[PATCH v2 00/25] genirq: Add support for percpu_devid IRQ affinity

[PATCH v2 00/25] genirq: Add support for percpu_devid IRQ affinity

[Marc Zyngier]

This is the second version of this series, originally posted at [1],
which aims at allowing percpu_devid interrupt requests on the basis of
an affinity mask. See the original submission for the details of why
this is a desirable outcome.

From v1, we have a number of changes, both functional and cosmetic,
but the fundamentals are pretty much the same (change log below), with
an even more appealing diffstat.

Thanks to Will, Thomas and Raphael for their constructive review
comments.

FWIW, I've pushed a branch at [2].

* From v1 [1]:

  - Fixed NMI handling by getting rid of the NMI-specific flow
    handler, which was pretty useless anyway (Will)

  - As a result, killed a metric buttload worth of GICv3 code

  - Moved irq_fwspec out of irq_fwspec_info, and passed it as a
    parameter to irq_get_fwspec_info(), renamed from irq_get_info(),
    and applied some generous sanitisation of the structure (Thomas)

  - Dropped the rather useless fwspec validity flag (Thomas)

  - Rejigged the PMU per-CPU handling to better deal with the DT/ACPI
    differences, and drop some now useless patches (Will)

  - Plenty of cosmetic rework (Raphael, Thomas)

[1] https://lore.kernel.org/r/20250908163127.2462948-1-maz@kernel.org
[2] git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git irq/ppi-affinity

Marc Zyngier (24):
  irqdomain: Add firmware info reporting interface
  ACPI: irq: Add IRQ affinity reporting interface
  of/irq: Add IRQ affinity reporting interface
  platform: Add firmware-agnostic irq and affinity retrieval interface
  irqchip/gic-v3: Add FW info retrieval support
  irqchip/apple-aic: Add FW info retrieval support
  coresight: trbe: Convert to new IRQ affinity retrieval API
  perf: arm_pmu: Convert to new IRQ affinity retrieval API
  perf: arm_spe_pmu: Convert to new IRQ affinity retrieval API
  irqchip/gic-v3: Switch high priority PPIs over to
    handle_percpu_devid_irq()
  genirq: Kill handle_percpu_devid_fasteoi_nmi()
  genirq: Merge irqaction::{dev_id,percpu_dev_id}
  genirq: Factor-in percpu irqaction creation
  genirq: Add affinity to percpu_devid interrupt requests
  genirq: Update request_percpu_nmi() to take an affinity
  genirq: Allow per-cpu interrupt sharing for non-overlapping affinities
  genirq: Add request_percpu_irq_affinity() helper
  perf: arm_spe_pmu: Request specific affinities for percpu IRQ
  coresight: trbe: Request specific affinities for percpu IRQ
  irqchip/gic-v3: Drop support for custom PPI partitions
  irqchip/apple-aic: Drop support for custom PMU irq partitions
  irqchip: Kill irq-partition-percpu
  genirq: Kill irq_{g,s}et_percpu_devid_partition()
  perf: arm_pmu: Kill last use of per-CPU cpu_armpmu pointer

Will Deacon (1):
  perf: arm_pmu: Request specific affinities for percpu NMI/IRQ

 arch/arm64/kernel/smp.c                      |   2 +-
 drivers/acpi/irq.c                           |  19 ++
 drivers/base/platform.c                      |  60 ++++-
 drivers/hwtracing/coresight/coresight-trbe.c |   9 +-
 drivers/irqchip/Kconfig                      |   4 -
 drivers/irqchip/Makefile                     |   1 -
 drivers/irqchip/irq-apple-aic.c              |  56 +++--
 drivers/irqchip/irq-gic-v3.c                 | 224 +++++------------
 drivers/irqchip/irq-partition-percpu.c       | 241 -------------------
 drivers/of/irq.c                             |  20 ++
 drivers/perf/arm_pmu.c                       |  50 ++--
 drivers/perf/arm_pmu_acpi.c                  |   2 +-
 drivers/perf/arm_pmu_platform.c              |  20 +-
 drivers/perf/arm_pmuv3.c                     |   2 +-
 drivers/perf/arm_spe_pmu.c                   |  13 +-
 include/linux/acpi.h                         |   7 +
 include/linux/interrupt.h                    |  24 +-
 include/linux/irq.h                          |   5 -
 include/linux/irqchip/irq-partition-percpu.h |  53 ----
 include/linux/irqdesc.h                      |   1 -
 include/linux/irqdomain.h                    |  28 +++
 include/linux/of_irq.h                       |   7 +
 include/linux/perf/arm_pmu.h                 |   6 +-
 include/linux/platform_device.h              |   2 +
 kernel/irq/chip.c                            |  36 +--
 kernel/irq/irqdesc.c                         |  24 +-
 kernel/irq/irqdomain.c                       |  32 ++-
 kernel/irq/manage.c                          | 124 +++++++---
 28 files changed, 423 insertions(+), 649 deletions(-)
 delete mode 100644 drivers/irqchip/irq-partition-percpu.c
 delete mode 100644 include/linux/irqchip/irq-partition-percpu.h

-- 
2.39.2

[PATCH v2 01/25] irqdomain: Add firmware info reporting interface

[Marc Zyngier]

Allow an irqdomain callback to report firmware-provided information
that is otherwise not available in a generic way. This is reported
using a new data structure (struct irq_fwspec_info).

This callback is optional and the only information that can be
reported currently is the affinity of an interrupt. However, the
containing structure is designed to be extensible, allowing other
potentially relevant information to be reported in the future.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 include/linux/irqdomain.h | 28 ++++++++++++++++++++++++++++
 kernel/irq/irqdomain.c    | 32 +++++++++++++++++++++++++++-----
 2 files changed, 55 insertions(+), 5 deletions(-)

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 4a86e6b915dd6..34993bf8293c4 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -44,6 +44,24 @@ struct irq_fwspec {
 	u32			param[IRQ_DOMAIN_IRQ_SPEC_PARAMS];
 };
 
+/**
+ * struct irq_fwspec_info - firmware provided IRQ information structure
+ *
+ * @fwspec:		Firmware-specific interrupt specifier
+ * @cpumask:		Affinity mask for this interrupt
+ * @flags:		Information validity flags
+ *
+ * This structure reports firmware-specific information about an
+ * interrupt. The only significant information is the affinity of a
+ * per-CPU interrupt, but this is designed to be extended as required.
+ */
+struct irq_fwspec_info {
+	unsigned long		flags;
+	const struct cpumask	*affinity;
+};
+
+#define IRQ_FWSPEC_INFO_AFFINITY_VALID	BIT(0)
+
 /* Conversion function from of_phandle_args fields to fwspec  */
 void of_phandle_args_to_fwspec(struct device_node *np, const u32 *args,
 			       unsigned int count, struct irq_fwspec *fwspec);
@@ -69,6 +87,9 @@ void of_phandle_args_to_fwspec(struct device_node *np, const u32 *args,
  * @translate:	Given @fwspec, decode the hardware irq number (@out_hwirq) and
  *		linux irq type value (@out_type). This is a generalised @xlate
  *		(over struct irq_fwspec) and is preferred if provided.
+ * @get_fwspec_info:
+ *		Given @fwspec, report additional firmware-provided information in
+ *		@info. Optional.
  * @debug_show:	For domains to show specific data for an interrupt in debugfs.
  *
  * Functions below are provided by the driver and called whenever a new mapping
@@ -96,6 +117,7 @@ struct irq_domain_ops {
 	void	(*deactivate)(struct irq_domain *d, struct irq_data *irq_data);
 	int	(*translate)(struct irq_domain *d, struct irq_fwspec *fwspec,
 			     unsigned long *out_hwirq, unsigned int *out_type);
+	int	(*get_fwspec_info)(struct irq_fwspec *fwspec, struct irq_fwspec_info *info);
 #endif
 #ifdef CONFIG_GENERIC_IRQ_DEBUGFS
 	void	(*debug_show)(struct seq_file *m, struct irq_domain *d,
@@ -602,6 +624,8 @@ void irq_domain_free_irqs_parent(struct irq_domain *domain, unsigned int irq_bas
 
 int irq_domain_disconnect_hierarchy(struct irq_domain *domain, unsigned int virq);
 
+int irq_populate_fwspec_info(struct irq_fwspec *fwspec, struct irq_fwspec_info *info);
+
 static inline bool irq_domain_is_hierarchy(struct irq_domain *domain)
 {
 	return domain->flags & IRQ_DOMAIN_FLAG_HIERARCHY;
@@ -685,6 +709,10 @@ static inline bool irq_domain_is_msi_device(struct irq_domain *domain)
 	return false;
 }
 
+static inline int irq_populate_fwspec_info(struct irq_fwspec *fwspec, struct irq_fwspec_info *info)
+{
+	return -EINVAL;
+}
 #endif	/* CONFIG_IRQ_DOMAIN_HIERARCHY */
 
 #ifdef CONFIG_GENERIC_MSI_IRQ
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index dc473faadcc81..2652c4cfd877f 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -867,13 +867,9 @@ void of_phandle_args_to_fwspec(struct device_node *np, const u32 *args,
 }
 EXPORT_SYMBOL_GPL(of_phandle_args_to_fwspec);
 
-unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
+static struct irq_domain *fwspec_to_domain(struct irq_fwspec *fwspec)
 {
 	struct irq_domain *domain;
-	struct irq_data *irq_data;
-	irq_hw_number_t hwirq;
-	unsigned int type = IRQ_TYPE_NONE;
-	int virq;
 
 	if (fwspec->fwnode) {
 		domain = irq_find_matching_fwspec(fwspec, DOMAIN_BUS_WIRED);
@@ -883,6 +879,32 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
 		domain = irq_default_domain;
 	}
 
+	return domain;
+}
+
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+int irq_populate_fwspec_info(struct irq_fwspec *fwspec, struct irq_fwspec_info *info)
+{
+	struct irq_domain *domain = fwspec_to_domain(fwspec);
+
+	memset(info, 0, sizeof(*info));
+
+	if (!domain || !domain->ops->get_fwspec_info)
+		return 0;
+
+	return domain->ops->get_fwspec_info(fwspec, info);
+}
+#endif
+
+unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
+{
+	unsigned int type = IRQ_TYPE_NONE;
+	struct irq_domain *domain;
+	struct irq_data *irq_data;
+	irq_hw_number_t hwirq;
+	int virq;
+
+	domain = fwspec_to_domain(fwspec);
 	if (!domain) {
 		pr_warn("no irq domain found for %s !\n",
 			of_node_full_name(to_of_node(fwspec->fwnode)));
-- 
2.39.2

Re: [PATCH v2 01/25] irqdomain: Add firmware info reporting interface

[Jonathan Cameron]

On Mon, 15 Sep 2025 09:56:38 +0100
Marc Zyngier <maz@kernel.org> wrote:

> Allow an irqdomain callback to report firmware-provided information
> that is otherwise not available in a generic way. This is reported
> using a new data structure (struct irq_fwspec_info).
> 
> This callback is optional and the only information that can be
> reported currently is the affinity of an interrupt. However, the
> containing structure is designed to be extensible, allowing other
> potentially relevant information to be reported in the future.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
Hi Marc,

> ---
>  include/linux/irqdomain.h | 28 ++++++++++++++++++++++++++++
>  kernel/irq/irqdomain.c    | 32 +++++++++++++++++++++++++++-----
>  2 files changed, 55 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
> index 4a86e6b915dd6..34993bf8293c4 100644
> --- a/include/linux/irqdomain.h
> +++ b/include/linux/irqdomain.h
> @@ -44,6 +44,24 @@ struct irq_fwspec {
>  	u32			param[IRQ_DOMAIN_IRQ_SPEC_PARAMS];
>  };
>  
> +/**
> + * struct irq_fwspec_info - firmware provided IRQ information structure
> + *
> + * @fwspec:		Firmware-specific interrupt specifier

Not aligning with what is in the structure that I can see.

> + * @cpumask:		Affinity mask for this interrupt
> + * @flags:		Information validity flags
> + *
> + * This structure reports firmware-specific information about an
> + * interrupt. The only significant information is the affinity of a
> + * per-CPU interrupt, but this is designed to be extended as required.
> + */
> +struct irq_fwspec_info {
> +	unsigned long		flags;
> +	const struct cpumask	*affinity;
> +};

Re: [PATCH v2 01/25] irqdomain: Add firmware info reporting interface

[Marc Zyngier]

On Tue, 16 Sep 2025 16:14:38 +0100,
Jonathan Cameron <jonathan.cameron@huawei.com> wrote:
> 
> On Mon, 15 Sep 2025 09:56:38 +0100
> Marc Zyngier <maz@kernel.org> wrote:
> 
> > Allow an irqdomain callback to report firmware-provided information
> > that is otherwise not available in a generic way. This is reported
> > using a new data structure (struct irq_fwspec_info).
> > 
> > This callback is optional and the only information that can be
> > reported currently is the affinity of an interrupt. However, the
> > containing structure is designed to be extensible, allowing other
> > potentially relevant information to be reported in the future.
> > 
> > Signed-off-by: Marc Zyngier <maz@kernel.org>
> Hi Marc,
> 
> > ---
> >  include/linux/irqdomain.h | 28 ++++++++++++++++++++++++++++
> >  kernel/irq/irqdomain.c    | 32 +++++++++++++++++++++++++++-----
> >  2 files changed, 55 insertions(+), 5 deletions(-)
> > 
> > diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
> > index 4a86e6b915dd6..34993bf8293c4 100644
> > --- a/include/linux/irqdomain.h
> > +++ b/include/linux/irqdomain.h
> > @@ -44,6 +44,24 @@ struct irq_fwspec {
> >  	u32			param[IRQ_DOMAIN_IRQ_SPEC_PARAMS];
> >  };
> >  
> > +/**
> > + * struct irq_fwspec_info - firmware provided IRQ information structure
> > + *
> > + * @fwspec:		Firmware-specific interrupt specifier
> 
> Not aligning with what is in the structure that I can see.

