Skip to content

cloud-kernel
cloud-kernel

openanolis / cloud-kernel
1 年多 前同步成功

通知 160
Star 36
Fork 7
cloud-kernel
cloud-kernel
切换分支/标签
  1. 10 5月, 2019 1 次提交
  3. 06 3月, 2019 1 次提交
  5. 14 11月, 2018 1 次提交
    • L
      genirq: Fix race on spurious interrupt detection · e6d2f788
      由 Lukas Wunner 提交于 
      commit 746a923b863a1065ef77324e1e43f19b1a3eab5c upstream.

Commit 1e77d0a1 ("genirq: Sanitize spurious interrupt detection of
threaded irqs") made detection of spurious interrupts work for threaded
handlers by:

a) incrementing a counter every time the thread returns IRQ_HANDLED, and
b) checking whether that counter has increased every time the thread is
   woken.

However for oneshot interrupts, the commit unmasks the interrupt before
incrementing the counter.  If another interrupt occurs right after
unmasking but before the counter is incremented, that interrupt is
incorrectly considered spurious:

time
 |  irq_thread()
 |    irq_thread_fn()
 |      action->thread_fn()
 |      irq_finalize_oneshot()
 |        unmask_threaded_irq()            /* interrupt is unmasked */
 |
 |                  /* interrupt fires, incorrectly deemed spurious */
 |
 |    atomic_inc(&desc->threads_handled); /* counter is incremented */
 v

This is observed with a hi3110 CAN controller receiving data at high volume
(from a separate machine sending with "cangen -g 0 -i -x"): The controller
signals a huge number of interrupts (hundreds of millions per day) and
every second there are about a dozen which are deemed spurious.

In theory with high CPU load and the presence of higher priority tasks, the
number of incorrectly detected spurious interrupts might increase beyond
the 99,900 threshold and cause disablement of the interrupt.

In practice it just increments the spurious interrupt count. But that can
cause people to waste time investigating it over and over.

Fix it by moving the accounting before the invocation of
irq_finalize_oneshot().

[ tglx: Folded change log update ]

Fixes: 1e77d0a1 ("genirq: Sanitize spurious interrupt detection of threaded irqs")
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Mathias Duckeck <m.duckeck@kunbus.de>
Cc: Akshay Bhat <akshay.bhat@timesys.com>
Cc: Casey Fitzpatrick <casey.fitzpatrick@timesys.com>
Cc: stable@vger.kernel.org # v3.16+
Link: https://lkml.kernel.org/r/1dfd8bbd16163940648045495e3e9698e63b50ad.1539867047.git.lukas@wunner.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e6d2f788
  7. 03 8月, 2018 1 次提交
    • T
      genirq: Make force irq threading setup more robust · d1f0301b
      由 Thomas Gleixner 提交于 
      The support of force threading interrupts which are set up with both a
primary and a threaded handler wreckaged the setup of regular requested
threaded interrupts (primary handler == NULL).

The reason is that it does not check whether the primary handler is set to
the default handler which wakes the handler thread. Instead it replaces the
thread handler with the primary handler as it would do with force threaded
interrupts which have been requested via request_irq(). So both the primary
and the thread handler become the same which then triggers the warnon that
the thread handler tries to wakeup a not configured secondary thread.

Fortunately this only happens when the driver omits the IRQF_ONESHOT flag
when requesting the threaded interrupt, which is normaly caught by the
sanity checks when force irq threading is disabled.

Fix it by skipping the force threading setup when a regular threaded
interrupt is requested. As a consequence the interrupt request which lacks
the IRQ_ONESHOT flag is rejected correctly instead of silently wreckaging
it.

