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

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

[Marc Zyngier]

The percpu_devid class of interrupts represent interrupts that are
generally produced by CPUs or per-CPU devices (timer, PMU), and are
more or less directly wired to that same CPU.

The core code has a baked-in assumption that all CPUs have the same
devices wired to the same interrupt, making the whole system
homogeneous in that respect.

Unfortunately, this is wishful thinking, and the big-little
contraption has proved more often than not that sanity was not
necessarily part of the design requirements.

The typical problem on ARM systems is that while all CPUs have a PMU,
not all PMUs are the same and require a slightly different programing
model. The driver therefore has to treat them differently. Another
problem is that some devices are only present on a subset of the CPUs,
and not others.

All in all, it means that these percpu_devid interrupts (which are
represented as PPIs on the GIC class of interrupt controllers) are not
ideally handled by the core code.

At least two interrupt controllers (GICv3 and Apple AIC) have invented
their own schemes to paper over these problems. In the GICv3 case (the
most over-engineered one), the low-level irqchip creates a mux irqchip
for each PPI (up to 64 of them), and each possible affinity class
represents an interrupt in this mux. Like this (compressed for
readability):

# grep pmu /proc/interrupts 
 38: 0    0    0    0    0    0  GICv3-23   0 Level     arm-pmu
 39: 0    0    0    0    0    0  GICv3-23   1 Level     arm-pmu

Yes, this is nuts. But by hiding that the PPI is split between two
affinity groups, and exposing two interrupts that are apparently
system-wide, we trick the core code into not exploding.

While this solution has worked for the past 9 years, it creates its
own class of issues. The most glaring one is that we cannot configure
these interrupts as NMIs, as they are muxed interrupts and we don't
allow NMIs outside of the root interrupt controller (this would imply
taking locks that are not safe in this context). As it turns out, some
of the heaviest users of profiling are also users of the most crazy
systems out there (cough phones cough)...

It is also pretty bad that the core IRQ code cannot handle natively
what has become an extremely common HW setup, for better or worse.

Finally, I have no desire to replicate the same horror on the next
generation of ARM interrupt controller (GICv5), and this is the
opportunity to put things right.

This series therefore aims at teaching the core code about these
interrupts, removing all sort of irqchip-specific handling, and allow
NMIs to be naturally handled in these setups.

We want:

- a single irqdesc representing the system-wide percpu interrupt

- the irqaction to carry the affinity the handler applies to

For that, we have a few problems to solve:

- communicating the affinity of an interrupt from the firmware to the
  device driver.

  This is currently done via the irq_{g,s}et_percpu_devid_partition(),
  but this is stored on a per-irqdesc basis, which wouldn't work
  anymore with the scheme described above.

  For that, we expose a new irqdomain op, implemented by the irqchips,
  that can retrieve FW-specific information including interrupt
  affinity, which then gets processed by ACPI and OF helpers to report
  the affinity to the platform layer. A new platform-level API can
  retrieve both the interrupt and its affinity, and the three drivers
  that make use of such affinity are updated to use this interface.

- teaching the core code about affinity-specific interrupts by
  allowing a percpu interrupt to be requested for a specific affinity.

  This involves tracking the affinity at the irqaction level and
  enforce that it isn't possible to request the interrupt twice with
  overlapping affinities. A new flavour of request_irq() is provided
  for that purpose, and the drivers updated to make use of it.

- kill the irqchip-specific infrastructure, allowing the normal flow
  of interrupt request to be restored.

With that, we end-up with this on the same platform as above:

# grep pmu /proc/interrupts
 27: 0   0   0   0    0    0  GICv3  23 Level     arm-pmu, arm-pmu

which is much more satisfactory, and allows the use of NMIs. It
doesn't hurt that the whole thing ends up with a negative diffstat.

Patches on top of v6.17-rc5, tested on a bunch of asymmetric systems:

- RK3399 (GICv3, DT)
- O6 (GICv3, ACPI)
- M1 (AIC, DT)

as well as on a saner symmetric system (Synquacer).