Ah crap, I missed that one. I'll stash another fix for the next
version.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

[PATCH v2 02/25] ACPI: irq: Add IRQ affinity reporting interface

[Marc Zyngier]

Plug the irq_populate_fwspec_info() helper into the ACPI layer
to offer an IRQ affinity reporting function. This is currently
only supported for the CONFIG_ACPI_GENERIC_GSI configurations,
but could later be extended to legacy architectures if necessary.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/acpi/irq.c   | 19 +++++++++++++++++++
 include/linux/acpi.h |  7 +++++++
 2 files changed, 26 insertions(+)

diff --git a/drivers/acpi/irq.c b/drivers/acpi/irq.c
index 76a856c32c4d0..d1595156c86a4 100644
--- a/drivers/acpi/irq.c
+++ b/drivers/acpi/irq.c
@@ -300,6 +300,25 @@ int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
 }
 EXPORT_SYMBOL_GPL(acpi_irq_get);
 
+const struct cpumask *acpi_irq_get_affinity(acpi_handle handle,
+					    unsigned int index)
+{
+	struct irq_fwspec_info info;
+	struct irq_fwspec fwspec;
+	unsigned long flags;
+
+	if (acpi_irq_parse_one(handle, index, &fwspec, &flags))
+		return NULL;
+
+	if (irq_populate_fwspec_info(&fwspec, &info))
+		return NULL;
+
+	if (!(info.flags & IRQ_FWSPEC_INFO_AFFINITY_VALID))
+		return NULL;
+
+	return info.affinity;
+}
+
 /**
  * acpi_set_irq_model - Setup the GSI irqdomain information
  * @model: the value assigned to acpi_irq_model
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 1c5bb1e887cd1..c506ae4bacc86 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1509,12 +1509,19 @@ static inline int acpi_parse_spcr(bool enable_earlycon, bool enable_console)
 
 #if IS_ENABLED(CONFIG_ACPI_GENERIC_GSI)
 int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res);
+const struct cpumask *acpi_irq_get_affinity(acpi_handle handle,
+					    unsigned int index);
 #else
 static inline
 int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
 {
 	return -EINVAL;
 }
+static inline const struct cpumask *acpi_irq_get_affinity(acpi_handle handle,
+							  unsigned int index)
+{
+	return NULL;
+}
 #endif
 
 #ifdef CONFIG_ACPI_LPIT
-- 
2.39.2

Re: [PATCH v2 02/25] ACPI: irq: Add IRQ affinity reporting interface

[Rafael J. Wysocki]

On Mon, Sep 15, 2025 at 10:57 AM Marc Zyngier <maz@kernel.org> wrote:
>
> Plug the irq_populate_fwspec_info() helper into the ACPI layer
> to offer an IRQ affinity reporting function. This is currently
> only supported for the CONFIG_ACPI_GENERIC_GSI configurations,
> but could later be extended to legacy architectures if necessary.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>

Acked-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>

> ---
>  drivers/acpi/irq.c   | 19 +++++++++++++++++++
>  include/linux/acpi.h |  7 +++++++
>  2 files changed, 26 insertions(+)
>
> diff --git a/drivers/acpi/irq.c b/drivers/acpi/irq.c
> index 76a856c32c4d0..d1595156c86a4 100644
> --- a/drivers/acpi/irq.c
> +++ b/drivers/acpi/irq.c
> @@ -300,6 +300,25 @@ int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
>  }
>  EXPORT_SYMBOL_GPL(acpi_irq_get);
>
> +const struct cpumask *acpi_irq_get_affinity(acpi_handle handle,
> +                                           unsigned int index)
> +{
> +       struct irq_fwspec_info info;
> +       struct irq_fwspec fwspec;
> +       unsigned long flags;
> +
> +       if (acpi_irq_parse_one(handle, index, &fwspec, &flags))
> +               return NULL;
> +
> +       if (irq_populate_fwspec_info(&fwspec, &info))
> +               return NULL;
> +
> +       if (!(info.flags & IRQ_FWSPEC_INFO_AFFINITY_VALID))
> +               return NULL;
> +
> +       return info.affinity;
> +}
> +
>  /**
>   * acpi_set_irq_model - Setup the GSI irqdomain information
>   * @model: the value assigned to acpi_irq_model
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 1c5bb1e887cd1..c506ae4bacc86 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -1509,12 +1509,19 @@ static inline int acpi_parse_spcr(bool enable_earlycon, bool enable_console)
>
>  #if IS_ENABLED(CONFIG_ACPI_GENERIC_GSI)
>  int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res);
> +const struct cpumask *acpi_irq_get_affinity(acpi_handle handle,
> +                                           unsigned int index);
>  #else
>  static inline
>  int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
>  {
>         return -EINVAL;
>  }
> +static inline const struct cpumask *acpi_irq_get_affinity(acpi_handle handle,
> +                                                         unsigned int index)
> +{
> +       return NULL;
> +}
>  #endif
>
>  #ifdef CONFIG_ACPI_LPIT
> --
> 2.39.2
>

[PATCH v2 03/25] of/irq: Add IRQ affinity reporting interface

[Marc Zyngier]

Plug the irq_populate_fwspec_info() helper into the OF layer
to offer an IRQ affinity reporting function.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/of/irq.c       | 20 ++++++++++++++++++++
 include/linux/of_irq.h |  7 +++++++
 2 files changed, 27 insertions(+)

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 74aaea61de13c..9a205cb033bda 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -479,6 +479,26 @@ int of_irq_get(struct device_node *dev, int index)
 }
 EXPORT_SYMBOL_GPL(of_irq_get);
 
+const struct cpumask *of_irq_get_affinity(struct device_node *dev, int index)
+{
+	struct of_phandle_args oirq;
+	struct irq_fwspec_info info;
+	struct irq_fwspec fwspec;
+	int rc;
+
+	rc = of_irq_parse_one(dev, index, &oirq);
+	if (rc)
+		return NULL;
+
+	of_phandle_args_to_fwspec(oirq.np, oirq.args, oirq.args_count,
+				  &fwspec);
+
+	if (!irq_populate_fwspec_info(&fwspec, &info))
+		return info.affinity;
+
+	return NULL;
+}
+
 /**
  * of_irq_get_byname - Decode a node's IRQ and return it as a Linux IRQ number
  * @dev: pointer to device tree node
diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
index a480063c9cb19..721cbdbc292df 100644
--- a/include/linux/of_irq.h
+++ b/include/linux/of_irq.h
@@ -43,6 +43,8 @@ extern int of_irq_parse_one(struct device_node *device, int index,
 			  struct of_phandle_args *out_irq);
 extern int of_irq_count(struct device_node *dev);
 extern int of_irq_get(struct device_node *dev, int index);
+extern const struct cpumask *of_irq_get_affinity(struct device_node *dev,
+						      int index);
 extern int of_irq_get_byname(struct device_node *dev, const char *name);
 extern int of_irq_to_resource_table(struct device_node *dev,
 		struct resource *res, int nr_irqs);
@@ -77,6 +79,11 @@ static inline int of_irq_get_byname(struct device_node *dev, const char *name)
 {
 	return 0;
 }
+static inline const struct cpumask *of_irq_get_affinity(struct device_node *dev,
+							int index)
+{
+	return NULL;
+}
 static inline int of_irq_to_resource_table(struct device_node *dev,
 					   struct resource *res, int nr_irqs)
 {
-- 
2.39.2

[PATCH v2 04/25] platform: Add firmware-agnostic irq and affinity retrieval interface

[Marc Zyngier]

Expand platform_get_irq_optional() to also return an affinity if
available, renaming it to platform_get_irq_affinity() in the
process.

platform_get_irq_optional() is preserved with its current semantics
by calling into the new helper with a NULL affinity pointer.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/base/platform.c         | 60 +++++++++++++++++++++++++++------
 include/linux/platform_device.h |  2 ++
 2 files changed, 52 insertions(+), 10 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 09450349cf323..fad33d6b2349a 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -150,25 +150,37 @@ devm_platform_ioremap_resource_byname(struct platform_device *pdev,
 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname);
 #endif /* CONFIG_HAS_IOMEM */
 
+static const struct cpumask *get_irq_affinity(struct platform_device *dev,
+					      unsigned int num)
+{
+	const struct cpumask *mask = NULL;
+#ifndef CONFIG_SPARC
+	struct fwnode_handle *fwnode = dev_fwnode(&dev->dev);
+
+	if (is_of_node(fwnode))
+		mask = of_irq_get_affinity(to_of_node(fwnode), num);
+	else if (is_acpi_device_node(fwnode))
+		mask = acpi_irq_get_affinity(ACPI_HANDLE_FWNODE(fwnode), num);
+#endif
+
+	return mask ?: cpu_possible_mask;
+}
+
 /**
- * platform_get_irq_optional - get an optional IRQ for a device
+ * platform_get_irq_affinity - get an optional IRQ and its affnity for a device
  * @dev: platform device
  * @num: IRQ number index
+ * @affinity: optional cpumask pointer to get the affinity of a per-cpu IRQ
  *
  * Gets an IRQ for a platform device. Device drivers should check the return
  * value for errors so as to not pass a negative integer value to the
- * request_irq() APIs. This is the same as platform_get_irq(), except that it
- * does not print an error message if an IRQ can not be obtained.
- *
- * For example::
- *
- *		int irq = platform_get_irq_optional(pdev, 0);
- *		if (irq < 0)
- *			return irq;
+ * request_irq() APIs. Optional affinity information is provided in the
+ * affinity pointer if available, and NULL otherwise.
  *
  * Return: non-zero IRQ number on success, negative error number on failure.
  */
-int platform_get_irq_optional(struct platform_device *dev, unsigned int num)
+int platform_get_irq_affinity(struct platform_device *dev, unsigned int num,
+			      const struct cpumask **affinity)
 {
 	int ret;
 #ifdef CONFIG_SPARC
@@ -236,8 +248,36 @@ int platform_get_irq_optional(struct platform_device *dev, unsigned int num)
 out:
 	if (WARN(!ret, "0 is an invalid IRQ number\n"))
 		return -EINVAL;
+
+	if (ret > 0 && affinity)
+		*affinity = get_irq_affinity(dev, num);
+
 	return ret;
 }
+EXPORT_SYMBOL_GPL(platform_get_irq_affinity);
+
+/**
+ * platform_get_irq_optional - get an optional IRQ for a device
+ * @dev: platform device
+ * @num: IRQ number index
+ *
+ * Gets an IRQ for a platform device. Device drivers should check the return
+ * value for errors so as to not pass a negative integer value to the
+ * request_irq() APIs. This is the same as platform_get_irq(), except that it
+ * does not print an error message if an IRQ can not be obtained.
+ *
+ * For example::
+ *
+ *		int irq = platform_get_irq_optional(pdev, 0);
+ *		if (irq < 0)
+ *			return irq;
+ *
+ * Return: non-zero IRQ number on success, negative error number on failure.
+ */
+int platform_get_irq_optional(struct platform_device *dev, unsigned int num)
+{
+	return platform_get_irq_affinity(dev, num, NULL);
+}
 EXPORT_SYMBOL_GPL(platform_get_irq_optional);
 
 /**
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 074754c23d330..ad66333ce85ce 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -102,6 +102,8 @@ devm_platform_ioremap_resource_byname(struct platform_device *pdev,
 
 extern int platform_get_irq(struct platform_device *, unsigned int);
 extern int platform_get_irq_optional(struct platform_device *, unsigned int);
+extern int platform_get_irq_affinity(struct platform_device *, unsigned int,
+				     const struct cpumask **);
 extern int platform_irq_count(struct platform_device *);
 extern int devm_platform_get_irqs_affinity(struct platform_device *dev,
 					   struct irq_affinity *affd,
-- 
2.39.2

Re: [PATCH v2 04/25] platform: Add firmware-agnostic irq and affinity retrieval interface

[Jonathan Cameron]

On Mon, 15 Sep 2025 09:56:41 +0100
Marc Zyngier <maz@kernel.org> wrote:

> Expand platform_get_irq_optional() to also return an affinity if
> available, renaming it to platform_get_irq_affinity() in the
> process.
> 
> platform_get_irq_optional() is preserved with its current semantics
> by calling into the new helper with a NULL affinity pointer.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>  drivers/base/platform.c         | 60 +++++++++++++++++++++++++++------
>  include/linux/platform_device.h |  2 ++
>  2 files changed, 52 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index 09450349cf323..fad33d6b2349a 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c

>  /**
> - * platform_get_irq_optional - get an optional IRQ for a device
> + * platform_get_irq_affinity - get an optional IRQ and its affnity for a device

affinity

>   * @dev: platform device
>   * @num: IRQ number index
> + * @affinity: optional cpumask pointer to get the affinity of a per-cpu IRQ
>   *


> diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
> index 074754c23d330..ad66333ce85ce 100644
> --- a/include/linux/platform_device.h
> +++ b/include/linux/platform_device.h
> @@ -102,6 +102,8 @@ devm_platform_ioremap_resource_byname(struct platform_device *pdev,
>  
>  extern int platform_get_irq(struct platform_device *, unsigned int);
>  extern int platform_get_irq_optional(struct platform_device *, unsigned int);
> +extern int platform_get_irq_affinity(struct platform_device *, unsigned int,
> +				     const struct cpumask **);
>  extern int platform_irq_count(struct platform_device *);
>  extern int devm_platform_get_irqs_affinity(struct platform_device *dev,
>  					   struct irq_affinity *affd,

[PATCH v2 05/25] irqchip/gic-v3: Add FW info retrieval support

[Marc Zyngier]

Plug the new .get_info() callback into the GICv3 core driver,
using some of the existing PPI affinity handling infrastructure.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/irqchip/irq-gic-v3.c | 53 ++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index dbeb85677b08c..71c278ddd1e39 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -69,6 +69,8 @@ struct gic_chip_data {
 	bool			has_rss;
 	unsigned int		ppi_nr;
 	struct partition_desc	**ppi_descs;
+	struct partition_affinity *parts;
+	unsigned int		nr_parts;
 };
 
 #define T241_CHIPS_MAX		4
@@ -1796,11 +1798,58 @@ static int gic_irq_domain_select(struct irq_domain *d,
 	return d == partition_get_domain(gic_data.ppi_descs[ppi_idx]);
 }
 
+static int gic_irq_get_fwspec_info(struct irq_fwspec *fwspec, struct irq_fwspec_info *info)
+{
+	const struct cpumask *mask = NULL;
+
+	info->flags = 0;
+	info->affinity = NULL;
+
+	/* ACPI is not capable of describing PPI affinity -- yet */
+	if (!is_of_node(fwspec->fwnode))
+		return 0;
+
+	/* If the specifier provides an affinity, use it */
+	if (fwspec->param_count == 4 && fwspec->param[3]) {
+		struct fwnode_handle *fw;
+
+		switch (fwspec->param[0]) {
+		case 1:			/* PPI */
+		case 3:			/* EPPI */
+			break;
+		default:
+			return 0;
+		}
+
+		fw = of_node_to_fwnode(of_find_node_by_phandle(fwspec->param[3]));
+		if (!fw)
+			return -ENOENT;
+
+		for (int i = 0; i < gic_data.nr_parts; i++) {
+			if (gic_data.parts[i].partition_id == fw) {
+				mask = &gic_data.parts[i].mask;
+				break;
+			}
+		}
+
+		if (!mask)
+			return -ENOENT;
+	} else {
+		mask = cpu_possible_mask;
+	}
+
+	info->affinity = mask;
+	info->flags = IRQ_FWSPEC_INFO_AFFINITY_VALID;
+
+	return 0;
+}
+
 static const struct irq_domain_ops gic_irq_domain_ops = {
 	.translate = gic_irq_domain_translate,
 	.alloc = gic_irq_domain_alloc,
 	.free = gic_irq_domain_free,
 	.select = gic_irq_domain_select,
+	.get_fwspec_info = gic_irq_get_fwspec_info,
 };
 
 static int partition_domain_translate(struct irq_domain *d,
@@ -1839,6 +1888,7 @@ static int partition_domain_translate(struct irq_domain *d,
 static const struct irq_domain_ops partition_domain_ops = {
 	.translate = partition_domain_translate,
 	.select = gic_irq_domain_select,
+	.get_fwspec_info = gic_irq_get_fwspec_info,
 };
 
 static bool gic_enable_quirk_msm8996(void *data)
@@ -2231,6 +2281,9 @@ static void __init gic_populate_ppi_partitions(struct device_node *gic_node)
 		part_idx++;
 	}
 