Fixes: 2a1d3ab8 ("genirq: Handle force threading of irqs with primary and thread handler")
Reported-by: NKurt Kanzenbach <kurt.kanzenbach@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NKurt Kanzenbach <kurt.kanzenbach@linutronix.de>
Cc: stable@vger.kernel.org
      d1f0301b
  9. 17 7月, 2018 1 次提交
  11. 24 6月, 2018 2 次提交
    • L
      genirq: Synchronize only with single thread on free_irq() · 519cc865
      由 Lukas Wunner 提交于 
      When pciehp is converted to threaded IRQ handling, removal of unplugged
devices below a PCIe hotplug port happens synchronously in the IRQ thread.
Removal of devices typically entails a call to free_irq() by their drivers.

If those devices share their IRQ with the hotplug port, __free_irq()
deadlocks because it calls synchronize_irq() to wait for all hard IRQ
handlers as well as all threads sharing the IRQ to finish.

Actually it's sufficient to wait only for the IRQ thread of the removed
device, so call synchronize_hardirq() to wait for all hard IRQ handlers to
finish, but no longer for any threads.  Compensate by rearranging the
control flow in irq_wait_for_interrupt() such that the device's thread is
allowed to run one last time after kthread_stop() has been called.

kthread_stop() blocks until the IRQ thread has completed.  On completion
the IRQ thread clears its oneshot thread_mask bit.  This is safe because
__free_irq() holds the request_mutex, thereby preventing __setup_irq() from
handing out the same oneshot thread_mask bit to a newly requested action.

Stack trace for posterity:
    INFO: task irq/17-pciehp:94 blocked for more than 120 seconds.
    schedule+0x28/0x80
    synchronize_irq+0x6e/0xa0
    __free_irq+0x15a/0x2b0
    free_irq+0x33/0x70
    pciehp_release_ctrl+0x98/0xb0
    pcie_port_remove_service+0x2f/0x40
    device_release_driver_internal+0x157/0x220
    bus_remove_device+0xe2/0x150
    device_del+0x124/0x340
    device_unregister+0x16/0x60
    remove_iter+0x1a/0x20
    device_for_each_child+0x4b/0x90
    pcie_port_device_remove+0x1e/0x30
    pci_device_remove+0x36/0xb0
    device_release_driver_internal+0x157/0x220
    pci_stop_bus_device+0x7d/0xa0
    pci_stop_bus_device+0x3d/0xa0
    pci_stop_and_remove_bus_device+0xe/0x20
    pciehp_unconfigure_device+0xb8/0x160
    pciehp_disable_slot+0x84/0x130
    pciehp_ist+0x158/0x190
    irq_thread_fn+0x1b/0x50
    irq_thread+0x143/0x1a0
    kthread+0x111/0x130
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: linux-pci@vger.kernel.org
Link: https://lkml.kernel.org/r/d72b41309f077c8d3bee6cc08ad3662d50b5d22a.1529828292.git.lukas@wunner.de
      519cc865
    • L
      genirq: Update code comments wrt recycled thread_mask · 836557bd
      由 Lukas Wunner 提交于 
      Previously a race existed between __free_irq() and __setup_irq() wherein
the thread_mask of a just removed action could be handed out to a newly
added action and the freed irq thread would then tread on the oneshot
mask bit of the newly added irq thread in irq_finalize_oneshot():

time
 |  __free_irq()
 |    raw_spin_lock_irqsave(&desc->lock, flags);
 |    <remove action from linked list>
 |    raw_spin_unlock_irqrestore(&desc->lock, flags);
 |
 |  __setup_irq()
 |    raw_spin_lock_irqsave(&desc->lock, flags);
 |    <traverse linked list to determine oneshot mask bit>
 |    raw_spin_unlock_irqrestore(&desc->lock, flags);
 |
 |  irq_thread() of freed irq (__free_irq() waits in synchronize_irq())
 |    irq_thread_fn()
 |      irq_finalize_oneshot()
 |        raw_spin_lock_irq(&desc->lock);
 |        desc->threads_oneshot &= ~action->thread_mask;
 |        raw_spin_unlock_irq(&desc->lock);
 v

The race was known at least since 2012 when it was documented in a code
comment by commit e04268b0 ("genirq: Remove paranoid warnons and bogus
fixups"). The race itself is harmless as nothing touches any of the
potentially freed data after synchronize_irq().

