linux.git/kernel/irq/internals.h, branch v6.11

genirq/debugfs: Print irqdomain flags as human-readable strings

2024-06-03T10:24:51+00:00

Improve the readability of irqdomain debugging information in debugfs by
printing the flags field of domain files as human-readable strings instead
of a raw bitmask, which aligned with the existing style used for irqchip
flags in the irq debug files.

Before:
	#cat :cpus:cpu@0:interrupt-controller
	name:   :cpus:cpu@0:interrupt-controller
	 size:   0
	 mapped: 2
	 flags:  0x00000003

After:
	#cat :cpus:cpu@0:interrupt-controller
	name:   :cpus:cpu@0:interrupt-controller
	 size:   0
	 mapped: 3
	 flags:  0x00000003
	            IRQ_DOMAIN_FLAG_HIERARCHY
	            IRQ_DOMAIN_NAME_ALLOCATED

Signed-off-by: Jinjie Ruan 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20240529091628.3666379-1-ruanjinjie@huawei.com

genirq: Reuse irq_is_nmi()

2024-04-24T18:42:57+00:00

Move irq_is_nmi() to the internal header file and reuse it all over the
place.

Signed-off-by: Jinjie Ruan 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20240423024037.3331215-1-ruanjinjie@huawei.com

genirq: Avoid summation loops for /proc/interrupts

2024-04-12T15:08:05+00:00

show_interrupts() unconditionally accumulates the per CPU interrupt
statistics to determine whether an interrupt was ever raised.

This can be avoided for all interrupts which are not strictly per CPU
and not of type NMI because those interrupts provide already an
accumulated counter. The required logic is already implemented in
kstat_irqs().

Split the inner access logic out of kstat_irqs() and use it for
kstat_irqs() and show_interrupts() to avoid the accumulation loop
when possible.

Originally-by: Thomas Gleixner 
Signed-off-by: Bitao Hu 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Liu Song 
Reviewed-by: Douglas Anderson 
Link: https://lore.kernel.org/r/20240411074134.30922-4-yaoma@linux.alibaba.com

genirq: Convert kstat_irqs to a struct

2024-04-12T15:08:05+00:00

The irq_desc::kstat_irqs member is a per-CPU variable of type int, which is
only capable of counting. A snapshot mechanism for interrupt statistics
will be added soon, which requires an additional variable to store the
snapshot.

To facilitate expansion, convert kstat_irqs here to a struct containing
only the count.

Originally-by: Thomas Gleixner 
Signed-off-by: Bitao Hu 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20240411074134.30922-2-yaoma@linux.alibaba.com

genirq: Remove unused extern declaration

2023-07-31T15:27:16+00:00

commit 3795de236d67 ("genirq: Distangle kernel/irq/handle.c")
left behind this.

Signed-off-by: YueHaibing 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20230720143625.29176-1-yuehaibing@huawei.com

genirq: Prevent nested thread vs synchronize_hardirq() deadlock

2023-07-31T15:24:22+00:00

There is a possibility of deadlock if synchronize_hardirq() is called
when the nested threaded interrupt is active.  The following scenario
was observed on a uniprocessor PREEMPT_NONE system:

 Thread 1                      Thread 2

 handle_nested_thread()
  Set INPROGRESS
  Call ->thread_fn()
   thread_fn goes to sleep

                              free_irq()
                               __synchronize_hardirq()
                                Busy-loop forever waiting for INPROGRESS
                                to be cleared

The INPROGRESS flag is only supposed to be used for hard interrupt
handlers.  Remove the incorrect usage in the nested threaded interrupt
case and instead re-use the threads_active / wait_for_threads mechanism
to wait for nested threaded interrupts to complete.

Signed-off-by: Vincent Whitchurch 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20230613-genirq-nested-v3-1-ae58221143eb@axis.com

Merge tag 'irqchip-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

2023-06-26T09:05:49+00:00

Pull irqchip updates from Marc Zyngier:

  - A number of Loogson/Loogarch fixes

  - Allow the core code to retrigger an interrupt that has
    fired while the same interrupt is being handled on another
    CPU, papering over a GICv3 architecture issue

  - Work around an integration problem on ASR8601, where the CPU
    numbering isn't representable in the GIC implementation...

  - Add some missing interrupt to the STM32 irqchip

  - A bunch of warning squashing triggered by W=1 builds

Link: https://lore.kernel.org/r/20230623224345.3577134-1-maz@kernel.org

genirq: Expand doc for PENDING and REPLAY flags

2023-06-16T11:22:05+00:00

Adding a bit more info about what the flags are used for may help future
code readers.

Signed-off-by: James Gowans 
Cc: Thomas Gleixner 
Cc: Marc Zyngier 
Cc: Liao Chang 
Signed-off-by: Marc Zyngier 
Link: https://lore.kernel.org/r/20230608120021.3273400-2-jgowans@amazon.com

genirq: Use a maple tree for interrupt descriptor management

2023-05-24T09:39:44+00:00

The current implementation uses a static bitmap for interrupt descriptor
allocation and a radix tree to pointer store the pointer for lookup.

However, the size of the bitmap is constrained by the build time macro
MAX_SPARSE_IRQS, which may not be sufficient to support high-end servers,
particularly those with GICv4.1 hardware, which require a large interrupt
space to cover LPIs and vSGIs.

Replace the bitmap and the radix tree with a maple tree, which not only
stores pointers for lookup, but also provides a mechanism to find free
ranges. That removes the build time hardcoded upper limit.

Signed-off-by: Shanker Donthineni 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20230519134902.1495562-4-sdonthineni@nvidia.com

genirq: Encapsulate sparse bitmap handling

2023-05-24T09:39:44+00:00

Move the open coded sparse bitmap handling into helper functions as
a preparatory step for converting the sparse interrupt management
to a maple tree.

No functional change.

Signed-off-by: Shanker Donthineni 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20230519134902.1495562-3-sdonthineni@nvidia.com