71fff5e6ca
This patch converts the x86_cpu_to_apicid array to be a per cpu variable. This saves sizeof(apicid) * NR unused cpus. Access is mostly from startup and CPU HOTPLUG functions. MP_processor_info() is one of the functions that require access to the x86_cpu_to_apicid array before the per_cpu data area is setup. For this case, a pointer to the __initdata array is initialized in setup_arch() and removed in smp_prepare_cpus() after the per_cpu data area is initialized. A second change is included to change the initial array value of ARCH i386 from 0xff to BAD_APICID to be consistent with ARCH x86_64. Signed-off-by: Mike Travis <travis@sgi.com> Cc: Andi Kleen <ak@suse.de> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
74 lines
1.8 KiB
C
74 lines
1.8 KiB
C
/*
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* Copyright 2004 James Cleverdon, IBM.
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* Subject to the GNU Public License, v.2
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*
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* Generic APIC sub-arch probe layer.
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*
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* Hacked for x86-64 by James Cleverdon from i386 architecture code by
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* Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
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* James Cleverdon.
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*/
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#include <linux/threads.h>
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#include <linux/cpumask.h>
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#include <linux/string.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/ctype.h>
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#include <linux/init.h>
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#include <asm/smp.h>
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#include <asm/ipi.h>
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#include <asm/genapic.h>
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#ifdef CONFIG_ACPI
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#include <acpi/acpi_bus.h>
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#endif
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/*
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* which logical CPU number maps to which CPU (physical APIC ID)
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*
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* The following static array is used during kernel startup
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* and the x86_cpu_to_apicid_ptr contains the address of the
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* array during this time. Is it zeroed when the per_cpu
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* data area is removed.
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*/
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u8 x86_cpu_to_apicid_init[NR_CPUS] __initdata
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= { [0 ... NR_CPUS-1] = BAD_APICID };
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void *x86_cpu_to_apicid_ptr;
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DEFINE_PER_CPU(u8, x86_cpu_to_apicid) = BAD_APICID;
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EXPORT_PER_CPU_SYMBOL(x86_cpu_to_apicid);
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struct genapic __read_mostly *genapic = &apic_flat;
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/*
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* Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
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*/
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void __init setup_apic_routing(void)
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{
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#ifdef CONFIG_ACPI
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/*
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* Quirk: some x86_64 machines can only use physical APIC mode
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* regardless of how many processors are present (x86_64 ES7000
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* is an example).
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*/
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if (acpi_gbl_FADT.header.revision > FADT2_REVISION_ID &&
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(acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL))
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genapic = &apic_physflat;
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else
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#endif
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if (cpus_weight(cpu_possible_map) <= 8)
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genapic = &apic_flat;
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else
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genapic = &apic_physflat;
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printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name);
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}
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/* Same for both flat and physical. */
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void send_IPI_self(int vector)
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{
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__send_IPI_shortcut(APIC_DEST_SELF, vector, APIC_DEST_PHYSICAL);
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}
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