In 2017 the race was close by commit 9114014c ("genirq: Add mutex to
irq desc to serialize request/free_irq()"), apparently inadvertantly so
because the race is neither mentioned in the commit message nor was the
code comment updated.  Make up for that.
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: linux-pci@vger.kernel.org
Link: https://lkml.kernel.org/r/32fc25aa35ecef4b2692f57687bb7fc2a57230e2.1529828292.git.lukas@wunner.de
      836557bd
  13. 19 6月, 2018 1 次提交
  15. 06 6月, 2018 2 次提交
  17. 20 3月, 2018 3 次提交
  19. 16 2月, 2018 1 次提交
  21. 13 11月, 2017 1 次提交
    • R
      genirq: Fix type of shifting literal 1 in __setup_irq() · ffc661c9
      由 Rasmus Villemoes 提交于 
      If ffz() ever returns a value >= 31 then the following shift is undefined
behaviour because the literal 1 which gets shifted is treated as signed
integer.

In practice, the bug is probably harmless, since the first undefined shift
count is 31 which results - ignoring UB - in (int)(0x80000000). This gets
sign extended so bit 32-63 will be set as well and all subsequent
__setup_irq() calls would just end up hitting the -EBUSY branch.

However, a sufficiently aggressive optimizer may use the UB of 1<<31
to decide that doesn't happen, and hence elide the sign-extension
code, so that subsequent calls can indeed get ffz > 31.

In any case, the right thing to do is to make the literal 1UL.

[ tglx: For this to happen a single interrupt would have to be shared by 32
  	devices. Hardware like that does not exist and would have way more
  	problems than that. ]
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20171030213548.16831-1-linux@rasmusvillemoes.dk
      ffc661c9
  23. 10 11月, 2017 1 次提交
    • M
      genirq: Track whether the trigger type has been set · 4f8413a3
      由 Marc Zyngier 提交于 
      When requesting a shared interrupt, we assume that the firmware
support code (DT or ACPI) has called irqd_set_trigger_type
already, so that we can retrieve it and check that the requester
is being reasonnable.

Unfortunately, we still have non-DT, non-ACPI systems around,
and these guys won't call irqd_set_trigger_type before requesting
the interrupt. The consequence is that we fail the request that
would have worked before.

We can either chase all these use cases (boring), or address it
in core code (easier). Let's have a per-irq_desc flag that
indicates whether irqd_set_trigger_type has been called, and
let's just check it when checking for a shared interrupt.
If it hasn't been set, just take whatever the interrupt
requester asks.

Fixes: 382bd4de ("genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQs")
Cc: stable@vger.kernel.org
Reported-and-tested-by: NPetr Cvek <petrcvekcz@gmail.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
      4f8413a3
  25. 29 10月, 2017 1 次提交
    • C
      genirq: Document vcpu_info usage for percpu_devid interrupts · 250a53d6
      由 Christoffer Dall 提交于 
      It is currently unclear how to set the VCPU affinity for a percpu_devid
interrupt , since the Linux irq_data structure describes the state for
multiple interrupts, one for each physical CPU on the system.  Since
each such interrupt can be associated with different VCPUs or none at
all, associating a single VCPU state with such an interrupt does not
capture the necessary semantics.

The implementers of irq_set_affinity are the Intel and AMD IOMMUs, and
the ARM GIC irqchip.  The Intel and AMD callers do not appear to use
percpu_devid interrupts, and the ARM GIC implementation only checks the
pointer against NULL vs. non-NULL.

