On 6/18/24 17:09, 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 files 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 can be 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.
For example:
$ ls /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/
50 51 52 53 54 55 56 57 58
Reviewed-by: Parav Pandit <parav@xxxxxxxxxx>
Signed-off-by: Shay Drory <shayd@xxxxxxxxxx>
---
v6-v7:
- dynamically creating irqs directory when first irq file created (Greg)
- removed irqs flag and simplified the dev_add() API (Greg)
- move sysfs related new code to a new auxiliary_sysfs.c file (Greg)
[...]
+static int auxiliary_irq_dir_prepare(struct auxiliary_device *auxdev)
+{
+ int ret = 0;
+
+ mutex_lock(&auxdev->lock);
+ if (auxdev->dir_exists)
+ goto unlock;
+
+ xa_init(&auxdev->irqs);
due to below error handling you could end up with calling xa_init()
twice (and this is a "library" code, so it does not matter how you
handle this error in the current sole user ;))
+ ret = devm_device_add_group(&auxdev->dev, &auxiliary_irqs_group);
+ if (!ret)
+ auxdev->dir_exists = 1;
+
+unlock:
+ mutex_unlock(&auxdev->lock);
+ return ret;
+}
+
[...]
--- a/include/linux/auxiliary_bus.h
+++ b/include/linux/auxiliary_bus.h
@@ -58,6 +58,7 @@
* 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,
*
* An auxiliary_device represents a part of its parent device's functionality.
* It is given a name that, combined with the registering drivers
@@ -138,7 +139,10 @@
struct auxiliary_device {
struct device dev;
const char *name;
+ struct xarray irqs;
+ struct mutex lock; /* Protects "irqs" directory creation */
u32 id;
+ u8 dir_exists:1;
nit: I would make it a bool, or `bool: 1` if you really want
};
[...]
