[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>

1 files changed, 0 insertions, 71 deletions

diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index 1ccf1b41c3ed..a02ed17d05dc 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -1283,72 +1283,6 @@ void disable_IO_APIC(void)
 }
 
 /*
- * 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();