[PATCH net-next v2 0/2] Introduce auxiliary bus IRQs sysfs

[PATCH net-next v2 0/2] Introduce auxiliary bus IRQs sysfs

[Shay Drory]

Today, PCI PFs and VFs, which are anchored on the PCI bus, display their
IRQ information in the <pci_device>/msi_irqs/<irq_num> sysfs files.
PCI subfunctions (SFs) are similar to PFs and VFs and these SFs are
anchored on the auxiliary bus. However, these PCI SFs lack such IRQ
information on the auxiliary bus, leaving users without visibility into
which IRQs are used by the SFs. This absence makes it impossible to debug
situations and to understand the source of interrupts/SFs for performance
tuning and debug.

Additionally, the SFs are multifunctional devices supporting RDMA,
network devices, clocks, and more, similar to their peer PCI PFs and
VFs. Therefore, it is desirable to have SFs' IRQ information available
at the bus/device level.

To overcome the above limitations, this short series extends the auxiliary
bus to display IRQ information in sysfs, similar to that of PFs and VFs.

It adds an 'irqs' directory under the auxiliary device and includes an
<irq_num> sysfs file within it. Sometimes, the PCI SF auxiliary devices
share the IRQ with other SFs, a detail that is also not available to the
users. Consequently, this <irq_num> file indicates whether the IRQ is
'exclusive' or 'shared'.

For example:
$ ls /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/
50  51  52  53  54  55  56  57  58
$ cat /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/52
exclusive

Patch summary:
==============
patch-1 adds auxiliary bus to support irqs used by auxiliary device
patch-2 mlx5 driver using exposing irqs for PCI SF devices via auxiliary
        bus

---
v1->v2:
- addressed comments from Greg, Simon H and kernel test boot in patch #1.

Shay Drory (2):
  driver core: auxiliary bus: show auxiliary device IRQs
  net/mlx5: Expose SFs IRQs

 Documentation/ABI/testing/sysfs-bus-auxiliary |  14 ++
 drivers/base/auxiliary.c                      | 170 +++++++++++++++++-
 drivers/net/ethernet/mellanox/mlx5/core/eq.c  |   6 +-
 .../mellanox/mlx5/core/irq_affinity.c         |  15 +-
 .../ethernet/mellanox/mlx5/core/mlx5_core.h   |   6 +
 .../ethernet/mellanox/mlx5/core/mlx5_irq.h    |  12 +-
 .../net/ethernet/mellanox/mlx5/core/pci_irq.c |  12 +-
 .../ethernet/mellanox/mlx5/core/sf/dev/dev.c  |   2 +-
 include/linux/auxiliary_bus.h                 |  15 +-
 9 files changed, 237 insertions(+), 15 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-auxiliary

-- 
2.38.1

[PATCH net-next v2 1/2] driver core: auxiliary bus: show auxiliary device IRQs

[Shay Drory]

PCI subfunctions (SF) are anchored on the auxiliary bus. PCI physical
and virtual functions are anchored on the PCI bus;  the irq information
of each such function is visible to users via sysfs directory "msi_irqs"
containing file for each irq entry. However, for PCI SFs such information
is unavailable. Due to this users have no visibility on IRQs used by the
SFs.
Secondly, an SF is a multi function device supporting rdma, netdevice
and more. Without irq information at the bus level, the user is unable
to view or use the affinity of the SF IRQs.

Hence to match to the equivalent PCI PFs and VFs, add "irqs" directory,
for supporting auxiliary devices, containing file for each irq entry.

Additionally, the PCI SFs sometimes share the IRQs with peer SFs. This
information is also not available to the users. To overcome this
limitation, each irq sysfs entry shows if irq is exclusive or shared.

For example:
$ ls /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/
50  51  52  53  54  55  56  57  58
$ cat /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/52
exclusive

Reviewed-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Shay Drory <shayd@nvidia.com>

---
v1->v2:
- move #ifdefs from drivers/base/auxiliary.c to
  include/linux/auxiliary_bus.h (Greg)
- use EXPORT_SYMBOL_GPL instead of EXPORT_SYMBOL (Greg)
- Fix kzalloc(ref) to kzalloc(*ref) (Simon)
- Add return description in auxiliary_device_sysfs_irq_add() kdoc (Simon)
- Fix auxiliary_irq_mode_show doc (kernel test boot)
---
 Documentation/ABI/testing/sysfs-bus-auxiliary |  14 ++
 drivers/base/auxiliary.c                      | 167 +++++++++++++++++-
 include/linux/auxiliary_bus.h                 |  20 ++-
 3 files changed, 198 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-auxiliary

diff --git a/Documentation/ABI/testing/sysfs-bus-auxiliary b/Documentation/ABI/testing/sysfs-bus-auxiliary
new file mode 100644
index 000000000000..3b8299d49d9e
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-auxiliary
@@ -0,0 +1,14 @@
+What:		/sys/bus/auxiliary/devices/.../irqs/
+Date:		April, 2024
+Contact:	Shay Drory <shayd@nvidia.com>
+Description:
+		The /sys/devices/.../irqs directory contains a variable set of
+		files, with each file is named as irq number similar to PCI PF
+		or VF's irq number located in msi_irqs directory.
+
+What:		/sys/bus/auxiliary/devices/.../irqs/<N>
+Date:		April, 2024
+Contact:	Shay Drory <shayd@nvidia.com>
+Description:
+		auxiliary devices can share IRQs. This attribute indicates if
+		the irq is shared with other SFs or exclusively used by the SF.
diff --git a/drivers/base/auxiliary.c b/drivers/base/auxiliary.c
index d3a2c40c2f12..43d12a147f1f 100644
--- a/drivers/base/auxiliary.c
+++ b/drivers/base/auxiliary.c
@@ -158,6 +158,164 @@
  *	};
  */
 
