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authorStoney Wang <song-bo.wang@hp.com>2013-02-07 10:53:02 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-03-04 06:09:06 +0800
commit2212f47b734e5b9461b5c3f555dc653ea7aa212f (patch)
treeac08eafb2474aaf6d29154d4a3dc7bdeb301099f /arch
parentf39edfbf6dbf8e29cfbafd67d93fa1e30196701c (diff)
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x86/apic: Work around boot failure on HP ProLiant DL980 G7 Server systems
commit cb214ede7657db458fd0b2a25ea0b28dbf900ebc upstream. 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> Signed-off-by: Zhang Lin-Bao <Linbao.zhang@hp.com> [ make a patch specially for 3.0.66] Link: http://lkml.kernel.org/r/1360263182-16226-1-git-send-email-yinghai@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/apic/x2apic_phys.c17
1 files changed, 12 insertions, 5 deletions
diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c
index f5373dfde21e..db4f70492ea7 100644
--- a/arch/x86/kernel/apic/x2apic_phys.c
+++ b/arch/x86/kernel/apic/x2apic_phys.c
@@ -20,12 +20,19 @@ static int set_x2apic_phys_mode(char *arg)
}
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)
{
- if (x2apic_phys)
- return x2apic_enabled();
- else
- return 0;
+ return x2apic_enabled() && (x2apic_phys || x2apic_fadt_phys());
}
static void
@@ -108,7 +115,7 @@ 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;