linux-toradex.git/arch/x86, branch v4.2.1

ACPI, PCI: Penalize legacy IRQ used by ACPI SCI

2015-09-21T17:10:58+00:00

commit 5d0ddfebb93069061880fc57ee4ba7246bd1e1ee upstream.

Nick Meier reported a regression with HyperV that "
  After rebooting the VM, the following messages are logged in syslog
  when trying to load the tulip driver:
    tulip: Linux Tulip drivers version 1.1.15 (Feb 27, 2007)
    tulip: 0000:00:0a.0: PCI INT A: failed to register GSI
    tulip: Cannot enable tulip board #0, aborting
    tulip: probe of 0000:00:0a.0 failed with error -16
  Errors occur in 3.19.0 kernel
  Works in 3.17 kernel.
"

According to the ACPI dump file posted by Nick at
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1440072

The ACPI MADT table includes an interrupt source overridden entry for
ACPI SCI:
[236h 0566  1]                Subtable Type : 02 
[237h 0567  1]                       Length : 0A
[238h 0568  1]                          Bus : 00
[239h 0569  1]                       Source : 09
[23Ah 0570  4]                    Interrupt : 00000009
[23Eh 0574  2]        Flags (decoded below) : 000D
                                   Polarity : 1
                               Trigger Mode : 3

And in DSDT table, we have _PRT method to define PCI interrupts, which
eventually goes to:
        Name (PRSA, ResourceTemplate ()
        {
            IRQ (Level, ActiveLow, Shared, )
                {3,4,5,7,9,10,11,12,14,15}
        })
        Name (PRSB, ResourceTemplate ()
        {
            IRQ (Level, ActiveLow, Shared, )
                {3,4,5,7,9,10,11,12,14,15}
        })
        Name (PRSC, ResourceTemplate ()
        {
            IRQ (Level, ActiveLow, Shared, )
                {3,4,5,7,9,10,11,12,14,15}
        })
        Name (PRSD, ResourceTemplate ()
        {
            IRQ (Level, ActiveLow, Shared, )
                {3,4,5,7,9,10,11,12,14,15}
        })

According to the MADT and DSDT tables, IRQ 9 may be used for:
 1) ACPI SCI in level, high mode
 2) PCI legacy IRQ in level, low mode
So there's a conflict in polarity setting for IRQ 9.

Prior to commit cd68f6bd53cf ("x86, irq, acpi: Get rid of special
handling of GSI for ACPI SCI"), ACPI SCI is handled specially and
there's no check for conflicts between ACPI SCI and PCI legagy IRQ.
And it seems that the HyperV hypervisor doesn't make use of the
polarity configuration in IOAPIC entry, so it just works.

Commit cd68f6bd53cf gets rid of the specially handling of ACPI SCI,
and then the pin attribute checking code discloses the conflicts
between ACPI SCI and PCI legacy IRQ on HyperV virtual machine,
and rejects the request to assign IRQ9 to PCI devices.

So penalize legacy IRQ used by ACPI SCI and mark it unusable if ACPI
SCI attributes conflict with PCI IRQ attributes.

Please refer to following links for more information:
https://bugzilla.kernel.org/show_bug.cgi?id=101301
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1440072

Fixes: cd68f6bd53cf ("x86, irq, acpi: Get rid of special handling of GSI for ACPI SCI")
Reported-and-tested-by: Nick Meier 
Acked-by: Thomas Gleixner 
Signed-off-by: Jiang Liu 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

x86/mce: Reenable CMCI banks when swiching back to interrupt mode

2015-09-21T17:10:57+00:00

commit 1b48465500611a2dc5e75800c61ac352e22d41c3 upstream.

Zhang Liguang reported the following issue:

1) System detects a CMCI storm on the current CPU.

2) Kernel disables the CMCI interrupt on banks owned by the
   current CPU and switches to poll mode

3) After the CMCI storm subsides, kernel switches back to
   interrupt mode

4) We expect the system to reenable the CMCI interrupt on banks
   owned by the current CPU

   mce_intel_adjust_timer
   |-> cmci_reenable
       |-> cmci_discover     # owned banks are ignored here

  static void cmci_discover(int banks)
	...
	for (i = 0; i < banks; i++) {
		...
		if (test_bit(i, owned))	# ownd banks is ignore here
			continue;

So convert cmci_storm_disable_banks() to
cmci_toggle_interrupt_mode() which controls whether to enable or
disable CMCI interrupts with its argument.

NB: We cannot clear the owned bit because the banks won't be
polled, otherwise. See:

  27f6c573e0f7 ("x86, CMCI: Add proper detection of end of CMCI storms")

for more info.