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
  perf: arm_pmu: Add PMU/CPU affinity tracking
  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_pmu: Request specific affinities for percpu NMI/IRQ
  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: Use a backend-specific pointer for percpu interrupt
    request

 arch/arm64/kernel/smp.c                      |   2 +-
 drivers/acpi/irq.c                           |  15 ++
 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              |  59 +++--
 drivers/irqchip/irq-gic-v3.c                 | 172 +++++--------
 drivers/irqchip/irq-partition-percpu.c       | 241 -------------------
 drivers/of/irq.c                             |  20 ++
 drivers/perf/arm_pmu.c                       |  61 +++--
 drivers/perf/arm_pmu_acpi.c                  |   7 +-
 drivers/perf/arm_pmu_platform.c              |  24 +-
 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                          |   4 -
 include/linux/irqchip/irq-partition-percpu.h |  53 ----
 include/linux/irqdesc.h                      |   1 -
 include/linux/irqdomain.h                    |  30 +++
 include/linux/of_irq.h                       |   7 +
 include/linux/perf/arm_pmu.h                 |   7 +-
 include/linux/platform_device.h              |   2 +
 kernel/irq/chip.c                            |   8 +-
 kernel/irq/irqdesc.c                         |  24 +-
 kernel/irq/irqdomain.c                       |  33 ++-
 kernel/irq/manage.c                          | 128 +++++++---
 28 files changed, 449 insertions(+), 569 deletions(-)
 delete mode 100644 drivers/irqchip/irq-partition-percpu.c
 delete mode 100644 include/linux/irqchip/irq-partition-percpu.h

-- 
2.39.2

[PATCH 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 | 30 ++++++++++++++++++++++++++++++
 kernel/irq/irqdomain.c    | 33 ++++++++++++++++++++++++++++-----
 2 files changed, 58 insertions(+), 5 deletions(-)

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 4a86e6b915dd6..9ec93fb2f5753 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -44,6 +44,27 @@ struct irq_fwspec {
 	u32			param[IRQ_DOMAIN_IRQ_SPEC_PARAMS];
 };
 
+/**
+ * struct irq_fwspec_info - firmware provided IRQ information structure
+ *
+ * @fwspec:		IRQ 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 {
+	struct irq_fwspec	fwspec;
+	const struct cpumask	*affinity;
+
+#define IRQ_FWSPEC_INFO_FWSPEC_VALID	BIT(0)
+#define IRQ_FWSPEC_INFO_AFFINITY_VALID	BIT(1)
+
+	unsigned long		flags;
+};
+
 /* 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 +90,8 @@ 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_info: Given @info, report additional firmware-provided information.
+ *            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 +119,7 @@ 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_info)(struct irq_fwspec_info *info);
 #endif
 #ifdef CONFIG_GENERIC_IRQ_DEBUGFS
 	void	(*debug_show)(struct seq_file *m, struct irq_domain *d,
@@ -602,6 +626,8 @@ 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_info *info);
+
 static inline bool irq_domain_is_hierarchy(struct irq_domain *domain)
 {
 	return domain->flags & IRQ_DOMAIN_FLAG_HIERARCHY;
@@ -685,6 +711,10 @@ static inline bool irq_domain_is_msi_device(struct irq_domain *domain)
 	return false;
 }
 
+static inline int irq_populate_fwspec_info(struct irq_fwspec_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..f857606e3ffbe 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 +879,33 @@ 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_info *info)
+{
+	struct irq_domain *domain;
+
+	domain = fwspec_to_domain(&info->fwspec);
+	if (!domain || !domain->ops->get_info) {
+		info->flags = 0;
+		return 0;
+	}
+
+	return domain->ops->get_info(info);
+}
+#endif
+
+unsigned int irq_create_fwspec_mapping(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;
+
+	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

[PATCH 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   | 15 +++++++++++++++
 include/linux/acpi.h |  7 +++++++
 2 files changed, 22 insertions(+)

diff --git a/drivers/acpi/irq.c b/drivers/acpi/irq.c
index 76a856c32c4d0..22f93fe23ddce 100644
--- a/drivers/acpi/irq.c
+++ b/drivers/acpi/irq.c
@@ -300,6 +300,21 @@ 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;
+	unsigned long flags;
+
+	if (!acpi_irq_parse_one(handle, index, &info.fwspec, &flags)) {
+		if (!irq_populate_fwspec_info(&info) &&
+		    info.flags & IRQ_FWSPEC_INFO_AFFINITY_VALID)
+			return info.affinity;
+	}
+
+	return NULL;
+}
+
 /**
  * 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 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..cb264f44bd6d8 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)
+{
+	int rc;
+	struct of_phandle_args oirq;
+	struct irq_fwspec_info info;
+
+	rc = of_irq_parse_one(dev, index, &oirq);
+	if (rc)
+		return NULL;
+
+	of_phandle_args_to_fwspec(oirq.np, oirq.args, oirq.args_count,
+				  &info.fwspec);
+
+	if (!irq_populate_fwspec_info(&info) &&
+	    info.flags & IRQ_FWSPEC_INFO_AFFINITY_VALID)
+		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 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