+#ifdef CONFIG_SYSFS
+/* Xarray of irqs to determine if irq is exclusive or shared. */
+static DEFINE_XARRAY(irqs);
+/* Protects insertions into the irtqs xarray. */
+static DEFINE_MUTEX(irqs_lock);
+
+struct auxiliary_irq_info {
+	struct device_attribute sysfs_attr;
+	int irq;
+};
+
+static struct attribute *auxiliary_irq_attrs[] = {
+	NULL
+};
+
+static const struct attribute_group auxiliary_irqs_group = {
+	.name = "irqs",
+	.attrs = auxiliary_irq_attrs,
+};
+
+/* Auxiliary devices can share IRQs. Expose to user whether the provided IRQ is
+ * shared or exclusive.
+ */
+static ssize_t auxiliary_irq_mode_show(struct device *dev,
+				       struct device_attribute *attr, char *buf)
+{
+	struct auxiliary_irq_info *info =
+		container_of(attr, struct auxiliary_irq_info, sysfs_attr);
+
+	if (refcount_read(xa_load(&irqs, info->irq)) > 1)
+		return sysfs_emit(buf, "%s\n", "shared");
+	else
+		return sysfs_emit(buf, "%s\n", "exclusive");
+}
+
+static void auxiliary_irq_destroy(int irq)
+{
+	refcount_t *ref;
+
+	xa_lock(&irqs);
+	ref = xa_load(&irqs, irq);
+	if (refcount_dec_and_test(ref)) {
+		__xa_erase(&irqs, irq);
+		kfree(ref);
+	}
+	xa_unlock(&irqs);
+}
+
+static int auxiliary_irq_create(int irq)
+{
+	refcount_t *ref;
+	int ret = 0;
+
+	mutex_lock(&irqs_lock);
+	ref = xa_load(&irqs, irq);
+	if (ref && refcount_inc_not_zero(ref))
+		goto out;
+
+	ref = kzalloc(sizeof(*ref), GFP_KERNEL);
+	if (!ref) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	refcount_set(ref, 1);
+	ret = xa_insert(&irqs, irq, ref, GFP_KERNEL);
+	if (ret)
+		kfree(ref);
+
+out:
+	mutex_unlock(&irqs_lock);
+	return ret;
+}
+
+/**
+ * auxiliary_device_sysfs_irq_add - add a sysfs entry for the given IRQ
+ * @auxdev: auxiliary bus device to add the sysfs entry.
+ * @irq: The associated Linux interrupt number.
+ *
+ * This function should be called after auxiliary device have successfully
+ * received the irq.
+ *
+ * Return: zero on success or an error code on failure.
+ */
+int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq)
+{
+	struct device *dev = &auxdev->dev;
+	struct auxiliary_irq_info *info;
+	int ret;
+
+	ret = auxiliary_irq_create(irq);
+	if (ret)
+		return ret;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info) {
+		ret = -ENOMEM;
+		goto info_err;
+	}
+
+	sysfs_attr_init(&info->sysfs_attr.attr);
+	info->sysfs_attr.attr.name = kasprintf(GFP_KERNEL, "%d", irq);
+	if (!info->sysfs_attr.attr.name) {
+		ret = -ENOMEM;
+		goto name_err;
+	}
+	info->irq = irq;
+	info->sysfs_attr.attr.mode = 0444;
+	info->sysfs_attr.show = auxiliary_irq_mode_show;
+
+	ret = xa_insert(&auxdev->irqs, irq, info, GFP_KERNEL);
+	if (ret)
+		goto auxdev_xa_err;
+
+	ret = sysfs_add_file_to_group(&dev->kobj, &info->sysfs_attr.attr,
+				      auxiliary_irqs_group.name);
+	if (ret)
+		goto sysfs_add_err;
+
+	return 0;
+
+sysfs_add_err:
+	xa_erase(&auxdev->irqs, irq);
+auxdev_xa_err:
+	kfree(info->sysfs_attr.attr.name);
+name_err:
+	kfree(info);
+info_err:
+	auxiliary_irq_destroy(irq);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_add);
+
+/**
+ * auxiliary_device_sysfs_irq_remove - remove a sysfs entry for the given IRQ
+ * @auxdev: auxiliary bus device to add the sysfs entry.
+ * @irq: the IRQ to remove.
+ *
+ * This function should be called to remove an IRQ sysfs entry.
+ */
+void auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, int irq)
+{
+	struct auxiliary_irq_info *info = xa_load(&auxdev->irqs, irq);
+	struct device *dev = &auxdev->dev;
+
+	if (WARN_ON(!info))
+		return;
+
+	sysfs_remove_file_from_group(&dev->kobj, &info->sysfs_attr.attr,
+				     auxiliary_irqs_group.name);
+	xa_erase(&auxdev->irqs, irq);
+	kfree(info->sysfs_attr.attr.name);
+	kfree(info);
+	auxiliary_irq_destroy(irq);
+}
+EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_remove);
+#endif
+
 static const struct auxiliary_device_id *auxiliary_match_id(const struct auxiliary_device_id *id,
 							    const struct auxiliary_device *auxdev)
 {
@@ -295,6 +453,7 @@ EXPORT_SYMBOL_GPL(auxiliary_device_init);
  * __auxiliary_device_add - add an auxiliary bus device
  * @auxdev: auxiliary bus device to add to the bus
  * @modname: name of the parent device's driver module
+ * @irqs_sysfs_enable: whether to enable IRQs sysfs
  *
  * This is the third step in the three-step process to register an
  * auxiliary_device.
@@ -310,7 +469,8 @@ EXPORT_SYMBOL_GPL(auxiliary_device_init);
  * parameter.  Only if a user requires a custom name would this version be
  * called directly.
  */
-int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname)
+int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname,
+			   bool irqs_sysfs_enable)
 {
 	struct device *dev = &auxdev->dev;
 	int ret;
@@ -325,6 +485,11 @@ int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname)
 		dev_err(dev, "auxiliary device dev_set_name failed: %d\n", ret);
 		return ret;
 	}
+	if (irqs_sysfs_enable) {
+		auxdev->groups[0] = &auxiliary_irqs_group;
+		xa_init(&auxdev->irqs);
+		dev->groups = auxdev->groups;
+	}
 
 	ret = device_add(dev);
 	if (ret)
diff --git a/include/linux/auxiliary_bus.h b/include/linux/auxiliary_bus.h
index de21d9d24a95..fe2c438c0217 100644
--- a/include/linux/auxiliary_bus.h
+++ b/include/linux/auxiliary_bus.h
@@ -58,6 +58,9 @@
  *       in
  * @name: Match name found by the auxiliary device driver,
  * @id: unique identitier if multiple devices of the same name are exported,
+ * @irqs: irqs xarray contains irq indices which are used by the device,
+ * @groups: first group is for irqs sysfs directory; it is a NULL terminated
+ *          array,
  *
  * An auxiliary_device represents a part of its parent device's functionality.
  * It is given a name that, combined with the registering drivers
@@ -138,6 +141,8 @@
 struct auxiliary_device {
 	struct device dev;
 	const char *name;
+	struct xarray irqs;
+	const struct attribute_group *groups[2];
 	u32 id;
 };
 
@@ -209,8 +214,19 @@ static inline struct auxiliary_driver *to_auxiliary_drv(struct device_driver *dr
 }
 
 int auxiliary_device_init(struct auxiliary_device *auxdev);
-int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname);
-#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev, KBUILD_MODNAME)
+int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname,
+			   bool irqs_sysfs_enable);
+#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev, KBUILD_MODNAME, false)
+#define auxiliary_device_add_with_irqs(auxdev) \
+	__auxiliary_device_add(auxdev, KBUILD_MODNAME, true)
+
+#ifdef CONFIG_SYSFS
+int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq);
+void auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, int irq);
+#else /* CONFIG_SYSFS */
+int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq) {return 0; }
+void auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, int irq) {}
+#endif
 
 static inline void auxiliary_device_uninit(struct auxiliary_device *auxdev)
 {
-- 
2.38.1

[PATCH net-next v2 2/2] net/mlx5: Expose SFs IRQs

[Shay Drory]

Expose the sysfs files for the IRQs that the mlx5 PCI SFs are using.
These entries are similar to PCI PFs and VFs in 'msi_irqs' directory.

