linux/arch/x86/kernel/apic/x2apic_phys.c
Suresh Siddha ce4e240c27 x86: add x2apic_wrmsr_fence() to x2apic flush tlb paths
Impact: optimize APIC IPI related barriers

Uncached MMIO accesses for xapic are inherently serializing and hence
we don't need explicit barriers for xapic IPI paths.

x2apic MSR writes/reads don't have serializing semantics and hence need
a serializing instruction or mfence, to make all the previous memory
stores globally visisble before the x2apic msr write for IPI.

Add x2apic_wrmsr_fence() in flush tlb path to x2apic specific paths.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "steiner@sgi.com" <steiner@sgi.com>
Cc: Nick Piggin <npiggin@suse.de>
LKML-Reference: <1237313814.27006.203.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-18 09:36:14 +01:00

235 lines
5.3 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 <asm/smp.h>
#include <asm/apic.h>
#include <asm/ipi.h>
int x2apic_phys;
static int set_x2apic_phys_mode(char *arg)
{
x2apic_phys = 1;
return 0;
}
early_param("x2apic_phys", set_x2apic_phys_mode);
static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
if (x2apic_phys)
return x2apic_enabled();
else
return 0;
}
/* Start with all IRQs pointing to boot CPU. IRQ balancing will shift them. */
static const struct cpumask *x2apic_target_cpus(void)
{
return cpumask_of(0);
}
static void x2apic_vector_allocation_domain(int cpu, struct cpumask *retmask)
{
cpumask_clear(retmask);
cpumask_set_cpu(cpu, retmask);
}
static void __x2apic_send_IPI_dest(unsigned int apicid, int vector,
unsigned int dest)
{
unsigned long cfg;
cfg = __prepare_ICR(0, vector, dest);
/*
* send the IPI.
*/
native_x2apic_icr_write(cfg, apicid);
}
static void x2apic_send_IPI_mask(const struct cpumask *mask, int vector)
{
unsigned long query_cpu;
unsigned long flags;
x2apic_wrmsr_fence();
local_irq_save(flags);
for_each_cpu(query_cpu, mask) {
__x2apic_send_IPI_dest(per_cpu(x86_cpu_to_apicid, query_cpu),
vector, APIC_DEST_PHYSICAL);
}
local_irq_restore(flags);
}
static void
x2apic_send_IPI_mask_allbutself(const struct cpumask *mask, int vector)
{
unsigned long this_cpu = smp_processor_id();
unsigned long query_cpu;
unsigned long flags;
x2apic_wrmsr_fence();
local_irq_save(flags);
for_each_cpu(query_cpu, mask) {
if (query_cpu != this_cpu)
__x2apic_send_IPI_dest(
per_cpu(x86_cpu_to_apicid, query_cpu),
vector, APIC_DEST_PHYSICAL);
}
local_irq_restore(flags);
}
static void x2apic_send_IPI_allbutself(int vector)
{
unsigned long this_cpu = smp_processor_id();
unsigned long query_cpu;
unsigned long flags;
x2apic_wrmsr_fence();
local_irq_save(flags);
for_each_online_cpu(query_cpu) {
if (query_cpu == this_cpu)
continue;
__x2apic_send_IPI_dest(per_cpu(x86_cpu_to_apicid, query_cpu),
vector, APIC_DEST_PHYSICAL);
}
local_irq_restore(flags);
}
static void x2apic_send_IPI_all(int vector)
{
x2apic_send_IPI_mask(cpu_online_mask, vector);
}
static int x2apic_apic_id_registered(void)
{
return 1;
}
static unsigned int x2apic_cpu_mask_to_apicid(const struct cpumask *cpumask)
{
/*
* We're using fixed IRQ delivery, can only return one phys 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_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 phys APIC ID.
* May as well be the first.
*/
for_each_cpu_and(cpu, cpumask, andmask) {
if (cpumask_test_cpu(cpu, cpu_online_mask))
break;
}
if (cpu < nr_cpu_ids)
return per_cpu(x86_cpu_to_apicid, cpu);
return BAD_APICID;
}
static unsigned int x2apic_phys_get_apic_id(unsigned long x)
{
return x;
}
static unsigned long set_apic_id(unsigned int id)
{
return id;
}
static int x2apic_phys_pkg_id(int initial_apicid, int index_msb)
{
return current_cpu_data.initial_apicid >> index_msb;
}
static void x2apic_send_IPI_self(int vector)
{
apic_write(APIC_SELF_IPI, vector);
}
static void init_x2apic_ldr(void)
{
}
struct apic apic_x2apic_phys = {
.name = "physical x2apic",
.probe = NULL,
.acpi_madt_oem_check = x2apic_acpi_madt_oem_check,
.apic_id_registered = x2apic_apic_id_registered,
.irq_delivery_mode = dest_Fixed,
.irq_dest_mode = 0, /* physical */
.target_cpus = x2apic_target_cpus,
.disable_esr = 0,
.dest_logical = 0,
.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,
.apicid_to_node = NULL,
.cpu_to_logical_apicid = 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_phys_get_apic_id,
.set_apic_id = 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,
.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,
};