linux/arch/x86/kernel/apic, branch v3.5

x86/ioapic: Fix NULL pointer dereference on CPU hotplug after disabling irqs

2012-06-06T10:03:25Z

In current Linux, percpu variable `vector_irq' is not cleared on offlined cpus while disabling devices' irqs. If the cpu that has the disabled irqs in vector_irq is hotplugged, __setup_vector_irq() hits invalid irq vector and may crash. This bug can be reproduced as following; # echo 0 > /sys/devices/system/cpu/cpu7/online # modprobe -r some_driver_using_interrupts # vector_irq@cpu7 uncleared # echo 1 > /sys/devices/system/cpu/cpu7/online # kernel may crash This patch fixes this bug by clearing vector_irq in __clear_irq_vector() even if the cpu is offlined. Signed-off-by: Tomoki Sekiyama Acked-by: Thomas Gleixner Cc: yrl.pp-manager.tt@hitachi.com Cc: ltc-kernel@ml.yrl.intra.hitachi.co.jp Cc: Suresh Siddha Cc: Yinghai Lu Cc: Alexander Gordeev Link: http://lkml.kernel.org/r/4FC340BE.7080101@hitachi.com Signed-off-by: Ingo Molnar

Merge branch 'delete-mca' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2012-05-24T00:12:06Z

Pull the MCA deletion branch from Paul Gortmaker: "It was good that we could support MCA machines back in the day, but realistically, nobody is using them anymore. They were mostly limited to 386-sx 16MHz CPU and some 486 class machines and never more than 64MB of RAM. Even the enthusiast hobbyist community seems to have dried up close to ten years ago, based on what you can find searching various websites dedicated to the relatively short lived hardware. So lets remove the support relating to CONFIG_MCA. There is no point carrying this forward, wasting cycles doing routine maintenance on it; wasting allyesconfig build time on validating it, wasting I/O on git grep'ping over it, and so on." Let's see if anybody screams. It generally has compiled, and James Bottomley pointed out that there was a MCA extension from NCR that allowed for up to 4GB of memory and PPro-class machines. So in *theory* there may be users out there. But even James (technically listed as a maintainer) doesn't actually have a system, and while Alan Cox claims to have a machine in his cellar that he offered to anybody who wants to take it off his hands, he didn't argue for keeping MCA support either. So we could bring it back. But somebody had better speak up and talk about how they have actually been using said MCA hardware with modern kernels for us to do that. And David already took the patch to delete all the networking driver code (commit a5e371f61ad3: "drivers/net: delete all code/drivers depending on CONFIG_MCA"). * 'delete-mca' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: MCA: delete all remaining traces of microchannel bus support. scsi: delete the MCA specific drivers and driver code serial: delete the MCA specific 8250 support. arm: remove ability to select CONFIG_MCA

Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2012-05-23T01:38:11Z

Pull x86/apic changes from Ingo Molnar: "Most of the changes are about helping virtualized guest kernels achieve better performance." Fix up trivial conflicts with the iommu updates to arch/x86/kernel/apic/io_apic.c * 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/apic: Implement EIO micro-optimization x86/apic: Add apic->eoi_write() callback x86/apic: Use symbolic APIC_EOI_ACK x86/apic: Fix typo EIO_ACK -> EOI_ACK and document it x86/xen/apic: Add missing #include x86/apic: Only compile local function if used with !CONFIG_GENERIC_PENDING_IRQ x86/apic: Fix UP boot crash x86: Conditionally update time when ack-ing pending irqs xen/apic: implement io apic read with hypercall Revert "xen/x86: Workaround 'x86/ioapic: Add register level checks to detect bogus io-apic entries'" xen/x86: Implement x86_apic_ops x86/apic: Replace io_apic_ops with x86_io_apic_ops.

