linux.git/kernel/irq, branch v5.10.258

genirq: Provide new interfaces for affinity hints

2025-10-02T11:35:39+00:00

[ Upstream commit 65c7cdedeb3026fabcc967a7aae2f755ad4d0783 ]

The discussion about removing the side effect of irq_set_affinity_hint() of
actually applying the cpumask (if not NULL) as affinity to the interrupt,
unearthed a few unpleasantries:

  1) The modular perf drivers rely on the current behaviour for the very
     wrong reasons.

  2) While none of the other drivers prevents user space from changing
     the affinity, a cursorily inspection shows that there are at least
     expectations in some drivers.

#1 needs to be cleaned up anyway, so that's not a problem

#2 might result in subtle regressions especially when irqbalanced (which
   nowadays ignores the affinity hint) is disabled.

Provide new interfaces:

  irq_update_affinity_hint()  - Only sets the affinity hint pointer
  irq_set_affinity_and_hint() - Set the pointer and apply the affinity to
                                the interrupt

Make irq_set_affinity_hint() a wrapper around irq_apply_affinity_hint() and
document it to be phased out.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Nitesh Narayan Lal 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Ming Lei 
Link: https://lore.kernel.org/r/20210501021832.743094-1-jesse.brandeburg@intel.com
Link: https://lore.kernel.org/r/20210903152430.244937-2-nitesh@redhat.com
Stable-dep-of: 915470e1b44e ("i40e: fix IRQ freeing in i40e_vsi_request_irq_msix error path")
Signed-off-by: Sasha Levin

genirq: Export affinity setter for modules

2025-10-02T11:35:39+00:00

[ Upstream commit 4d80d6ca5d77fde9880da8466e5b64f250e5bf82 ]

Perf modules abuse irq_set_affinity_hint() to set the affinity of system
PMU interrupts just because irq_set_affinity() was not exported.

The fact that irq_set_affinity_hint() actually sets the affinity is a
non-documented side effect and the name is clearly saying it's a hint.

To clean this up, export the real affinity setter.

Signed-off-by: Thomas Gleixner 
Acked-by: Mark Rutland 
Link: https://lore.kernel.org/r/20210518093117.968251441@linutronix.de
Stable-dep-of: 915470e1b44e ("i40e: fix IRQ freeing in i40e_vsi_request_irq_msix error path")
Signed-off-by: Sasha Levin

genirq/affinity: Add irq_update_affinity_desc()

2025-10-02T11:35:38+00:00

[ Upstream commit 1d3aec89286254487df7641c30f1b14ad1d127a5 ]

Add a function to allow the affinity of an interrupt be switched to
managed, such that interrupts allocated for platform devices may be
managed.

This new interface has certain limitations, and attempts to use it in the
following circumstances will fail:
- For when the kernel is configured for generic IRQ reservation mode (in
  config GENERIC_IRQ_RESERVATION_MODE). The reason being that it could
  conflict with managed vs. non-managed interrupt accounting.
- The interrupt is already started, which should not be the case during
  init
- The interrupt is already configured as managed, which means double init

Suggested-by: Thomas Gleixner 
Signed-off-by: John Garry 
Signed-off-by: Marc Zyngier 
Link: https://lore.kernel.org/r/1606905417-183214-2-git-send-email-john.garry@huawei.com
Stable-dep-of: 915470e1b44e ("i40e: fix IRQ freeing in i40e_vsi_request_irq_msix error path")
Signed-off-by: Sasha Levin

genirq: Make handle_enforce_irqctx() unconditionally available

2025-03-13T11:46:45+00:00

[ Upstream commit 8d187a77f04c14fb459a5301d69f733a5a1396bc ]

Commit 1b57d91b969c ("irqchip/gic-v2, v3: Prevent SW resends entirely")
sett the flag which enforces interrupt handling in interrupt context and
prevents software base resends for ARM GIC v2/v3.

But it missed that the helper function which checks the flag was hidden
behind CONFIG_GENERIC_PENDING_IRQ, which is not set by ARM[64].

Make the helper unconditionally available so that the enforcement actually
works.

Fixes: 1b57d91b969c ("irqchip/gic-v2, v3: Prevent SW resends entirely")
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20241210101811.497716609@linutronix.de
Signed-off-by: Sasha Levin

kernel: Initialize cpumask before parsing

2025-01-09T12:25:04+00:00

[ Upstream commit c5e3a41187ac01425f5ad1abce927905e4ac44e4 ]

KMSAN complains that new_value at cpumask_parse_user() from
write_irq_affinity() from irq_affinity_proc_write() is uninitialized.

  [  148.133411][ T5509] =====================================================
  [  148.135383][ T5509] BUG: KMSAN: uninit-value in find_next_bit+0x325/0x340
  [  148.137819][ T5509]
  [  148.138448][ T5509] Local variable ----new_value.i@irq_affinity_proc_write created at:
  [  148.140768][ T5509]  irq_affinity_proc_write+0xc3/0x3d0
  [  148.142298][ T5509]  irq_affinity_proc_write+0xc3/0x3d0
  [  148.143823][ T5509] =====================================================

Since bitmap_parse() from cpumask_parse_user() calls find_next_bit(),
any alloc_cpumask_var() + cpumask_parse_user() sequence has possibility
that find_next_bit() accesses uninitialized cpu mask variable. Fix this
problem by replacing alloc_cpumask_var() with zalloc_cpumask_var().