+	gic_data.parts = parts;
+	gic_data.nr_parts = nr_parts;
+
 	for (i = 0; i < gic_data.ppi_nr; i++) {
 		unsigned int irq;
 		struct partition_desc *desc;
-- 
2.39.2

Re: [PATCH v2 05/25] irqchip/gic-v3: Add FW info retrieval support

[Jonathan Cameron]

On Mon, 15 Sep 2025 09:56:42 +0100
Marc Zyngier <maz@kernel.org> wrote:

> Plug the new .get_info() callback into the GICv3 core driver,
> using some of the existing PPI affinity handling infrastructure.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
Hi Marc,

Yet another trivial comment. It's one of those days it seems :)

> ---
>  drivers/irqchip/irq-gic-v3.c | 53 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
> 
> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
> index dbeb85677b08c..71c278ddd1e39 100644
> --- a/drivers/irqchip/irq-gic-v3.c
> +++ b/drivers/irqchip/irq-gic-v3.c
> @@ -69,6 +69,8 @@ struct gic_chip_data {
>  	bool			has_rss;
>  	unsigned int		ppi_nr;
>  	struct partition_desc	**ppi_descs;
> +	struct partition_affinity *parts;
> +	unsigned int		nr_parts;
>  };
>  
>  #define T241_CHIPS_MAX		4
> @@ -1796,11 +1798,58 @@ static int gic_irq_domain_select(struct irq_domain *d,
>  	return d == partition_get_domain(gic_data.ppi_descs[ppi_idx]);
>  }
>  
> +static int gic_irq_get_fwspec_info(struct irq_fwspec *fwspec, struct irq_fwspec_info *info)
> +{
> +	const struct cpumask *mask = NULL;
> +
> +	info->flags = 0;
> +	info->affinity = NULL;
> +
> +	/* ACPI is not capable of describing PPI affinity -- yet */
> +	if (!is_of_node(fwspec->fwnode))
> +		return 0;
> +
> +	/* If the specifier provides an affinity, use it */
> +	if (fwspec->param_count == 4 && fwspec->param[3]) {
> +		struct fwnode_handle *fw;
> +
> +		switch (fwspec->param[0]) {
> +		case 1:			/* PPI */
> +		case 3:			/* EPPI */
> +			break;
> +		default:
> +			return 0;
> +		}
> +
> +		fw = of_node_to_fwnode(of_find_node_by_phandle(fwspec->param[3]));

of_node_to_fwnode() has a note that says it'll be removed in the merge window.
It was enough of an oddity I wondered why it existed.

Of course it did say it would be removed in the previous merge window and wasn't...
Probably want of_fwnode_handle()



> +		if (!fw)
> +			return -ENOENT;
> +
> +		for (int i = 0; i < gic_data.nr_parts; i++) {
> +			if (gic_data.parts[i].partition_id == fw) {
> +				mask = &gic_data.parts[i].mask;
> +				break;
> +			}
> +		}
> +
> +		if (!mask)
> +			return -ENOENT;
> +	} else {
> +		mask = cpu_possible_mask;
> +	}
> +
> +	info->affinity = mask;
> +	info->flags = IRQ_FWSPEC_INFO_AFFINITY_VALID;
> +
> +	return 0;

Re: [PATCH v2 05/25] irqchip/gic-v3: Add FW info retrieval support

[Marc Zyngier]

On Tue, 16 Sep 2025 16:34:13 +0100,
Jonathan Cameron <jonathan.cameron@huawei.com> wrote:
> 
> On Mon, 15 Sep 2025 09:56:42 +0100
> Marc Zyngier <maz@kernel.org> wrote:
> 
> > Plug the new .get_info() callback into the GICv3 core driver,
> > using some of the existing PPI affinity handling infrastructure.
> > 
> > Signed-off-by: Marc Zyngier <maz@kernel.org>
> Hi Marc,
> 
> Yet another trivial comment. It's one of those days it seems :)

No worries, your trivial comments are far more interesting than some
of the emails I'm otherwise getting.. ;-)

> 
> > ---
> >  drivers/irqchip/irq-gic-v3.c | 53 ++++++++++++++++++++++++++++++++++++
> >  1 file changed, 53 insertions(+)
> > 
> > diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
> > index dbeb85677b08c..71c278ddd1e39 100644
> > --- a/drivers/irqchip/irq-gic-v3.c
> > +++ b/drivers/irqchip/irq-gic-v3.c
> > @@ -69,6 +69,8 @@ struct gic_chip_data {
> >  	bool			has_rss;
> >  	unsigned int		ppi_nr;
> >  	struct partition_desc	**ppi_descs;
> > +	struct partition_affinity *parts;
> > +	unsigned int		nr_parts;
> >  };
> >  
> >  #define T241_CHIPS_MAX		4
> > @@ -1796,11 +1798,58 @@ static int gic_irq_domain_select(struct irq_domain *d,
> >  	return d == partition_get_domain(gic_data.ppi_descs[ppi_idx]);
> >  }
> >  
> > +static int gic_irq_get_fwspec_info(struct irq_fwspec *fwspec, struct irq_fwspec_info *info)
> > +{
> > +	const struct cpumask *mask = NULL;
> > +
> > +	info->flags = 0;
> > +	info->affinity = NULL;
> > +
> > +	/* ACPI is not capable of describing PPI affinity -- yet */
> > +	if (!is_of_node(fwspec->fwnode))
> > +		return 0;
> > +
> > +	/* If the specifier provides an affinity, use it */
> > +	if (fwspec->param_count == 4 && fwspec->param[3]) {
> > +		struct fwnode_handle *fw;
> > +
> > +		switch (fwspec->param[0]) {
> > +		case 1:			/* PPI */
> > +		case 3:			/* EPPI */
> > +			break;
> > +		default:
> > +			return 0;
> > +		}
> > +
> > +		fw = of_node_to_fwnode(of_find_node_by_phandle(fwspec->param[3]));
> 
> of_node_to_fwnode() has a note that says it'll be removed in the merge window.
> It was enough of an oddity I wondered why it existed.

Cargo culted, obviously. And yet another sign that I've been sitting
on these patches for way too long...

> Of course it did say it would be removed in the previous merge window and wasn't...
> Probably want of_fwnode_handle()

Thanks for the hint, I'll add that to v3.

	M.

-- 
Without deviation from the norm, progress is not possible.

[PATCH v2 06/25] irqchip/apple-aic: Add FW info retrieval support

[Marc Zyngier]

Plug the new .get_info() callback into the Apple AIC driver,
using some of the existing FIQ affinity handling infrastructure.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/irqchip/irq-apple-aic.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/irqchip/irq-apple-aic.c b/drivers/irqchip/irq-apple-aic.c
index 032d66dceb8ec..cb8b6f40ce8d3 100644
--- a/drivers/irqchip/irq-apple-aic.c
+++ b/drivers/irqchip/irq-apple-aic.c
@@ -651,6 +651,33 @@ static int aic_irq_domain_map(struct irq_domain *id, unsigned int irq,
 	return 0;
 }
 
+static int aic_irq_get_fwspec_info(struct irq_fwspec *fwspec, struct irq_fwspec_info *info)
+{
+	const struct cpumask *mask;
+	u32 intid;
+
+	info->flags = 0;
+	info->affinity = NULL;
+
+	if (fwspec->param[0] != AIC_FIQ)
+		return 0;
+
+	if (fwspec->param_count == 3)
+		intid = fwspec->param[1];
+	else
+		intid = fwspec->param[2];
+
+	if (aic_irqc->fiq_aff[intid])
+		mask = &aic_irqc->fiq_aff[intid]->aff;
+	else
+		mask = cpu_possible_mask;
+
+	info->affinity = mask;
+	info->flags = IRQ_FWSPEC_INFO_AFFINITY_VALID;
+
+	return 0;
+}
+
 static int aic_irq_domain_translate(struct irq_domain *id,
 				    struct irq_fwspec *fwspec,
 				    unsigned long *hwirq,
@@ -753,6 +780,7 @@ static const struct irq_domain_ops aic_irq_domain_ops = {
 	.translate	= aic_irq_domain_translate,
 	.alloc		= aic_irq_domain_alloc,
 	.free		= aic_irq_domain_free,
+	.get_fwspec_info = aic_irq_get_fwspec_info,
 };
 
 /*
-- 
2.39.2

Re: [PATCH v2 06/25] irqchip/apple-aic: Add FW info retrieval support

[Sven Peter]

On 15.09.25 10:56, Marc Zyngier wrote:
> Plug the new .get_info() callback into the Apple AIC driver,
> using some of the existing FIQ affinity handling infrastructure.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---

Acked-by: Sven Peter <sven@kernel.org>



Best,


Sven

[PATCH v2 07/25] coresight: trbe: Convert to new IRQ affinity retrieval API

[Marc Zyngier]

Now that the relevant interrupt controllers are equipped with
a callback returning the affinity of per-CPU interrupts, switch
the TRBE driver over to this new method.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/hwtracing/coresight/coresight-trbe.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index 8267dd1a2130d..c512f8faa6012 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -1472,9 +1472,10 @@ static void arm_trbe_remove_cpuhp(struct trbe_drvdata *drvdata)
 static int arm_trbe_probe_irq(struct platform_device *pdev,
 			      struct trbe_drvdata *drvdata)
 {
+	const struct cpumask *affinity;
 	int ret;
 
-	drvdata->irq = platform_get_irq(pdev, 0);
+	drvdata->irq = platform_get_irq_affinity(pdev, 0, &affinity);
 	if (drvdata->irq < 0) {
 		pr_err("IRQ not found for the platform device\n");
 		return drvdata->irq;
@@ -1485,8 +1486,7 @@ static int arm_trbe_probe_irq(struct platform_device *pdev,
 		return -EINVAL;
 	}
 
-	if (irq_get_percpu_devid_partition(drvdata->irq, &drvdata->supported_cpus))
-		return -EINVAL;
+	cpumask_copy(&drvdata->supported_cpus, affinity);
 
 	drvdata->handle = alloc_percpu(struct perf_output_handle *);
 	if (!drvdata->handle)
-- 
2.39.2

Re: [PATCH v2 07/25] coresight: trbe: Convert to new IRQ affinity retrieval API

[Suzuki K Poulose]

On 15/09/2025 09:56, Marc Zyngier wrote:
> Now that the relevant interrupt controllers are equipped with
> a callback returning the affinity of per-CPU interrupts, switch
> the TRBE driver over to this new method.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>

Assuming this goes via irqchip tree,

Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>


> ---
>   drivers/hwtracing/coresight/coresight-trbe.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
> index 8267dd1a2130d..c512f8faa6012 100644
> --- a/drivers/hwtracing/coresight/coresight-trbe.c
> +++ b/drivers/hwtracing/coresight/coresight-trbe.c
> @@ -1472,9 +1472,10 @@ static void arm_trbe_remove_cpuhp(struct trbe_drvdata *drvdata)
>   static int arm_trbe_probe_irq(struct platform_device *pdev,
>   			      struct trbe_drvdata *drvdata)
>   {
> +	const struct cpumask *affinity;
>   	int ret;
>   
> -	drvdata->irq = platform_get_irq(pdev, 0);
> +	drvdata->irq = platform_get_irq_affinity(pdev, 0, &affinity);
>   	if (drvdata->irq < 0) {
>   		pr_err("IRQ not found for the platform device\n");
>   		return drvdata->irq;
> @@ -1485,8 +1486,7 @@ static int arm_trbe_probe_irq(struct platform_device *pdev,
>   		return -EINVAL;
>   	}
>   
> -	if (irq_get_percpu_devid_partition(drvdata->irq, &drvdata->supported_cpus))
> -		return -EINVAL;
> +	cpumask_copy(&drvdata->supported_cpus, affinity);
>   
>   	drvdata->handle = alloc_percpu(struct perf_output_handle *);
>   	if (!drvdata->handle)

[PATCH v2 08/25] perf: arm_pmu: Convert to new IRQ affinity retrieval API

[Marc Zyngier]

Now that the relevant interrupt controllers are equipped with
a callback returning the affinity of per-CPU interrupts, switch
the OF side of the ARM PMU driver over to this new method.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/perf/arm_pmu_platform.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/perf/arm_pmu_platform.c b/drivers/perf/arm_pmu_platform.c
index 118170a5cedef..9c0494d8a867a 100644
--- a/drivers/perf/arm_pmu_platform.c
+++ b/drivers/perf/arm_pmu_platform.c
@@ -42,14 +42,13 @@ static int probe_current_pmu(struct arm_pmu *pmu,
 	return ret;
 }
 
-static int pmu_parse_percpu_irq(struct arm_pmu *pmu, int irq)
+static int pmu_parse_percpu_irq(struct arm_pmu *pmu, int irq,
+				const struct cpumask *affinity)
 {
-	int cpu, ret;
 	struct pmu_hw_events __percpu *hw_events = pmu->hw_events;
+	int cpu;
 
-	ret = irq_get_percpu_devid_partition(irq, &pmu->supported_cpus);
-	if (ret)
-		return ret;
+	cpumask_copy(&pmu->supported_cpus, affinity);
 
 	for_each_cpu(cpu, &pmu->supported_cpus)
 		per_cpu(hw_events->irq, cpu) = irq;
@@ -115,9 +114,12 @@ static int pmu_parse_irqs(struct arm_pmu *pmu)
 	}
 
 	if (num_irqs == 1) {
-		int irq = platform_get_irq(pdev, 0);
+		const struct cpumask *affinity;
+		int irq;
+
+		irq = platform_get_irq_affinity(pdev, 0, &affinity);
 		if ((irq > 0) && irq_is_percpu_devid(irq))
-			return pmu_parse_percpu_irq(pmu, irq);
+			return pmu_parse_percpu_irq(pmu, irq, affinity);
 	}
 
 	if (nr_cpu_ids != 1 && !pmu_has_irq_affinity(dev->of_node))
-- 
2.39.2

[PATCH v2 09/25] perf: arm_spe_pmu: Convert to new IRQ affinity retrieval API

[Marc Zyngier]

Now that the relevant interrupt controllers are equipped with
a callback returning the affinity of per-CPU interrupts, switch
the ARM SPE driver over to this new method.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/perf/arm_spe_pmu.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c
index 369e77ad5f13f..a1c86a1f21427 100644
--- a/drivers/perf/arm_spe_pmu.c
+++ b/drivers/perf/arm_spe_pmu.c
@@ -1211,8 +1211,10 @@ static void arm_spe_pmu_dev_teardown(struct arm_spe_pmu *spe_pmu)
 static int arm_spe_pmu_irq_probe(struct arm_spe_pmu *spe_pmu)
 {
 	struct platform_device *pdev = spe_pmu->pdev;
-	int irq = platform_get_irq(pdev, 0);
+	const struct cpumask *affinity;
+	int irq;
 
+	irq = platform_get_irq_affinity(pdev, 0, &affinity);
 	if (irq < 0)
 		return -ENXIO;
 
@@ -1221,10 +1223,7 @@ static int arm_spe_pmu_irq_probe(struct arm_spe_pmu *spe_pmu)
 		return -EINVAL;
 	}
 
-	if (irq_get_percpu_devid_partition(irq, &spe_pmu->supported_cpus)) {
-		dev_err(&pdev->dev, "failed to get PPI partition (%d)\n", irq);
-		return -EINVAL;
-	}
+	cpumask_copy(&spe_pmu->supported_cpus, affinity);
 
 	spe_pmu->irq = irq;
 	return 0;
-- 
2.39.2

[PATCH v2 10/25] irqchip/gic-v3: Switch high priority PPIs over to handle_percpu_devid_irq()

[Marc Zyngier]

It so appears that handle_percpu_devid_irq() is extremely similar to
handle_percpu_devid_fasteoi_nmi(), and that the differences do no
justify the horrid machinery we have in the GICv3 driver to handle
the flow handler switch.

