linux-hardened/include/asm-x86/ipi.h
Mike Travis 71fff5e6ca x86: convert cpu_to_apicid to be a per cpu variable
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>
2007-10-19 20:35:03 +02:00

128 lines
2.7 KiB
C

#ifndef __ASM_IPI_H
#define __ASM_IPI_H
/*
* Copyright 2004 James Cleverdon, IBM.
* Subject to the GNU Public License, v.2
*
* Generic APIC InterProcessor Interrupt code.
*
* Moved to include file by James Cleverdon from
* arch/x86-64/kernel/smp.c
*
* Copyrights from kernel/smp.c:
*
* (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
* (c) 1998-99, 2000 Ingo Molnar <mingo@redhat.com>
* (c) 2002,2003 Andi Kleen, SuSE Labs.
* Subject to the GNU Public License, v.2
*/
#include <asm/hw_irq.h>
#include <asm/apic.h>
/*
* the following functions deal with sending IPIs between CPUs.
*
* We use 'broadcast', CPU->CPU IPIs and self-IPIs too.
*/
static inline unsigned int __prepare_ICR (unsigned int shortcut, int vector, unsigned int dest)
{
unsigned int icr = shortcut | dest;
switch (vector) {
default:
icr |= APIC_DM_FIXED | vector;
break;
case NMI_VECTOR:
icr |= APIC_DM_NMI;
break;
}
return icr;
}
static inline int __prepare_ICR2 (unsigned int mask)
{
return SET_APIC_DEST_FIELD(mask);
}
static inline void __send_IPI_shortcut(unsigned int shortcut, int vector, unsigned int dest)
{
/*
* Subtle. In the case of the 'never do double writes' workaround
* we have to lock out interrupts to be safe. As we don't care
* of the value read we use an atomic rmw access to avoid costly
* cli/sti. Otherwise we use an even cheaper single atomic write
* to the APIC.
*/
unsigned int cfg;
/*
* Wait for idle.
*/
apic_wait_icr_idle();
/*
* No need to touch the target chip field
*/
cfg = __prepare_ICR(shortcut, vector, dest);
/*
* Send the IPI. The write to APIC_ICR fires this off.
*/
apic_write(APIC_ICR, cfg);
}
/*
* This is used to send an IPI with no shorthand notation (the destination is
* specified in bits 56 to 63 of the ICR).
*/
static inline void __send_IPI_dest_field(unsigned int mask, int vector, unsigned int dest)
{
unsigned long cfg;
/*
* Wait for idle.
*/
if (unlikely(vector == NMI_VECTOR))
safe_apic_wait_icr_idle();
else
apic_wait_icr_idle();
/*
* prepare target chip field
*/
cfg = __prepare_ICR2(mask);
apic_write(APIC_ICR2, cfg);
/*
* program the ICR
*/
cfg = __prepare_ICR(0, vector, dest);
/*
* Send the IPI. The write to APIC_ICR fires this off.
*/
apic_write(APIC_ICR, cfg);
}
static inline void send_IPI_mask_sequence(cpumask_t mask, int vector)
{
unsigned long flags;
unsigned long query_cpu;
/*
* Hack. The clustered APIC addressing mode doesn't allow us to send
* to an arbitrary mask, so I do a unicast to each CPU instead.
* - mbligh
*/
local_irq_save(flags);
for_each_cpu_mask(query_cpu, mask) {
__send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, query_cpu),
vector, APIC_DEST_PHYSICAL);
}
local_irq_restore(flags);
}
#endif /* __ASM_IPI_H */