Reviewed-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Shay Drory <shayd@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/eq.c      |  6 +++---
 .../ethernet/mellanox/mlx5/core/irq_affinity.c    | 15 ++++++++++++++-
 .../net/ethernet/mellanox/mlx5/core/mlx5_core.h   |  6 ++++++
 .../net/ethernet/mellanox/mlx5/core/mlx5_irq.h    | 12 ++++++++----
 drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c | 12 +++++++++---
 .../net/ethernet/mellanox/mlx5/core/sf/dev/dev.c  |  2 +-
 6 files changed, 41 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eq.c b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
index 40a6cb052a2d..85b93bac2529 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
@@ -708,7 +708,7 @@ static int create_async_eqs(struct mlx5_core_dev *dev)
 err1:
 	mlx5_cmd_allowed_opcode(dev, CMD_ALLOWED_OPCODE_ALL);
 	mlx5_eq_notifier_unregister(dev, &table->cq_err_nb);
-	mlx5_ctrl_irq_release(table->ctrl_irq);
+	mlx5_ctrl_irq_release(dev, table->ctrl_irq);
 	return err;
 }
 
@@ -723,7 +723,7 @@ static void destroy_async_eqs(struct mlx5_core_dev *dev)
 	cleanup_async_eq(dev, &table->cmd_eq, "cmd");
 	mlx5_cmd_allowed_opcode(dev, CMD_ALLOWED_OPCODE_ALL);
 	mlx5_eq_notifier_unregister(dev, &table->cq_err_nb);
-	mlx5_ctrl_irq_release(table->ctrl_irq);
+	mlx5_ctrl_irq_release(dev, table->ctrl_irq);
 }
 
 struct mlx5_eq *mlx5_get_async_eq(struct mlx5_core_dev *dev)
@@ -911,7 +911,7 @@ static int comp_irq_request_sf(struct mlx5_core_dev *dev, u16 vecidx)
 	af_desc.is_managed = 1;
 	cpumask_copy(&af_desc.mask, cpu_online_mask);
 	cpumask_andnot(&af_desc.mask, &af_desc.mask, &table->used_cpus);
-	irq = mlx5_irq_affinity_request(pool, &af_desc);
+	irq = mlx5_irq_affinity_request(dev, pool, &af_desc);
 	if (IS_ERR(irq))
 		return PTR_ERR(irq);
 
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/irq_affinity.c b/drivers/net/ethernet/mellanox/mlx5/core/irq_affinity.c
index 612e666ec263..9803ab0029b8 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/irq_affinity.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/irq_affinity.c
@@ -112,15 +112,18 @@ irq_pool_find_least_loaded(struct mlx5_irq_pool *pool, const struct cpumask *req
 
 /**
  * mlx5_irq_affinity_request - request an IRQ according to the given mask.
+ * @dev: mlx5 core device which is requesting the IRQ.
  * @pool: IRQ pool to request from.
  * @af_desc: affinity descriptor for this IRQ.
  *
  * This function returns a pointer to IRQ, or ERR_PTR in case of error.
  */
 struct mlx5_irq *
-mlx5_irq_affinity_request(struct mlx5_irq_pool *pool, struct irq_affinity_desc *af_desc)
+mlx5_irq_affinity_request(struct mlx5_core_dev *dev, struct mlx5_irq_pool *pool,
+			  struct irq_affinity_desc *af_desc)
 {
 	struct mlx5_irq *least_loaded_irq, *new_irq;
+	int ret;
 
 	mutex_lock(&pool->lock);
 	least_loaded_irq = irq_pool_find_least_loaded(pool, &af_desc->mask);
@@ -152,6 +155,13 @@ mlx5_irq_affinity_request(struct mlx5_irq_pool *pool, struct irq_affinity_desc *
 					     mlx5_irq_get_index(least_loaded_irq)), pool->name,
 			      mlx5_irq_read_locked(least_loaded_irq) / MLX5_EQ_REFS_PER_IRQ);
 unlock:
+	if (mlx5_irq_pool_is_sf_pool(pool)) {
+		ret = auxiliary_device_sysfs_irq_add(mlx5_sf_coredev_to_adev(dev),
+						     mlx5_irq_get_irq(least_loaded_irq));
+		if (ret)
+			mlx5_core_err(dev, "Failed to create sysfs entry for irq %d\n",
+				      mlx5_irq_get_irq(least_loaded_irq));
+	}
 	mutex_unlock(&pool->lock);
 	return least_loaded_irq;
 }
@@ -164,6 +174,9 @@ void mlx5_irq_affinity_irq_release(struct mlx5_core_dev *dev, struct mlx5_irq *i
 	cpu = cpumask_first(mlx5_irq_get_affinity_mask(irq));
 	synchronize_irq(pci_irq_vector(pool->dev->pdev,
 				       mlx5_irq_get_index(irq)));
+	if (mlx5_irq_pool_is_sf_pool(pool))
+		auxiliary_device_sysfs_irq_remove(mlx5_sf_coredev_to_adev(dev),
+						  mlx5_irq_get_irq(irq));
 	if (mlx5_irq_put(irq))
 		if (pool->irqs_per_cpu)
 			cpu_put(pool, cpu);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
index 58732f44940f..469d86afbfb4 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
@@ -320,6 +320,12 @@ static inline bool mlx5_core_is_sf(const struct mlx5_core_dev *dev)
 	return dev->coredev_type == MLX5_COREDEV_SF;
 }
 
+static inline struct auxiliary_device *
+mlx5_sf_coredev_to_adev(struct mlx5_core_dev *mdev)
+{
+	return container_of(mdev->device, struct auxiliary_device, dev);
+}
+
 int mlx5_mdev_init(struct mlx5_core_dev *dev, int profile_idx);
 void mlx5_mdev_uninit(struct mlx5_core_dev *dev);
 int mlx5_init_one(struct mlx5_core_dev *dev);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_irq.h b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_irq.h
index 1088114e905d..0881e961d8b1 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_irq.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_irq.h
@@ -25,7 +25,7 @@ int mlx5_set_msix_vec_count(struct mlx5_core_dev *dev, int devfn,
 int mlx5_get_default_msix_vec_count(struct mlx5_core_dev *dev, int num_vfs);
 
 struct mlx5_irq *mlx5_ctrl_irq_request(struct mlx5_core_dev *dev);
-void mlx5_ctrl_irq_release(struct mlx5_irq *ctrl_irq);
+void mlx5_ctrl_irq_release(struct mlx5_core_dev *dev, struct mlx5_irq *ctrl_irq);
 struct mlx5_irq *mlx5_irq_request(struct mlx5_core_dev *dev, u16 vecidx,
 				  struct irq_affinity_desc *af_desc,
 				  struct cpu_rmap **rmap);
@@ -36,13 +36,15 @@ int mlx5_irq_attach_nb(struct mlx5_irq *irq, struct notifier_block *nb);
 int mlx5_irq_detach_nb(struct mlx5_irq *irq, struct notifier_block *nb);
 struct cpumask *mlx5_irq_get_affinity_mask(struct mlx5_irq *irq);
 int mlx5_irq_get_index(struct mlx5_irq *irq);
+int mlx5_irq_get_irq(const struct mlx5_irq *irq);
 