Therefore, simply update the function documentation to explain the
expected use in the context of percpu_devid interrupts, allowing future
changes or additions to irqchip implementers to do the right thing.
Signed-off-by: NChristoffer Dall <cdall@linaro.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: kvm@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: kvmarm@lists.cs.columbia.edu
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/1509093281-15225-13-git-send-email-cdall@linaro.org
      250a53d6
  27. 09 10月, 2017 2 次提交
    • T
      genirq/cpuhotplug: Enforce affinity setting on startup of managed irqs · e43b3b58
      由 Thomas Gleixner 提交于 
      Managed interrupts can end up in a stale state on CPU hotplug. If the
interrupt is not targeting a single CPU, i.e. the affinity mask spawns
multiple CPUs then the following can happen:

After boot:

dstate:   0x01601200
            IRQD_ACTIVATED
            IRQD_IRQ_STARTED
            IRQD_SINGLE_TARGET
            IRQD_AFFINITY_SET
            IRQD_AFFINITY_MANAGED
node:     0
affinity: 24-31
effectiv: 24
pending:  0

After offlining CPU 31 - 24

dstate:   0x01a31000
            IRQD_IRQ_DISABLED
            IRQD_IRQ_MASKED
            IRQD_SINGLE_TARGET
            IRQD_AFFINITY_SET
            IRQD_AFFINITY_MANAGED
            IRQD_MANAGED_SHUTDOWN
node:     0
affinity: 24-31
effectiv: 24
pending:  0

Now CPU 25 gets onlined again, so it should get the effective interrupt
affinity for this interruopt, but due to the x86 interrupt affinity setter
restrictions this ends up after restarting the interrupt with:

dstate:   0x01601300
            IRQD_ACTIVATED
            IRQD_IRQ_STARTED
            IRQD_SINGLE_TARGET
            IRQD_AFFINITY_SET
            IRQD_SETAFFINITY_PENDING
            IRQD_AFFINITY_MANAGED
node:     0
affinity: 24-31
effectiv: 24
pending:  24-31

So the interrupt is still affine to CPU 24, which was the last CPU to go
offline of that affinity set and the move to an online CPU within 24-31,
in this case 25, is pending. This mechanism is x86/ia64 specific as those
architectures cannot move interrupts from thread context and do this when
an interrupt is actually handled. So the move is set to pending.

Whats worse is that offlining CPU 25 again results in:

dstate:   0x01601300
            IRQD_ACTIVATED
            IRQD_IRQ_STARTED
            IRQD_SINGLE_TARGET
            IRQD_AFFINITY_SET
            IRQD_SETAFFINITY_PENDING
            IRQD_AFFINITY_MANAGED
node:     0
affinity: 24-31
effectiv: 24
pending:  24-31

This means the interrupt has not been shut down, because the outgoing CPU
is not in the effective affinity mask, but of course nothing notices that
the effective affinity mask is pointing at an offline CPU.

In the case of restarting a managed interrupt the move restriction does not
apply, so the affinity setting can be made unconditional. This needs to be
done _before_ the interrupt is started up as otherwise the condition for
moving it from thread context would not longer be fulfilled.

With that change applied onlining CPU 25 after offlining 31-24 results in:

dstate:   0x01600200
            IRQD_ACTIVATED
            IRQD_IRQ_STARTED
            IRQD_SINGLE_TARGET
            IRQD_AFFINITY_MANAGED
node:     0
affinity: 24-31
effectiv: 25
pending:  

And after offlining CPU 25:

dstate:   0x01a30000
            IRQD_IRQ_DISABLED
            IRQD_IRQ_MASKED
            IRQD_SINGLE_TARGET
            IRQD_AFFINITY_MANAGED
            IRQD_MANAGED_SHUTDOWN
node:     0
affinity: 24-31
effectiv: 25
pending:  

which is the correct and expected result.

