linux.git/arch/x86/kernel/apic/vector.c, branch v4.18

x86/apic/vector: Print APIC control bits in debugfs

2018-06-06T13:18:22+00:00

Extend the debugability of the vector management by adding the state bits
to the debugfs output.

Signed-off-by: Thomas Gleixner 
Tested-by: Song Liu 
Cc: Joerg Roedel 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Mike Travis 
Cc: Borislav Petkov 
Cc: Tariq Toukan 
Link: https://lkml.kernel.org/r/20180604162224.908136099@linutronix.de

x86/apic: Provide apic_ack_irq()

2018-06-06T13:18:20+00:00

apic_ack_edge() is explicitely for handling interrupt affinity cleanup when
interrupt remapping is not available or disable.

Remapped interrupts and also some of the platform specific special
interrupts, e.g. UV, invoke ack_APIC_irq() directly.

To address the issue of failing an affinity update with -EBUSY the delayed
affinity mechanism can be reused, but ack_APIC_irq() does not handle
that. Adding this to ack_APIC_irq() is not possible, because that function
is also used for exceptions and directly handled interrupts like IPIs.

Create a new function, which just contains the conditional invocation of
irq_move_irq() and the final ack_APIC_irq().

Reuse the new function in apic_ack_edge().

Preparatory change for the real fix.

Fixes: dccfe3147b42 ("x86/vector: Simplify vector move cleanup")
Signed-off-by: Thomas Gleixner 
Tested-by: Song Liu 
Cc: Joerg Roedel 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: stable@vger.kernel.org
Cc: Mike Travis 
Cc: Borislav Petkov 
Cc: Tariq Toukan 
Link: https://lkml.kernel.org/r/20180604162224.471925894@linutronix.de

x86/apic/vector: Prevent hlist corruption and leaks

2018-06-06T13:18:19+00:00

Several people observed the WARN_ON() in irq_matrix_free() which triggers
when the caller tries to free an vector which is not in the allocation
range. Song provided the trace information which allowed to decode the root
cause.

The rework of the vector allocation mechanism failed to preserve a sanity
check, which prevents setting a new target vector/CPU when the previous
affinity change has not fully completed.

As a result a half finished affinity change can be overwritten, which can
cause the leak of a irq descriptor pointer on the previous target CPU and
double enqueue of the hlist head into the cleanup lists of two or more
CPUs. After one CPU cleaned up its vector the next CPU will invoke the
cleanup handler with vector 0, which triggers the out of range warning in
the matrix allocator.

Prevent this by checking the apic_data of the interrupt whether the
move_in_progress flag is false and the hlist node is not hashed. Return
-EBUSY if not.

This prevents the damage and restores the behaviour before the vector
allocation rework, but due to other changes in that area it also widens the
chance that user space can observe -EBUSY. In theory this should be fine,
but actually not all user space tools handle -EBUSY correctly. Addressing
that is not part of this fix, but will be addressed in follow up patches.

Fixes: 69cde0004a4b ("x86/vector: Use matrix allocator for vector assignment")
Reported-by: Dmitry Safonov <0x7f454c46@gmail.com>
Reported-by: Tariq Toukan 
Reported-by: Song Liu 
Signed-off-by: Thomas Gleixner 
Tested-by: Song Liu 
Cc: Joerg Roedel 
Cc: Peter Zijlstra 
Cc: stable@vger.kernel.org
Cc: Mike Travis 
Cc: Borislav Petkov 
Link: https://lkml.kernel.org/r/20180604162224.303870257@linutronix.de

x86/apic/vector: Handle vector release on CPU unplug correctly

2018-02-23T07:02:00+00:00

When a irq vector is replaced, then the previous vector is normally
released when the first interrupt happens on the new vector. If the target
CPU of the previous vector is already offline when the new vector is
installed, then the previous vector is silently discarded, which leads to
accounting issues causing suspend failures and other problems.