Let's stick with the standard flow handler, even for NMIs.

Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/irqchip/irq-gic-v3.c | 54 ++----------------------------------
 1 file changed, 2 insertions(+), 52 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 71c278ddd1e39..a14fd4c269692 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -230,9 +230,6 @@ static void __init gic_prio_init(void)
 		!cpus_have_group0);
 }
 
-/* rdist_nmi_refs[n] == number of cpus having the rdist interrupt n set as NMI */
-static refcount_t *rdist_nmi_refs;
-
 static struct gic_kvm_info gic_v3_kvm_info __initdata;
 static DEFINE_PER_CPU(bool, has_rss);
 
@@ -608,24 +605,6 @@ static u32 __gic_get_ppi_index(irq_hw_number_t hwirq)
 	}
 }
 
-static u32 __gic_get_rdist_index(irq_hw_number_t hwirq)
-{
-	switch (__get_intid_range(hwirq)) {
-	case SGI_RANGE:
-	case PPI_RANGE:
-		return hwirq;
-	case EPPI_RANGE:
-		return hwirq - EPPI_BASE_INTID + 32;
-	default:
-		unreachable();
-	}
-}
-
-static u32 gic_get_rdist_index(struct irq_data *d)
-{
-	return __gic_get_rdist_index(d->hwirq);
-}
-
 static int gic_irq_nmi_setup(struct irq_data *d)
 {
 	struct irq_desc *desc = irq_to_desc(d->irq);
@@ -646,20 +625,8 @@ static int gic_irq_nmi_setup(struct irq_data *d)
 		return -EINVAL;
 
 	/* desc lock should already be held */
-	if (gic_irq_in_rdist(d)) {
-		u32 idx = gic_get_rdist_index(d);
-
-		/*
-		 * Setting up a percpu interrupt as NMI, only switch handler
-		 * for first NMI
-		 */
-		if (!refcount_inc_not_zero(&rdist_nmi_refs[idx])) {
-			refcount_set(&rdist_nmi_refs[idx], 1);
-			desc->handle_irq = handle_percpu_devid_fasteoi_nmi;
-		}
-	} else {
+	if (!gic_irq_in_rdist(d))
 		desc->handle_irq = handle_fasteoi_nmi;
-	}
 
 	gic_irq_set_prio(d, dist_prio_nmi);
 
@@ -686,15 +653,8 @@ static void gic_irq_nmi_teardown(struct irq_data *d)
 		return;
 
 	/* desc lock should already be held */
-	if (gic_irq_in_rdist(d)) {
-		u32 idx = gic_get_rdist_index(d);
-
-		/* Tearing down NMI, only switch handler for last NMI */
-		if (refcount_dec_and_test(&rdist_nmi_refs[idx]))
-			desc->handle_irq = handle_percpu_devid_irq;
-	} else {
+	if (!gic_irq_in_rdist(d))
 		desc->handle_irq = handle_fasteoi_irq;
-	}
 
 	gic_irq_set_prio(d, dist_prio_irq);
 }
@@ -2079,19 +2039,9 @@ static const struct gic_quirk gic_quirks[] = {
 
 static void gic_enable_nmi_support(void)
 {
-	int i;
-
 	if (!gic_prio_masking_enabled() || nmi_support_forbidden)
 		return;
 
-	rdist_nmi_refs = kcalloc(gic_data.ppi_nr + SGI_NR,
-				 sizeof(*rdist_nmi_refs), GFP_KERNEL);
-	if (!rdist_nmi_refs)
-		return;
-
-	for (i = 0; i < gic_data.ppi_nr + SGI_NR; i++)
-		refcount_set(&rdist_nmi_refs[i], 0);
-
 	pr_info("Pseudo-NMIs enabled using %s ICC_PMR_EL1 synchronisation\n",
 		gic_has_relaxed_pmr_sync() ? "relaxed" : "forced");
 
-- 
2.39.2

[PATCH v2 11/25] genirq: Kill handle_percpu_devid_fasteoi_nmi()

[Marc Zyngier]

There is no in-tree user of this flow handler anymore, so simply
remove it.

Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 include/linux/irq.h |  1 -
 kernel/irq/chip.c   | 28 ++--------------------------
 2 files changed, 2 insertions(+), 27 deletions(-)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 1d6b606a81efe..1381f9d1f5c9d 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -655,7 +655,6 @@ extern void handle_bad_irq(struct irq_desc *desc);
 extern void handle_nested_irq(unsigned int irq);
 
 extern void handle_fasteoi_nmi(struct irq_desc *desc);
-extern void handle_percpu_devid_fasteoi_nmi(struct irq_desc *desc);
 
 extern int irq_chip_compose_msi_msg(struct irq_data *data, struct msi_msg *msg);
 extern int irq_chip_pm_get(struct irq_data *data);
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 0d0276378c707..869068ec6ac91 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -892,7 +892,8 @@ void handle_percpu_irq(struct irq_desc *desc)
  *
  * action->percpu_dev_id is a pointer to percpu variables which
  * contain the real device id for the cpu on which this handler is
- * called
+ * called. This is also used for per-CPU NMIs, so special care is
+ * required.
  */
 void handle_percpu_devid_irq(struct irq_desc *desc)
 {
@@ -929,31 +930,6 @@ void handle_percpu_devid_irq(struct irq_desc *desc)
 		chip->irq_eoi(&desc->irq_data);
 }
 
-/**
- * handle_percpu_devid_fasteoi_nmi - Per CPU local NMI handler with per cpu
- *				     dev ids
- * @desc:	the interrupt description structure for this irq
- *
- * Similar to handle_fasteoi_nmi, but handling the dev_id cookie
- * as a percpu pointer.
- */
-void handle_percpu_devid_fasteoi_nmi(struct irq_desc *desc)
-{
-	struct irq_chip *chip = irq_desc_get_chip(desc);
-	struct irqaction *action = desc->action;
-	unsigned int irq = irq_desc_get_irq(desc);
-	irqreturn_t res;
-
-	__kstat_incr_irqs_this_cpu(desc);
-
-	trace_irq_handler_entry(irq, action);
-	res = action->handler(irq, raw_cpu_ptr(action->percpu_dev_id));
-	trace_irq_handler_exit(irq, action, res);
-
-	if (chip->irq_eoi)
-		chip->irq_eoi(&desc->irq_data);
-}
-
 static void
 __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle,
 		     int is_chained, const char *name)
-- 
2.39.2

Re: [PATCH v2 11/25] genirq: Kill handle_percpu_devid_fasteoi_nmi()

[Jonathan Cameron]

On Mon, 15 Sep 2025 09:56:48 +0100
Marc Zyngier <maz@kernel.org> wrote:

> There is no in-tree user of this flow handler anymore, so simply
> remove it.
> 
> Suggested-by: Will Deacon <will@kernel.org>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---

> diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
> index 0d0276378c707..869068ec6ac91 100644
> --- a/kernel/irq/chip.c
> +++ b/kernel/irq/chip.c
> @@ -892,7 +892,8 @@ void handle_percpu_irq(struct irq_desc *desc)
>   *
>   * action->percpu_dev_id is a pointer to percpu variables which
>   * contain the real device id for the cpu on which this handler is
> - * called
> + * called. This is also used for per-CPU NMIs, so special care is
> + * required.

Probably belongs in previous patch as not really related to removing
the unused code, but meh.

>   */

Re: [PATCH v2 11/25] genirq: Kill handle_percpu_devid_fasteoi_nmi()

[Marc Zyngier]

On Tue, 16 Sep 2025 16:38:38 +0100,
Jonathan Cameron <jonathan.cameron@huawei.com> wrote:
> 
> On Mon, 15 Sep 2025 09:56:48 +0100
> Marc Zyngier <maz@kernel.org> wrote:
> 
> > There is no in-tree user of this flow handler anymore, so simply
> > remove it.
> > 
> > Suggested-by: Will Deacon <will@kernel.org>
> > Signed-off-by: Marc Zyngier <maz@kernel.org>
> > ---
> 
> > diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
> > index 0d0276378c707..869068ec6ac91 100644
> > --- a/kernel/irq/chip.c
> > +++ b/kernel/irq/chip.c
> > @@ -892,7 +892,8 @@ void handle_percpu_irq(struct irq_desc *desc)
> >   *
> >   * action->percpu_dev_id is a pointer to percpu variables which
> >   * contain the real device id for the cpu on which this handler is
> > - * called
> > + * called. This is also used for per-CPU NMIs, so special care is
> > + * required.
> 
> Probably belongs in previous patch as not really related to removing
> the unused code, but meh.

Actually, I think I'll simply drop this comment. It really doesn't
bring much to the table.

Thanks,

	M.

-- 
Jazz isn't dead. It just smells funny.

[PATCH v2 12/25] genirq: Merge irqaction::{dev_id,percpu_dev_id}

[Marc Zyngier]

When irqaction::percpu_dev_id was introduced, it was hoped that it
could be part of an anonymous union with dev_id, as the two fields
are mutually exclusive.

However, toolchains used at the time were often showing terrible
support for anonymous unions, breaking the build on a number of
architectures. It was therefore decided to keep the two fields separate
and address this down the line.

14 years later, the compiler dark age is over, and there is universal
support for anonymous unions. Let's get a whole pointer back that can
immediately be spent on something else.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 include/linux/interrupt.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 51b6484c04934..0ec1a71ab4e84 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -121,8 +121,10 @@ typedef irqreturn_t (*irq_handler_t)(int, void *);
  */
 struct irqaction {
 	irq_handler_t		handler;
-	void			*dev_id;
-	void __percpu		*percpu_dev_id;
+	union {
+		void		*dev_id;
+		void __percpu	*percpu_dev_id;
+	};
 	struct irqaction	*next;
 	irq_handler_t		thread_fn;
 	struct task_struct	*thread;
-- 
2.39.2

[PATCH v2 13/25] genirq: Factor-in percpu irqaction creation

[Marc Zyngier]

Move the code creating a per-cpu irqaction into its own helper, so that
future changes to this code can be kept localised.

At the same time, fix the documentation which appears to say the wrong
thing when it comes to interrupts being automatically enabled
(percpu_devid interrupts never are).

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 kernel/irq/manage.c | 40 ++++++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index c94837382037e..d9ddc30678b5d 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -2442,6 +2442,24 @@ int setup_percpu_irq(unsigned int irq, struct irqaction *act)
 	return retval;
 }
 
+static
+struct irqaction *create_percpu_irqaction(irq_handler_t handler, unsigned long flags,
+					  const char *devname, void __percpu *dev_id)
+{
+	struct irqaction *action;
+
+	action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
+	if (!action)
+		return NULL;
+
+	action->handler = handler;
+	action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
+	action->name = devname;
+	action->percpu_dev_id = dev_id;
+
+	return action;
+}
+
 /**
  * __request_percpu_irq - allocate a percpu interrupt line
  * @irq:	Interrupt line to allocate
@@ -2450,9 +2468,9 @@ int setup_percpu_irq(unsigned int irq, struct irqaction *act)
  * @devname:	An ascii name for the claiming device
  * @dev_id:	A percpu cookie passed back to the handler function
  *
- * This call allocates interrupt resources and enables the interrupt on the
- * local CPU. If the interrupt is supposed to be enabled on other CPUs, it
- * has to be done on each CPU using enable_percpu_irq().
+ * This call allocates interrupt resources, but doesn't enable the interrupt
+ * on any CPU, as all percpu-devid interrupts are flagged with IRQ_NOAUTOEN.
+ * It has to be done on each CPU using enable_percpu_irq().
  *
  * @dev_id must be globally unique. It is a per-cpu variable, and
  * the handler gets called with the interrupted CPU's instance of
@@ -2477,15 +2495,10 @@ int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
 	if (flags && flags != IRQF_TIMER)
 		return -EINVAL;
 
-	action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
+	action = create_percpu_irqaction(handler, flags, devname, dev_id);
 	if (!action)
 		return -ENOMEM;
 
-	action->handler = handler;
-	action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
-	action->name = devname;
-	action->percpu_dev_id = dev_id;
-
 	retval = irq_chip_pm_get(&desc->irq_data);
 	if (retval < 0) {
 		kfree(action);
@@ -2546,16 +2559,11 @@ int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
 	if (irq_is_nmi(desc))
 		return -EINVAL;
 
-	action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
+	action = create_percpu_irqaction(handler, IRQF_NO_THREAD | IRQF_NOBALANCING,
+					 name, dev_id);
 	if (!action)
 		return -ENOMEM;
 
-	action->handler = handler;
-	action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD
-		| IRQF_NOBALANCING;
-	action->name = name;
-	action->percpu_dev_id = dev_id;
-
 	retval = irq_chip_pm_get(&desc->irq_data);
 	if (retval < 0)
 		goto err_out;
-- 
2.39.2

Re: [PATCH v2 13/25] genirq: Factor-in percpu irqaction creation

[Jonathan Cameron]

On Mon, 15 Sep 2025 09:56:50 +0100
Marc Zyngier <maz@kernel.org> wrote:

> Move the code creating a per-cpu irqaction into its own helper, so that
> future changes to this code can be kept localised.
> 
> At the same time, fix the documentation which appears to say the wrong
> thing when it comes to interrupts being automatically enabled
> (percpu_devid interrupts never are).
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>

[PATCH v2 14/25] genirq: Add affinity to percpu_devid interrupt requests

[Marc Zyngier]

Add an affinity field to both the irqaction structure and the interrupt
request primitives. Nothing is making use of it yet, and the only value
used it NULL, which is used as a shorthand for cpu_possible_mask.