[PATCH 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 | 55 ++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index dbeb85677b08c..4a90dbf9daedb 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 +1798,60 @@ 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_info(struct irq_fwspec_info *info)
+{
+	struct irq_fwspec *fwspec = &info->fwspec;
+	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))
+		goto out;
+
+	/* 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:
+			goto out;
+		}
+
+		fw = of_node_to_fwnode(of_find_node_by_phandle(fwspec->param[3]));
+		if (!fw)
+			goto out;
+
+		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)
+			goto out;
+	} else {
+		mask = cpu_possible_mask;
+	}
+
+	info->affinity = mask;
+	info->flags = (IRQ_FWSPEC_INFO_FWSPEC_VALID |
+		       IRQ_FWSPEC_INFO_AFFINITY_VALID);
+out:
+	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_info = gic_irq_get_info,
 };
 
 static int partition_domain_translate(struct irq_domain *d,
@@ -1839,6 +1890,7 @@ 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_info = gic_irq_get_info,
 };
 
 static bool gic_enable_quirk_msm8996(void *data)
@@ -2231,6 +2283,9 @@ 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

[PATCH 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 | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/drivers/irqchip/irq-apple-aic.c b/drivers/irqchip/irq-apple-aic.c
index 032d66dceb8ec..dd89e50a72e83 100644
--- a/drivers/irqchip/irq-apple-aic.c
+++ b/drivers/irqchip/irq-apple-aic.c
@@ -651,6 +651,36 @@ static int aic_irq_domain_map(struct irq_domain *id, unsigned int irq,
 	return 0;
 }
 
+static int aic_irq_get_info(struct irq_fwspec_info *info)
+{
+	struct irq_fwspec *fwspec = &info->fwspec;
+	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_FWSPEC_VALID |
+		       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 +783,7 @@ 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_info	= aic_irq_get_info,
 };
 
 /*
-- 
2.39.2

[PATCH 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

[PATCH 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 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 10/25] perf: arm_pmu: Add PMU/CPU affinity tracking

[Marc Zyngier]

The ARM PMU code is built around the assumption that different CPU
affinities (either a single CPU in the case of an SPI, or a group
of CPUs for a PPI) must result in different IRQ numbers.

This scheme is about to be removed, so the driver must be able to match
the new behaviour.

For this purpose, add a new per-CPU variable that tracks the PMU
affinities on a per-CPU basis, so that the driver can, from any CPU,
find out which other CPUs it is sharing an interrupt number with.

It is likely that some simplifications could result from this scheme,
but this is good enough to get started.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/perf/arm_pmu.c          | 37 +++++++++++++++++++++++++--------
 drivers/perf/arm_pmu_acpi.c     |  5 +++++
 drivers/perf/arm_pmu_platform.c |  4 ++++
 include/linux/perf/arm_pmu.h    |  1 +
 4 files changed, 38 insertions(+), 9 deletions(-)

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 5c310e803dd78..6e3c72e9b41cd 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -26,7 +26,7 @@
 
 #include <asm/irq_regs.h>
 
-static int armpmu_count_irq_users(const int irq);
+static int armpmu_count_irq_users(const int this_cpu, const int irq);
 
 struct pmu_irq_ops {
 	void (*enable_pmuirq)(unsigned int irq);
@@ -64,7 +64,7 @@ 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)
+	if (armpmu_count_irq_users(cpu, irq) == 1)
 		free_percpu_irq(irq, devid);
 }
 
@@ -89,7 +89,7 @@ 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)
+	if (armpmu_count_irq_users(cpu, irq) == 1)
 		free_percpu_nmi(irq, devid);
 }
 
@@ -100,11 +100,20 @@ static const struct pmu_irq_ops percpu_pmunmi_ops = {
 };
 
 DEFINE_PER_CPU(struct arm_pmu *, cpu_armpmu);
+static DEFINE_PER_CPU(const struct cpumask *, pmu_affinity);
 static DEFINE_PER_CPU(int, cpu_irq);
 static DEFINE_PER_CPU(const struct pmu_irq_ops *, cpu_irq_ops);
 
 static bool has_nmi;
 