Fixes: 761ea388 ("genirq: Handle managed irqs gracefully in irq_startup()")
Reported-by: NYASUAKI ISHIMATSU <yasu.isimatu@gmail.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: axboe@kernel.dk
Cc: linux-scsi@vger.kernel.org
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: mpe@ellerman.id.au
Cc: Shivasharan Srikanteshwara <shivasharan.srikanteshwara@broadcom.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: keith.busch@intel.com
Cc: peterz@infradead.org
Cc: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1710042208400.2406@nanos
      e43b3b58
    • T
      genirq: Warn when effective affinity is not updated · 19e1d4e9
      由 Thomas Gleixner 提交于 
      Emit a one time warning when the effective affinity mask is enabled in
Kconfig, but the interrupt chip does not update the mask in its
irq_set_affinity() callback,
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1710042208400.2406@nanos
      19e1d4e9
  29. 26 9月, 2017 2 次提交
    • T
      genirq: Separate activation and startup · c942cee4
      由 Thomas Gleixner 提交于 
      Activation of an interrupt and startup are currently a combo
functionlity. That works so far, but upcoming changes require a strict
separation because the activation can fail in future.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NJuergen Gross <jgross@suse.com>
Tested-by: NYu Chen <yu.c.chen@intel.com>
Acked-by: NJuergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213152.754334077@linutronix.de
      c942cee4
    • T
      genirq/debugfs: Show debug information for all irq descriptors · e0b47794
      由 Thomas Gleixner 提交于 
      Currently the debugfs shows only information about actively used interrupts
like /proc/irq/ does. That's fine for most cases, but not helpful when
internals of allocated, but unused interrupt descriptors have to
debugged. It's also useful to provide information about all descriptors so
leaks can be debugged in a simpler way.

Move the debugfs registration to the descriptor allocation code.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NJuergen Gross <jgross@suse.com>
Tested-by: NYu Chen <yu.c.chen@intel.com>
Acked-by: NJuergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213152.355525908@linutronix.de
      e0b47794
  31. 25 9月, 2017 1 次提交
  33. 23 8月, 2017 1 次提交
  35. 12 7月, 2017 1 次提交
    • T
      genirq: Keep chip buslock across irq_request/release_resources() · 19d39a38
      由 Thomas Gleixner 提交于 
      Moving the irq_request/release_resources() callbacks out of the spinlocked,
irq disabled and bus locked region, unearthed an interesting abuse of the
irq_bus_lock/irq_bus_sync_unlock() callbacks.

The OMAP GPIO driver does merily power management inside of them. The
irq_request_resources() callback of this GPIO irqchip calls a function
which reads a GPIO register. That read aborts now because the clock of the
GPIO block is not magically enabled via the irq_bus_lock() callback.

Move the callbacks under the bus lock again to prevent this. In the
free_irq() path this requires to drop the bus_lock before calling
synchronize_irq() and reaquiring it before calling the
irq_release_resources() callback.

The bus lock can't be held because:

   1) The data which has been changed between bus_lock/un_lock is cached in
      the irq chip driver private data and needs to go out to the irq chip
      via the slow bus (usually SPI or I2C) before calling
      synchronize_irq().

      That's the reason why this bus_lock/unlock magic exists in the first
      place, as you cannot do SPI/I2C transactions while holding desc->lock
      with interrupts disabled.

   2) synchronize_irq() will actually deadlock, if there is a handler on
      flight. These chips use threaded handlers for obvious reasons, as
      they allow to do SPI/I2C communication. When the threaded handler
      returns then bus_lock needs to be taken in irq_finalize_oneshot() as
      we need to talk to the actual irq chip once more. After that the
      threaded handler is marked done, which makes synchronize_irq() return.

      So if we hold bus_lock accross the synchronize_irq() call, the
      handler cannot mark itself done because it blocks on the bus
      lock. That in turn makes synchronize_irq() wait forever on the
      threaded handler to complete....

Add the missing unlock of desc->request_mutex in the error path of
__free_irq() and add a bunch of comments to explain the locking and
protection rules.