Signed-off-by: Tetsuo Handa 
Signed-off-by: Thomas Gleixner 
Acked-by: Steven Rostedt (VMware) 
Link: https://lore.kernel.org/r/20210401055823.3929-1-penguin-kernel@I-love.SAKURA.ne.jp
Stable-dep-of: 98feccbf32cf ("tracing: Prevent bad count for tracing_cpumask_write")
Signed-off-by: Sasha Levin

genirq/irqdesc: Honor caller provided affinity in alloc_desc()

2024-08-19T03:41:19+00:00

commit edbbaae42a56f9a2b39c52ef2504dfb3fb0a7858 upstream.

Currently, whenever a caller is providing an affinity hint for an
interrupt, the allocation code uses it to calculate the node and copies the
cpumask into irq_desc::affinity.

If the affinity for the interrupt is not marked 'managed' then the startup
of the interrupt ignores irq_desc::affinity and uses the system default
affinity mask.

Prevent this by setting the IRQD_AFFINITY_SET flag for the interrupt in the
allocator, which causes irq_setup_affinity() to use irq_desc::affinity on
interrupt startup if the mask contains an online CPU.

[ tglx: Massaged changelog ]

Fixes: 45ddcecbfa94 ("genirq: Use affinity hint in irqdesc allocation")
Signed-off-by: Shay Drory 
Signed-off-by: Thomas Gleixner 
Cc: 
Link: https://lore.kernel.org/all/20240806072044.837827-1-shayd@nvidia.com
Signed-off-by: Greg Kroah-Hartman

genirq: Allow irq_chip registration functions to take a const irq_chip

2024-08-19T03:41:10+00:00

[ Upstream commit 393e1280f765661cf39785e967676a4e57324126 ]

In order to let a const irqchip be fed to the irqchip layer, adjust
the various prototypes. An extra cast in irq_set_chip()() is required
to avoid a warning.

Signed-off-by: Marc Zyngier 
Acked-by: Linus Walleij 
Link: https://lore.kernel.org/r/20220209162607.1118325-3-maz@kernel.org
Signed-off-by: Sasha Levin

genirq: Allow the PM device to originate from irq domain

2024-08-19T03:41:07+00:00

[ Upstream commit 1f8863bfb5ca500ea1c7669b16b1931ba27fce20 ]

As a preparation to moving the reference to the device used for
runtime power management, add a new 'dev' field to the irqdomain
structure for that exact purpose.

The irq_chip_pm_{get,put}() helpers are made aware of the dual
location via a new private helper.

No functional change intended.

Signed-off-by: Marc Zyngier 
Reviewed-by: Geert Uytterhoeven 
Tested-by: Geert Uytterhoeven 
Tested-by: Tony Lindgren 
Acked-by: Bartosz Golaszewski 
Link: https://lore.kernel.org/r/20220201120310.878267-2-maz@kernel.org
Stable-dep-of: 33b1c47d1fc0 ("irqchip/imx-irqsteer: Handle runtime power management correctly")
Signed-off-by: Sasha Levin

task_work: s/task_work_cancel()/task_work_cancel_func()/

2024-08-19T03:40:57+00:00

commit 68cbd415dd4b9c5b9df69f0f091879e56bf5907a upstream.

A proper task_work_cancel() API that actually cancels a callback and not
*any* callback pointing to a given function is going to be needed for
perf events event freeing. Do the appropriate rename to prepare for
that.

Signed-off-by: Frederic Weisbecker 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240621091601.18227-2-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman

genirq/cpuhotplug, x86/vector: Prevent vector leak during CPU offline

2024-06-16T11:32:30+00:00

commit a6c11c0a5235fb144a65e0cb2ffd360ddc1f6c32 upstream.

The absence of IRQD_MOVE_PCNTXT prevents immediate effectiveness of
interrupt affinity reconfiguration via procfs. Instead, the change is
deferred until the next instance of the interrupt being triggered on the
original CPU.

When the interrupt next triggers on the original CPU, the new affinity is
enforced within __irq_move_irq(). A vector is allocated from the new CPU,
but the old vector on the original CPU remains and is not immediately
reclaimed. Instead, apicd->move_in_progress is flagged, and the reclaiming
process is delayed until the next trigger of the interrupt on the new CPU.

Upon the subsequent triggering of the interrupt on the new CPU,
irq_complete_move() adds a task to the old CPU's vector_cleanup list if it
remains online. Subsequently, the timer on the old CPU iterates over its
vector_cleanup list, reclaiming old vectors.

However, a rare scenario arises if the old CPU is outgoing before the
interrupt triggers again on the new CPU.

In that case irq_force_complete_move() is not invoked on the outgoing CPU
to reclaim the old apicd->prev_vector because the interrupt isn't currently
affine to the outgoing CPU, and irq_needs_fixup() returns false. Even
though __vector_schedule_cleanup() is later called on the new CPU, it
doesn't reclaim apicd->prev_vector; instead, it simply resets both
apicd->move_in_progress and apicd->prev_vector to 0.

As a result, the vector remains unreclaimed in vector_matrix, leading to a
CPU vector leak.

To address this issue, move the invocation of irq_force_complete_move()
before the irq_needs_fixup() call to reclaim apicd->prev_vector, if the
interrupt is currently or used to be affine to the outgoing CPU.

Additionally, reclaim the vector in __vector_schedule_cleanup() as well,
following a warning message, although theoretically it should never see
apicd->move_in_progress with apicd->prev_cpu pointing to an offline CPU.

Fixes: f0383c24b485 ("genirq/cpuhotplug: Add support for cleaning up move in progress")
Signed-off-by: Dongli Zhang 
Signed-off-by: Thomas Gleixner 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240522220218.162423-1-dongli.zhang@oracle.com
Signed-off-by: Greg Kroah-Hartman