swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 4d856f72c10ecb060868ed10ff1b1453943fc6c8 authored by Linus Torvalds on 15 September 2019, 21:19:32 UTC
Linux 5.3
Linux 5.3
Tip revision: 4d856f7
ipi.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/cpumask.h>
#include <linux/interrupt.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/cpu.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>
#include <asm/ipi.h>
void __default_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.
*/
__xapic_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.
*/
native_apic_mem_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).
*/
void __default_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
__xapic_wait_icr_idle();
/*
* prepare target chip field
*/
cfg = __prepare_ICR2(mask);
native_apic_mem_write(APIC_ICR2, cfg);
/*
* program the ICR
*/
cfg = __prepare_ICR(0, vector, dest);
/*
* Send the IPI. The write to APIC_ICR fires this off.
*/
native_apic_mem_write(APIC_ICR, cfg);
}
void default_send_IPI_single_phys(int cpu, int vector)
{
unsigned long flags;
local_irq_save(flags);
__default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, cpu),
vector, APIC_DEST_PHYSICAL);
local_irq_restore(flags);
}
void default_send_IPI_mask_sequence_phys(const struct cpumask *mask, int vector)
{
unsigned long query_cpu;
unsigned long flags;
/*
* 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(query_cpu, mask) {
__default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid,
query_cpu), vector, APIC_DEST_PHYSICAL);
}
local_irq_restore(flags);
}
void default_send_IPI_mask_allbutself_phys(const struct cpumask *mask,
int vector)
{
unsigned int this_cpu = smp_processor_id();
unsigned int query_cpu;
unsigned long flags;
/* See Hack comment above */
local_irq_save(flags);
for_each_cpu(query_cpu, mask) {
if (query_cpu == this_cpu)
continue;
__default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid,
query_cpu), vector, APIC_DEST_PHYSICAL);
}
local_irq_restore(flags);
}
/*
* Helper function for APICs which insist on cpumasks
*/
void default_send_IPI_single(int cpu, int vector)
{
apic->send_IPI_mask(cpumask_of(cpu), vector);
}
#ifdef CONFIG_X86_32
void default_send_IPI_mask_sequence_logical(const struct cpumask *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_cpu(query_cpu, mask)
__default_send_IPI_dest_field(
early_per_cpu(x86_cpu_to_logical_apicid, query_cpu),
vector, apic->dest_logical);
local_irq_restore(flags);
}
void default_send_IPI_mask_allbutself_logical(const struct cpumask *mask,
int vector)
{
unsigned long flags;
unsigned int query_cpu;
unsigned int this_cpu = smp_processor_id();
/* See Hack comment above */
local_irq_save(flags);
for_each_cpu(query_cpu, mask) {
if (query_cpu == this_cpu)
continue;
__default_send_IPI_dest_field(
early_per_cpu(x86_cpu_to_logical_apicid, query_cpu),
vector, apic->dest_logical);
}
local_irq_restore(flags);
}
/*
* This is only used on smaller machines.
*/
void default_send_IPI_mask_logical(const struct cpumask *cpumask, int vector)
{
unsigned long mask = cpumask_bits(cpumask)[0];
unsigned long flags;
if (!mask)
return;
local_irq_save(flags);
WARN_ON(mask & ~cpumask_bits(cpu_online_mask)[0]);
__default_send_IPI_dest_field(mask, vector, apic->dest_logical);
local_irq_restore(flags);
}
void default_send_IPI_allbutself(int vector)
{
/*
* if there are no other CPUs in the system then we get an APIC send
* error if we try to broadcast, thus avoid sending IPIs in this case.
*/
if (!(num_online_cpus() > 1))
return;
__default_local_send_IPI_allbutself(vector);
}
void default_send_IPI_all(int vector)
{
__default_local_send_IPI_all(vector);
}
void default_send_IPI_self(int vector)
{
__default_send_IPI_shortcut(APIC_DEST_SELF, vector, apic->dest_logical);
}
/* must come after the send_IPI functions above for inlining */
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