This will shortly get used with actual affinities.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 include/linux/interrupt.h |  5 +++--
 kernel/irq/manage.c       | 14 ++++++++++----
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 0ec1a71ab4e84..52147d5f432b3 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -125,6 +125,7 @@ struct irqaction {
 		void		*dev_id;
 		void __percpu	*percpu_dev_id;
 	};
+	const struct cpumask	*affinity;
 	struct irqaction	*next;
 	irq_handler_t		thread_fn;
 	struct task_struct	*thread;
@@ -181,7 +182,7 @@ request_any_context_irq(unsigned int irq, irq_handler_t handler,
 extern int __must_check
 __request_percpu_irq(unsigned int irq, irq_handler_t handler,
 		     unsigned long flags, const char *devname,
-		     void __percpu *percpu_dev_id);
+		     const cpumask_t *affinity, void __percpu *percpu_dev_id);
 
 extern int __must_check
 request_nmi(unsigned int irq, irq_handler_t handler, unsigned long flags,
@@ -192,7 +193,7 @@ request_percpu_irq(unsigned int irq, irq_handler_t handler,
 		   const char *devname, void __percpu *percpu_dev_id)
 {
 	return __request_percpu_irq(irq, handler, 0,
-				    devname, percpu_dev_id);
+				    devname, NULL, percpu_dev_id);
 }
 
 extern int __must_check
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index d9ddc30678b5d..5f4c651677436 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -2444,10 +2444,14 @@ int setup_percpu_irq(unsigned int irq, struct irqaction *act)
 
 static
 struct irqaction *create_percpu_irqaction(irq_handler_t handler, unsigned long flags,
-					  const char *devname, void __percpu *dev_id)
+					  const char *devname, const cpumask_t *affinity,
+					  void __percpu *dev_id)
 {
 	struct irqaction *action;
 
+	if (!affinity)
+		affinity = cpu_possible_mask;
+
 	action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
 	if (!action)
 		return NULL;
@@ -2456,6 +2460,7 @@ struct irqaction *create_percpu_irqaction(irq_handler_t handler, unsigned long f
 	action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
 	action->name = devname;
 	action->percpu_dev_id = dev_id;
+	action->affinity = affinity;
 
 	return action;
 }
@@ -2466,6 +2471,7 @@ struct irqaction *create_percpu_irqaction(irq_handler_t handler, unsigned long f
  * @handler:	Function to be called when the IRQ occurs.
  * @flags:	Interrupt type flags (IRQF_TIMER only)
  * @devname:	An ascii name for the claiming device
+ * @affinity:	A cpumask describing the target CPUs for this interrupt
  * @dev_id:	A percpu cookie passed back to the handler function
  *
  * This call allocates interrupt resources, but doesn't enable the interrupt
@@ -2478,7 +2484,7 @@ struct irqaction *create_percpu_irqaction(irq_handler_t handler, unsigned long f
  */
 int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
 			 unsigned long flags, const char *devname,
-			 void __percpu *dev_id)
+			 const cpumask_t *affinity, void __percpu *dev_id)
 {
 	struct irqaction *action;
 	struct irq_desc *desc;
@@ -2495,7 +2501,7 @@ int __request_percpu_irq(unsigned int irq, irq_handler_t handler,
 	if (flags && flags != IRQF_TIMER)
 		return -EINVAL;
 
-	action = create_percpu_irqaction(handler, flags, devname, dev_id);
+	action = create_percpu_irqaction(handler, flags, devname, affinity, dev_id);
 	if (!action)
 		return -ENOMEM;
 
@@ -2560,7 +2566,7 @@ int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
 		return -EINVAL;
 
 	action = create_percpu_irqaction(handler, IRQF_NO_THREAD | IRQF_NOBALANCING,
-					 name, dev_id);
+					 name, NULL, dev_id);
 	if (!action)
 		return -ENOMEM;
 
-- 
2.39.2

[PATCH v2 15/25] genirq: Update request_percpu_nmi() to take an affinity

[Marc Zyngier]

Continue spreading the notion of affinity to the percpu interrupt
request code by updating the call sites that use request_percpu_nmi()
(all two of them) to take an affinity pointer. This pointer is
firmly NULL for now.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kernel/smp.c   |  2 +-
 drivers/perf/arm_pmu.c    |  4 +++-
 include/linux/interrupt.h |  4 ++--
 kernel/irq/manage.c       | 11 +++++++----
 4 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 68cea3a4a35ca..6fb838eee2e7d 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -1094,7 +1094,7 @@ static void ipi_setup_sgi(int ipi)
 	irq = ipi_irq_base + ipi;
 
 	if (ipi_should_be_nmi(ipi)) {
-		err = request_percpu_nmi(irq, ipi_handler, "IPI", &irq_stat);
+		err = request_percpu_nmi(irq, ipi_handler, "IPI", NULL, &irq_stat);
 		WARN(err, "Could not request IRQ %d as NMI, err=%d\n", irq, err);
 	} else {
 		err = request_percpu_irq(irq, ipi_handler, "IPI", &irq_stat);
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 5c310e803dd78..de9eca2290a97 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -659,7 +659,9 @@ int armpmu_request_irq(int irq, int cpu)
 			irq_ops = &pmunmi_ops;
 		}
 	} else if (armpmu_count_irq_users(irq) == 0) {
-		err = request_percpu_nmi(irq, handler, "arm-pmu", &cpu_armpmu);
+		err = request_percpu_nmi(irq, handler, "arm-pmu",
+					 NULL,
+					 &cpu_armpmu);
 
 		/* If cannot get an NMI, get a normal interrupt */
 		if (err) {
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 52147d5f432b3..2134e7c08c169 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -197,8 +197,8 @@ request_percpu_irq(unsigned int irq, irq_handler_t handler,
 }
 
 extern int __must_check
-request_percpu_nmi(unsigned int irq, irq_handler_t handler,
-		   const char *devname, void __percpu *dev);
+request_percpu_nmi(unsigned int irq, irq_handler_t handler, const char *devname,
+		   const struct cpumask *affinity, void __percpu *dev_id);
 
 extern const void *free_irq(unsigned int, void *);
 extern void free_percpu_irq(unsigned int, void __percpu *);
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 5f4c651677436..49c237aca2a70 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -2527,6 +2527,7 @@ EXPORT_SYMBOL_GPL(__request_percpu_irq);
  * @irq:	Interrupt line to allocate
  * @handler:	Function to be called when the IRQ occurs.
  * @name:	An ascii name for the claiming device
+ * @affinity:	A cpumask describing the target CPUs for this interrupt
  * @dev_id:	A percpu cookie passed back to the handler function
  *
  * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
@@ -2544,7 +2545,8 @@ EXPORT_SYMBOL_GPL(__request_percpu_irq);
  * will fail returning a negative value.
  */
 int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
-		       const char *name, void __percpu *dev_id)
+		       const char *name,
+		       const struct cpumask *affinity, void __percpu *dev_id)
 {
 	struct irqaction *action;
 	struct irq_desc *desc;
@@ -2561,12 +2563,13 @@ int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
 	    !irq_supports_nmi(desc))
 		return -EINVAL;
 
-	/* The line cannot already be NMI */
-	if (irq_is_nmi(desc))
+	/* The line cannot be NMI already if the new request covers all CPUs */
+	if (irq_is_nmi(desc) &&
+	    (!affinity || cpumask_equal(affinity, cpu_possible_mask)))
 		return -EINVAL;
 
 	action = create_percpu_irqaction(handler, IRQF_NO_THREAD | IRQF_NOBALANCING,
-					 name, NULL, dev_id);
+					 name, affinity, dev_id);
 	if (!action)
 		return -ENOMEM;
 
-- 
2.39.2

Re: [PATCH v2 15/25] genirq: Update request_percpu_nmi() to take an affinity

[Jonathan Cameron]

On Mon, 15 Sep 2025 09:56:52 +0100
Marc Zyngier <maz@kernel.org> wrote:

> Continue spreading the notion of affinity to the percpu interrupt
> request code by updating the call sites that use request_percpu_nmi()
> (all two of them) to take an affinity pointer. This pointer is
> firmly NULL for now.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
A few fussy reviewer comments inline.

> ---
>  arch/arm64/kernel/smp.c   |  2 +-
>  drivers/perf/arm_pmu.c    |  4 +++-
>  include/linux/interrupt.h |  4 ++--
>  kernel/irq/manage.c       | 11 +++++++----
>  4 files changed, 13 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> index 68cea3a4a35ca..6fb838eee2e7d 100644
> --- a/arch/arm64/kernel/smp.c
> +++ b/arch/arm64/kernel/smp.c
> @@ -1094,7 +1094,7 @@ static void ipi_setup_sgi(int ipi)
>  	irq = ipi_irq_base + ipi;
>  
>  	if (ipi_should_be_nmi(ipi)) {
> -		err = request_percpu_nmi(irq, ipi_handler, "IPI", &irq_stat);
> +		err = request_percpu_nmi(irq, ipi_handler, "IPI", NULL, &irq_stat);
>  		WARN(err, "Could not request IRQ %d as NMI, err=%d\n", irq, err);
>  	} else {
>  		err = request_percpu_irq(irq, ipi_handler, "IPI", &irq_stat);
> diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
> index 5c310e803dd78..de9eca2290a97 100644
> --- a/drivers/perf/arm_pmu.c
> +++ b/drivers/perf/arm_pmu.c
> @@ -659,7 +659,9 @@ int armpmu_request_irq(int irq, int cpu)
>  			irq_ops = &pmunmi_ops;
>  		}
>  	} else if (armpmu_count_irq_users(irq) == 0) {
> -		err = request_percpu_nmi(irq, handler, "arm-pmu", &cpu_armpmu);
> +		err = request_percpu_nmi(irq, handler, "arm-pmu",
> +					 NULL,

I was assuming this odd formatting was to help reduce churn in a later patch, but nope
this whole block get replaced in patch 18.  So might as well move NULL up a line
an have a cleaner intermediate state.

> +					 &cpu_armpmu);
>  
>  		/* If cannot get an NMI, get a normal interrupt */
>  		if (err) {
> diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
> index 52147d5f432b3..2134e7c08c169 100644
> --- a/include/linux/interrupt.h
> +++ b/include/linux/interrupt.h
> @@ -197,8 +197,8 @@ request_percpu_irq(unsigned int irq, irq_handler_t handler,
>  }
>  
>  extern int __must_check
> -request_percpu_nmi(unsigned int irq, irq_handler_t handler,
> -		   const char *devname, void __percpu *dev);
> +request_percpu_nmi(unsigned int irq, irq_handler_t handler, const char *devname,
Odd inconsistency in parameter naming devname/name

Perhaps worth tidying that up whilst here. I only noticed because of the
wrap comment below.


> +		   const struct cpumask *affinity, void __percpu *dev_id);
>  
>  extern const void *free_irq(unsigned int, void *);
>  extern void free_percpu_irq(unsigned int, void __percpu *);
> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
> index 5f4c651677436..49c237aca2a70 100644
> --- a/kernel/irq/manage.c
> +++ b/kernel/irq/manage.c
> @@ -2527,6 +2527,7 @@ EXPORT_SYMBOL_GPL(__request_percpu_irq);
>   * @irq:	Interrupt line to allocate
>   * @handler:	Function to be called when the IRQ occurs.
>   * @name:	An ascii name for the claiming device
> + * @affinity:	A cpumask describing the target CPUs for this interrupt
>   * @dev_id:	A percpu cookie passed back to the handler function
>   *
>   * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs
> @@ -2544,7 +2545,8 @@ EXPORT_SYMBOL_GPL(__request_percpu_irq);
>   * will fail returning a negative value.
>   */
>  int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
> -		       const char *name, void __percpu *dev_id)
> +		       const char *name,
> +		       const struct cpumask *affinity, void __percpu *dev_id)

This seems like an odd wrap and I can't immediately see it making more sense
in later patches.

>  {

>  

[PATCH v2 16/25] genirq: Allow per-cpu interrupt sharing for non-overlapping affinities

[Marc Zyngier]

Interrupt sharing for percpu-devid interrupts is forbidden, and
for good reasons. These are interrupts generated *from* a CPU and
handled by itself (timer, for example). Nobody in their right mind
would put two devices on the same pin (and if they have, they get to
keep the pieces...).

But this also prevents more benign cases, where devices are connected
to groups of CPUs, and for which the affinities are not overlapping.
Effectively, the only thing they share is the interrupt number, and
nothing else.

Let's tweak the definition of IRQF_SHARED applied to percpu_devid
interrupts to allow this particular case. This results in extra
validation at the point of the interrupt being setup and freed,
as well as a tiny bit of extra complexity for interrupts at handling
time (to pick the correct irqaction).

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 kernel/irq/chip.c   |  8 ++++--
 kernel/irq/manage.c | 67 +++++++++++++++++++++++++++++++++++++--------
 2 files changed, 61 insertions(+), 14 deletions(-)

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 869068ec6ac91..f60a2268fad1f 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -898,8 +898,9 @@ void handle_percpu_irq(struct irq_desc *desc)
 void handle_percpu_devid_irq(struct irq_desc *desc)
 {
 	struct irq_chip *chip = irq_desc_get_chip(desc);
-	struct irqaction *action = desc->action;
 	unsigned int irq = irq_desc_get_irq(desc);
+	unsigned int cpu = smp_processor_id();
+	struct irqaction *action;
 	irqreturn_t res;
 
 	/*
@@ -911,12 +912,15 @@ void handle_percpu_devid_irq(struct irq_desc *desc)
 	if (chip->irq_ack)
 		chip->irq_ack(&desc->irq_data);
 
+	for (action = desc->action; action; action = action->next)
+		if (cpumask_test_cpu(cpu, action->affinity))
+			break;
+
 	if (likely(action)) {
 		trace_irq_handler_entry(irq, action);
 		res = action->handler(irq, raw_cpu_ptr(action->percpu_dev_id));
 		trace_irq_handler_exit(irq, action, res);
 	} else {
-		unsigned int cpu = smp_processor_id();
 		bool enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
 
 		if (enabled)
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 49c237aca2a70..39db60a5f36f3 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1418,6 +1418,19 @@ setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
 	return 0;
 }
 
+static bool valid_percpu_irqaction(struct irqaction *old, struct irqaction *new)
+{
+	do {
+		if (cpumask_intersects(old->affinity, new->affinity) ||
+		    old->percpu_dev_id == new->percpu_dev_id)
+			return false;
+
+		old = old->next;
+	} while (old);
+
+	return true;
+}
+
 /*
  * Internal function to register an irqaction - typically used to
  * allocate special interrupts that are part of the architecture.
@@ -1438,6 +1451,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 	struct irqaction *old, **old_ptr;
 	unsigned long flags, thread_mask = 0;
 	int ret, nested, shared = 0;
+	bool per_cpu_devid;
 
 	if (!desc)
 		return -EINVAL;
@@ -1447,6 +1461,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 	if (!try_module_get(desc->owner))
 		return -ENODEV;
 
+	per_cpu_devid = irq_settings_is_per_cpu_devid(desc);
+
 	new->irq = irq;
 
 	/*
@@ -1554,13 +1570,20 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 		 */
 		unsigned int oldtype;
 
-		if (irq_is_nmi(desc)) {
+		if (irq_is_nmi(desc) && !per_cpu_devid) {
 			pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n",
 				new->name, irq, desc->irq_data.chip->name);
 			ret = -EINVAL;
 			goto out_unlock;
 		}
 