+void armpmu_register_affinity_group(const struct cpumask *aff_grp)
+{
+	int cpu;
+
+	for_each_cpu(cpu, aff_grp)
+		per_cpu(pmu_affinity, cpu) = aff_grp;
+}
+
 static inline u64 arm_pmu_event_max_period(struct perf_event *event)
 {
 	if (event->hw.flags & ARMPMU_EVT_64BIT)
@@ -580,11 +589,16 @@ 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 int this_cpu, const int irq)
 {
+	const struct cpumask *affinity;
 	int cpu, count = 0;
 
-	for_each_possible_cpu(cpu) {
+	affinity = per_cpu(pmu_affinity, this_cpu);
+	if (WARN_ON(!affinity))
+		return 0;
+
+	for_each_cpu(cpu, affinity) {
 		if (per_cpu(cpu_irq, cpu) == irq)
 			count++;
 	}
@@ -592,12 +606,17 @@ 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(int this_cpu, int irq)
 {
 	const struct pmu_irq_ops *ops = NULL;
+	const struct cpumask *affinity;
 	int cpu;
 
-	for_each_possible_cpu(cpu) {
+	affinity = per_cpu(pmu_affinity, this_cpu);
+	if (!affinity)
+		return NULL;
+
+	for_each_cpu(cpu, affinity) {
 		if (per_cpu(cpu_irq, cpu) != irq)
 			continue;
 
@@ -658,7 +677,7 @@ int armpmu_request_irq(int irq, int cpu)
 			has_nmi = true;
 			irq_ops = &pmunmi_ops;
 		}
-	} else if (armpmu_count_irq_users(irq) == 0) {
+	} else if (armpmu_count_irq_users(cpu, irq) == 0) {
 		err = request_percpu_nmi(irq, handler, "arm-pmu", &cpu_armpmu);
 
 		/* If cannot get an NMI, get a normal interrupt */
@@ -672,7 +691,7 @@ 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(cpu, 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..a5956fa728070 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -212,6 +212,11 @@ static int arm_pmu_acpi_parse_irqs(void)
 			pr_warn("No ACPI PMU IRQ for CPU%d\n", cpu);
 		}
 
+		if (irq_is_percpu_devid(irq))
+			armpmu_register_affinity_group(cpu_possible_mask);
+		else
+			armpmu_register_affinity_group(cpumask_of(cpu));
+
 		/*
 		 * Log and request the IRQ so the core arm_pmu code can manage
 		 * it. We'll have to sanity-check IRQs later when we associate
diff --git a/drivers/perf/arm_pmu_platform.c b/drivers/perf/arm_pmu_platform.c
index 9c0494d8a867a..0c7d5065e9074 100644
--- a/drivers/perf/arm_pmu_platform.c
+++ b/drivers/perf/arm_pmu_platform.c
@@ -53,6 +53,8 @@ static int pmu_parse_percpu_irq(struct arm_pmu *pmu, int irq,
 	for_each_cpu(cpu, &pmu->supported_cpus)
 		per_cpu(hw_events->irq, cpu) = irq;
 
+	armpmu_register_affinity_group(&pmu->supported_cpus);
+
 	return 0;
 }
 
@@ -152,6 +154,8 @@ static int pmu_parse_irqs(struct arm_pmu *pmu)
 		cpumask_set_cpu(cpu, &pmu->supported_cpus);
 	}
 
+	armpmu_register_affinity_group(&pmu->supported_cpus);
+
 	return 0;
 }
 
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index 93c9a26492fcf..7bf548678b288 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -171,6 +171,7 @@ struct pmu_probe_info {
 int arm_pmu_device_probe(struct platform_device *pdev,
 			 const struct of_device_id *of_table,
 			 const struct pmu_probe_info *probe_table);
+void armpmu_register_affinity_group(const struct cpumask *);
 
 #ifdef CONFIG_ACPI
 int arm_pmu_acpi_probe(armpmu_init_fn init_fn);
-- 
2.39.2

[PATCH 11/25] 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 12/25] 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 | 43 +++++++++++++++++++++++++++----------------
 1 file changed, 27 insertions(+), 16 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index c94837382037e..980725bd93e95 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -2442,6 +2442,26 @@ 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 +2470,9 @@ 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 +2497,10 @@ 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 +2561,12 @@ 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