 struct mlx5_irq_pool;
 #ifdef CONFIG_MLX5_SF
 struct mlx5_irq *mlx5_irq_affinity_irq_request_auto(struct mlx5_core_dev *dev,
 						    struct cpumask *used_cpus, u16 vecidx);
-struct mlx5_irq *mlx5_irq_affinity_request(struct mlx5_irq_pool *pool,
-					   struct irq_affinity_desc *af_desc);
+struct mlx5_irq *
+mlx5_irq_affinity_request(struct mlx5_core_dev *dev, struct mlx5_irq_pool *pool,
+			  struct irq_affinity_desc *af_desc);
 void mlx5_irq_affinity_irq_release(struct mlx5_core_dev *dev, struct mlx5_irq *irq);
 #else
 static inline
@@ -53,7 +55,8 @@ struct mlx5_irq *mlx5_irq_affinity_irq_request_auto(struct mlx5_core_dev *dev,
 }
 
 static inline struct mlx5_irq *
-mlx5_irq_affinity_request(struct mlx5_irq_pool *pool, struct irq_affinity_desc *af_desc)
+mlx5_irq_affinity_request(struct mlx5_core_dev *dev, struct mlx5_irq_pool *pool,
+			  struct irq_affinity_desc *af_desc)
 {
 	return ERR_PTR(-EOPNOTSUPP);
 }
@@ -61,6 +64,7 @@ mlx5_irq_affinity_request(struct mlx5_irq_pool *pool, struct irq_affinity_desc *
 static inline
 void mlx5_irq_affinity_irq_release(struct mlx5_core_dev *dev, struct mlx5_irq *irq)
 {
+	mlx5_irq_release_vector(irq);
 }
 #endif
 #endif /* __MLX5_IRQ_H__ */
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
index 4dcf995cb1a2..831efde44b2d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
@@ -365,6 +365,11 @@ struct cpumask *mlx5_irq_get_affinity_mask(struct mlx5_irq *irq)
 	return irq->mask;
 }
 
+int mlx5_irq_get_irq(const struct mlx5_irq *irq)
+{
+	return irq->map.virq;
+}
+
 int mlx5_irq_get_index(struct mlx5_irq *irq)
 {
 	return irq->map.index;
@@ -438,11 +443,12 @@ static void _mlx5_irq_release(struct mlx5_irq *irq)
 
 /**
  * mlx5_ctrl_irq_release - release a ctrl IRQ back to the system.
+ * @dev: mlx5 device that releasing the IRQ.
  * @ctrl_irq: ctrl IRQ to be released.
  */
-void mlx5_ctrl_irq_release(struct mlx5_irq *ctrl_irq)
+void mlx5_ctrl_irq_release(struct mlx5_core_dev *dev, struct mlx5_irq *ctrl_irq)
 {
-	_mlx5_irq_release(ctrl_irq);
+	mlx5_irq_affinity_irq_release(dev, ctrl_irq);
 }
 
 /**
@@ -471,7 +477,7 @@ struct mlx5_irq *mlx5_ctrl_irq_request(struct mlx5_core_dev *dev)
 		/* Allocate the IRQ in index 0. The vector was already allocated */
 		irq = irq_pool_request_vector(pool, 0, &af_desc, NULL);
 	} else {
-		irq = mlx5_irq_affinity_request(pool, &af_desc);
+		irq = mlx5_irq_affinity_request(dev, pool, &af_desc);
 	}
 
 	return irq;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sf/dev/dev.c b/drivers/net/ethernet/mellanox/mlx5/core/sf/dev/dev.c
index 99219ea52c4b..39fad18fc58c 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/sf/dev/dev.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/sf/dev/dev.c
@@ -127,7 +127,7 @@ static void mlx5_sf_dev_add(struct mlx5_core_dev *dev, u16 sf_index, u16 fn_id,
 		goto add_err;
 	}
 
-	err = auxiliary_device_add(&sf_dev->adev);
+	err = auxiliary_device_add_with_irqs(&sf_dev->adev);
 	if (err) {
 		auxiliary_device_uninit(&sf_dev->adev);
 		goto add_err;
-- 
2.38.1

RE: [PATCH net-next v2 1/2] driver core: auxiliary bus: show auxiliary device IRQs

[Parav Pandit]

> From: Shay Drori <shayd@nvidia.com>
> Sent: Sunday, May 5, 2024 7:53 AM


> diff --git a/include/linux/auxiliary_bus.h b/include/linux/auxiliary_bus.h
> index de21d9d24a95..fe2c438c0217 100644
> --- a/include/linux/auxiliary_bus.h
> +++ b/include/linux/auxiliary_bus.h
> @@ -58,6 +58,9 @@
>   *       in
>   * @name: Match name found by the auxiliary device driver,
>   * @id: unique identitier if multiple devices of the same name are exported,
> + * @irqs: irqs xarray contains irq indices which are used by the
> + device,
> + * @groups: first group is for irqs sysfs directory; it is a NULL terminated
> + *          array,
>   *
>   * An auxiliary_device represents a part of its parent device's functionality.
>   * It is given a name that, combined with the registering drivers @@ -138,6
> +141,8 @@  struct auxiliary_device {
>  	struct device dev;
>  	const char *name;
> +	struct xarray irqs;
> +	const struct attribute_group *groups[2];
>  	u32 id;
>  };
> 
> @@ -209,8 +214,19 @@ static inline struct auxiliary_driver
> *to_auxiliary_drv(struct device_driver *dr  }
> 
>  int auxiliary_device_init(struct auxiliary_device *auxdev); -int
> __auxiliary_device_add(struct auxiliary_device *auxdev, const char
> *modname); -#define auxiliary_device_add(auxdev)
> __auxiliary_device_add(auxdev, KBUILD_MODNAME)
> +int __auxiliary_device_add(struct auxiliary_device *auxdev, const char
> *modname,
> +			   bool irqs_sysfs_enable);
> +#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev,
> +KBUILD_MODNAME, false) #define auxiliary_device_add_with_irqs(auxdev)
> \
> +	__auxiliary_device_add(auxdev, KBUILD_MODNAME, true)
> +

> +#ifdef CONFIG_SYSFS
> +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int
> +irq); void auxiliary_device_sysfs_irq_remove(struct auxiliary_device
> +*auxdev, int irq); #else /* CONFIG_SYSFS */ int
> +auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int
> +irq) {return 0; } void auxiliary_device_sysfs_irq_remove(struct
> +auxiliary_device *auxdev, int irq) {} #endif
>
Above definitions need to be static inline and should under 80 characters.
Please fix them.

