Messages in this thread Patch in this message | | | From | Yinghai Lu <> | Subject | [PATCH] x86, apic: Check fadt x2apic phys in x2apic_phys_probe() | Date | Mon, 4 Feb 2013 12:29:27 -0800 |
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From: Stoney Wang <song-bo.wang@hp.com>
When HP ProLiant DL980 G7 Server boot without x2apic_phys, there will be intermittent lost interrupts and could result in a hang or data loss.
Those systems only work with x2apic phys mode so BIOS set ACPI_FADT_APIC_PHYSICAL in FADT table. Also because all apicids are less then 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:
When user specify x2apic_phys, or FADT indicates PHYSICAL. During madt oem check, apic driver is set with xapic logical or xapic phys driver at first. Later enable_IR_x2apic() will enable x2apic_mode. After that, x2apic_phys_probe() will install right x2apic phys driver if user specify x2apic_phys, but will skip and let x2apic_cluster_probe to take over to install wrong apic driver (x2apic cluster) when 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.
-v3: update the change according to Ingo.
[ changelog, and simplify code - Yinghai Lu ] Signed-off-by: Stoney Wang <song-bo.wang@hp.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: stable@kernel.org
--- arch/x86/kernel/apic/x2apic_phys.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-)
Index: linux-2.6/arch/x86/kernel/apic/x2apic_phys.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/apic/x2apic_phys.c +++ linux-2.6/arch/x86/kernel/apic/x2apic_phys.c @@ -20,18 +20,19 @@ static int set_x2apic_phys_mode(char *ar } early_param("x2apic_phys", set_x2apic_phys_mode); -static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id) +static bool x2apic_fadt_phys(void) { - if (x2apic_phys) - return x2apic_enabled(); - else if ((acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) && - (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL) && - x2apic_enabled()) { + 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 1; + return true; } - else - return 0; + 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 @@ -82,7 +83,7 @@ static void init_x2apic_ldr(void) static int x2apic_phys_probe(void) { - if (x2apic_mode && x2apic_phys) + if (x2apic_mode && (x2apic_phys || x2apic_fadt_phys())) return 1; return apic == &apic_x2apic_phys;
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