Messages in this thread Patch in this message | | | From | "Zhang, Lin-Bao (Linux Kernel R&D)" <> | Subject | [ stable-3.0] x86/apic: Work around boot failure on HP ProLiant DL980 G7 Server systems | Date | Fri, 22 Feb 2013 11:04:42 +0000 |
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Hi Greg, I am very pleased to see this patch has been put into 3.8,3.7.9,and 3.4.4. thanks for your works. Do you have any plan to put it into stable-3.0.y version ? and other mainline ,such as 3.1.x,3.2.x,3.3.x ,etc. afterwards ? I see 3.0.66 is just released 8 hours ago, but without this patch. I guess maybe you are hard working on backporting this patch to 3.0.
certainly ,3.0 is too old, but fortunately, I basicly review some key parts ,for example ,variables , acpi_gbl_FADT don't change through these versions. So I feel that 3.0 is very suitable to apply this patch. I tested 2.6.32 and 3.0 ,they all have this issue(cluster by default). I did a patch for 3.0.66 just like original patch, I delete the same contents to save words. Hopefully this will save your time to merge.
diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c index f5373df..0f8cb3a 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; -- 1.7.9
-- Bob(LinBao Zhang) HP linux kernel enginner
> -----Original Message----- > From: Greg Kroah-Hartman [mailto:gregkh@linuxfoundation.org] > Sent: 2013年2月16日 6:56 > To: linux-kernel@vger.kernel.org > Cc: Greg Kroah-Hartman; stable@vger.kernel.org; Wang, Song-Bo (Stoney); > Yinghai Lu; Ingo Molnar > Subject: [ 3/8] x86/apic: Work around boot failure on HP ProLiant DL980 G7 > Server systems > > 3.4-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Stoney Wang <song-bo.wang@hp.com> > > 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> > 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> > > --- > arch/x86/kernel/apic/x2apic_phys.c | 21 +++++++++++---------- > 1 file changed, 11 insertions(+), 10 deletions(-) > > --- a/arch/x86/kernel/apic/x2apic_phys.c > +++ b/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 > @@ -114,7 +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; >
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