[PATCH 13/25] 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       | 13 ++++++++++---
 2 files changed, 13 insertions(+), 5 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 980725bd93e95..ac394f0b422b8 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -2446,10 +2446,14 @@ static
 struct irqaction *create_percpu_irqaction(irq_handler_t handler,
 					  unsigned long flags,
 					  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;
@@ -2458,6 +2462,7 @@ struct irqaction *create_percpu_irqaction(irq_handler_t handler,
 	action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND;
 	action->name = devname;
 	action->percpu_dev_id = dev_id;
+	action->affinity = affinity;
 
 	return action;
 }
@@ -2468,6 +2473,7 @@ struct irqaction *create_percpu_irqaction(irq_handler_t handler,
  * @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
@@ -2480,7 +2486,7 @@ struct irqaction *create_percpu_irqaction(irq_handler_t handler,
  */
 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;
@@ -2497,7 +2503,8 @@ 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;
 
@@ -2563,7 +2570,7 @@ int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
 
 	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 14/25] 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 6e3c72e9b41cd..d1f738eb77f1e 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -678,7 +678,9 @@ int armpmu_request_irq(int irq, int cpu)
 			irq_ops = &pmunmi_ops;
 		}
 	} else if (armpmu_count_irq_users(cpu, 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 ac394f0b422b8..a17ac522622e7 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -2530,6 +2530,7 @@ 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
@@ -2547,7 +2548,8 @@ 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;
@@ -2564,13 +2566,14 @@ 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

[PATCH 15/25] 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 0d0276378c707..af90dd440d5ee 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -897,8 +897,9 @@ 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;
 
 	/*
@@ -910,12 +911,15 @@ 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 a17ac522622e7..1ac79df0e5f76 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);
@@ -2464,6 +2499,14 @@ struct irqaction *create_percpu_irqaction(irq_handler_t handler,
 	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 16/25] 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 17/25] perf: arm_pmu: Use a backend-specific pointer for percpu interrupt request

[Marc Zyngier]

From: Will Deacon <will@kernel.org>

DT and ACPI significantly differ in the way the PMU probing is
conducted, resulting in different data being available at different
times.

Work around this by providing a per-cpu 'struct arm_pmu *' as
a parameter, instead of sampling it from a per-cpu variable.

Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/perf/arm_pmu.c          | 10 +++++-----
 drivers/perf/arm_pmu_acpi.c     |  2 +-
 drivers/perf/arm_pmu_platform.c |  4 ++--
 include/linux/perf/arm_pmu.h    |  4 ++--
 4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index d1f738eb77f1e..044c9c6296997 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -628,20 +628,20 @@ static const struct pmu_irq_ops *armpmu_find_irq_ops(int this_cpu, 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 *armpmu, int irq, int cpu)
 {
 	int err = 0;
 	const irq_handler_t handler = armpmu_dispatch_irq;
@@ -666,12 +666,12 @@ int armpmu_request_irq(int irq, int cpu)
 			    IRQF_NO_THREAD;
 
 		err = request_nmi(irq, handler, irq_flags, "arm-pmu",
-				  per_cpu_ptr(&cpu_armpmu, cpu));
+				  per_cpu_ptr(armpmu, cpu));
 
 		/* 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));
+					  per_cpu_ptr(armpmu, cpu));
 			irq_ops = &pmuirq_ops;
 		} else {
 			has_nmi = true;
diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
index a5956fa728070..a28352e2bff0a 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -223,7 +223,7 @@ 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 0c7d5065e9074..d9b0e8f6debf2 100644
--- a/drivers/perf/arm_pmu_platform.c
+++ b/drivers/perf/arm_pmu_platform.c
@@ -169,7 +169,7 @@ 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;
 	}
@@ -185,7 +185,7 @@ 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 7bf548678b288..395d03c282e8c 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -191,8 +191,8 @@ 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 18/25] perf: arm_pmu: Request specific affinities for percpu NMI/IRQ

[Marc Zyngier]

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

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

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 044c9c6296997..0d64e929d9bf0 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -679,13 +679,14 @@ int armpmu_request_irq(struct arm_pmu * __percpu *armpmu, int irq, int cpu)
 		}
 	} else if (armpmu_count_irq_users(cpu, irq) == 0) {
 		err = request_percpu_nmi(irq, handler, "arm-pmu",
-					 NULL,
-					 &cpu_armpmu);
+					 per_cpu(pmu_affinity, cpu),
+					 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",
+							  per_cpu(pmu_affinity, cpu),
+							  armpmu);
 			irq_ops = &percpu_pmuirq_ops;
 		} else {
 			has_nmi = true;
-- 
2.39.2

[PATCH 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 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

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

[Marc Zyngier]

We are finally getting there. The only thing getting in the way of
correctly handling PPIs in the way they were intended is to drop
the GICv3 hack that deals with PPI partitions.