Adjust the logic so that the previous vector is freed in the underlying
matrix allocator to ensure that the accounting stays correct.

Fixes: 69cde0004a4b ("x86/vector: Use matrix allocator for vector assignment")
Reported-by: Yuriy Vostrikov 
Signed-off-by: Thomas Gleixner 
Tested-by: Yuriy Vostrikov 
Cc: Peter Zijlstra 
Cc: Randy Dunlap 
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180222112316.930791749@linutronix.de
Signed-off-by: Ingo Molnar

x86/apic/vector: Fix off by one in error path

2018-01-17T11:11:36+00:00

Keith reported the following warning:

WARNING: CPU: 28 PID: 1420 at kernel/irq/matrix.c:222 irq_matrix_remove_managed+0x10f/0x120
  x86_vector_free_irqs+0xa1/0x180
  x86_vector_alloc_irqs+0x1e4/0x3a0
  msi_domain_alloc+0x62/0x130

The reason for this is that if the vector allocation fails the error
handling code tries to free the failed vector as well, which causes the
above imbalance warning to trigger.

Adjust the error path to handle this correctly.

Fixes: b5dc8e6c21e7 ("x86/irq: Use hierarchical irqdomain to manage CPU interrupt vectors")
Reported-by: Keith Busch 
Signed-off-by: Thomas Gleixner 
Tested-by: Keith Busch 
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801161217300.1823@nanos

genirq/msi, x86/vector: Prevent reservation mode for non maskable MSI

2017-12-29T20:13:05+00:00

The new reservation mode for interrupts assigns a dummy vector when the
interrupt is allocated and assigns a real vector when the interrupt is
requested. The reservation mode prevents vector pressure when devices with
a large amount of queues/interrupts are initialized, but only a minimal
subset of those queues/interrupts is actually used.

This mode has an issue with MSI interrupts which cannot be masked. If the
driver is not careful or the hardware emits an interrupt before the device
irq is requestd by the driver then the interrupt ends up on the dummy
vector as a spurious interrupt which can cause malfunction of the device or
in the worst case a lockup of the machine.

Change the logic for the reservation mode so that the early activation of
MSI interrupts checks whether:

 - the device is a PCI/MSI device
 - the reservation mode of the underlying irqdomain is activated
 - PCI/MSI masking is globally enabled
 - the PCI/MSI device uses either MSI-X, which supports masking, or
   MSI with the maskbit supported.

If one of those conditions is false, then clear the reservation mode flag
in the irq data of the interrupt and invoke irq_domain_activate_irq() with
the reserve argument cleared. In the x86 vector code, clear the can_reserve
flag in the vector allocation data so a subsequent free_irq() won't create
the same situation again. The interrupt stays assigned to a real vector
until pci_disable_msi() is invoked and all allocations are undone.

Fixes: 4900be83602b ("x86/vector/msi: Switch to global reservation mode")
Reported-by: Alexandru Chirvasitu 
Reported-by: Andy Shevchenko 
Signed-off-by: Thomas Gleixner 
Tested-by: Alexandru Chirvasitu 
Tested-by: Andy Shevchenko 
Cc: Dou Liyang 
Cc: Pavel Machek 
Cc: Maciej W. Rozycki 
Cc: Mikael Pettersson 
Cc: Josh Poulson 
Cc: Mihai Costache 
Cc: Stephen Hemminger 
Cc: Marc Zyngier 
Cc: linux-pci@vger.kernel.org
Cc: Haiyang Zhang 
Cc: Dexuan Cui 
Cc: Simon Xiao 
Cc: Saeed Mahameed 
Cc: Jork Loeser 
Cc: Bjorn Helgaas 
Cc: devel@linuxdriverproject.org
Cc: KY Srinivasan 
Cc: Alan Cox 
Cc: Sakari Ailus ,
Cc: linux-media@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712291406420.1899@nanos
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712291409460.1899@nanos

genirq/irqdomain: Rename early argument of irq_domain_activate_irq()

2017-12-29T20:13:04+00:00

The 'early' argument of irq_domain_activate_irq() is actually used to
denote reservation mode. To avoid confusion, rename it before abuse
happens.