Reported-by: Zhang Liguang 
Signed-off-by: Xie XiuQi 
Signed-off-by: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: huawei.libin@huawei.com
Cc: linux-edac 
Cc: rui.xiang@huawei.com
Link: http://lkml.kernel.org/r/1439396985-12812-10-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

KVM: MMU: fix validation of mmio page fault

2015-09-21T17:10:55+00:00

commit 6f691251c0350ac52a007c54bf3ef62e9d8cdc5e upstream.

We got the bug that qemu complained with "KVM: unknown exit, hardware
reason 31" and KVM shown these info:
[84245.284948] EPT: Misconfiguration.
[84245.285056] EPT: GPA: 0xfeda848
[84245.285154] ept_misconfig_inspect_spte: spte 0x5eaef50107 level 4
[84245.285344] ept_misconfig_inspect_spte: spte 0x5f5fadc107 level 3
[84245.285532] ept_misconfig_inspect_spte: spte 0x5141d18107 level 2
[84245.285723] ept_misconfig_inspect_spte: spte 0x52e40dad77 level 1

This is because we got a mmio #PF and the handler see the mmio spte becomes
normal (points to the ram page)

However, this is valid after introducing fast mmio spte invalidation which
increases the generation-number instead of zapping mmio sptes, a example
is as follows:
1. QEMU drops mmio region by adding a new memslot
2. invalidate all mmio sptes
3.

        VCPU 0                        VCPU 1
    access the invalid mmio spte
                            access the region originally was MMIO before
                            set the spte to the normal ram map

    mmio #PF
    check the spte and see it becomes normal ram mapping !!!

This patch fixes the bug just by dropping the check in mmio handler, it's
good for backport. Full check will be introduced in later patches

Reported-by: Pavel Shirshov 
Tested-by: Pavel Shirshov 
Signed-off-by: Xiao Guangrong 
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

crypto: ghash-clmulni: specify context size for ghash async algorithm

2015-09-21T17:10:55+00:00

commit 71c6da846be478a61556717ef1ee1cea91f5d6a8 upstream.

Currently context size (cra_ctxsize) doesn't specified for
ghash_async_alg. Which means it's zero. Thus crypto_create_tfm()
doesn't allocate needed space for ghash_async_ctx, so any
read/write to ctx (e.g. in ghash_async_init_tfm()) is not valid.

Signed-off-by: Andrey Ryabinin 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

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

2015-08-25T16:01:05+00:00

Pull x86 fix from Thomas Gleixner:
 "A single fix for a APIC regression introduced in 4.0 which went
  undetected until now.

  I screwed up the x2apic cleanup in a subtle way.  The screwup is only
  visible on systems which have x2apic preenabled in the BIOS and need
  to disable it during boot"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic: Fix fallout from x2apic cleanup

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

2015-08-22T15:15:36+00:00

Pull x86 fixes from Ingo Molnar:
 "Various low level fixes: fix more fallout from the FPU rework and the
  asm entry code rework, plus an MSI rework fix, and an idle-tracing fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu/math-emu: Fix crash in fork()
  x86/fpu/math-emu: Fix math-emu boot crash
  x86/idle: Restore trace_cpu_idle to mwait_idle() calls
  x86/irq: Build correct vector mapping for multiple MSI interrupts
  Revert "sched/x86_64: Don't save flags on context switch"

x86/apic: Fix fallout from x2apic cleanup

2015-08-22T15:01:48+00:00

In the recent x2apic cleanup I got two things really wrong:
1) The safety check in __disable_x2apic which allows the function to
   be called unconditionally is backwards. The check is there to
   prevent access to the apic MSR in case that the machine has no
   apic. Though right now it returns if the machine has an apic and
   therefor the disabling of x2apic is never invoked.

2) x2apic_disable() sets x2apic_mode to 0 after registering the local
   apic. That's wrong, because register_lapic_address() checks x2apic
   mode and therefor takes the wrong code path.

This results in boot failures on machines with x2apic preenabled by
BIOS and can also lead to an fatal MSR access on machines without
apic.

