kernel-fxtec-pro1x/arch/x86/kernel/apic/x2apic_cluster.c
Michael S. Tsirkin 0ab711ae6a x86/apic: Implement EIO micro-optimization
We know both register and value for eoi beforehand,
so there's no need to check it and no need to do math
to calculate the msr. Saves instructions/branches
on each EOI when using x2apic.

I looked at the objdump output to verify that the
generated code looks right and actually is shorter.

The real improvemements will be on the KVM guest side
though, those come in a later patch.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: gleb@redhat.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/e019d1a125316f10d3e3a4b2f6bda41473f4fb72.1337184153.git.mst@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-18 09:46:09 +02:00

270 lines
6.9 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 unsigned int x2apic_cpu_mask_to_apicid(const struct cpumask *cpumask)
{
/*
* We're using fixed IRQ delivery, can only return one logical APIC ID.
* May as well be the first.
*/
int cpu = cpumask_first(cpumask);
if ((unsigned)cpu < nr_cpu_ids)
return per_cpu(x86_cpu_to_logical_apicid, cpu);
else
return BAD_APICID;
}
static unsigned int
x2apic_cpu_mask_to_apicid_and(const struct cpumask *cpumask,
const struct cpumask *andmask)
{
int cpu;
/*
* We're using fixed IRQ delivery, can only return one logical APIC ID.
* May as well be the first.
*/
for_each_cpu_and(cpu, cpumask, andmask) {
if (cpumask_test_cpu(cpu, cpu_online_mask))
break;
}
return per_cpu(x86_cpu_to_logical_apicid, cpu);
}
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 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_target_cpus,
.disable_esr = 0,
.dest_logical = APIC_DEST_LOGICAL,
.check_apicid_used = NULL,
.check_apicid_present = NULL,
.vector_allocation_domain = x2apic_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 = x2apic_cpu_mask_to_apicid,
.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);