Fixes: 46e48e25 ("genirq: Move irq resource handling out of spinlocked region")
Reported-and-tested-by: NSebastian Reichel <sebastian.reichel@collabora.co.uk>
Reported-and-tested-by: NTony Lindgren <tony@atomide.com>
Reported-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Not-longer-ranted-at-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
      19d39a38
  37. 07 7月, 2017 1 次提交
    • D
      genirq: Allow to pass the IRQF_TIMER flag with percpu irq request · c80081b9
      由 Daniel Lezcano 提交于 
      The irq timings infrastructure tracks when interrupts occur in order to
statistically predict te next interrupt event.

There is no point to track timer interrupts and try to predict them because
the next expiration time is already known. This can be avoided via the
IRQF_TIMER flag which is passed by timer drivers in request_irq(). It marks
the interrupt as timer based which alloes to ignore these interrupts in the
timings code.

Per CPU interrupts which are requested via request_percpu_+irq() have no
flag argument, so marking per cpu timer interrupts is not possible and they
get tracked pointlessly.

Add __request_percpu_irq() as a variant of request_percpu_irq() with a
flags argument and make request_percpu_irq() an inline wrapper passing
flags = 0.

The flag parameter is restricted to IRQF_TIMER as all other IRQF_ flags
make no sense for per cpu interrupts.

The next step is to convert all existing users of request_percpu_irq() and
then remove the wrapper and the underscores.

[ tglx: Massaged changelog ]
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: nicolas.pitre@linaro.org
Cc: vincent.guittot@linaro.org
Cc: rafael@kernel.org
Link: http://lkml.kernel.org/r/1499344144-3964-1-git-send-email-daniel.lezcano@linaro.org
      c80081b9
  39. 04 7月, 2017 4 次提交
  41. 24 6月, 2017 1 次提交
    • D
      genirq/timings: Add infrastructure to track the interrupt timings · b2d3d61a
      由 Daniel Lezcano 提交于 
      The interrupt framework gives a lot of information about each interrupt. It
does not keep track of when those interrupts occur though, which is a
prerequisite for estimating the next interrupt arrival for power management
purposes.

Add a mechanism to record the timestamp for each interrupt occurrences in a
per-CPU circular buffer to help with the prediction of the next occurrence
using a statistical model.

Each CPU can store up to IRQ_TIMINGS_SIZE events <irq, timestamp>, the
current value of IRQ_TIMINGS_SIZE is 32.

Each event is encoded into a single u64, where the high 48 bits are used
for the timestamp and the low 16 bits are for the irq number.

A static key is introduced so when the irq prediction is switched off at
runtime, the overhead is near to zero.

It results in most of the code in internals.h for inline reasons and a very
few in the new file timings.c. The latter will contain more in the next patch
which will provide the statistical model for the next event prediction.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: "Rafael J . Wysocki" <rafael@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1498227072-5980-1-git-send-email-daniel.lezcano@linaro.org
      b2d3d61a
  43. 23 6月, 2017 6 次提交
    • T
      genirq: Add force argument to irq_startup() · 4cde9c6b
      由 Thomas Gleixner 提交于 
      In order to handle managed interrupts gracefully on irq_startup() so they
won't lose their assigned affinity, it's necessary to allow startups which
keep the interrupts in managed shutdown state, if none of the assigend CPUs
is online. This allows drivers to request interrupts w/o the CPUs being
online, which avoid online/offline churn in drivers.

Add a force argument which can override that decision and let only
request_irq() and enable_irq() allow the managed shutdown
handling. enable_irq() is required, because the interrupt might be
requested with IRQF_NOAUTOEN and enable_irq() invokes irq_startup() which
would then wreckage the assignment again. All other callers force startup
and potentially break the assigned affinity.

No functional change as this only adds the function argument.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235447.112094565@linutronix.de
      4cde9c6b
    • C
      genirq: Move pending helpers to internal.h · 137221df
      由 Christoph Hellwig 提交于 
      So that the affinity code can reuse them.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170619235445.109426284@linutronix.de
      137221df
    • T
      genirq: Move initial affinity setup to irq_startup() · 2e051552
      由 Thomas Gleixner 提交于 
      The startup vs. setaffinity ordering of interrupts depends on the
IRQF_NOAUTOEN flag. Chained interrupts are not getting any affinity
assignment at all.