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 4a90dbf9daedb..cdf6fac32908d 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);
@@ -596,18 +597,6 @@ 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 u32 __gic_get_rdist_index(irq_hw_number_t hwirq)
 {
 	switch (__get_intid_range(hwirq)) {
@@ -1668,13 +1657,6 @@ 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;
 		}
@@ -1683,10 +1665,8 @@ 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;
 	}
 
@@ -1743,32 +1723,11 @@ 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 */
@@ -1787,15 +1746,7 @@ 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_info(struct irq_fwspec_info *info)
@@ -1854,45 +1805,6 @@ static const struct irq_domain_ops gic_irq_domain_ops = {
 	.get_info = gic_irq_get_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_info = gic_irq_get_info,
-};
-
 static bool gic_enable_quirk_msm8996(void *data)
 {
 	struct gic_chip_data *d = data;
@@ -2225,12 +2137,7 @@ 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;
 
@@ -2286,30 +2193,6 @@ 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 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 dd89e50a72e83..5688411f9f0b8 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);
 	}
@@ -735,6 +717,10 @@ 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 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 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 1d6b606a81efe..c107125f51283 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -717,10 +717,6 @@ 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 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 0d64e929d9bf0..8b3d7022a2d83 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -99,7 +99,6 @@ 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(const struct cpumask *, pmu_affinity);
 static DEFINE_PER_CPU(int, cpu_irq);
 static DEFINE_PER_CPU(const struct pmu_irq_ops *, cpu_irq_ops);
@@ -739,8 +738,6 @@ 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);
@@ -760,8 +757,6 @@ 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 395d03c282e8c..b54c309a74f0f 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

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

[Rafael J. Wysocki]

On Mon, Sep 8, 2025 at 6:31 PM 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>
> ---
>  drivers/acpi/irq.c   | 15 +++++++++++++++
>  include/linux/acpi.h |  7 +++++++
>  2 files changed, 22 insertions(+)
>
> diff --git a/drivers/acpi/irq.c b/drivers/acpi/irq.c
> index 76a856c32c4d0..22f93fe23ddce 100644
> --- a/drivers/acpi/irq.c
> +++ b/drivers/acpi/irq.c
> @@ -300,6 +300,21 @@ 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;
> +       unsigned long flags;
> +
> +       if (!acpi_irq_parse_one(handle, index, &info.fwspec, &flags)) {
> +               if (!irq_populate_fwspec_info(&info) &&
> +                   info.flags & IRQ_FWSPEC_INFO_AFFINITY_VALID)
> +                       return info.affinity;
> +       }

I would prefer fewer logical negations to be used in this, for instance:

if (acpi_irq_parse_one(handle, index, &info.fwspec, &flags))
      return NULL;

if (irq_populate_fwspec_info(&info))
       return NULL;

if (info.flags & IRQ_FWSPEC_INFO_AFFINITY_VALID)
       return info.affinity;

return NULL;

> +
> +       return NULL;
> +}
> +
>  /**
>   * 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
> --

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

[Thomas Gleixner]

On Mon, Sep 08 2025 at 17:31, Marc Zyngier wrote:
> +/**
> + * struct irq_fwspec_info - firmware provided IRQ information structure
> + *
> + * @fwspec:		IRQ specifier

s/IRQ/interrupt/g

> + * @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 {
> +	struct irq_fwspec	fwspec;
> +	const struct cpumask	*affinity;
> +
> +#define IRQ_FWSPEC_INFO_FWSPEC_VALID	BIT(0)
> +#define IRQ_FWSPEC_INFO_AFFINITY_VALID	BIT(1)
> +
> +	unsigned long		flags;

Can you please not stick the defines into the struct. That makes my eyes
bleed.

Also the ordering looks strange as flags should be before the fields it
validates for readability sake, no?

> +};
> +
>  /* 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 +90,8 @@ 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_info: Given @info, report additional firmware-provided information.
> + *            Optional.

get_info() is pretty generic. Can we have some more descriptive name for
that? Also please keep the tabular formatting of the doc intact.

