x86/ioapic: Make io_apic_get_unique_id() simpler

No need to go through APIC callbacks. It's already established that this is
an ancient APIC. So just copy the present mask and use the direct physid*
functions all over the place.

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/20240212154639.119261725@linutronix.de

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index a4219b9c0f91bd52489701ef0ec488b915a669d2..8dc91d075b6bf74a670954275ab08dd0f9d9ddb6 100644 (file)
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2498,17 +2498,9 @@ static int io_apic_get_unique_id(int ioapic, int apic_id)
        unsigned long flags;
        int i = 0;
 
-       /*
-        * The P4 platform supports up to 256 APIC IDs on two separate APIC
-        * buses (one for LAPICs, one for IOAPICs), where predecessors only
-        * supports up to 16 on one shared APIC bus.
-        *
-        * TBD: Expand LAPIC/IOAPIC support on P4-class systems to take full
-        *      advantage of new APIC bus architecture.
-        */
-
+       /* Initialize the ID map */
        if (physids_empty(apic_id_map))
-               apic->ioapic_phys_id_map(&phys_cpu_present_map, &apic_id_map);
+               apic_id_map = phys_cpu_present_map;
 
        raw_spin_lock_irqsave(&ioapic_lock, flags);
        reg_00.raw = io_apic_read(ioapic, 0);
@@ -2520,14 +2512,10 @@ static int io_apic_get_unique_id(int ioapic, int apic_id)
                apic_id = reg_00.bits.ID;
        }
 
-       /*
-        * Every APIC in a system must have a unique ID or we get lots of nice
-        * 'stuck on smp_invalidate_needed IPI wait' messages.
-        */
-       if (apic->check_apicid_used(&apic_id_map, apic_id)) {
-
+       /* Every APIC in a system must have a unique ID */
+       if (physid_isset(apic_id, apic_id_map)) {
                for (i = 0; i < broadcast_id; i++) {
-                       if (!apic->check_apicid_used(&apic_id_map, i))
+                       if (!physid_isset(i, apic_id_map))
                                break;
                }