online_cpu(cpu) {
+			per_cpu(misaligned_access_speed, cpu) = RISCV_HWPROBE_MISALIGNED_FAST;
+		}
+		return 0;
+	}
+
+	all_cpus_emulated = check_unaligned_access_emulated_all_cpus();
 
 	if (!all_cpus_emulated)
 		return check_unaligned_access_speed_all_cpus();
 
 	return 0;
 }
-#else /* CONFIG_RISCV_PROBE_UNALIGNED_ACCESS */
-static int check_unaligned_access_all_cpus(void)
-{
-	check_unaligned_access_emulated_all_cpus();
-
-	return 0;
-}
-#endif
 
 arch_initcall(check_unaligned_access_all_cpus);
-- 
2.45.2


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