+		if (per_cpu_devid && !valid_percpu_irqaction(old, new)) {
+			pr_err("Overlapping affinities for %s (irq %d) on irqchip %s.\n",
+				new->name, irq, desc->irq_data.chip->name);
+			ret = -EINVAL;
+			goto out_unlock;
+		}
+
 		/*
 		 * If nobody did set the configuration before, inherit
 		 * the one provided by the requester.
@@ -1711,7 +1734,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 		if (!(new->flags & IRQF_NO_AUTOEN) &&
 		    irq_settings_can_autoenable(desc)) {
 			irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
-		} else {
+		} else if (!per_cpu_devid) {
 			/*
 			 * Shared interrupts do not go well with disabling
 			 * auto enable. The sharing interrupt might request
@@ -2346,7 +2369,7 @@ void disable_percpu_nmi(unsigned int irq)
 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
-	struct irqaction *action;
+	struct irqaction *action, **action_ptr;
 
 	WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
 
@@ -2354,21 +2377,33 @@ static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_
 		return NULL;
 
 	scoped_guard(raw_spinlock_irqsave, &desc->lock) {
-		action = desc->action;
-		if (!action || action->percpu_dev_id != dev_id) {
-			WARN(1, "Trying to free already-free IRQ %d\n", irq);
-			return NULL;
+		action_ptr = &desc->action;
+		for (;;) {
+			action = *action_ptr;
+
+			if (!action) {
+				WARN(1, "Trying to free already-free IRQ %d\n", irq);
+				return NULL;
+			}
+
+			if (action->percpu_dev_id == dev_id)
+				break;
+
+			action_ptr = &action->next;
 		}
 
-		if (!cpumask_empty(desc->percpu_enabled)) {
-			WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
-			     irq, cpumask_first(desc->percpu_enabled));
+		if (cpumask_intersects(desc->percpu_enabled, action->affinity)) {
+			WARN(1, "percpu IRQ %d still enabled on CPU%d!\n", irq,
+			     cpumask_first_and(desc->percpu_enabled, action->affinity));
 			return NULL;
 		}
 
 		/* Found it - now remove it from the list of entries: */
-		desc->action = NULL;
-		desc->istate &= ~IRQS_NMI;
+		*action_ptr = action->next;
+
+		/* Demote from NMI if we killed the last action */
+		if (!desc->action)
+			desc->istate &= ~IRQS_NMI;
 	}
 
 	unregister_handler_proc(irq, action);
@@ -2462,6 +2497,14 @@ struct irqaction *create_percpu_irqaction(irq_handler_t handler, unsigned long f
 	action->percpu_dev_id = dev_id;
 	action->affinity = affinity;
 
+	/*
+	 * We allow some form of sharing for non-overlapping affinity
+	 * masks. Obviously, covering all CPUs prevents any sharing
+	 * the first place.
+	 */
+	if (!cpumask_equal(affinity, cpu_possible_mask))
+		action->flags |= IRQF_SHARED;
+
 	return action;
 }
 
-- 
2.39.2

[PATCH v2 17/25] genirq: Add request_percpu_irq_affinity() helper

[Marc Zyngier]

While it would be nice to simply make request_percpu_irq() take
an affinity mask, the churn is likely to be on the irritating side
given that most drivers do not give a damn about affinities.

So take the more innocuous path to provide a helper that parallels
request_percpu_irq(), with an affinity as a bonus argument.

Yes, request_percpu_irq_affinity() is a bit of a mouthful.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 include/linux/interrupt.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 2134e7c08c169..c8e6f4895782c 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -196,6 +196,15 @@ request_percpu_irq(unsigned int irq, irq_handler_t handler,
 				    devname, NULL, percpu_dev_id);
 }
 
+static inline int __must_check
+request_percpu_irq_affinity(unsigned int irq, irq_handler_t handler,
+			    const char *devname, const cpumask_t *affinity,
+			    void __percpu *percpu_dev_id)
+{
+	return __request_percpu_irq(irq, handler, 0,
+				    devname, affinity, percpu_dev_id);
+}
+
 extern int __must_check
 request_percpu_nmi(unsigned int irq, irq_handler_t handler, const char *devname,
 		   const struct cpumask *affinity, void __percpu *dev_id);
-- 
2.39.2

[PATCH v2 18/25] perf: arm_pmu: Request specific affinities for percpu NMI/IRQ

[Marc Zyngier]

From: Will Deacon <will@kernel.org>

Let the PMU driver request both NMI and normal IRQs with an affinity
mask matching the PMU affinity.

Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/perf/arm_pmu.c          | 47 +++++++++++++++++++--------------
 drivers/perf/arm_pmu_acpi.c     |  2 +-
 drivers/perf/arm_pmu_platform.c |  4 +--
 include/linux/perf/arm_pmu.h    |  4 +--
 4 files changed, 32 insertions(+), 25 deletions(-)

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index de9eca2290a97..23814707cf771 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -26,7 +26,8 @@
 
 #include <asm/irq_regs.h>
 
-static int armpmu_count_irq_users(const int irq);
+static int armpmu_count_irq_users(const struct cpumask *affinity,
+				  const int irq);
 
 struct pmu_irq_ops {
 	void (*enable_pmuirq)(unsigned int irq);
@@ -64,7 +65,9 @@ static void armpmu_enable_percpu_pmuirq(unsigned int irq)
 static void armpmu_free_percpu_pmuirq(unsigned int irq, int cpu,
 				   void __percpu *devid)
 {
-	if (armpmu_count_irq_users(irq) == 1)
+	struct arm_pmu *armpmu = *per_cpu_ptr((void * __percpu *)devid, cpu);
+
+	if (armpmu_count_irq_users(&armpmu->supported_cpus, irq) == 1)
 		free_percpu_irq(irq, devid);
 }
 
@@ -89,7 +92,9 @@ static void armpmu_disable_percpu_pmunmi(unsigned int irq)
 static void armpmu_free_percpu_pmunmi(unsigned int irq, int cpu,
 				      void __percpu *devid)
 {
-	if (armpmu_count_irq_users(irq) == 1)
+	struct arm_pmu *armpmu = *per_cpu_ptr((void * __percpu *)devid, cpu);
+
+	if (armpmu_count_irq_users(&armpmu->supported_cpus, irq) == 1)
 		free_percpu_nmi(irq, devid);
 }
 
@@ -580,11 +585,11 @@ static const struct attribute_group armpmu_common_attr_group = {
 	.attrs = armpmu_common_attrs,
 };
 
-static int armpmu_count_irq_users(const int irq)
+static int armpmu_count_irq_users(const struct cpumask *affinity, const int irq)
 {
 	int cpu, count = 0;
 
-	for_each_possible_cpu(cpu) {
+	for_each_cpu(cpu, affinity) {
 		if (per_cpu(cpu_irq, cpu) == irq)
 			count++;
 	}
@@ -592,12 +597,13 @@ static int armpmu_count_irq_users(const int irq)
 	return count;
 }
 
-static const struct pmu_irq_ops *armpmu_find_irq_ops(int irq)
+static const struct pmu_irq_ops *
+armpmu_find_irq_ops(const struct cpumask *affinity, int irq)
 {
 	const struct pmu_irq_ops *ops = NULL;
 	int cpu;
 
-	for_each_possible_cpu(cpu) {
+	for_each_cpu(cpu, affinity) {
 		if (per_cpu(cpu_irq, cpu) != irq)
 			continue;
 
@@ -609,22 +615,25 @@ static const struct pmu_irq_ops *armpmu_find_irq_ops(int irq)
 	return ops;
 }
 
-void armpmu_free_irq(int irq, int cpu)
+void armpmu_free_irq(struct arm_pmu * __percpu *armpmu, int irq, int cpu)
 {
 	if (per_cpu(cpu_irq, cpu) == 0)
 		return;
 	if (WARN_ON(irq != per_cpu(cpu_irq, cpu)))
 		return;
 
-	per_cpu(cpu_irq_ops, cpu)->free_pmuirq(irq, cpu, &cpu_armpmu);
+	per_cpu(cpu_irq_ops, cpu)->free_pmuirq(irq, cpu, armpmu);
 
 	per_cpu(cpu_irq, cpu) = 0;
 	per_cpu(cpu_irq_ops, cpu) = NULL;
 }
 
-int armpmu_request_irq(int irq, int cpu)
+int armpmu_request_irq(struct arm_pmu * __percpu *pcpu_armpmu, int irq, int cpu)
 {
 	int err = 0;
+	struct arm_pmu **armpmu = per_cpu_ptr(pcpu_armpmu, cpu);
+	const struct cpumask *affinity = *armpmu ? &(*armpmu)->supported_cpus :
+						   cpu_possible_mask; /* ACPI */
 	const irq_handler_t handler = armpmu_dispatch_irq;
 	const struct pmu_irq_ops *irq_ops;
 
@@ -646,27 +655,25 @@ int armpmu_request_irq(int irq, int cpu)
 			    IRQF_NOBALANCING | IRQF_NO_AUTOEN |
 			    IRQF_NO_THREAD;
 
-		err = request_nmi(irq, handler, irq_flags, "arm-pmu",
-				  per_cpu_ptr(&cpu_armpmu, cpu));
+		err = request_nmi(irq, handler, irq_flags, "arm-pmu", armpmu);
 
 		/* If cannot get an NMI, get a normal interrupt */
 		if (err) {
 			err = request_irq(irq, handler, irq_flags, "arm-pmu",
-					  per_cpu_ptr(&cpu_armpmu, cpu));
+					  armpmu);
 			irq_ops = &pmuirq_ops;
 		} else {
 			has_nmi = true;
 			irq_ops = &pmunmi_ops;
 		}
-	} else if (armpmu_count_irq_users(irq) == 0) {
-		err = request_percpu_nmi(irq, handler, "arm-pmu",
-					 NULL,
-					 &cpu_armpmu);
+	} else if (armpmu_count_irq_users(affinity, irq) == 0) {
+		err = request_percpu_nmi(irq, handler, "arm-pmu", affinity,
+					 pcpu_armpmu);
 
 		/* If cannot get an NMI, get a normal interrupt */
 		if (err) {
-			err = request_percpu_irq(irq, handler, "arm-pmu",
-						 &cpu_armpmu);
+			err = request_percpu_irq_affinity(irq, handler, "arm-pmu",
+							  affinity, pcpu_armpmu);
 			irq_ops = &percpu_pmuirq_ops;
 		} else {
 			has_nmi = true;
@@ -674,7 +681,7 @@ int armpmu_request_irq(int irq, int cpu)
 		}
 	} else {
 		/* Per cpudevid irq was already requested by another CPU */
-		irq_ops = armpmu_find_irq_ops(irq);
+		irq_ops = armpmu_find_irq_ops(affinity, irq);
 
 		if (WARN_ON(!irq_ops))
 			err = -EINVAL;
diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
index 05dda19c5359a..e80f76d95e68b 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -218,7 +218,7 @@ static int arm_pmu_acpi_parse_irqs(void)
 		 * them with their PMUs.
 		 */
 		per_cpu(pmu_irqs, cpu) = irq;
-		err = armpmu_request_irq(irq, cpu);
+		err = armpmu_request_irq(&probed_pmus, irq, cpu);
 		if (err)
 			goto out_err;
 	}
diff --git a/drivers/perf/arm_pmu_platform.c b/drivers/perf/arm_pmu_platform.c
index 9c0494d8a867a..1c9e50a132015 100644
--- a/drivers/perf/arm_pmu_platform.c
+++ b/drivers/perf/arm_pmu_platform.c
@@ -165,7 +165,7 @@ static int armpmu_request_irqs(struct arm_pmu *armpmu)
 		if (!irq)
 			continue;
 
-		err = armpmu_request_irq(irq, cpu);
+		err = armpmu_request_irq(&hw_events->percpu_pmu, irq, cpu);
 		if (err)
 			break;
 	}
@@ -181,7 +181,7 @@ static void armpmu_free_irqs(struct arm_pmu *armpmu)
 	for_each_cpu(cpu, &armpmu->supported_cpus) {
 		int irq = per_cpu(hw_events->irq, cpu);
 
-		armpmu_free_irq(irq, cpu);
+		armpmu_free_irq(&hw_events->percpu_pmu, irq, cpu);
 	}
 }
 
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index 93c9a26492fcf..6690bd77aa4ee 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -190,8 +190,8 @@ bool arm_pmu_irq_is_nmi(void);
 struct arm_pmu *armpmu_alloc(void);
 void armpmu_free(struct arm_pmu *pmu);
 int armpmu_register(struct arm_pmu *pmu);
-int armpmu_request_irq(int irq, int cpu);
-void armpmu_free_irq(int irq, int cpu);
+int armpmu_request_irq(struct arm_pmu * __percpu *armpmu, int irq, int cpu);
+void armpmu_free_irq(struct arm_pmu * __percpu *armpmu, int irq, int cpu);
 
 #define ARMV8_PMU_PDEV_NAME "armv8-pmu"
 
-- 
2.39.2

[PATCH v2 19/25] perf: arm_spe_pmu: Request specific affinities for percpu IRQ

[Marc Zyngier]

Let the SPE driver request IRQs with an affinity mask matching
the SPE implementation affinity.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/perf/arm_spe_pmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c
index a1c86a1f21427..f8763f0771776 100644
--- a/drivers/perf/arm_spe_pmu.c
+++ b/drivers/perf/arm_spe_pmu.c
@@ -1183,8 +1183,8 @@ static int arm_spe_pmu_dev_init(struct arm_spe_pmu *spe_pmu)
 		return -ENXIO;
 
 	/* Request our PPIs (note that the IRQ is still disabled) */
-	ret = request_percpu_irq(spe_pmu->irq, arm_spe_pmu_irq_handler, DRVNAME,
-				 spe_pmu->handle);
+	ret = request_percpu_irq_affinity(spe_pmu->irq, arm_spe_pmu_irq_handler,
+					  DRVNAME, mask, spe_pmu->handle);
 	if (ret)
 		return ret;
 
-- 
2.39.2

[PATCH v2 20/25] coresight: trbe: Request specific affinities for percpu IRQ

[Marc Zyngier]

Let the TRBE driver request IRQs with an affinity mask matching
the TRBE implementation affinity.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/hwtracing/coresight/coresight-trbe.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index c512f8faa6012..4a84a6bc2e8fc 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -1492,7 +1492,8 @@ static int arm_trbe_probe_irq(struct platform_device *pdev,
 	if (!drvdata->handle)
 		return -ENOMEM;
 
-	ret = request_percpu_irq(drvdata->irq, arm_trbe_irq_handler, DRVNAME, drvdata->handle);
+	ret = request_percpu_irq_affinity(drvdata->irq, arm_trbe_irq_handler, DRVNAME,
+					  affinity, drvdata->handle);
 	if (ret) {
 		free_percpu(drvdata->handle);
 		return ret;
-- 
2.39.2

Re: [PATCH v2 20/25] coresight: trbe: Request specific affinities for percpu IRQ

[Suzuki K Poulose]

On 15/09/2025 09:56, Marc Zyngier wrote:
> Let the TRBE driver request IRQs with an affinity mask matching
> the TRBE implementation affinity.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>   drivers/hwtracing/coresight/coresight-trbe.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
> index c512f8faa6012..4a84a6bc2e8fc 100644
> --- a/drivers/hwtracing/coresight/coresight-trbe.c
> +++ b/drivers/hwtracing/coresight/coresight-trbe.c
> @@ -1492,7 +1492,8 @@ static int arm_trbe_probe_irq(struct platform_device *pdev,
>   	if (!drvdata->handle)
>   		return -ENOMEM;
>   
> -	ret = request_percpu_irq(drvdata->irq, arm_trbe_irq_handler, DRVNAME, drvdata->handle);
> +	ret = request_percpu_irq_affinity(drvdata->irq, arm_trbe_irq_handler, DRVNAME,
> +					  affinity, drvdata->handle);
>   	if (ret) {
>   		free_percpu(drvdata->handle);
>   		return ret;


Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>

[PATCH v2 21/25] irqchip/gic-v3: Drop support for custom PPI partitions

[Marc Zyngier]

The only thing getting in the way of correctly handling PPIs the way
they were intended is the GICv3 hack that deals with PPI partitions.