Re: [PATCH net-next v2 1/2] driver core: auxiliary bus: show auxiliary device IRQs

[Przemek Kitszel]

On 5/5/24 16:53, Shay Drory wrote:
> PCI subfunctions (SF) are anchored on the auxiliary bus. PCI physical
> and virtual functions are anchored on the PCI bus;  the irq information
> of each such function is visible to users via sysfs directory "msi_irqs"
> containing file for each irq entry. However, for PCI SFs such information
> is unavailable. Due to this users have no visibility on IRQs used by the
> SFs.
> Secondly, an SF is a multi function device supporting rdma, netdevice
> and more. Without irq information at the bus level, the user is unable
> to view or use the affinity of the SF IRQs.
> 
> Hence to match to the equivalent PCI PFs and VFs, add "irqs" directory,
> for supporting auxiliary devices, containing file for each irq entry.
> 
> Additionally, the PCI SFs sometimes share the IRQs with peer SFs. This
> information is also not available to the users. To overcome this
> limitation, each irq sysfs entry shows if irq is exclusive or shared.
> 
> For example:
> $ ls /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/
> 50  51  52  53  54  55  56  57  58
> $ cat /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/52
> exclusive
> 
> Reviewed-by: Parav Pandit <parav@nvidia.com>
> Signed-off-by: Shay Drory <shayd@nvidia.com>
> 
> ---
> v1->v2:
> - move #ifdefs from drivers/base/auxiliary.c to
>    include/linux/auxiliary_bus.h (Greg)
> - use EXPORT_SYMBOL_GPL instead of EXPORT_SYMBOL (Greg)
> - Fix kzalloc(ref) to kzalloc(*ref) (Simon)
> - Add return description in auxiliary_device_sysfs_irq_add() kdoc (Simon)
> - Fix auxiliary_irq_mode_show doc (kernel test boot)
> ---
>   Documentation/ABI/testing/sysfs-bus-auxiliary |  14 ++
>   drivers/base/auxiliary.c                      | 167 +++++++++++++++++-
>   include/linux/auxiliary_bus.h                 |  20 ++-
>   3 files changed, 198 insertions(+), 3 deletions(-)
>   create mode 100644 Documentation/ABI/testing/sysfs-bus-auxiliary
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-auxiliary b/Documentation/ABI/testing/sysfs-bus-auxiliary
> new file mode 100644
> index 000000000000..3b8299d49d9e
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-auxiliary
> @@ -0,0 +1,14 @@
> +What:		/sys/bus/auxiliary/devices/.../irqs/
> +Date:		April, 2024
> +Contact:	Shay Drory <shayd@nvidia.com>
> +Description:
> +		The /sys/devices/.../irqs directory contains a variable set of
> +		files, with each file is named as irq number similar to PCI PF
> +		or VF's irq number located in msi_irqs directory.
> +
> +What:		/sys/bus/auxiliary/devices/.../irqs/<N>
> +Date:		April, 2024
> +Contact:	Shay Drory <shayd@nvidia.com>
> +Description:
> +		auxiliary devices can share IRQs. This attribute indicates if
> +		the irq is shared with other SFs or exclusively used by the SF.
> diff --git a/drivers/base/auxiliary.c b/drivers/base/auxiliary.c
> index d3a2c40c2f12..43d12a147f1f 100644
> --- a/drivers/base/auxiliary.c
> +++ b/drivers/base/auxiliary.c
> @@ -158,6 +158,164 @@
>    *	};
>    */
>   
> +#ifdef CONFIG_SYSFS
> +/* Xarray of irqs to determine if irq is exclusive or shared. */
> +static DEFINE_XARRAY(irqs);
> +/* Protects insertions into the irtqs xarray. */
> +static DEFINE_MUTEX(irqs_lock);
> +
> +struct auxiliary_irq_info {
> +	struct device_attribute sysfs_attr;
> +	int irq;
> +};
> +
> +static struct attribute *auxiliary_irq_attrs[] = {
> +	NULL
> +};
> +
> +static const struct attribute_group auxiliary_irqs_group = {
> +	.name = "irqs",
> +	.attrs = auxiliary_irq_attrs,
> +};
> +
> +/* Auxiliary devices can share IRQs. Expose to user whether the provided IRQ is
> + * shared or exclusive.
> + */
> +static ssize_t auxiliary_irq_mode_show(struct device *dev,
> +				       struct device_attribute *attr, char *buf)
> +{
> +	struct auxiliary_irq_info *info =
> +		container_of(attr, struct auxiliary_irq_info, sysfs_attr);
> +
> +	if (refcount_read(xa_load(&irqs, info->irq)) > 1)
> +		return sysfs_emit(buf, "%s\n", "shared");
> +	else
> +		return sysfs_emit(buf, "%s\n", "exclusive");
> +}
> +
> +static void auxiliary_irq_destroy(int irq)
> +{
> +	refcount_t *ref;
> +
> +	xa_lock(&irqs);
> +	ref = xa_load(&irqs, irq);
> +	if (refcount_dec_and_test(ref)) {
> +		__xa_erase(&irqs, irq);
> +		kfree(ref);
> +	}
> +	xa_unlock(&irqs);
> +}
> +
> +static int auxiliary_irq_create(int irq)
> +{
> +	refcount_t *ref;
> +	int ret = 0;
> +
> +	mutex_lock(&irqs_lock);
> +	ref = xa_load(&irqs, irq);
> +	if (ref && refcount_inc_not_zero(ref))
> +		goto out;
> +
> +	ref = kzalloc(sizeof(*ref), GFP_KERNEL);
> +	if (!ref) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	refcount_set(ref, 1);
> +	ret = xa_insert(&irqs, irq, ref, GFP_KERNEL);
> +	if (ret)
> +		kfree(ref);
> +
> +out:
> +	mutex_unlock(&irqs_lock);
> +	return ret;
> +}
> +
> +/**
> + * auxiliary_device_sysfs_irq_add - add a sysfs entry for the given IRQ
> + * @auxdev: auxiliary bus device to add the sysfs entry.
> + * @irq: The associated Linux interrupt number.
> + *
> + * This function should be called after auxiliary device have successfully
> + * received the irq.

s/received/registered/?

> + *
> + * Return: zero on success or an error code on failure.
> + */
> +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq)
> +{
> +	struct device *dev = &auxdev->dev;
> +	struct auxiliary_irq_info *info;
> +	int ret;
> +
> +	ret = auxiliary_irq_create(irq);
> +	if (ret)
> +		return ret;
> +
> +	info = kzalloc(sizeof(*info), GFP_KERNEL);
> +	if (!info) {
> +		ret = -ENOMEM;
> +		goto info_err;
> +	}
> +
> +	sysfs_attr_init(&info->sysfs_attr.attr);
> +	info->sysfs_attr.attr.name = kasprintf(GFP_KERNEL, "%d", irq);
> +	if (!info->sysfs_attr.attr.name) {
> +		ret = -ENOMEM;
> +		goto name_err;
> +	}
> +	info->irq = irq;
> +	info->sysfs_attr.attr.mode = 0444;
> +	info->sysfs_attr.show = auxiliary_irq_mode_show;
> +
> +	ret = xa_insert(&auxdev->irqs, irq, info, GFP_KERNEL);
> +	if (ret)
> +		goto auxdev_xa_err;
> +
> +	ret = sysfs_add_file_to_group(&dev->kobj, &info->sysfs_attr.attr,
> +				      auxiliary_irqs_group.name);
> +	if (ret)
> +		goto sysfs_add_err;
> +
> +	return 0;
> +
> +sysfs_add_err:
> +	xa_erase(&auxdev->irqs, irq);
> +auxdev_xa_err:
> +	kfree(info->sysfs_attr.attr.name);
> +name_err:
> +	kfree(info);
> +info_err:
> +	auxiliary_irq_destroy(irq);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_add);
> +
> +/**
> + * auxiliary_device_sysfs_irq_remove - remove a sysfs entry for the given IRQ
> + * @auxdev: auxiliary bus device to add the sysfs entry.
> + * @irq: the IRQ to remove.
> + *
> + * This function should be called to remove an IRQ sysfs entry.
> + */
> +void auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, int irq)

(not an issue, just a question)
do you need to select IRQ to remove? ...