A regular interrupt is started up and then the affinity is set. A
IRQF_NOAUTOEN marked interrupt is not started up, but the affinity is set
nevertheless.

Move the affinity setup to startup_irq() so the ordering is always the same
and chained interrupts get the proper default affinity assigned as well.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235445.020534783@linutronix.de
      2e051552
    • T
      genirq: Rename setup_affinity() to irq_setup_affinity() · 43564bd9
      由 Thomas Gleixner 提交于 
      Rename it with a proper irq_ prefix and make it available for other files
in the core code. Preparatory patch for moving the irq affinity setup
around.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235444.928501004@linutronix.de
      43564bd9
    • T
      genirq: Remove mask argument from setup_affinity() · cba4235e
      由 Thomas Gleixner 提交于 
      No point to have this alloc/free dance of cpumasks. Provide a static mask
for setup_affinity() and protect it proper.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235444.851571573@linutronix.de
      cba4235e
    • T
      genirq/debugfs: Add proper debugfs interface · 087cdfb6
      由 Thomas Gleixner 提交于 
      Debugging (hierarchical) interupt domains is tedious as there is no
information about the hierarchy and no information about states of
interrupts in the various domain levels.

Add a debugfs directory 'irq' and subdirectories 'domains' and 'irqs'.

The domains directory contains the domain files. The content is information
about the domain. If the domain is part of a hierarchy then the parent
domains are printed as well.

# ls /sys/kernel/debug/irq/domains/
default     INTEL-IR-2	    INTEL-IR-MSI-2  IO-APIC-IR-2  PCI-MSI
DMAR-MSI    INTEL-IR-3	    INTEL-IR-MSI-3  IO-APIC-IR-3  unknown-1
INTEL-IR-0  INTEL-IR-MSI-0  IO-APIC-IR-0    IO-APIC-IR-4  VECTOR
INTEL-IR-1  INTEL-IR-MSI-1  IO-APIC-IR-1    PCI-HT

# cat /sys/kernel/debug/irq/domains/VECTOR 
name:   VECTOR
 size:   0
 mapped: 216
 flags:  0x00000041

# cat /sys/kernel/debug/irq/domains/IO-APIC-IR-0 
name:   IO-APIC-IR-0
 size:   24
 mapped: 19
 flags:  0x00000041
 parent: INTEL-IR-3
    name:   INTEL-IR-3
     size:   65536
     mapped: 167
     flags:  0x00000041
     parent: VECTOR
        name:   VECTOR
         size:   0
         mapped: 216
         flags:  0x00000041

Unfortunately there is no per cpu information about the VECTOR domain (yet).

The irqs directory contains detailed information about mapped interrupts.

# cat /sys/kernel/debug/irq/irqs/3
handler:  handle_edge_irq
status:   0x00004000
istate:   0x00000000
ddepth:   1
wdepth:   0
dstate:   0x01018000
            IRQD_IRQ_DISABLED
            IRQD_SINGLE_TARGET
            IRQD_MOVE_PCNTXT
node:     0
affinity: 0-143
effectiv: 0
pending:  
domain:  IO-APIC-IR-0
 hwirq:   0x3
 chip:    IR-IO-APIC
  flags:   0x10
             IRQCHIP_SKIP_SET_WAKE
 parent:
    domain:  INTEL-IR-3
     hwirq:   0x20000
     chip:    INTEL-IR
      flags:   0x0
     parent:
        domain:  VECTOR
         hwirq:   0x3
         chip:    APIC
          flags:   0x0

This was developed to simplify the debugging of the managed affinity
changes.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235444.537566163@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      087cdfb6
  45. 13 6月, 2017 1 次提交
  47. 04 6月, 2017 2 次提交
  49. 19 4月, 2017 1 次提交