Remove that code, allowing the common code to kick in.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/irqchip/Kconfig      |   1 -
 drivers/irqchip/irq-gic-v3.c | 133 +++--------------------------------
 2 files changed, 8 insertions(+), 126 deletions(-)

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 6d12c6ab9ea47..c31d2f99d7b91 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -36,7 +36,6 @@ config GIC_NON_BANKED
 config ARM_GIC_V3
 	bool
 	select IRQ_DOMAIN_HIERARCHY
-	select PARTITION_PERCPU
 	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
 	select HAVE_ARM_SMCCC_DISCOVERY
 	select IRQ_MSI_IOMMU
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index a14fd4c269692..0d8a6f46e9300 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -26,7 +26,6 @@
 #include <linux/irqchip/arm-gic-common.h>
 #include <linux/irqchip/arm-gic-v3.h>
 #include <linux/irqchip/arm-gic-v3-prio.h>
-#include <linux/irqchip/irq-partition-percpu.h>
 #include <linux/bitfield.h>
 #include <linux/bits.h>
 #include <linux/arm-smccc.h>
@@ -46,8 +45,6 @@ static u8 dist_prio_nmi __ro_after_init = GICV3_PRIO_NMI;
 #define FLAGS_WORKAROUND_ASR_ERRATUM_8601001	(1ULL << 2)
 #define FLAGS_WORKAROUND_INSECURE		(1ULL << 3)
 
-#define GIC_IRQ_TYPE_PARTITION	(GIC_IRQ_TYPE_LPI + 1)
-
 static struct cpumask broken_rdists __read_mostly __maybe_unused;
 
 struct redist_region {
@@ -68,11 +65,15 @@ struct gic_chip_data {
 	u64			flags;
 	bool			has_rss;
 	unsigned int		ppi_nr;
-	struct partition_desc	**ppi_descs;
 	struct partition_affinity *parts;
 	unsigned int		nr_parts;
 };
 
+struct partition_affinity {
+	cpumask_t			mask;
+	struct fwnode_handle		*partition_id;
+};
+
 #define T241_CHIPS_MAX		4
 static void __iomem *t241_dist_base_alias[T241_CHIPS_MAX] __read_mostly;
 static DEFINE_STATIC_KEY_FALSE(gic_nvidia_t241_erratum);
@@ -593,18 +594,6 @@ static void gic_irq_set_prio(struct irq_data *d, u8 prio)
 	writeb_relaxed(prio, base + offset + index);
 }
 
-static u32 __gic_get_ppi_index(irq_hw_number_t hwirq)
-{
-	switch (__get_intid_range(hwirq)) {
-	case PPI_RANGE:
-		return hwirq - 16;
-	case EPPI_RANGE:
-		return hwirq - EPPI_BASE_INTID + 16;
-	default:
-		unreachable();
-	}
-}
-
 static int gic_irq_nmi_setup(struct irq_data *d)
 {
 	struct irq_desc *desc = irq_to_desc(d->irq);
@@ -1628,13 +1617,6 @@ static int gic_irq_domain_translate(struct irq_domain *d,
 		case GIC_IRQ_TYPE_LPI:	/* LPI */
 			*hwirq = fwspec->param[1];
 			break;
-		case GIC_IRQ_TYPE_PARTITION:
-			*hwirq = fwspec->param[1];
-			if (fwspec->param[1] >= 16)
-				*hwirq += EPPI_BASE_INTID - 16;
-			else
-				*hwirq += 16;
-			break;
 		default:
 			return -EINVAL;
 		}
@@ -1643,10 +1625,8 @@ static int gic_irq_domain_translate(struct irq_domain *d,
 
 		/*
 		 * Make it clear that broken DTs are... broken.
-		 * Partitioned PPIs are an unfortunate exception.
 		 */
-		WARN_ON(*type == IRQ_TYPE_NONE &&
-			fwspec->param[0] != GIC_IRQ_TYPE_PARTITION);
+		WARN_ON(*type == IRQ_TYPE_NONE);
 		return 0;
 	}
 
@@ -1703,32 +1683,11 @@ static void gic_irq_domain_free(struct irq_domain *domain, unsigned int virq,
 	}
 }
 
-static bool fwspec_is_partitioned_ppi(struct irq_fwspec *fwspec,
-				      irq_hw_number_t hwirq)
-{
-	enum gic_intid_range range;
-
-	if (!gic_data.ppi_descs)
-		return false;
-
-	if (!is_of_node(fwspec->fwnode))
-		return false;
-
-	if (fwspec->param_count < 4 || !fwspec->param[3])
-		return false;
-
-	range = __get_intid_range(hwirq);
-	if (range != PPI_RANGE && range != EPPI_RANGE)
-		return false;
-
-	return true;
-}
-
 static int gic_irq_domain_select(struct irq_domain *d,
 				 struct irq_fwspec *fwspec,
 				 enum irq_domain_bus_token bus_token)
 {
-	unsigned int type, ret, ppi_idx;
+	unsigned int type, ret;
 	irq_hw_number_t hwirq;
 
 	/* Not for us */
@@ -1747,15 +1706,7 @@ static int gic_irq_domain_select(struct irq_domain *d,
 	if (WARN_ON_ONCE(ret))
 		return 0;
 
-	if (!fwspec_is_partitioned_ppi(fwspec, hwirq))
-		return d == gic_data.domain;
-
-	/*
-	 * If this is a PPI and we have a 4th (non-null) parameter,
-	 * then we need to match the partition domain.
-	 */
-	ppi_idx = __gic_get_ppi_index(hwirq);
-	return d == partition_get_domain(gic_data.ppi_descs[ppi_idx]);
+	return d == gic_data.domain;
 }
 
 static int gic_irq_get_fwspec_info(struct irq_fwspec *fwspec, struct irq_fwspec_info *info)
@@ -1812,45 +1763,6 @@ static const struct irq_domain_ops gic_irq_domain_ops = {
 	.get_fwspec_info = gic_irq_get_fwspec_info,
 };
 
-static int partition_domain_translate(struct irq_domain *d,
-				      struct irq_fwspec *fwspec,
-				      unsigned long *hwirq,
-				      unsigned int *type)
-{
-	unsigned long ppi_intid;
-	struct device_node *np;
-	unsigned int ppi_idx;
-	int ret;
-
-	if (!gic_data.ppi_descs)
-		return -ENOMEM;
-
-	np = of_find_node_by_phandle(fwspec->param[3]);
-	if (WARN_ON(!np))
-		return -EINVAL;
-
-	ret = gic_irq_domain_translate(d, fwspec, &ppi_intid, type);
-	if (WARN_ON_ONCE(ret))
-		return 0;
-
-	ppi_idx = __gic_get_ppi_index(ppi_intid);
-	ret = partition_translate_id(gic_data.ppi_descs[ppi_idx],
-				     of_fwnode_handle(np));
-	if (ret < 0)
-		return ret;
-
-	*hwirq = ret;
-	*type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
-
-	return 0;
-}
-
-static const struct irq_domain_ops partition_domain_ops = {
-	.translate = partition_domain_translate,
-	.select = gic_irq_domain_select,
-	.get_fwspec_info = gic_irq_get_fwspec_info,
-};
-
 static bool gic_enable_quirk_msm8996(void *data)
 {
 	struct gic_chip_data *d = data;
@@ -2173,12 +2085,7 @@ static void __init gic_populate_ppi_partitions(struct device_node *gic_node)
 	if (!parts_node)
 		return;
 
-	gic_data.ppi_descs = kcalloc(gic_data.ppi_nr, sizeof(*gic_data.ppi_descs), GFP_KERNEL);
-	if (!gic_data.ppi_descs)
-		goto out_put_node;
-
 	nr_parts = of_get_child_count(parts_node);
-
 	if (!nr_parts)
 		goto out_put_node;
 
@@ -2234,30 +2141,6 @@ static void __init gic_populate_ppi_partitions(struct device_node *gic_node)
 	gic_data.parts = parts;
 	gic_data.nr_parts = nr_parts;
 
-	for (i = 0; i < gic_data.ppi_nr; i++) {
-		unsigned int irq;
-		struct partition_desc *desc;
-		struct irq_fwspec ppi_fwspec = {
-			.fwnode		= gic_data.fwnode,
-			.param_count	= 3,
-			.param		= {
-				[0]	= GIC_IRQ_TYPE_PARTITION,
-				[1]	= i,
-				[2]	= IRQ_TYPE_NONE,
-			},
-		};
-
-		irq = irq_create_fwspec_mapping(&ppi_fwspec);
-		if (WARN_ON(!irq))
-			continue;
-		desc = partition_create_desc(gic_data.fwnode, parts, nr_parts,
-					     irq, &partition_domain_ops);
-		if (WARN_ON(!desc))
-			continue;
-
-		gic_data.ppi_descs[i] = desc;
-	}
-
 out_put_node:
 	of_node_put(parts_node);
 }
-- 
2.39.2

[PATCH v2 22/25] irqchip/apple-aic: Drop support for custom PMU irq partitions

[Marc Zyngier]

Similarly to what has been done for GICv3, drop the irq partitioning
support from the AIC driver, effectively merging the two per-cpu
interrupts for the PMU.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/irqchip/irq-apple-aic.c | 28 +++++++---------------------
 1 file changed, 7 insertions(+), 21 deletions(-)

diff --git a/drivers/irqchip/irq-apple-aic.c b/drivers/irqchip/irq-apple-aic.c
index cb8b6f40ce8d3..6305d25b9e77b 100644
--- a/drivers/irqchip/irq-apple-aic.c
+++ b/drivers/irqchip/irq-apple-aic.c
@@ -578,16 +578,9 @@ static void __exception_irq_entry aic_handle_fiq(struct pt_regs *regs)
 	}
 
 	if ((read_sysreg_s(SYS_IMP_APL_PMCR0_EL1) & (PMCR0_IMODE | PMCR0_IACT)) ==
-			(FIELD_PREP(PMCR0_IMODE, PMCR0_IMODE_FIQ) | PMCR0_IACT)) {
-		int irq;
-		if (cpumask_test_cpu(smp_processor_id(),
-				     &aic_irqc->fiq_aff[AIC_CPU_PMU_P]->aff))
-			irq = AIC_CPU_PMU_P;
-		else
-			irq = AIC_CPU_PMU_E;
+			(FIELD_PREP(PMCR0_IMODE, PMCR0_IMODE_FIQ) | PMCR0_IACT))
 		generic_handle_domain_irq(aic_irqc->hw_domain,
-					  AIC_FIQ_HWIRQ(irq));
-	}
+					  AIC_FIQ_HWIRQ(AIC_CPU_PMU_P));
 
 	if (static_branch_likely(&use_fast_ipi) &&
 	    (FIELD_GET(UPMCR0_IMODE, read_sysreg_s(SYS_IMP_APL_UPMCR0_EL1)) == UPMCR0_IMODE_FIQ) &&
@@ -632,18 +625,7 @@ static int aic_irq_domain_map(struct irq_domain *id, unsigned int irq,
 				    handle_fasteoi_irq, NULL, NULL);
 		irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(irq)));
 	} else {
-		int fiq = FIELD_GET(AIC_EVENT_NUM, hw);
-
-		switch (fiq) {
-		case AIC_CPU_PMU_P:
-		case AIC_CPU_PMU_E:
-			irq_set_percpu_devid_partition(irq, &ic->fiq_aff[fiq]->aff);
-			break;
-		default:
-			irq_set_percpu_devid(irq);
-			break;
-		}
-
+		irq_set_percpu_devid(irq);
 		irq_domain_set_info(id, irq, hw, &fiq_chip, id->host_data,
 				    handle_percpu_devid_irq, NULL, NULL);
 	}
@@ -732,6 +714,10 @@ static int aic_irq_domain_translate(struct irq_domain *id,
 				break;
 			}
 		}
+
+		/* Merge the two PMUs on a single interrupt */
+		if (*hwirq == AIC_CPU_PMU_E)
+			*hwirq = AIC_CPU_PMU_P;
 		break;
 	default:
 		return -EINVAL;
-- 
2.39.2

[PATCH v2 23/25] irqchip: Kill irq-partition-percpu

[Marc Zyngier]

This code is now completely unused, and nobody will ever miss it.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/irqchip/Kconfig                      |   3 -
 drivers/irqchip/Makefile                     |   1 -
 drivers/irqchip/irq-partition-percpu.c       | 241 -------------------
 include/linux/irqchip/irq-partition-percpu.h |  53 ----
 4 files changed, 298 deletions(-)
 delete mode 100644 drivers/irqchip/irq-partition-percpu.c
 delete mode 100644 include/linux/irqchip/irq-partition-percpu.h

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index c31d2f99d7b91..4bb25d21f6e9b 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -450,9 +450,6 @@ config LS_SCFG_MSI
 	depends on PCI_MSI
 	select IRQ_MSI_LIB
 
