https://github.com/torvalds/linux
Tip revision: 5dd34572ad9a3be430632dd42e4af2ea370b397b authored by Linus Torvalds on 12 June 2008, 21:22:24 UTC
Linux 2.6.26-rc6
Linux 2.6.26-rc6
Tip revision: 5dd3457
ipi.c
#include <linux/cpumask.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/kernel_stat.h>
#include <linux/mc146818rtc.h>
#include <linux/cache.h>
#include <linux/interrupt.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <asm/smp.h>
#include <asm/mtrr.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
#include <asm/apic.h>
#include <asm/proto.h>
#ifdef CONFIG_X86_32
#include <mach_apic.h>
/*
* the following functions deal with sending IPIs between CPUs.
*
* We use 'broadcast', CPU->CPU IPIs and self-IPIs too.
*/
static inline int __prepare_ICR(unsigned int shortcut, int vector)
{
unsigned int icr = shortcut | APIC_DEST_LOGICAL;
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);
}
void __send_IPI_shortcut(unsigned int shortcut, int vector)
{
/*
* 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);
/*
* Send the IPI. The write to APIC_ICR fires this off.
*/
apic_write_around(APIC_ICR, cfg);
}
void send_IPI_self(int vector)
{
__send_IPI_shortcut(APIC_DEST_SELF, vector);
}
/*
* 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 long mask, int vector)
{
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_around(APIC_ICR2, cfg);
/*
* program the ICR
*/
cfg = __prepare_ICR(0, vector);
/*
* Send the IPI. The write to APIC_ICR fires this off.
*/
apic_write_around(APIC_ICR, cfg);
}
/*
* This is only used on smaller machines.
*/
void send_IPI_mask_bitmask(cpumask_t cpumask, int vector)
{
unsigned long mask = cpus_addr(cpumask)[0];
unsigned long flags;
local_irq_save(flags);
WARN_ON(mask & ~cpus_addr(cpu_online_map)[0]);
__send_IPI_dest_field(mask, vector);
local_irq_restore(flags);
}
void send_IPI_mask_sequence(cpumask_t mask, int vector)
{
unsigned long flags;
unsigned int query_cpu;
/*
* Hack. The clustered APIC addressing mode doesn't allow us to send
* to an arbitrary mask, so I do a unicasts to each CPU instead. This
* should be modified to do 1 message per cluster ID - mbligh
*/
local_irq_save(flags);
for_each_possible_cpu(query_cpu) {
if (cpu_isset(query_cpu, mask)) {
__send_IPI_dest_field(cpu_to_logical_apicid(query_cpu),
vector);
}
}
local_irq_restore(flags);
}
/* must come after the send_IPI functions above for inlining */
#include <mach_ipi.h>
static int convert_apicid_to_cpu(int apic_id)
{
int i;
for_each_possible_cpu(i) {
if (per_cpu(x86_cpu_to_apicid, i) == apic_id)
return i;
}
return -1;
}
int safe_smp_processor_id(void)
{
int apicid, cpuid;
if (!boot_cpu_has(X86_FEATURE_APIC))
return 0;
apicid = hard_smp_processor_id();
if (apicid == BAD_APICID)
return 0;
cpuid = convert_apicid_to_cpu(apicid);
return cpuid >= 0 ? cpuid : 0;
}
#endif