[PATCH] Remove MPS table APIC renumbering

The MPS table specification says that the operating system should
renumber the IO-APICs following the table as needed.  However in
ACPI this is not allowed or neeeded and all x86-64 systems are ACPI
compliant.

The code was already disabled on some systems because it caused
problems there. Remove it completely now.

CC: mdomsch@dell.com
Signed-off-by: Andi Kleen <ak@suse.de>

diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index 1ccf1b4..a02ed17 100644 (file)
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -1282,72 +1282,6 @@ void disable_IO_APIC(void)
        disconnect_bsp_APIC(ioapic_i8259.pin != -1);
 }
 
-/*
- * function to set the IO-APIC physical IDs based on the
- * values stored in the MPC table.
- *
- * by Matt Domsch <Matt_Domsch@dell.com>  Tue Dec 21 12:25:05 CST 1999
- */
-
-static void __init setup_ioapic_ids_from_mpc (void)
-{
-       union IO_APIC_reg_00 reg_00;
-       int apic;
-       int i;
-       unsigned char old_id;
-       unsigned long flags;
-
-       /*
-        * Set the IOAPIC ID to the value stored in the MPC table.
-        */
-       for (apic = 0; apic < nr_ioapics; apic++) {
-
-               /* Read the register 0 value */
-               spin_lock_irqsave(&ioapic_lock, flags);
-               reg_00.raw = io_apic_read(apic, 0);
-               spin_unlock_irqrestore(&ioapic_lock, flags);
-               
-               old_id = mp_ioapics[apic].mpc_apicid;
-
-
-               printk(KERN_INFO "Using IO-APIC %d\n", mp_ioapics[apic].mpc_apicid);
-
-
-               /*
-                * We need to adjust the IRQ routing table
-                * if the ID changed.
-                */
-               if (old_id != mp_ioapics[apic].mpc_apicid)
-                       for (i = 0; i < mp_irq_entries; i++)
-                               if (mp_irqs[i].mpc_dstapic == old_id)
-                                       mp_irqs[i].mpc_dstapic
-                                               = mp_ioapics[apic].mpc_apicid;
-
-               /*
-                * Read the right value from the MPC table and
-                * write it into the ID register.
-                */
-               apic_printk(APIC_VERBOSE,KERN_INFO "...changing IO-APIC physical APIC ID to %d ...",
-                               mp_ioapics[apic].mpc_apicid);
-
-               reg_00.bits.ID = mp_ioapics[apic].mpc_apicid;
-               spin_lock_irqsave(&ioapic_lock, flags);
-               io_apic_write(apic, 0, reg_00.raw);
-               spin_unlock_irqrestore(&ioapic_lock, flags);
-
-               /*
-                * Sanity check
-                */
-               spin_lock_irqsave(&ioapic_lock, flags);
-               reg_00.raw = io_apic_read(apic, 0);
-               spin_unlock_irqrestore(&ioapic_lock, flags);
-               if (reg_00.bits.ID != mp_ioapics[apic].mpc_apicid)
-                       printk("could not set ID!\n");
-               else
-                       apic_printk(APIC_VERBOSE," ok.\n");
-       }
-}
-
 /*
  * There is a nasty bug in some older SMP boards, their mptable lies
  * about the timer IRQ. We do the following to work around the situation:
@@ -1863,11 +1797,6 @@ void __init setup_IO_APIC(void)
 
        apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n");
 
-       /*
-        * Set up the IO-APIC IRQ routing table.
-        */
-       if (!acpi_ioapic)
-               setup_ioapic_ids_from_mpc();
        sync_Arb_IDs();
        setup_IO_APIC_irqs();
        init_IO_APIC_traps();