[PATCH] x86_64: Remove unique APIC/IO-APIC ID check

It is unnecessary on modern Intel or AMD systems, and that is all we support
on x86-64

Also causes problems on various systems

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 1 insertions, 72 deletions

diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index 60be58617eb..ac768432495 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -1804,76 +1804,6 @@ device_initcall(ioapic_init_sysfs);
 
 #define IO_APIC_MAX_ID          0xFE
 
-int __init io_apic_get_unique_id (int ioapic, int apic_id)
-{
-        union IO_APIC_reg_00 reg_00;
-        static physid_mask_t apic_id_map;
-        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.
-         */
-
-        if (physids_empty(apic_id_map))
-                apic_id_map = phys_cpu_present_map;
-
-        spin_lock_irqsave(&ioapic_lock, flags);
-        reg_00.raw = io_apic_read(ioapic, 0);
-        spin_unlock_irqrestore(&ioapic_lock, flags);
-
-        if (apic_id >= IO_APIC_MAX_ID) {
-                apic_printk(APIC_QUIET, KERN_WARNING "IOAPIC[%d]: Invalid apic_id %d, trying "
-                        "%d\n", ioapic, apic_id, reg_00.bits.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 (physid_isset(apic_id, apic_id_map)) {
-
-                for (i = 0; i < IO_APIC_MAX_ID; i++) {
-                        if (!physid_isset(i, apic_id_map))
-                                break;
-                }
-
-                if (i == IO_APIC_MAX_ID)
-                        panic("Max apic_id exceeded!\n");
-
-                apic_printk(APIC_VERBOSE, KERN_WARNING "IOAPIC[%d]: apic_id %d already used, "
-                        "trying %d\n", ioapic, apic_id, i);
-
-                apic_id = i;
-        } 
-
-        physid_set(apic_id, apic_id_map);
-
-        if (reg_00.bits.ID != apic_id) {
-                reg_00.bits.ID = apic_id;
-
-                spin_lock_irqsave(&ioapic_lock, flags);
-                io_apic_write(ioapic, 0, reg_00.raw);
-                reg_00.raw = io_apic_read(ioapic, 0);
-                spin_unlock_irqrestore(&ioapic_lock, flags);
-
-                /* Sanity check */
-                if (reg_00.bits.ID != apic_id)
-                        panic("IOAPIC[%d]: Unable change apic_id!\n", ioapic);
-        }
-
-        apic_printk(APIC_VERBOSE,KERN_INFO "IOAPIC[%d]: Assigned apic_id %d\n", ioapic, apic_id);
-
-        return apic_id;
-}
-
-
 int __init io_apic_get_version (int ioapic)
 {
         union IO_APIC_reg_01    reg_01;
diff --git a/arch/x86_64/kernel/mpparse.c b/arch/x86_64/kernel/mpparse.c
index 7ec031c6ca1..f221231cd0a 100644
--- a/arch/x86_64/kernel/mpparse.c
+++ b/arch/x86_64/kernel/mpparse.c
@@ -759,7 +759,7 @@ void __init mp_register_ioapic (
         mp_ioapics[idx].mpc_apicaddr = address;
 
         set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address);
-        mp_ioapics[idx].mpc_apicid = io_apic_get_unique_id(idx, id);
+        mp_ioapics[idx].mpc_apicid = id;
         mp_ioapics[idx].mpc_apicver = io_apic_get_version(idx);
         
         /* 
diff --git a/include/asm-x86_64/io_apic.h b/include/asm-x86_64/io_apic.h
index 7efc932e8f0..32573749004 100644
--- a/include/asm-x86_64/io_apic.h
+++ b/include/asm-x86_64/io_apic.h
@@ -202,7 +202,6 @@ extern int skip_ioapic_setup;
 #define io_apic_assign_pci_irqs (mp_irq_entries && !skip_ioapic_setup && io_apic_irqs)
 
 #ifdef CONFIG_ACPI_BOOT
-extern int io_apic_get_unique_id (int ioapic, int apic_id);
 extern int io_apic_get_version (int ioapic);
 extern int io_apic_get_redir_entries (int ioapic);
 extern int io_apic_set_pci_routing (int ioapic, int pin, int irq, int, int);