The solutions are simple:
1) Correct the sanity check for apic availability
2) Clear x2apic_mode _before_ calling register_lapic_address()

Fixes: 659006bf3ae3 'x86/x2apic: Split enable and setup function'
Reported-and-tested-by: Javier Monteagudo 
Signed-off-by: Thomas Gleixner 
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1224764
Cc: stable@vger.kernel.org # 4.0+
Cc: Laura Abbott 
Cc: Jiang Liu 
Cc: Joerg Roedel 
Cc: Tony Luck 
Cc: Borislav Petkov

x86/fpu/math-emu: Fix crash in fork()

2015-08-22T08:23:03+00:00

During later stages of math-emu bootup the following crash triggers:

	 math_emulate: 0060:c100d0a8
	 Kernel panic - not syncing: Math emulation needed in kernel
	 CPU: 0 PID: 1511 Comm: login Not tainted 4.2.0-rc7+ #1012
	 [...]
	 Call Trace:
	  [] dump_stack+0x41/0x52
	  [] panic+0x77/0x189
	  [] ? math_error+0x140/0x140
	  [] math_emulate+0xba7/0xbd0
	  [] ? fpu__copy+0x138/0x1c0
	  [] ? __alloc_pages_nodemask+0x12c/0x870
	  [] ? proc_clear_tty+0x40/0x70
	  [] ? session_clear_tty+0x1e/0x30
	  [] ? math_error+0x140/0x140
	  [] do_device_not_available+0x45/0x70
	  [] ? fpu__copy+0x138/0x1c0
	  [] error_code+0x5a/0x60
	  [] ? math_error+0x140/0x140
	  [] ? fpu__copy+0x138/0x1c0
	  [] arch_dup_task_struct+0x25/0x30
	  [] copy_process.part.51+0xea/0x1480
	  [] ? dput+0x175/0x200
	  [] ? no_tty+0x30/0x30
	  [] ? do_vfs_ioctl+0x322/0x540
	  [] _do_fork+0xca/0x340
	  [] ? SyS_rt_sigaction+0x66/0x90
	  [] SyS_clone+0x27/0x30
	  [] sysenter_do_call+0x12/0x12

The reason is the incorrect assumption in fpu_copy(), that FNSAVE
can be executed from math-emu kernels as well.

Don't try to copy the registers, the soft state will be copied
by fork anyway, so the child task inherits the parent task's
soft math state.

With this fix applied math-emu kernels boot up fine on modern
hardware and the 'no387 nofxsr' boot options.

Cc: Andy Lutomirski 
Cc: Bobby Powers 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Denys Vlasenko 
Cc: Fenghua Yu 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Quentin Casasnovas 
Cc: Thomas Gleixner 
Signed-off-by: Ingo Molnar

x86/fpu/math-emu: Fix math-emu boot crash

2015-08-22T08:02:04+00:00

On a math-emu bootup the following crash occurs:

	Initializing CPU#0
	------------[ cut here ]------------
	kernel BUG at arch/x86/kernel/traps.c:779!
	invalid opcode: 0000 [#1] SMP
	[...]
	EIP is at do_device_not_available+0xe/0x70
	[...]
	Call Trace:
	 [] error_code+0x5a/0x60
	 [] ? math_error+0x140/0x140
	 [] ? fpu__init_cpu+0x59/0xa0
	 [] cpu_init+0x202/0x330
	 [] ? __native_set_fixmap+0x1f/0x30
	 [] trap_init+0x305/0x346
	 [] start_kernel+0x1a5/0x35d
	 [] i386_start_kernel+0x82/0x86

The reason is that in the following commit:

  b1276c48e91b ("x86/fpu: Initialize fpregs in fpu__init_cpu_generic()")

I failed to consider math-emu's limitation that it cannot execute the
FNINIT instruction in kernel mode.

The long term fix might be to allow math-emu to execute (certain) kernel
mode FPU instructions, but for now apply the safe (albeit somewhat ugly)
fix: initialize the emulation state explicitly without trapping out to
the FPU emulator.

Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Denys Vlasenko 
Cc: Fenghua Yu 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Quentin Casasnovas 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

x86/idle: Restore trace_cpu_idle to mwait_idle() calls

2015-08-20T19:37:45+00:00

Commit b253149b843f ("sched/idle/x86: Restore mwait_idle() to fix boot
hangs, to improve power savings and to improve performance") restores
mwait_idle(), but the trace_cpu_idle related calls are missing. This
causes powertop on my old desktop powered by Intel Core2 E6550 to
report zero wakeups and zero events.

Add them back to restore the proper behaviour.

Fixes: b253149b843f ("sched/idle/x86: Restore mwait_idle() to ...")
Signed-off-by: Jisheng Zhang 
Cc: 
Cc: stable@vger.kernel.org # 4.1
Link: http://lkml.kernel.org/r/1440046479-4262-1-git-send-email-jszhang@marvell.com
Signed-off-by: Thomas Gleixner