x86/apic: Implement EIO micro-optimization

2012-05-18T07:46:09Z

We know both register and value for eoi beforehand, so there's no need to check it and no need to do math to calculate the msr. Saves instructions/branches on each EOI when using x2apic. I looked at the objdump output to verify that the generated code looks right and actually is shorter. The real improvemements will be on the KVM guest side though, those come in a later patch. Signed-off-by: Michael S. Tsirkin Cc: Avi Kivity Cc: Marcelo Tosatti Cc: gleb@redhat.com Cc: Linus Torvalds Link: http://lkml.kernel.org/r/e019d1a125316f10d3e3a4b2f6bda41473f4fb72.1337184153.git.mst@redhat.com Signed-off-by: Ingo Molnar

x86/apic: Add apic->eoi_write() callback

2012-05-18T07:46:08Z

Add eoi_write callback so that kvm can override eoi accesses without touching the rest of the apic. As a side-effect, this will enable a micro-optimization for apics using msr. Signed-off-by: Michael S. Tsirkin Cc: Avi Kivity Cc: Marcelo Tosatti Cc: gleb@redhat.com Cc: Linus Torvalds Link: http://lkml.kernel.org/r/0df425d746c49ac2ecc405174df87752869629d2.1337184153.git.mst@redhat.com [ tidied it up a bit ] Signed-off-by: Ingo Molnar

MCA: delete all remaining traces of microchannel bus support.

2012-05-17T23:06:13Z

Hardware with MCA bus is limited to 386 and 486 class machines that are now 20+ years old and typically with less than 32MB of memory. A quick search on the internet, and you see that even the MCA hobbyist/enthusiast community has lost interest in the early 2000 era and never really even moved ahead from the 2.4 kernels to the 2.6 series. This deletes anything remaining related to CONFIG_MCA from core kernel code and from the x86 architecture. There is no point in carrying this any further into the future. One complication to watch for is inadvertently scooping up stuff relating to machine check, since there is overlap in the TLA name space (e.g. arch/x86/boot/mca.c). Cc: Thomas Gleixner Cc: James Bottomley Cc: x86@kernel.org Acked-by: Ingo Molnar Acked-by: H. Peter Anvin Signed-off-by: Paul Gortmaker

x86/apic: Only compile local function if used with !CONFIG_GENERIC_PENDING_IRQ

2012-05-08T09:23:15Z

The local function io_apic_level_ack_pending() is only called from io_apic_level_ack_pending(). The later function is only compiled if CONFIG_GENERIC_PENDING_IRQ is defined. Move the io_apic_level_ack_pending() to the existing #ifdef CONFIG_GENERIC_PENDING_IRQ code block. This will remove the following warning message during compiling without CONFIG_GENERIC_PENDING_IRQ defined: * arch/x86/kernel/apic/io_apic.c:382: warning: ‘io_apic_level_ack_pending’ defined but not used Signed-off-by: Márton Németh Signed-off-by: Suresh Siddha Cc: Yinghai Lu Cc: Naga Chumbalkar Link: http://lkml.kernel.org/r/1336461860.2296.3.camel@sbsiddha-mobl2 Signed-off-by: Ingo Molnar

x86: Conditionally update time when ack-ing pending irqs

2012-05-07T14:25:28Z

On virtual environments, apic_read could take a long time. As a result, under certain conditions the ack pending loop may exit without any queued irqs left, but after more than one second. A warning will be printed needlessly in this case. If the loop is about to exit regardless of max_loops, don't update it. Signed-off-by: Shai Fultheim [ rebased and reworded the commit message] Signed-off-by: Ido Yariv Acked-by: Thomas Gleixner Link: http://lkml.kernel.org/r/1334873552-31346-1-git-send-email-ido@wizery.com Signed-off-by: Ingo Molnar

iommu: rename intr_remapping.[ch] to irq_remapping.[ch]

2012-05-07T12:35:00Z

Make the file names consistent with the naming conventions of irq subsystem. Signed-off-by: Suresh Siddha Cc: Joerg Roedel Cc: Yinghai Lu Cc: David Woodhouse Cc: Alex Williamson Signed-off-by: Joerg Roedel

iommu: rename intr_remapping references to irq_remapping

2012-05-07T12:35:00Z

Make the code consistent with the naming conventions of irq subsystem. Signed-off-by: Suresh Siddha Cc: Joerg Roedel Cc: Yinghai Lu Cc: David Woodhouse Cc: Alex Williamson Signed-off-by: Joerg Roedel