[patch V2 19/40] genirq/msi: Split msi_domain_alloc_irq_at()

From: Thomas Gleixner
Date: Mon Nov 21 2022 - 09:49:23 EST


In preparation for providing a special allocation function for wired
interrupt which are connected to a wire to MSI bridge, split the inner
workings of msi_domain_alloc_irq_at() out into a helper function so the
code can be shared.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/irq/msi.c | 76 +++++++++++++++++++++++++++++++------------------------
1 file changed, 43 insertions(+), 33 deletions(-)

--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -1465,34 +1465,10 @@ int msi_domain_alloc_irqs_all_locked(str
return msi_domain_alloc_locked(dev, &ctrl);
}

-/**
- * msi_domain_alloc_irq_at - Allocate an interrupt from a MSI interrupt domain at
- * a given index - or at the next free index
- *
- * @dev: Pointer to device struct of the device for which the interrupts
- * are allocated
- * @domid: Id of the interrupt domain to operate on
- * @index: Index for allocation. If @index == %MSI_ANY_INDEX the allocation
- * uses the next free index.
- * @affdesc: Optional pointer to an interrupt affinity descriptor structure
- * @icookie: Optional pointer to a domain specific per instance cookie. If
- * non-NULL the content of the cookie is stored in msi_desc::data.
- * Must be NULL for MSI-X allocations
- *
- * This requires a MSI interrupt domain which lets the core code manage the
- * MSI descriptors.
- *
- * Return: struct msi_map
- *
- * On success msi_map::index contains the allocated index number and
- * msi_map::virq the corresponding Linux interrupt number
- *
- * On failure msi_map::index contains the error code and msi_map::virq
- * is %0.
- */
-struct msi_map msi_domain_alloc_irq_at(struct device *dev, unsigned int domid, unsigned int index,
- const struct irq_affinity_desc *affdesc,
- union msi_instance_cookie *icookie)
+static struct msi_map __msi_domain_alloc_irq_at(struct device *dev, unsigned int domid,
+ unsigned int index,
+ const struct irq_affinity_desc *affdesc,
+ union msi_instance_cookie *icookie)
{
struct msi_ctrl ctrl = { .domid = domid, .nirqs = 1, };
struct msi_domain_info *info;
@@ -1501,17 +1477,16 @@ struct msi_map msi_domain_alloc_irq_at(s
struct msi_desc *desc;
int ret;

- msi_lock_descs(dev);
domain = msi_get_device_domain(dev, domid);
if (!domain) {
map.index = -ENODEV;
- goto unlock;
+ return map;
}

desc = msi_alloc_desc(dev, 1, affdesc);
if (!desc) {
map.index = -ENOMEM;
- goto unlock;
+ return map;
}

if (icookie)
@@ -1520,7 +1495,7 @@ struct msi_map msi_domain_alloc_irq_at(s
ret = msi_insert_desc(dev, desc, domid, index);
if (ret) {
map.index = ret;
- goto unlock;
+ return map;
}

ctrl.first = ctrl.last = desc->msi_index;
@@ -1534,7 +1509,42 @@ struct msi_map msi_domain_alloc_irq_at(s
map.index = desc->msi_index;
map.virq = desc->irq;
}
-unlock:
+ return map;
+}
+
+/**
+ * msi_domain_alloc_irq_at - Allocate an interrupt from a MSI interrupt domain at
+ * a given index - or at the next free index
+ *
+ * @dev: Pointer to device struct of the device for which the interrupts
+ * are allocated
+ * @domid: Id of the interrupt domain to operate on
+ * @index: Index for allocation. If @index == %MSI_ANY_INDEX the allocation
+ * uses the next free index.
+ * @affdesc: Optional pointer to an interrupt affinity descriptor structure
+ * @icookie: Optional pointer to a domain specific per instance cookie. If
+ * non-NULL the content of the cookie is stored in msi_desc::data.
+ * Must be NULL for MSI-X allocations
+ *
+ * This requires a MSI interrupt domain which lets the core code manage the
+ * MSI descriptors.
+ *
+ * Return: struct msi_map
+ *
+ * On success msi_map::index contains the allocated index number and
+ * msi_map::virq the corresponding Linux interrupt number
+ *
+ * On failure msi_map::index contains the error code and msi_map::virq
+ * is %0.
+ */
+struct msi_map msi_domain_alloc_irq_at(struct device *dev, unsigned int domid, unsigned int index,
+ const struct irq_affinity_desc *affdesc,
+ union msi_instance_cookie *icookie)
+{
+ struct msi_map map;
+
+ msi_lock_descs(dev);
+ map = __msi_domain_alloc_irq_at(dev, domid, index, affdesc, icookie);
msi_unlock_descs(dev);
return map;
}