diff options
authorStoney Wang2013-02-07 12:53:02 -0600
committerGreg Kroah-Hartman2013-03-03 16:09:06 -0600
commit2212f47b734e5b9461b5c3f555dc653ea7aa212f (patch)
parentf39edfbf6dbf8e29cfbafd67d93fa1e30196701c (diff)
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>
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 f5373dfde21..db4f70492ea 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)
20} 20}
21early_param("x2apic_phys", set_x2apic_phys_mode); 21early_param("x2apic_phys", set_x2apic_phys_mode);
22 22
23static bool x2apic_fadt_phys(void)
25 if ((acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) &&
26 (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) {
27 printk(KERN_DEBUG "System requires x2apic physical mode\n");
28 return true;
29 }
30 return false;
23static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id) 33static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
24{ 34{
25 if (x2apic_phys) 35 return x2apic_enabled() && (x2apic_phys || x2apic_fadt_phys());
26 return x2apic_enabled();
27 else
28 return 0;
29} 36}
30 37
31static void 38static void
@@ -108,7 +115,7 @@ static void init_x2apic_ldr(void)
108 115
109static int x2apic_phys_probe(void) 116static int x2apic_phys_probe(void)
110{ 117{
111 if (x2apic_mode && x2apic_phys) 118 if (x2apic_mode && (x2apic_phys || x2apic_fadt_phys()))
112 return 1; 119 return 1;
113 120
114 return apic == &apic_x2apic_phys; 121 return apic == &apic_x2apic_phys;