>   * @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 +119,7 @@ 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_info)(struct irq_fwspec_info *info);

TAB between int and '(*'

>  #endif
>  #ifdef CONFIG_GENERIC_IRQ_DEBUGFS
>  	void	(*debug_show)(struct seq_file *m, struct irq_domain *d,
> @@ -602,6 +626,8 @@ 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_info *info);
> +
> +
> +#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY

Stray TAB

> +int irq_populate_fwspec_info(struct irq_fwspec_info *info)
> +{
> +	struct irq_domain *domain;
> +
> +	domain = fwspec_to_domain(&info->fwspec);

Just move that to the declaration line

> +	if (!domain || !domain->ops->get_info) {
> +		info->flags = 0;
> +		return 0;
> +	}
> +
> +	return domain->ops->get_info(info);
> +}
> +#endif
> +
> +unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
> +{
> +	struct irq_domain *domain;
> +	struct irq_data *irq_data;
> +	irq_hw_number_t hwirq;
> +	unsigned int type = IRQ_TYPE_NONE;

I know you moved it from the original function, but can you please
reorder it in reverse fir tree order?

> +	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)));

Thanks,

        tglx

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

[Thomas Gleixner]

On Tue, Sep 09 2025 at 11:18, Thomas Gleixner wrote:
> On Mon, Sep 08 2025 at 17:31, Marc Zyngier wrote:
>> +int irq_populate_fwspec_info(struct irq_fwspec_info *info)
>> +{
>> +	struct irq_domain *domain;
>> +
>> +	domain = fwspec_to_domain(&info->fwspec);
>
> Just move that to the declaration line
>
>> +	if (!domain || !domain->ops->get_info) {
>> +		info->flags = 0;

It looks like @info is not initialized except for info::fwspec. That's a
patently bad idea.

Why has fwspec to be in info in the first place? What's wrong with doing
the obvious:

int irq_populate_fwspec_info(struct irq_fwspec *fwspec, struct irq_fwspec_info *info)
{
        memset(info, 0, sizeof(info));

        ....

No?

Thanks,

        tglx

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

[Thomas Gleixner]

On Mon, Sep 08 2025 at 17:31, Marc Zyngier wrote:
> +static int gic_irq_get_info(struct irq_fwspec_info *info)
> +{
> +	struct irq_fwspec *fwspec = &info->fwspec;
> +	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))
> +		goto out;

'goto out' to return 0? Seriously?

> +	/* 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:
> +			goto out;
> +		}
> +
> +		fw = of_node_to_fwnode(of_find_node_by_phandle(fwspec->param[3]));
> +		if (!fw)
> +			goto out;
> +
> +		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)
> +			goto out;
> +	} else {
> +		mask = cpu_possible_mask;
> +	}
> +
> +	info->affinity = mask;
> +	info->flags = (IRQ_FWSPEC_INFO_FWSPEC_VALID |
> +		       IRQ_FWSPEC_INFO_AFFINITY_VALID);

It's not really clear to me what the purpose
ofIRQ_FWSPEC_INFO_FWSPEC_VALID is. That firmware spec was handed in by
the caller, so it should be valid no matter what, no? 

Thanks,

        tglx

Re: [PATCH 12/25] genirq: Factor-in percpu irqaction creation

[Thomas Gleixner]

On Mon, Sep 08 2025 at 17:31, Marc Zyngier wrote:
>  
> +static
> +struct irqaction *create_percpu_irqaction(irq_handler_t handler,
> +					  unsigned long flags,
> +					  const char *devname,
> +					  void __percpu *dev_id)

static struct irqaction *create_percpu_irqaction(irq_handler_t handler, unsigned long flags,
						 const char *devname, void __percpu *dev_id)
{

No?


> +{
> +	struct irqaction *action;
> +
> +	action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);

	struct irqaction *action = kzalloc(sizeof(*action),.....;
> -	action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
> +	action = create_percpu_irqaction(handler,
> +					 IRQF_NO_THREAD | IRQF_NOBALANCING,
> +					 name, dev_id);

Please get rid of these artifical line breaks. You have 100 characters.

Thanks,

        tglx

Re: [PATCH 14/25] genirq: Update request_percpu_nmi() to take an affinity

[Thomas Gleixner]

On Mon, Sep 08 2025 at 17:31, Marc Zyngier wrote:
> @@ -2564,13 +2566,14 @@ 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;

This check looks odd. What makes sure that the affinities do not
overlap?