No functional change.

Fixes: 72491643469a ("genirq/irqdomain: Update irq_domain_ops.activate() signature")
Signed-off-by: Thomas Gleixner 
Cc: Alexandru Chirvasitu 
Cc: Andy Shevchenko 
Cc: Dou Liyang 
Cc: Pavel Machek 
Cc: Maciej W. Rozycki 
Cc: Mikael Pettersson 
Cc: Josh Poulson 
Cc: Mihai Costache 
Cc: Stephen Hemminger 
Cc: Marc Zyngier 
Cc: linux-pci@vger.kernel.org
Cc: Haiyang Zhang 
Cc: Dexuan Cui 
Cc: Simon Xiao 
Cc: Saeed Mahameed 
Cc: Jork Loeser 
Cc: Bjorn Helgaas 
Cc: devel@linuxdriverproject.org
Cc: KY Srinivasan 
Cc: Alan Cox 
Cc: Sakari Ailus ,
Cc: linux-media@vger.kernel.org

x86/vector: Use IRQD_CAN_RESERVE flag

2017-12-29T20:13:04+00:00

Set the new CAN_RESERVE flag when the initial reservation for an interrupt
happens. The flag is used in a subsequent patch to disable reservation mode
for a certain class of MSI devices.

Signed-off-by: Thomas Gleixner 
Tested-by: Alexandru Chirvasitu 
Tested-by: Andy Shevchenko 
Cc: Dou Liyang 
Cc: Pavel Machek 
Cc: Maciej W. Rozycki 
Cc: Mikael Pettersson 
Cc: Josh Poulson 
Cc: Mihai Costache 
Cc: Stephen Hemminger 
Cc: Marc Zyngier 
Cc: linux-pci@vger.kernel.org
Cc: Haiyang Zhang 
Cc: Dexuan Cui 
Cc: Simon Xiao 
Cc: Saeed Mahameed 
Cc: Jork Loeser 
Cc: Bjorn Helgaas 
Cc: devel@linuxdriverproject.org
Cc: KY Srinivasan 
Cc: Alan Cox 
Cc: Sakari Ailus ,
Cc: linux-media@vger.kernel.org

x86: Fix Sparse warnings about non-static functions

2017-12-06T18:32:58+00:00

Functions x86_vector_debug_show(), uv_handle_nmi() and uv_nmi_setup_common()
are local to the source and do not need to be in global scope, so make them
static.

Fixes up various sparse warnings.

Signed-off-by: Colin Ian King 
Acked-by: Mike Travis 
Cc: H. Peter Anvin 
Cc: Jiri Kosina 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Russ Anderson 
Cc: Thomas Gleixner 
Cc: kernel-janitors@vger.kernel.org
Cc: travis@sgi.com
Link: http://lkml.kernel.org/r/20171206173358.24388-1-colin.king@canonical.com
Signed-off-by: Ingo Molnar

x86/PCI: Remove unused HyperTransport interrupt support

2017-11-23T19:18:18+00:00

There are no in-tree callers of ht_create_irq(), the driver interface for
HyperTransport interrupts, left.  Remove the unused entry point and all the
supporting code.

See 8b955b0dddb3 ("[PATCH] Initial generic hypertransport interrupt
support").

Signed-off-by: Bjorn Helgaas 
Signed-off-by: Thomas Gleixner 
Acked-by: "Eric W. Biederman" 
Cc: Andi Kleen 
Cc: Greg Kroah-Hartman 
Cc: linux-pci@vger.kernel.org
Cc: Benjamin Herrenschmidt 
Link: https://lkml.kernel.org/r/20171122221337.3877.23362.stgit@bhelgaas-glaptop.roam.corp.google.com