[PATCH v2] powerpc/dt_cpu_ftrs: Avoid separate strlen() in scan_callback()

[Thorsten Blum <thorsten.blum@linux.dev>]

Check only the first byte instead of scanning the entire string with
strlen().  While at it, keep dt_cpu_name static, but move it into
dt_cpu_ftrs_scan_callback(), where it is assigned.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
Changes in v2:
- Check only the first byte since strscpy() copies empty strings (David)
- v1: https://lore.kernel.org/lkml/20260630154657.693088-2-thorsten.blum@linux.dev/
---
 arch/powerpc/kernel/dt_cpu_ftrs.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c
index 3af6c06af02f..4f0799c8daa9 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -90,8 +90,6 @@ static void __restore_cpu_cpufeatures(void)
 		init_pmu_registers();
 }
 
-static char dt_cpu_name[64];
-
 static struct cpu_spec __initdata base_cpu_spec = {
 	.cpu_name		= NULL,
 	.cpu_features		= CPU_FTRS_DT_CPU_BASE,
@@ -1069,6 +1067,7 @@ static int __init count_cpufeatures_subnodes(unsigned long node,
 static int __init dt_cpu_ftrs_scan_callback(unsigned long node, const char
 					    *uname, int depth, void *data)
 {
+	static char dt_cpu_name[64];
 	const __be32 *prop;
 	int count, i;
 	u32 isa;
@@ -1106,8 +1105,8 @@ static int __init dt_cpu_ftrs_scan_callback(unsigned long node, const char
 	}
 
 	prop = of_get_flat_dt_prop(node, "display-name", NULL);
-	if (prop && strlen((char *)prop) != 0) {
-		strscpy(dt_cpu_name, (char *)prop, sizeof(dt_cpu_name));
+	if (prop && *(char *)prop != 0) {
+		strscpy(dt_cpu_name, (char *)prop);
 		cur_cpu_spec->cpu_name = dt_cpu_name;
 	}