Thanks,

        tglx

Re: [PATCH 14/25] genirq: Update request_percpu_nmi() to take an affinity

[Marc Zyngier]

On Tue, 09 Sep 2025 10:45:36 +0100,
Thomas Gleixner <tglx@linutronix.de> wrote:
> 
> On Mon, Sep 08 2025 at 17:31, Marc Zyngier wrote:
> > @@ -2564,13 +2566,14 @@ 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;
> 
> This check looks odd. What makes sure that the affinities do not
> overlap?

The following patch in the series does, at the point of adding the new
irqaction to the list. This is modelled after the current handling of
shared interrupts.

	M.

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

Re: [PATCH 15/25] genirq: Allow per-cpu interrupt sharing for non-overlapping affinities

[Marc Zyngier]

On Mon, 08 Sep 2025 17:31:17 +0100,
Marc Zyngier <maz@kernel.org> wrote:
> 
> 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 0d0276378c707..af90dd440d5ee 100644
> --- a/kernel/irq/chip.c
> +++ b/kernel/irq/chip.c
> @@ -897,8 +897,9 @@ 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;
>  
>  	/*
> @@ -910,12 +911,15 @@ 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)

As Will points out off the list, the above lacks the a similar
handling for percpu_devid NMIs, leading to NMIs that are only handled
on the first affinity group.

It's easy enough to move the above to common code and share it with
handle_percpu_devid_fasteoi_nmi(), but at this point there is hardly
any difference with handle_percpu_devid_irq().

Any objection to simply killing the NMI version?

Thanks,

	M.

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

Re: [PATCH 15/25] genirq: Allow per-cpu interrupt sharing for non-overlapping affinities

[Thomas Gleixner]

On Wed, Sep 10 2025 at 09:28, Marc Zyngier wrote:
> On Mon, 08 Sep 2025 17:31:17 +0100,
> As Will points out off the list, the above lacks the a similar
> handling for percpu_devid NMIs, leading to NMIs that are only handled
> on the first affinity group.
>
> It's easy enough to move the above to common code and share it with
> handle_percpu_devid_fasteoi_nmi(), but at this point there is hardly
> any difference with handle_percpu_devid_irq().
>
> Any objection to simply killing the NMI version?

Removing code is always appreciated :)

Re: [PATCH 15/25] genirq: Allow per-cpu interrupt sharing for non-overlapping affinities

[Marc Zyngier]

On Wed, 10 Sep 2025 15:47:01 +0100,
Thomas Gleixner <tglx@linutronix.de> wrote:
> 
> On Wed, Sep 10 2025 at 09:28, Marc Zyngier wrote:
> > On Mon, 08 Sep 2025 17:31:17 +0100,
> > As Will points out off the list, the above lacks the a similar
> > handling for percpu_devid NMIs, leading to NMIs that are only handled
> > on the first affinity group.
> >
> > It's easy enough to move the above to common code and share it with
> > handle_percpu_devid_fasteoi_nmi(), but at this point there is hardly
> > any difference with handle_percpu_devid_irq().
> >
> > Any objection to simply killing the NMI version?
> 
> Removing code is always appreciated :)
>

Works for me!

	M.

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

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

[Marc Zyngier]

On Tue, 09 Sep 2025 10:18:01 +0100,
Thomas Gleixner <tglx@linutronix.de> wrote:
> 
> On Mon, Sep 08 2025 at 17:31, Marc Zyngier wrote:

[...]

> > @@ -69,6 +90,8 @@ 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_info: Given @info, report additional firmware-provided information.
> > + *            Optional.
> 
> get_info() is pretty generic. Can we have some more descriptive name for
> that? Also please keep the tabular formatting of the doc intact.

Would get_fwspec_info() be descriptive enough?

	M.

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

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

[Thomas Gleixner]

On Thu, Sep 11 2025 at 15:13, Marc Zyngier wrote:

> On Tue, 09 Sep 2025 10:18:01 +0100,
> Thomas Gleixner <tglx@linutronix.de> wrote:
>> 
>> On Mon, Sep 08 2025 at 17:31, Marc Zyngier wrote:
>
> [...]
>
>> > @@ -69,6 +90,8 @@ 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_info: Given @info, report additional firmware-provided information.
>> > + *            Optional.
>> 
>> get_info() is pretty generic. Can we have some more descriptive name for
>> that? Also please keep the tabular formatting of the doc intact.
>
> Would get_fwspec_info() be descriptive enough?

I think so