> +{
> +	struct auxiliary_irq_info *info = xa_load(&auxdev->irqs, irq);
> +	struct device *dev = &auxdev->dev;
> +
> +	if (WARN_ON(!info))
> +		return;
> +
> +	sysfs_remove_file_from_group(&dev->kobj, &info->sysfs_attr.attr,
> +				     auxiliary_irqs_group.name);

... because there is an option to remove whole group at once

> +	xa_erase(&auxdev->irqs, irq);
> +	kfree(info->sysfs_attr.attr.name);
> +	kfree(info);
> +	auxiliary_irq_destroy(irq);
> +}
> +EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_remove);
> +#endif
> +
>   static const struct auxiliary_device_id *auxiliary_match_id(const struct auxiliary_device_id *id,
>   							    const struct auxiliary_device *auxdev)
>   {
> @@ -295,6 +453,7 @@ EXPORT_SYMBOL_GPL(auxiliary_device_init);
>    * __auxiliary_device_add - add an auxiliary bus device
>    * @auxdev: auxiliary bus device to add to the bus
>    * @modname: name of the parent device's driver module
> + * @irqs_sysfs_enable: whether to enable IRQs sysfs
>    *
>    * This is the third step in the three-step process to register an
>    * auxiliary_device.
> @@ -310,7 +469,8 @@ EXPORT_SYMBOL_GPL(auxiliary_device_init);
>    * parameter.  Only if a user requires a custom name would this version be
>    * called directly.
>    */
> -int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname)
> +int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname,
> +			   bool irqs_sysfs_enable)
>   {
>   	struct device *dev = &auxdev->dev;
>   	int ret;
> @@ -325,6 +485,11 @@ int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname)
>   		dev_err(dev, "auxiliary device dev_set_name failed: %d\n", ret);
>   		return ret;
>   	}
> +	if (irqs_sysfs_enable) {
> +		auxdev->groups[0] = &auxiliary_irqs_group;

I would remove this array ...

> +		xa_init(&auxdev->irqs);
> +		dev->groups = auxdev->groups;

... and use &auxiliary_irqs_group directly here
(you will need to change it to 2 elem array though)

> +	}
>   
>   	ret = device_add(dev);
>   	if (ret)
> diff --git a/include/linux/auxiliary_bus.h b/include/linux/auxiliary_bus.h
> index de21d9d24a95..fe2c438c0217 100644
> --- a/include/linux/auxiliary_bus.h
> +++ b/include/linux/auxiliary_bus.h
> @@ -58,6 +58,9 @@
>    *       in
>    * @name: Match name found by the auxiliary device driver,
>    * @id: unique identitier if multiple devices of the same name are exported,
> + * @irqs: irqs xarray contains irq indices which are used by the device,
> + * @groups: first group is for irqs sysfs directory; it is a NULL terminated
> + *          array,
>    *
>    * An auxiliary_device represents a part of its parent device's functionality.
>    * It is given a name that, combined with the registering drivers
> @@ -138,6 +141,8 @@
>   struct auxiliary_device {
>   	struct device dev;
>   	const char *name;
> +	struct xarray irqs;
> +	const struct attribute_group *groups[2];
>   	u32 id;
>   };
>   
> @@ -209,8 +214,19 @@ static inline struct auxiliary_driver *to_auxiliary_drv(struct device_driver *dr
>   }
>   
>   int auxiliary_device_init(struct auxiliary_device *auxdev);
> -int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname);
> -#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev, KBUILD_MODNAME)
> +int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname,
> +			   bool irqs_sysfs_enable);
> +#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev, KBUILD_MODNAME, false)
> +#define auxiliary_device_add_with_irqs(auxdev) \
> +	__auxiliary_device_add(auxdev, KBUILD_MODNAME, true)
> +
> +#ifdef CONFIG_SYSFS
> +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq);
> +void auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, int irq);
> +#else /* CONFIG_SYSFS */
> +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq) {return 0; }
> +void auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, int irq) {}
> +#endif
>   
>   static inline void auxiliary_device_uninit(struct auxiliary_device *auxdev)
>   {

Re: [PATCH net-next v2 1/2] driver core: auxiliary bus: show auxiliary device IRQs

[Shay Drori]

On 06/05/2024 18:15, Parav Pandit wrote:
> 
>> From: Shay Drori <shayd@nvidia.com>
>> Sent: Sunday, May 5, 2024 7:53 AM
> 
> 
>> diff --git a/include/linux/auxiliary_bus.h b/include/linux/auxiliary_bus.h
>> index de21d9d24a95..fe2c438c0217 100644
>> --- a/include/linux/auxiliary_bus.h
>> +++ b/include/linux/auxiliary_bus.h
>> @@ -58,6 +58,9 @@
>>    *       in
>>    * @name: Match name found by the auxiliary device driver,
>>    * @id: unique identitier if multiple devices of the same name are exported,
>> + * @irqs: irqs xarray contains irq indices which are used by the
>> + device,
>> + * @groups: first group is for irqs sysfs directory; it is a NULL terminated
>> + *          array,
>>    *
>>    * An auxiliary_device represents a part of its parent device's functionality.
>>    * It is given a name that, combined with the registering drivers @@ -138,6
>> +141,8 @@  struct auxiliary_device {
>>   	struct device dev;
>>   	const char *name;
>> +	struct xarray irqs;
>> +	const struct attribute_group *groups[2];
>>   	u32 id;
>>   };
>>
>> @@ -209,8 +214,19 @@ static inline struct auxiliary_driver
>> *to_auxiliary_drv(struct device_driver *dr  }
>>
>>   int auxiliary_device_init(struct auxiliary_device *auxdev); -int
>> __auxiliary_device_add(struct auxiliary_device *auxdev, const char
>> *modname); -#define auxiliary_device_add(auxdev)
>> __auxiliary_device_add(auxdev, KBUILD_MODNAME)
>> +int __auxiliary_device_add(struct auxiliary_device *auxdev, const char
>> *modname,
>> +			   bool irqs_sysfs_enable);
>> +#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev,
>> +KBUILD_MODNAME, false) #define auxiliary_device_add_with_irqs(auxdev)
>> \
>> +	__auxiliary_device_add(auxdev, KBUILD_MODNAME, true)
>> +
> 
>> +#ifdef CONFIG_SYSFS
>> +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int
>> +irq); void auxiliary_device_sysfs_irq_remove(struct auxiliary_device
>> +*auxdev, int irq); #else /* CONFIG_SYSFS */ int
>> +auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int
>> +irq) {return 0; } void auxiliary_device_sysfs_irq_remove(struct
>> +auxiliary_device *auxdev, int irq) {} #endif
>>
> Above definitions need to be static inline and should under 80 characters.
> Please fix them.


will fix in v3.

