linux-toradex.git/arch/x86/kernel/apic/vector.c, branch v4.2.7

x86/irq: Probe for PIC presence before allocating descs for legacy IRQs

2015-12-09T19:31:13+00:00

commit 8c058b0b9c34d8c8d7912880956543769323e2d8 upstream.

Commit d32932d02e18 ("x86/irq: Convert IOAPIC to use hierarchical irqdomain
interfaces") brought a regression for Hyper-V Gen2 instances. These
instances don't have i8259 legacy PIC but they use legacy IRQs for serial
port, rtc, and acpi. With this commit included we end up with these IRQs
not initialized. Earlier, there was a special workaround for legacy IRQs
in mp_map_pin_to_irq() doing mp_irqdomain_map() without looking at
nr_legacy_irqs() and now we fail in __irq_domain_alloc_irqs() when
irq_domain_alloc_descs() returns -EEXIST.

The essence of the issue seems to be that early_irq_init() calls
arch_probe_nr_irqs() to figure out the number of legacy IRQs before
we probe for i8259 and gets 16. Later when init_8259A() is called we switch
to NULL legacy PIC and nr_legacy_irqs() starts to return 0 but we already
have 16 descs allocated.

Solve the issue by separating i8259 probe from init and calling it in
arch_probe_nr_irqs() before we actually use nr_legacy_irqs() information.

Fixes: d32932d02e18 ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces")
Signed-off-by: Vitaly Kuznetsov 
Cc: Jiang Liu 
Cc: K. Y. Srinivasan 
Link: http://lkml.kernel.org/r/1446543614-3621-1-git-send-email-vkuznets@redhat.com
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

x86/irq: Build correct vector mapping for multiple MSI interrupts

2015-08-18T16:18:55+00:00

Alex Deucher, Mark Rustad and Alexander Holler reported a regression
with the latest v4.2-rc4 kernel, which breaks some SATA controllers.
With multi-MSI capable SATA controllers, only the first port works,
all other ports time out when executing SATA commands.

This happens because the first argument to assign_irq_vector_policy()
is always the base linux irq number of the multi MSI interrupt block,
so all subsequent vector assignments operate on the base linux irq
number, so all MSI irqs are handled as the first irq number. Therefor
the other MSI irqs of a device are never set up correctly and never
fire.

Add the loop iterator to the base irq number so all vectors are
assigned correctly.

Fixes: b5dc8e6c21e7 "x86/irq: Use hierarchical irqdomain to manage CPU interrupt vectors"
Reported-and-tested-by: Alex Deucher 
Reported-and-tested-by: Mark Rustad 
Reported-and-tested-by: Alexander Holler 
Signed-off-by: Jiang Liu 
Cc: Tony Luck 
Link: http://lkml.kernel.org/r/1439911228-9880-1-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner

x86/irq: Plug irq vector hotplug race

2015-07-07T09:54:04+00:00

Jin debugged a nasty cpu hotplug race which results in leaking a irq
vector on the newly hotplugged cpu.

cpu N				cpu M
native_cpu_up                   device_shutdown
  do_boot_cpu			  free_msi_irqs
  start_secondary                   arch_teardown_msi_irqs
    smp_callin                        default_teardown_msi_irqs
       setup_vector_irq                  arch_teardown_msi_irq
        __setup_vector_irq		   native_teardown_msi_irq
          lock(vector_lock)		     destroy_irq 
          install vectors
          unlock(vector_lock)
					       lock(vector_lock)
--->                                  	       __clear_irq_vector
                                    	       unlock(vector_lock)
    lock(vector_lock)
    set_cpu_online
    unlock(vector_lock)

This leaves the irq vector(s) which are torn down on CPU M stale in
the vector array of CPU N, because CPU M does not see CPU N online
yet. There is a similar issue with concurrent newly setup interrupts.

The alloc/free protection of irq descriptors does not prevent the
above race, because it merily prevents interrupt descriptors from
going away or changing concurrently.

Prevent this by moving the call to setup_vector_irq() into the
vector_lock held region which protects set_cpu_online():

cpu N				cpu M
native_cpu_up                   device_shutdown
  do_boot_cpu			  free_msi_irqs
  start_secondary                   arch_teardown_msi_irqs
    smp_callin                        default_teardown_msi_irqs
       lock(vector_lock)                arch_teardown_msi_irq
       setup_vector_irq()
        __setup_vector_irq		   native_teardown_msi_irq
          install vectors		     destroy_irq 
       set_cpu_online
       unlock(vector_lock)
					       lock(vector_lock)
                                  	       __clear_irq_vector
                                    	       unlock(vector_lock)

So cpu M either sees the cpu N online before clearing the vector or
cpu N installs the vectors after cpu M has cleared it.

