linux_dsm_epyc7002/arch/x86/kernel/apic/x2apic_phys.c
Stoney Wang cb214ede76 x86/apic: Work around boot failure on HP ProLiant DL980 G7 Server systems
When a HP ProLiant DL980 G7 Server boots a regular kernel,
there will be intermittent lost interrupts which could
result in a hang or (in extreme cases) data loss.

The reason is that this system only supports x2apic physical
mode, while the kernel boots with a logical-cluster default
setting.

This bug can be worked around by specifying the "x2apic_phys" or
"nox2apic" boot option, but we want to handle this system
without requiring manual workarounds.

The BIOS sets ACPI_FADT_APIC_PHYSICAL in FADT table.
As all apicids are smaller than 255, BIOS need to pass the
control to the OS with xapic mode, according to x2apic-spec,
chapter 2.9.

Current code handle x2apic when BIOS pass with xapic mode
enabled:

When user specifies x2apic_phys, or FADT indicates PHYSICAL:

1. During madt oem check, apic driver is set with xapic logical
   or xapic phys driver at first.

2. enable_IR_x2apic() will enable x2apic_mode.

3. if user specifies x2apic_phys on the boot line, x2apic_phys_probe()
   will install the correct x2apic phys driver and use x2apic phys mode.
   Otherwise it will skip the driver will let x2apic_cluster_probe to
   take over to install x2apic cluster driver (wrong one) even though FADT
   indicates PHYSICAL, because x2apic_phys_probe does not check
   FADT PHYSICAL.

Add checking x2apic_fadt_phys in x2apic_phys_probe() to fix the
problem.

Signed-off-by: Stoney Wang <song-bo.wang@hp.com>
[ updated the changelog and simplified the code ]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: stable@kernel.org
Link: http://lkml.kernel.org/r/1360263182-16226-1-git-send-email-yinghai@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-02-11 11:13:00 +01:00

151 lines
3.8 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/x2apic.h>
int x2apic_phys;
static struct apic apic_x2apic_phys;
static int set_x2apic_phys_mode(char *arg)
{
x2apic_phys = 1;
return 0;
}
early_param("x2apic_phys", set_x2apic_phys_mode);
static bool x2apic_fadt_phys(void)
{
if ((acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) &&
(acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) {
printk(KERN_DEBUG "System requires x2apic physical mode\n");
return true;
}
return false;
}
static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
return x2apic_enabled() && (x2apic_phys || x2apic_fadt_phys());
}
static void
__x2apic_send_IPI_mask(const struct cpumask *mask, int vector, int apic_dest)
{
unsigned long query_cpu;
unsigned long this_cpu;
unsigned long flags;
x2apic_wrmsr_fence();
local_irq_save(flags);
this_cpu = smp_processor_id();
for_each_cpu(query_cpu, mask) {
if (apic_dest == APIC_DEST_ALLBUT && this_cpu == query_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_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 void init_x2apic_ldr(void)
{
}
static int x2apic_phys_probe(void)
{
if (x2apic_mode && (x2apic_phys || x2apic_fadt_phys()))
return 1;
return apic == &apic_x2apic_phys;
}
static struct apic apic_x2apic_phys = {
.name = "physical x2apic",
.probe = x2apic_phys_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_Fixed,
.irq_dest_mode = 0, /* physical */
.target_cpus = online_target_cpus,
.disable_esr = 0,
.dest_logical = 0,
.check_apicid_used = NULL,
.check_apicid_present = NULL,
.vector_allocation_domain = default_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 = default_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_phys);