Re: [PATCH net-next v2 1/2] driver core: auxiliary bus: show auxiliary device IRQs

[Shay Drori]

On 07/05/2024 11:12, Przemek Kitszel wrote:
> External email: Use caution opening links or attachments
> 
> 
> On 5/5/24 16:53, Shay Drory wrote:
>> PCI subfunctions (SF) are anchored on the auxiliary bus. PCI physical
>> and virtual functions are anchored on the PCI bus;  the irq information
>> of each such function is visible to users via sysfs directory "msi_irqs"
>> containing file for each irq entry. However, for PCI SFs such information
>> is unavailable. Due to this users have no visibility on IRQs used by the
>> SFs.
>> Secondly, an SF is a multi function device supporting rdma, netdevice
>> and more. Without irq information at the bus level, the user is unable
>> to view or use the affinity of the SF IRQs.
>>
>> Hence to match to the equivalent PCI PFs and VFs, add "irqs" directory,
>> for supporting auxiliary devices, containing file for each irq entry.
>>
>> Additionally, the PCI SFs sometimes share the IRQs with peer SFs. This
>> information is also not available to the users. To overcome this
>> limitation, each irq sysfs entry shows if irq is exclusive or shared.
>>
>> For example:
>> $ ls /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/
>> 50  51  52  53  54  55  56  57  58
>> $ cat /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/52
>> exclusive
>>
>> Reviewed-by: Parav Pandit <parav@nvidia.com>
>> Signed-off-by: Shay Drory <shayd@nvidia.com>
>>
>> ---
>> v1->v2:
>> - move #ifdefs from drivers/base/auxiliary.c to
>>    include/linux/auxiliary_bus.h (Greg)
>> - use EXPORT_SYMBOL_GPL instead of EXPORT_SYMBOL (Greg)
>> - Fix kzalloc(ref) to kzalloc(*ref) (Simon)
>> - Add return description in auxiliary_device_sysfs_irq_add() kdoc (Simon)
>> - Fix auxiliary_irq_mode_show doc (kernel test boot)
>> ---
>>   Documentation/ABI/testing/sysfs-bus-auxiliary |  14 ++
>>   drivers/base/auxiliary.c                      | 167 +++++++++++++++++-
>>   include/linux/auxiliary_bus.h                 |  20 ++-
>>   3 files changed, 198 insertions(+), 3 deletions(-)
>>   create mode 100644 Documentation/ABI/testing/sysfs-bus-auxiliary
>>
>> diff --git a/Documentation/ABI/testing/sysfs-bus-auxiliary 
>> b/Documentation/ABI/testing/sysfs-bus-auxiliary
>> new file mode 100644
>> index 000000000000..3b8299d49d9e
>> --- /dev/null
>> +++ b/Documentation/ABI/testing/sysfs-bus-auxiliary
>> @@ -0,0 +1,14 @@
>> +What:                /sys/bus/auxiliary/devices/.../irqs/
>> +Date:                April, 2024
>> +Contact:     Shay Drory <shayd@nvidia.com>
>> +Description:
>> +             The /sys/devices/.../irqs directory contains a variable 
>> set of
>> +             files, with each file is named as irq number similar to 
>> PCI PF
>> +             or VF's irq number located in msi_irqs directory.
>> +
>> +What:                /sys/bus/auxiliary/devices/.../irqs/<N>
>> +Date:                April, 2024
>> +Contact:     Shay Drory <shayd@nvidia.com>
>> +Description:
>> +             auxiliary devices can share IRQs. This attribute 
>> indicates if
>> +             the irq is shared with other SFs or exclusively used by 
>> the SF.
>> diff --git a/drivers/base/auxiliary.c b/drivers/base/auxiliary.c
>> index d3a2c40c2f12..43d12a147f1f 100644
>> --- a/drivers/base/auxiliary.c
>> +++ b/drivers/base/auxiliary.c
>> @@ -158,6 +158,164 @@
>>    *  };
>>    */
>>
>> +#ifdef CONFIG_SYSFS
>> +/* Xarray of irqs to determine if irq is exclusive or shared. */
>> +static DEFINE_XARRAY(irqs);
>> +/* Protects insertions into the irtqs xarray. */
>> +static DEFINE_MUTEX(irqs_lock);
>> +
>> +struct auxiliary_irq_info {
>> +     struct device_attribute sysfs_attr;
>> +     int irq;
>> +};
>> +
>> +static struct attribute *auxiliary_irq_attrs[] = {
>> +     NULL
>> +};
>> +
>> +static const struct attribute_group auxiliary_irqs_group = {
>> +     .name = "irqs",
>> +     .attrs = auxiliary_irq_attrs,
>> +};
>> +
>> +/* Auxiliary devices can share IRQs. Expose to user whether the 
>> provided IRQ is
>> + * shared or exclusive.
>> + */
>> +static ssize_t auxiliary_irq_mode_show(struct device *dev,
>> +                                    struct device_attribute *attr, 
>> char *buf)
>> +{
>> +     struct auxiliary_irq_info *info =
>> +             container_of(attr, struct auxiliary_irq_info, sysfs_attr);
>> +
>> +     if (refcount_read(xa_load(&irqs, info->irq)) > 1)
>> +             return sysfs_emit(buf, "%s\n", "shared");
>> +     else
>> +             return sysfs_emit(buf, "%s\n", "exclusive");
>> +}
>> +
>> +static void auxiliary_irq_destroy(int irq)
>> +{
>> +     refcount_t *ref;
>> +
>> +     xa_lock(&irqs);
>> +     ref = xa_load(&irqs, irq);
>> +     if (refcount_dec_and_test(ref)) {
>> +             __xa_erase(&irqs, irq);
>> +             kfree(ref);
>> +     }
>> +     xa_unlock(&irqs);
>> +}
>> +
>> +static int auxiliary_irq_create(int irq)
>> +{
>> +     refcount_t *ref;
>> +     int ret = 0;
>> +
>> +     mutex_lock(&irqs_lock);
>> +     ref = xa_load(&irqs, irq);
>> +     if (ref && refcount_inc_not_zero(ref))
>> +             goto out;
>> +
>> +     ref = kzalloc(sizeof(*ref), GFP_KERNEL);
>> +     if (!ref) {
>> +             ret = -ENOMEM;
>> +             goto out;
>> +     }
>> +
>> +     refcount_set(ref, 1);
>> +     ret = xa_insert(&irqs, irq, ref, GFP_KERNEL);
>> +     if (ret)
>> +             kfree(ref);
>> +
>> +out:
>> +     mutex_unlock(&irqs_lock);
>> +     return ret;
>> +}
>> +
>> +/**
>> + * auxiliary_device_sysfs_irq_add - add a sysfs entry for the given IRQ
>> + * @auxdev: auxiliary bus device to add the sysfs entry.
>> + * @irq: The associated Linux interrupt number.
>> + *
>> + * This function should be called after auxiliary device have 
>> successfully
>> + * received the irq.
> 
> s/received/registered/?

I used received on purpose. as mention in the commit message: "the PCI 
SFs sometimes share the IRQs with peer SFs." This means some SFs won't 
register the IRQ.

