Re: [patch 21/33] genirq/msi: Provide msi_domain_alloc_irq_at()

[Thomas Gleixner <tglx@linutronix.de>]

On Fri, Nov 18 2022 at 10:15, Thomas Gleixner wrote:
> On Fri, Nov 18 2022 at 01:58, Thomas Gleixner wrote:
> Of course I "tested" this by flipping default and secondary domain
> around and doing dynamic allocations from PCI/MSI-X but that won't catch
> the bug because PCI/MSI-X does not have the ALLOC_SIMPLE_DESCS flag set.
>
> Let me fix that.

Delta patch against

  git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git devmsi-v1G-part3

below.

Thanks,

        tglx
---
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index d4f26649a185..d243ad3e5489 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -141,7 +141,7 @@ static int msi_insert_desc(struct device *dev, struct msi_desc *desc,
 		if (ret)
 			goto fail;
 
-		desc->msi_index = index;
+		desc->msi_index = index - baseidx;
 		return 0;
 	} else {
 		if (index >= hwsize) {
@@ -1476,9 +1476,10 @@ struct msi_map msi_domain_alloc_irq_at(struct device *dev, unsigned int domid, u
 				       const struct irq_affinity_desc *affdesc,
 				       union msi_dev_cookie *cookie)
 {
+	struct msi_ctrl ctrl = { .domid	= domid, .nirqs = 1, };
+	struct msi_domain_info *info;
 	struct irq_domain *domain;
 	struct msi_map map = { };
-	struct msi_desc *desc;
 	int ret;
 
 	msi_lock_descs(dev);
@@ -1503,12 +1504,16 @@ struct msi_map msi_domain_alloc_irq_at(struct device *dev, unsigned int domid, u
 		goto unlock;
 	}
 
-	map.index = desc->msi_index;
-	ret = msi_domain_alloc_irqs_range_locked(dev, domid, map.index, map.index);
-	if (ret)
+	ctrl.first = ctrl.last = desc->msi_index;
+	info = domain->host_data;
+
+	ret = __msi_domain_alloc_irqs(dev, domain, &ctrl);
+	if (ret) {
 		map.index = ret;
-	else
+		msi_domain_free_locked(dev, &ctrl);
+	} else {
 		map.virq = desc->irq;
+	}
 unlock:
 	msi_unlock_descs(dev);
 	return map;