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linux-2.6/arch/x86/kernel/apic/x2apic_phys.c
Suresh Siddha 18374d89e5 x86, irq: Allow 0xff for /proc/irq/[n]/smp_affinity on an 8-cpu system
John Blackwood reported:
> on an older Dell PowerEdge 6650 system with 8 cpus (4 are hyper-threaded),
> and  32 bit (x86) kernel, once you change the irq smp_affinity of an irq
> to be less than all cpus in the system, you can never change really the
> irq smp_affinity back to be all cpus in the system (0xff) again,
> even though no error status is returned on the "/bin/echo ff >
> /proc/irq/[n]/smp_affinity" operation.
>
> This is due to that fact that BAD_APICID has the same value as
> all cpus (0xff) on 32bit kernels, and thus the value returned from
> set_desc_affinity() via the cpu_mask_to_apicid_and() function is treated
> as a failure in set_ioapic_affinity_irq_desc(), and no affinity changes
> are made.

set_desc_affinity() is already checking if the incoming cpu mask
intersects with the cpu online mask or not. So there is no need
for the apic op cpu_mask_to_apicid_and() to check again
and return BAD_APICID.

Remove the BAD_APICID return value from cpu_mask_to_apicid_and()
and also fix set_desc_affinity() to return -1 instead of using BAD_APICID
to represent error conditions (as cpu_mask_to_apicid_and() can return
logical or physical apicid values and BAD_APICID is really to represent
bad physical apic id).

Reported-by: John Blackwood <john.blackwood@ccur.com>
Root-caused-by: John Blackwood <john.blackwood@ccur.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1261103386.2535.409.camel@sbs-t61>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-12-17 22:03:06 -08:00

234 lines
5.2 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;
}
/*
* need to use more than cpu 0, because we need more vectors when
* MSI-X are used.
*/
static const struct cpumask *x2apic_target_cpus(void)
{
return cpu_online_mask;
}
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;
}
return per_cpu(x86_cpu_to_apicid, cpu);
}
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 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,
};