> 
>> + *
>> + * Return: zero on success or an error code on failure.
>> + */
>> +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, 
>> int irq)
>> +{
>> +     struct device *dev = &auxdev->dev;
>> +     struct auxiliary_irq_info *info;
>> +     int ret;
>> +
>> +     ret = auxiliary_irq_create(irq);
>> +     if (ret)
>> +             return ret;
>> +
>> +     info = kzalloc(sizeof(*info), GFP_KERNEL);
>> +     if (!info) {
>> +             ret = -ENOMEM;
>> +             goto info_err;
>> +     }
>> +
>> +     sysfs_attr_init(&info->sysfs_attr.attr);
>> +     info->sysfs_attr.attr.name = kasprintf(GFP_KERNEL, "%d", irq);
>> +     if (!info->sysfs_attr.attr.name) {
>> +             ret = -ENOMEM;
>> +             goto name_err;
>> +     }
>> +     info->irq = irq;
>> +     info->sysfs_attr.attr.mode = 0444;
>> +     info->sysfs_attr.show = auxiliary_irq_mode_show;
>> +
>> +     ret = xa_insert(&auxdev->irqs, irq, info, GFP_KERNEL);
>> +     if (ret)
>> +             goto auxdev_xa_err;
>> +
>> +     ret = sysfs_add_file_to_group(&dev->kobj, &info->sysfs_attr.attr,
>> +                                   auxiliary_irqs_group.name);
>> +     if (ret)
>> +             goto sysfs_add_err;
>> +
>> +     return 0;
>> +
>> +sysfs_add_err:
>> +     xa_erase(&auxdev->irqs, irq);
>> +auxdev_xa_err:
>> +     kfree(info->sysfs_attr.attr.name);
>> +name_err:
>> +     kfree(info);
>> +info_err:
>> +     auxiliary_irq_destroy(irq);
>> +     return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_add);
>> +
>> +/**
>> + * auxiliary_device_sysfs_irq_remove - remove a sysfs entry for the 
>> given IRQ
>> + * @auxdev: auxiliary bus device to add the sysfs entry.
>> + * @irq: the IRQ to remove.
>> + *
>> + * This function should be called to remove an IRQ sysfs entry.
>> + */
>> +void auxiliary_device_sysfs_irq_remove(struct auxiliary_device 
>> *auxdev, int irq)
> 
> (not an issue, just a question)
> do you need to select IRQ to remove? ...

yes. in order to keep a symetry between add and remove flows.

> 
>> +{
>> +     struct auxiliary_irq_info *info = xa_load(&auxdev->irqs, irq);
>> +     struct device *dev = &auxdev->dev;
>> +
>> +     if (WARN_ON(!info))
>> +             return;
>> +
>> +     sysfs_remove_file_from_group(&dev->kobj, &info->sysfs_attr.attr,
>> +                                  auxiliary_irqs_group.name);
> 
> ... because there is an option to remove whole group at once
> 
>> +     xa_erase(&auxdev->irqs, irq);
>> +     kfree(info->sysfs_attr.attr.name);
>> +     kfree(info);
>> +     auxiliary_irq_destroy(irq);
>> +}
>> +EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_remove);
>> +#endif
>> +
>>   static const struct auxiliary_device_id *auxiliary_match_id(const 
>> struct auxiliary_device_id *id,
>>                                                           const struct 
>> auxiliary_device *auxdev)
>>   {
>> @@ -295,6 +453,7 @@ EXPORT_SYMBOL_GPL(auxiliary_device_init);
>>    * __auxiliary_device_add - add an auxiliary bus device
>>    * @auxdev: auxiliary bus device to add to the bus
>>    * @modname: name of the parent device's driver module
>> + * @irqs_sysfs_enable: whether to enable IRQs sysfs
>>    *
>>    * This is the third step in the three-step process to register an
>>    * auxiliary_device.
>> @@ -310,7 +469,8 @@ EXPORT_SYMBOL_GPL(auxiliary_device_init);
>>    * parameter.  Only if a user requires a custom name would this 
>> version be
>>    * called directly.
>>    */
>> -int __auxiliary_device_add(struct auxiliary_device *auxdev, const 
>> char *modname)
>> +int __auxiliary_device_add(struct auxiliary_device *auxdev, const 
>> char *modname,
>> +                        bool irqs_sysfs_enable)
>>   {
>>       struct device *dev = &auxdev->dev;
>>       int ret;
>> @@ -325,6 +485,11 @@ int __auxiliary_device_add(struct 
>> auxiliary_device *auxdev, const char *modname)
>>               dev_err(dev, "auxiliary device dev_set_name failed: 
>> %d\n", ret);
>>               return ret;
>>       }
>> +     if (irqs_sysfs_enable) {
>> +             auxdev->groups[0] = &auxiliary_irqs_group;
> 
> I would remove this array ...
> 
>> +             xa_init(&auxdev->irqs);
>> +             dev->groups = auxdev->groups;
> 
> ... and use &auxiliary_irqs_group directly here
> (you will need to change it to 2 elem array though)

thanks. will change in v3.

> 
>> +     }
>>
>>       ret = device_add(dev);
>>       if (ret)
>> diff --git a/include/linux/auxiliary_bus.h 
>> b/include/linux/auxiliary_bus.h
>> index de21d9d24a95..fe2c438c0217 100644
>> --- a/include/linux/auxiliary_bus.h
>> +++ b/include/linux/auxiliary_bus.h
>> @@ -58,6 +58,9 @@
>>    *       in
>>    * @name: Match name found by the auxiliary device driver,
>>    * @id: unique identitier if multiple devices of the same name are 
>> exported,
>> + * @irqs: irqs xarray contains irq indices which are used by the device,
>> + * @groups: first group is for irqs sysfs directory; it is a NULL 
>> terminated
>> + *          array,
>>    *
>>    * An auxiliary_device represents a part of its parent device's 
>> functionality.
>>    * It is given a name that, combined with the registering drivers
>> @@ -138,6 +141,8 @@
>>   struct auxiliary_device {
>>       struct device dev;
>>       const char *name;
>> +     struct xarray irqs;
>> +     const struct attribute_group *groups[2];
>>       u32 id;
>>   };
>>
>> @@ -209,8 +214,19 @@ static inline struct auxiliary_driver 
>> *to_auxiliary_drv(struct device_driver *dr
>>   }
>>
>>   int auxiliary_device_init(struct auxiliary_device *auxdev);
>> -int __auxiliary_device_add(struct auxiliary_device *auxdev, const 
>> char *modname);
>> -#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev, 
>> KBUILD_MODNAME)
>> +int __auxiliary_device_add(struct auxiliary_device *auxdev, const 
>> char *modname,
>> +                        bool irqs_sysfs_enable);
>> +#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev, 
>> KBUILD_MODNAME, false)
>> +#define auxiliary_device_add_with_irqs(auxdev) \
>> +     __auxiliary_device_add(auxdev, KBUILD_MODNAME, true)
>> +
>> +#ifdef CONFIG_SYSFS
>> +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, 
>> int irq);
>> +void auxiliary_device_sysfs_irq_remove(struct auxiliary_device 
>> *auxdev, int irq);
>> +#else /* CONFIG_SYSFS */
>> +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, 
>> int irq) {return 0; }
>> +void auxiliary_device_sysfs_irq_remove(struct auxiliary_device 
>> *auxdev, int irq) {}
>> +#endif
>>
>>   static inline void auxiliary_device_uninit(struct auxiliary_device 
>> *auxdev)
>>   {
>