kernel-fxtec-pro1x/arch/x86/kernel/apic/x2apic_cluster.c
Suresh Siddha d872818dbb x86/apic/x2apic: Use multiple cluster members for the irq destination only with the explicit affinity
During boot or driver load etc, interrupt destination is setup
using default target cpu's. Later the user (irqbalance etc) or
the driver (irq_set_affinity/ irq_set_affinity_hint) can request
the interrupt to be migrated to some specific set of cpu's.

In the x2apic cluster routing, for the default scenario use
single cpu as the interrupt destination and when there is an
explicit interrupt affinity request, route the interrupt to
multiple members of a x2apic cluster specified in the cpumask of
the migration request.

This will minmize the vector pressure when there are lot of
interrupt sources and relatively few x2apic clusters (for
example a single socket server). This will allow the performance
critical interrupts to be routed to multiple cpu's in the x2apic
cluster (irqbalance for example uses the cache siblings etc
while specifying the interrupt destination) and allow
non-critical interrupts to be serviced by a single logical cpu.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Alexander Gordeev <agordeev@redhat.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Link: http://lkml.kernel.org/r/1340656709-11423-4-git-send-email-suresh.b.siddha@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-07-06 11:00:23 +02:00

296 lines
7.5 KiB
C

#include <linux/threads.h>
#include <linux/cpumask.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/dmar.h>
#include <linux/cpu.h>
#include <asm/smp.h>
#include <asm/x2apic.h>
static DEFINE_PER_CPU(u32, x86_cpu_to_logical_apicid);
static DEFINE_PER_CPU(cpumask_var_t, cpus_in_cluster);
static DEFINE_PER_CPU(cpumask_var_t, ipi_mask);
static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
return x2apic_enabled();
}
static inline u32 x2apic_cluster(int cpu)
{
return per_cpu(x86_cpu_to_logical_apicid, cpu) >> 16;
}
static void
__x2apic_send_IPI_mask(const struct cpumask *mask, int vector, int apic_dest)
{
struct cpumask *cpus_in_cluster_ptr;
struct cpumask *ipi_mask_ptr;
unsigned int cpu, this_cpu;
unsigned long flags;
u32 dest;
x2apic_wrmsr_fence();
local_irq_save(flags);
this_cpu = smp_processor_id();
/*
* We are to modify mask, so we need an own copy
* and be sure it's manipulated with irq off.
*/
ipi_mask_ptr = __raw_get_cpu_var(ipi_mask);
cpumask_copy(ipi_mask_ptr, mask);
/*
* The idea is to send one IPI per cluster.
*/
for_each_cpu(cpu, ipi_mask_ptr) {
unsigned long i;
cpus_in_cluster_ptr = per_cpu(cpus_in_cluster, cpu);
dest = 0;
/* Collect cpus in cluster. */
for_each_cpu_and(i, ipi_mask_ptr, cpus_in_cluster_ptr) {
if (apic_dest == APIC_DEST_ALLINC || i != this_cpu)
dest |= per_cpu(x86_cpu_to_logical_apicid, i);
}
if (!dest)
continue;
__x2apic_send_IPI_dest(dest, vector, apic->dest_logical);
/*
* Cluster sibling cpus should be discared now so
* we would not send IPI them second time.
*/
cpumask_andnot(ipi_mask_ptr, ipi_mask_ptr, cpus_in_cluster_ptr);
}
local_irq_restore(flags);
}
static void x2apic_send_IPI_mask(const struct cpumask *mask, int vector)
{
__x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLINC);
}
static void
x2apic_send_IPI_mask_allbutself(const struct cpumask *mask, int vector)
{
__x2apic_send_IPI_mask(mask, vector, APIC_DEST_ALLBUT);
}
static void x2apic_send_IPI_allbutself(int vector)
{
__x2apic_send_IPI_mask(cpu_online_mask, vector, APIC_DEST_ALLBUT);
}
static void x2apic_send_IPI_all(int vector)
{
__x2apic_send_IPI_mask(cpu_online_mask, vector, APIC_DEST_ALLINC);
}
static int
x2apic_cpu_mask_to_apicid_and(const struct cpumask *cpumask,
const struct cpumask *andmask,
unsigned int *apicid)
{
u32 dest = 0;
u16 cluster;
int i;
for_each_cpu_and(i, cpumask, andmask) {
if (!cpumask_test_cpu(i, cpu_online_mask))
continue;
dest = per_cpu(x86_cpu_to_logical_apicid, i);
cluster = x2apic_cluster(i);
break;
}
if (!dest)
return -EINVAL;
for_each_cpu_and(i, cpumask, andmask) {
if (!cpumask_test_cpu(i, cpu_online_mask))
continue;
if (cluster != x2apic_cluster(i))
continue;
dest |= per_cpu(x86_cpu_to_logical_apicid, i);
}
*apicid = dest;
return 0;
}
static void init_x2apic_ldr(void)
{
unsigned int this_cpu = smp_processor_id();
unsigned int cpu;
per_cpu(x86_cpu_to_logical_apicid, this_cpu) = apic_read(APIC_LDR);
