Commit edd96522 authored by Andi Kleen's avatar Andi Kleen Committed by Andi Kleen
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[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: default avatarAndi Kleen <ak@suse.de>
parent 606bd58d

arch/x86_64/kernel/io_apic.c

+0 −71
Original line number Diff line number Diff line
@@ -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();

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