x86/smpboot: Make error message actually useful

"smpboot: native_kick_ap: bad cpu 33" is absolutely useless information.

Replace it with something meaningful which allows to decode the failure
condition.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.170806023@linutronix.de

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index bfb99b5c56061cdb9d267192207ef83a15e1a289..d850faca946d177649547768604b96240428a6a9 100644 (file)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1072,9 +1072,13 @@ int native_kick_ap(unsigned int cpu, struct task_struct *tidle)
 
        pr_debug("++++++++++++++++++++=_---CPU UP  %u\n", cpu);
 
-       if (apicid == BAD_APICID || !test_bit(apicid, phys_cpu_present_map) ||
-           !apic_id_valid(apicid)) {
-               pr_err("%s: bad cpu %d\n", __func__, cpu);
+       if (apicid == BAD_APICID || !apic_id_valid(apicid)) {
+               pr_err("CPU %u has invalid APIC ID %x. Aborting bringup\n", cpu, apicid);
+               return -EINVAL;
+       }
+
+       if (!test_bit(apicid, phys_cpu_present_map)) {
+               pr_err("CPU %u APIC ID %x is not present. Aborting bringup\n", cpu, apicid);
                return -EINVAL;
        }