Reported-by: xiao jin 
Signed-off-by: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: Joerg Roedel 
Cc: Borislav Petkov 
Cc: Yanmin Zhang 
Link: http://lkml.kernel.org/r/20150705171102.141898931@linutronix.de

x86: Use entering[_ack]_irq() instead of open coding it

2015-05-15T14:03:18+00:00

Signed-off-by: Thomas Gleixner

x86, irq: Allocate CPU vectors from device local CPUs if possible

2015-05-13T07:50:24+00:00

On NUMA systems, an IO device may be associated with a NUMA node.
It may improve IO performance to allocate resources, such as memory
and interrupts, from device local node.

This patch introduces a mechanism to support CPU vector allocation
policies. It tries to allocate CPU vectors from CPUs on device local
node first, and then fallback to all online(global) CPUs.

This mechanism may be used to support NumaConnect systems to allocate
CPU vectors from device local node.

Signed-off-by: Jiang Liu 
Tested-by: Daniel J Blueman 
Cc: Konrad Rzeszutek Wilk 
Cc: Tony Luck 
Cc: Bjorn Helgaas 
Cc: Benjamin Herrenschmidt 
Cc: Rafael J. Wysocki 
Cc: Randy Dunlap 
Cc: Yinghai Lu 
Cc: Borislav Petkov 
Link: http://lkml.kernel.org/r/1430967244-28905-1-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner

Merge branch 'x86/asm' into x86/apic, to resolve a conflict

2015-05-11T14:05:09+00:00

Conflicts:
	arch/x86/kernel/apic/io_apic.c
	arch/x86/kernel/apic/vector.c

Signed-off-by: Ingo Molnar

x86/asm/entry/irq: Clean up IRQn_VECTOR macros

2015-05-10T10:34:28+00:00

Since the ISA irqs are in a single block, use
ISA_IRQ_VECTOR(irq) instead of individual macros.

Signed-off-by: Brian Gerst 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1431185813-15413-5-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar

x86: Constify irqdomain ops

2015-05-05T09:14:48+00:00

Nothing changes those ops. Make the initializers readable while at it.

Reported-by: Krzysztof Kozlowski 
Signed-off-by: Thomas Gleixner

x86/irq: Avoid memory allocation in __assign_irq_vector()

2015-04-24T13:36:55+00:00

Function __assign_irq_vector() is protected by vector_lock, so use
a global temporary cpu_mask to avoid allocating/freeing cpu_mask.

Signed-off-by: Jiang Liu 
Cc: Konrad Rzeszutek Wilk 
Cc: David Cohen 
Cc: Sander Eikelenboom 
Cc: David Vrabel 
Cc: Tony Luck 
Cc: Joerg Roedel 
Cc: Greg Kroah-Hartman 
Cc: Bjorn Helgaas 
Cc: Benjamin Herrenschmidt 
Cc: Rafael J. Wysocki 
Cc: Randy Dunlap 
Cc: Yinghai Lu 
Cc: Borislav Petkov 
Cc: Dimitri Sivanich 
Link: http://lkml.kernel.org/r/1428978610-28986-34-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner

x86/irq: Move irqdomain specific code into asm/irqdomain.h

2015-04-24T13:36:55+00:00

Now we have dedicated asm/irqdomain.h, so move irqdomain specific
code into it.

Signed-off-by: Jiang Liu 
Cc: Konrad Rzeszutek Wilk 
Cc: David Cohen 
Cc: Sander Eikelenboom 
Cc: David Vrabel 
Cc: Tony Luck 
Cc: Joerg Roedel 
Cc: Greg Kroah-Hartman 
Cc: Bjorn Helgaas 
Cc: Benjamin Herrenschmidt 
Cc: Rafael J. Wysocki 
Cc: Randy Dunlap 
Cc: Yinghai Lu 
Cc: Borislav Petkov 
Cc: Dimitri Sivanich 
Cc: Joerg Roedel 
Cc: Andy Lutomirski 
Link: http://lkml.kernel.org/r/1428978610-28986-33-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner