This is a note to let you know that I've just added the patch titled
x86/apic: Work around boot failure on HP ProLiant DL980 G7 Server systems
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-apic-work-around-boot-failure-on-hp-proliant-dl980-g7-server-systems.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cb214ede7657db458fd0b2a25ea0b28dbf900ebc Mon Sep 17 00:00:00 2001
From: Stoney Wang <song-bo.wang@xxxxxx>
Date: Thu, 7 Feb 2013 10:53:02 -0800
Subject: x86/apic: Work around boot failure on HP ProLiant DL980 G7 Server systems
From: Stoney Wang <song-bo.wang@xxxxxx>
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@xxxxxx>
[ updated the changelog and simplified the code ]
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Signed-off-by: Zhang Lin-Bao <Linbao.zhang@xxxxxx>
[ make a patch specially for 3.0.66]
Link: http://lkml.kernel.org/r/1360263182-16226-1-git-send-email-yinghai@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/apic/x2apic_phys.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
--- 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 *ar
}
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;
Patches currently in stable-queue which might be from song-bo.wang@xxxxxx are
queue-3.0/x86-apic-work-around-boot-failure-on-hp-proliant-dl980-g7-server-systems.patch
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