-config PARTITION_PERCPU
-	bool
-
 config STM32MP_EXTI
 	tristate "STM32MP extended interrupts and event controller"
 	depends on (ARCH_STM32 && !ARM_SINGLE_ARMV7M) || COMPILE_TEST
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 93e3ced023bb8..da429f3e29ec7 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -36,7 +36,6 @@ obj-$(CONFIG_ARM_GIC_V3)		+= irq-gic-v3.o irq-gic-v3-mbi.o irq-gic-common.o
 obj-$(CONFIG_ARM_GIC_ITS_PARENT)	+= irq-gic-its-msi-parent.o
 obj-$(CONFIG_ARM_GIC_V3_ITS)		+= irq-gic-v3-its.o irq-gic-v4.o
 obj-$(CONFIG_ARM_GIC_V3_ITS_FSL_MC)	+= irq-gic-v3-its-fsl-mc-msi.o
-obj-$(CONFIG_PARTITION_PERCPU)		+= irq-partition-percpu.o
 obj-$(CONFIG_ARM_GIC_V5)		+= irq-gic-v5.o irq-gic-v5-irs.o irq-gic-v5-its.o \
 					   irq-gic-v5-iwb.o
 obj-$(CONFIG_HISILICON_IRQ_MBIGEN)	+= irq-mbigen.o
diff --git a/drivers/irqchip/irq-partition-percpu.c b/drivers/irqchip/irq-partition-percpu.c
deleted file mode 100644
index 4441ffe149ea0..0000000000000
--- a/drivers/irqchip/irq-partition-percpu.c
+++ /dev/null
@@ -1,241 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2016 ARM Limited, All Rights Reserved.
- * Author: Marc Zyngier <marc.zyngier@arm.com>
- */
-
-#include <linux/bitops.h>
-#include <linux/interrupt.h>
-#include <linux/irqchip.h>
-#include <linux/irqchip/chained_irq.h>
-#include <linux/irqchip/irq-partition-percpu.h>
-#include <linux/irqdomain.h>
-#include <linux/seq_file.h>
-#include <linux/slab.h>
-
-struct partition_desc {
-	int				nr_parts;
-	struct partition_affinity	*parts;
-	struct irq_domain		*domain;
-	struct irq_desc			*chained_desc;
-	unsigned long			*bitmap;
-	struct irq_domain_ops		ops;
-};
-
-static bool partition_check_cpu(struct partition_desc *part,
-				unsigned int cpu, unsigned int hwirq)
-{
-	return cpumask_test_cpu(cpu, &part->parts[hwirq].mask);
-}
-
-static void partition_irq_mask(struct irq_data *d)
-{
-	struct partition_desc *part = irq_data_get_irq_chip_data(d);
-	struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
-	struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
-
-	if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
-	    chip->irq_mask)
-		chip->irq_mask(data);
-}
-
-static void partition_irq_unmask(struct irq_data *d)
-{
-	struct partition_desc *part = irq_data_get_irq_chip_data(d);
-	struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
-	struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
-
-	if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
-	    chip->irq_unmask)
-		chip->irq_unmask(data);
-}
-
-static int partition_irq_set_irqchip_state(struct irq_data *d,
-					   enum irqchip_irq_state which,
-					   bool val)
-{
-	struct partition_desc *part = irq_data_get_irq_chip_data(d);
-	struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
-	struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
-
-	if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
-	    chip->irq_set_irqchip_state)
-		return chip->irq_set_irqchip_state(data, which, val);
-
-	return -EINVAL;
-}
-
-static int partition_irq_get_irqchip_state(struct irq_data *d,
-					   enum irqchip_irq_state which,
-					   bool *val)
-{
-	struct partition_desc *part = irq_data_get_irq_chip_data(d);
-	struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
-	struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
-
-	if (partition_check_cpu(part, smp_processor_id(), d->hwirq) &&
-	    chip->irq_get_irqchip_state)
-		return chip->irq_get_irqchip_state(data, which, val);
-
-	return -EINVAL;
-}
-
-static int partition_irq_set_type(struct irq_data *d, unsigned int type)
-{
-	struct partition_desc *part = irq_data_get_irq_chip_data(d);
-	struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
-	struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
-
-	if (chip->irq_set_type)
-		return chip->irq_set_type(data, type);
-
-	return -EINVAL;
-}
-
-static void partition_irq_print_chip(struct irq_data *d, struct seq_file *p)
-{
-	struct partition_desc *part = irq_data_get_irq_chip_data(d);
-	struct irq_chip *chip = irq_desc_get_chip(part->chained_desc);
-	struct irq_data *data = irq_desc_get_irq_data(part->chained_desc);
-
-	seq_printf(p, "%5s-%lu", chip->name, data->hwirq);
-}
-
-static struct irq_chip partition_irq_chip = {
-	.irq_mask		= partition_irq_mask,
-	.irq_unmask		= partition_irq_unmask,
-	.irq_set_type		= partition_irq_set_type,
-	.irq_get_irqchip_state	= partition_irq_get_irqchip_state,
-	.irq_set_irqchip_state	= partition_irq_set_irqchip_state,
-	.irq_print_chip		= partition_irq_print_chip,
-};
-
-static void partition_handle_irq(struct irq_desc *desc)
-{
-	struct partition_desc *part = irq_desc_get_handler_data(desc);
-	struct irq_chip *chip = irq_desc_get_chip(desc);
-	int cpu = smp_processor_id();
-	int hwirq;
-
-	chained_irq_enter(chip, desc);
-
-	for_each_set_bit(hwirq, part->bitmap, part->nr_parts) {
-		if (partition_check_cpu(part, cpu, hwirq))
-			break;
-	}
-
-	if (unlikely(hwirq == part->nr_parts))
-		handle_bad_irq(desc);
-	else
-		generic_handle_domain_irq(part->domain, hwirq);
-
-	chained_irq_exit(chip, desc);
-}
-
-static int partition_domain_alloc(struct irq_domain *domain, unsigned int virq,
-				  unsigned int nr_irqs, void *arg)
-{
-	int ret;
-	irq_hw_number_t hwirq;
-	unsigned int type;
-	struct irq_fwspec *fwspec = arg;
-	struct partition_desc *part;
-
-	BUG_ON(nr_irqs != 1);
-	ret = domain->ops->translate(domain, fwspec, &hwirq, &type);
-	if (ret)
-		return ret;
-
-	part = domain->host_data;
-
-	set_bit(hwirq, part->bitmap);
-	irq_set_chained_handler_and_data(irq_desc_get_irq(part->chained_desc),
-					 partition_handle_irq, part);
-	irq_set_percpu_devid_partition(virq, &part->parts[hwirq].mask);
-	irq_domain_set_info(domain, virq, hwirq, &partition_irq_chip, part,
-			    handle_percpu_devid_irq, NULL, NULL);
-	irq_set_status_flags(virq, IRQ_NOAUTOEN);
-
-	return 0;
-}
-
-static void partition_domain_free(struct irq_domain *domain, unsigned int virq,
-				  unsigned int nr_irqs)
-{
-	struct irq_data *d;
-
-	BUG_ON(nr_irqs != 1);
-
-	d = irq_domain_get_irq_data(domain, virq);
-	irq_set_handler(virq, NULL);
-	irq_domain_reset_irq_data(d);
-}
-
-int partition_translate_id(struct partition_desc *desc, void *partition_id)
-{
-	struct partition_affinity *part = NULL;
-	int i;
-
-	for (i = 0; i < desc->nr_parts; i++) {
-		if (desc->parts[i].partition_id == partition_id) {
-			part = &desc->parts[i];
-			break;
-		}
-	}
-
-	if (WARN_ON(!part)) {
-		pr_err("Failed to find partition\n");
-		return -EINVAL;
-	}
-
-	return i;
-}
-
-struct partition_desc *partition_create_desc(struct fwnode_handle *fwnode,
-					     struct partition_affinity *parts,
-					     int nr_parts,
-					     int chained_irq,
-					     const struct irq_domain_ops *ops)
-{
-	struct partition_desc *desc;
-	struct irq_domain *d;
-
-	BUG_ON(!ops->select || !ops->translate);
-
-	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
-	if (!desc)
-		return NULL;
-
-	desc->ops = *ops;
-	desc->ops.free = partition_domain_free;
-	desc->ops.alloc = partition_domain_alloc;
-
-	d = irq_domain_create_linear(fwnode, nr_parts, &desc->ops, desc);
-	if (!d)
-		goto out;
-	desc->domain = d;
-
-	desc->bitmap = bitmap_zalloc(nr_parts, GFP_KERNEL);
-	if (WARN_ON(!desc->bitmap))
-		goto out;
-
-	desc->chained_desc = irq_to_desc(chained_irq);
-	desc->nr_parts = nr_parts;
-	desc->parts = parts;
-
-	return desc;
-out:
-	if (d)
-		irq_domain_remove(d);
-	kfree(desc);
-
-	return NULL;
-}
-
-struct irq_domain *partition_get_domain(struct partition_desc *dsc)
-{
-	if (dsc)
-		return dsc->domain;
-
-	return NULL;
-}
diff --git a/include/linux/irqchip/irq-partition-percpu.h b/include/linux/irqchip/irq-partition-percpu.h
deleted file mode 100644
index b35ee22c278f8..0000000000000
--- a/include/linux/irqchip/irq-partition-percpu.h
+++ /dev/null
@@ -1,53 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2016 ARM Limited, All Rights Reserved.
- * Author: Marc Zyngier <marc.zyngier@arm.com>
- */
-
-#ifndef __LINUX_IRQCHIP_IRQ_PARTITION_PERCPU_H
-#define __LINUX_IRQCHIP_IRQ_PARTITION_PERCPU_H
-
-#include <linux/fwnode.h>
-#include <linux/cpumask_types.h>
-#include <linux/irqdomain.h>
-
-struct partition_affinity {
-	cpumask_t			mask;
-	void				*partition_id;
-};
-
-struct partition_desc;
-
-#ifdef CONFIG_PARTITION_PERCPU
-int partition_translate_id(struct partition_desc *desc, void *partition_id);
-struct partition_desc *partition_create_desc(struct fwnode_handle *fwnode,
-					     struct partition_affinity *parts,
-					     int nr_parts,
-					     int chained_irq,
-					     const struct irq_domain_ops *ops);
-struct irq_domain *partition_get_domain(struct partition_desc *dsc);
-#else
-static inline int partition_translate_id(struct partition_desc *desc,
-					 void *partition_id)
-{
-	return -EINVAL;
-}
-
-static inline
-struct partition_desc *partition_create_desc(struct fwnode_handle *fwnode,
-					     struct partition_affinity *parts,
-					     int nr_parts,
-					     int chained_irq,
-					     const struct irq_domain_ops *ops)
-{
-	return NULL;
-}
-
-static inline
-struct irq_domain *partition_get_domain(struct partition_desc *dsc)
-{
-	return NULL;
-}
-#endif
-
-#endif /* __LINUX_IRQCHIP_IRQ_PARTITION_PERCPU_H */
-- 
2.39.2

[PATCH v2 24/25] genirq: Kill irq_{g,s}et_percpu_devid_partition()

[Marc Zyngier]

These two helpers do not have any user anymore, and can be removed,
together with the affinity field kept in the irqdesc structure.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 include/linux/irq.h     |  4 ----
 include/linux/irqdesc.h |  1 -
 kernel/irq/irqdesc.c    | 24 +-----------------------
 3 files changed, 1 insertion(+), 28 deletions(-)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 1381f9d1f5c9d..4cac9bc33aa34 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -716,10 +716,6 @@ static inline void irq_set_chip_and_handler(unsigned int irq,
 }
 
 extern int irq_set_percpu_devid(unsigned int irq);
-extern int irq_set_percpu_devid_partition(unsigned int irq,
-					  const struct cpumask *affinity);
-extern int irq_get_percpu_devid_partition(unsigned int irq,
-					  struct cpumask *affinity);
 
 extern void
 __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index fd091c35d5721..37e0b5b5600a4 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -82,7 +82,6 @@ struct irq_desc {
 	int			threads_handled_last;
 	raw_spinlock_t		lock;
 	struct cpumask		*percpu_enabled;
-	const struct cpumask	*percpu_affinity;
 #ifdef CONFIG_SMP
 	const struct cpumask	*affinity_hint;
 	struct irq_affinity_notify *affinity_notify;
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index b64c57b44c203..79df6e3bc3958 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -886,8 +886,7 @@ void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
 		chip_bus_sync_unlock(desc);
 }
 
-int irq_set_percpu_devid_partition(unsigned int irq,
-				   const struct cpumask *affinity)
+int irq_set_percpu_devid(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
 
@@ -899,31 +898,10 @@ int irq_set_percpu_devid_partition(unsigned int irq,
 	if (!desc->percpu_enabled)
 		return -ENOMEM;
 
-	desc->percpu_affinity = affinity ? : cpu_possible_mask;
-
 	irq_set_percpu_devid_flags(irq);
 	return 0;
 }
 
-int irq_set_percpu_devid(unsigned int irq)
-{
-	return irq_set_percpu_devid_partition(irq, NULL);
-}
-
-int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
-{
-	struct irq_desc *desc = irq_to_desc(irq);
-
-	if (!desc || !desc->percpu_enabled)
-		return -EINVAL;
-
-	if (affinity)
-		cpumask_copy(affinity, desc->percpu_affinity);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);
-
 void kstat_incr_irq_this_cpu(unsigned int irq)
 {
 	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
-- 
2.39.2

[PATCH v2 25/25] perf: arm_pmu: Kill last use of per-CPU cpu_armpmu pointer

[Marc Zyngier]

Having removed the use of the cpu_armpmu per-CPU variable from the
interrupt handling, the only user left is the BRBE scheduler hook.

It is easy to drop the use of this variable by following the pointer
to the generic PMU structure, and get the arm_pmu structure from there.

Perform the conversion and kill cpu_armpmu altogether.

Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/perf/arm_pmu.c       | 5 -----
 drivers/perf/arm_pmuv3.c     | 2 +-
 include/linux/perf/arm_pmu.h | 2 --
 3 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 23814707cf771..7171d8e0d27a5 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -104,7 +104,6 @@ static const struct pmu_irq_ops percpu_pmunmi_ops = {
 	.free_pmuirq = armpmu_free_percpu_pmunmi
 };
 
-DEFINE_PER_CPU(struct arm_pmu *, cpu_armpmu);
 static DEFINE_PER_CPU(int, cpu_irq);
 static DEFINE_PER_CPU(const struct pmu_irq_ops *, cpu_irq_ops);
 
@@ -726,8 +725,6 @@ static int arm_perf_starting_cpu(unsigned int cpu, struct hlist_node *node)
 	if (pmu->reset)
 		pmu->reset(pmu);
 
-	per_cpu(cpu_armpmu, cpu) = pmu;
-
 	irq = armpmu_get_cpu_irq(pmu, cpu);
 	if (irq)
 		per_cpu(cpu_irq_ops, cpu)->enable_pmuirq(irq);
@@ -747,8 +744,6 @@ static int arm_perf_teardown_cpu(unsigned int cpu, struct hlist_node *node)
 	if (irq)
 		per_cpu(cpu_irq_ops, cpu)->disable_pmuirq(irq);
 
-	per_cpu(cpu_armpmu, cpu) = NULL;
-
 	return 0;
 }
 
diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c
index f6d7bab5d555c..2dee2d928aaef 100644
--- a/drivers/perf/arm_pmuv3.c
+++ b/drivers/perf/arm_pmuv3.c
@@ -1039,7 +1039,7 @@ static int armv8pmu_user_event_idx(struct perf_event *event)
 static void armv8pmu_sched_task(struct perf_event_pmu_context *pmu_ctx,
 				struct task_struct *task, bool sched_in)
 {
-	struct arm_pmu *armpmu = *this_cpu_ptr(&cpu_armpmu);
+	struct arm_pmu *armpmu = to_arm_pmu(pmu_ctx->pmu);
 	struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events);
 
 	if (!hw_events->branch_users)
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index 6690bd77aa4ee..bab26a7d79f4c 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -132,8 +132,6 @@ struct arm_pmu {
 
 #define to_arm_pmu(p) (container_of(p, struct arm_pmu, pmu))
 
-DECLARE_PER_CPU(struct arm_pmu *, cpu_armpmu);
-
 u64 armpmu_event_update(struct perf_event *event);
 
 int armpmu_event_set_period(struct perf_event *event);
-- 
2.39.2