__cpu_set(this_cpu, per_cpu(cpus_in_cluster, this_cpu));
for_each_online_cpu(cpu) {
if (x2apic_cluster(this_cpu) != x2apic_cluster(cpu))
continue;
__cpu_set(this_cpu, per_cpu(cpus_in_cluster, cpu));
__cpu_set(cpu, per_cpu(cpus_in_cluster, this_cpu));
}
}
/*
* At CPU state changes, update the x2apic cluster sibling info.
*/
static int __cpuinit
update_clusterinfo(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
unsigned int this_cpu = (unsigned long)hcpu;
unsigned int cpu;
int err = 0;
switch (action) {
case CPU_UP_PREPARE:
if (!zalloc_cpumask_var(&per_cpu(cpus_in_cluster, this_cpu),
GFP_KERNEL)) {
err = -ENOMEM;
} else if (!zalloc_cpumask_var(&per_cpu(ipi_mask, this_cpu),
GFP_KERNEL)) {
free_cpumask_var(per_cpu(cpus_in_cluster, this_cpu));
err = -ENOMEM;
}
break;
case CPU_UP_CANCELED:
case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
for_each_online_cpu(cpu) {
if (x2apic_cluster(this_cpu) != x2apic_cluster(cpu))
continue;
__cpu_clear(this_cpu, per_cpu(cpus_in_cluster, cpu));
__cpu_clear(cpu, per_cpu(cpus_in_cluster, this_cpu));
}
free_cpumask_var(per_cpu(cpus_in_cluster, this_cpu));
free_cpumask_var(per_cpu(ipi_mask, this_cpu));
break;
}
return notifier_from_errno(err);
}
static struct notifier_block __refdata x2apic_cpu_notifier = {
.notifier_call = update_clusterinfo,
};
static int x2apic_init_cpu_notifier(void)
{
int cpu = smp_processor_id();
zalloc_cpumask_var(&per_cpu(cpus_in_cluster, cpu), GFP_KERNEL);
zalloc_cpumask_var(&per_cpu(ipi_mask, cpu), GFP_KERNEL);
BUG_ON(!per_cpu(cpus_in_cluster, cpu) || !per_cpu(ipi_mask, cpu));
__cpu_set(cpu, per_cpu(cpus_in_cluster, cpu));
register_hotcpu_notifier(&x2apic_cpu_notifier);
return 1;
}
static int x2apic_cluster_probe(void)
{
if (x2apic_mode)
return x2apic_init_cpu_notifier();
else
return 0;
}
static const struct cpumask *x2apic_cluster_target_cpus(void)
{
return cpu_all_mask;
}
/*
* Each x2apic cluster is an allocation domain.
*/
static void cluster_vector_allocation_domain(int cpu, struct cpumask *retmask,
const struct cpumask *mask)
{
/*
* To minimize vector pressure, default case of boot, device bringup
* etc will use a single cpu for the interrupt destination.
*
* On explicit migration requests coming from irqbalance etc,
* interrupts will be routed to the x2apic cluster (cluster-id
* derived from the first cpu in the mask) members specified
* in the mask.
*/
if (mask == x2apic_cluster_target_cpus())
cpumask_copy(retmask, cpumask_of(cpu));
else
cpumask_and(retmask, mask, per_cpu(cpus_in_cluster, cpu));
}
static struct apic apic_x2apic_cluster = {
.name = "cluster x2apic",
.probe = x2apic_cluster_probe,
.acpi_madt_oem_check = x2apic_acpi_madt_oem_check,
.apic_id_valid = x2apic_apic_id_valid,
.apic_id_registered = x2apic_apic_id_registered,
.irq_delivery_mode = dest_LowestPrio,
.irq_dest_mode = 1, /* logical */
.target_cpus = x2apic_cluster_target_cpus,
.disable_esr = 0,
.dest_logical = APIC_DEST_LOGICAL,
.check_apicid_used = NULL,
.check_apicid_present = NULL,
.vector_allocation_domain = cluster_vector_allocation_domain,
.init_apic_ldr = init_x2apic_ldr,
.ioapic_phys_id_map = NULL,
.setup_apic_routing = NULL,
.multi_timer_check = NULL,
.cpu_present_to_apicid = default_cpu_present_to_apicid,
.apicid_to_cpu_present = NULL,
.setup_portio_remap = NULL,
.check_phys_apicid_present = default_check_phys_apicid_present,
.enable_apic_mode = NULL,
.phys_pkg_id = x2apic_phys_pkg_id,
.mps_oem_check = NULL,
.get_apic_id = x2apic_get_apic_id,
.set_apic_id = x2apic_set_apic_id,
.apic_id_mask = 0xFFFFFFFFu,
.cpu_mask_to_apicid_and = x2apic_cpu_mask_to_apicid_and,
.send_IPI_mask = x2apic_send_IPI_mask,
.send_IPI_mask_allbutself = x2apic_send_IPI_mask_allbutself,
.send_IPI_allbutself = x2apic_send_IPI_allbutself,
.send_IPI_all = x2apic_send_IPI_all,
.send_IPI_self = x2apic_send_IPI_self,
.trampoline_phys_low = DEFAULT_TRAMPOLINE_PHYS_LOW,
.trampoline_phys_high = DEFAULT_TRAMPOLINE_PHYS_HIGH,
.wait_for_init_deassert = NULL,
.smp_callin_clear_local_apic = NULL,
.inquire_remote_apic = NULL,
.read = native_apic_msr_read,
.write = native_apic_msr_write,
.eoi_write = native_apic_msr_eoi_write,
.icr_read = native_x2apic_icr_read,
.icr_write = native_x2apic_icr_write,
.wait_icr_idle = native_x2apic_wait_icr_idle,
.safe_wait_icr_idle = native_safe_x2apic_wait_icr_idle,
};
apic_driver(apic_x2apic_cluster);