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authorThomas Gleixner <tglx@linutronix.de>2022-11-25 00:26:16 +0100
committerThomas Gleixner <tglx@linutronix.de>2022-12-05 22:22:33 +0100
commit8f986fd7755bec8b8c5776824afa1bd1151986d9 (patch)
tree1ab7feecf14a1dbfbc70ffa57ed4536b99d3f111
parentefd42049657e958797a483f793e4064042faa49c (diff)
genirq/msi: Provide msi_domain_ops:: Prepare_desc()
The existing MSI domain ops msi_prepare() and set_desc() turned out to be unsuitable for implementing IMS support. msi_prepare() does not operate on the MSI descriptors. set_desc() lacks an irq_domain pointer and has a completely different purpose. Introduce a prepare_desc() op which allows IMS implementations to amend an MSI descriptor which was allocated by the core code, e.g. by adjusting the iomem base or adding some data based on the allocated index. This is way better than requiring that all IMS domain implementations preallocate the MSI descriptor and then allocate the interrupt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221124232326.444560717@linutronix.de
-rw-r--r--include/linux/msi.h6
-rw-r--r--kernel/irq/msi.c3
2 files changed, 8 insertions, 1 deletions
diff --git a/include/linux/msi.h b/include/linux/msi.h
index dca3b801428f..cb0bee3f43a7 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -410,6 +410,8 @@ struct msi_domain_info;
* @msi_init: Domain specific init function for MSI interrupts
* @msi_free: Domain specific function to free a MSI interrupts
* @msi_prepare: Prepare the allocation of the interrupts in the domain
+ * @prepare_desc: Optional function to prepare the allocated MSI descriptor
+ * in the domain
* @set_desc: Set the msi descriptor for an interrupt
* @domain_alloc_irqs: Optional function to override the default allocation
* function.
@@ -421,7 +423,7 @@ struct msi_domain_info;
* @get_hwirq, @msi_init and @msi_free are callbacks used by the underlying
* irqdomain.
*
- * @msi_check, @msi_prepare and @set_desc are callbacks used by the
+ * @msi_check, @msi_prepare, @prepare_desc and @set_desc are callbacks used by the
* msi_domain_alloc/free_irqs*() variants.
*
* @domain_alloc_irqs, @domain_free_irqs can be used to override the
@@ -444,6 +446,8 @@ struct msi_domain_ops {
int (*msi_prepare)(struct irq_domain *domain,
struct device *dev, int nvec,
msi_alloc_info_t *arg);
+ void (*prepare_desc)(struct irq_domain *domain, msi_alloc_info_t *arg,
+ struct msi_desc *desc);
void (*set_desc)(msi_alloc_info_t *arg,
struct msi_desc *desc);
int (*domain_alloc_irqs)(struct irq_domain *domain,
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 0749e661e459..6370ea53ff4a 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -1254,6 +1254,9 @@ static int __msi_domain_alloc_irqs(struct device *dev, struct irq_domain *domain
if (WARN_ON_ONCE(allocated >= ctrl->nirqs))
return -EINVAL;
+ if (ops->prepare_desc)
+ ops->prepare_desc(domain, &arg, desc);
+
ops->set_desc(&arg, desc);
virq = __irq_domain_alloc_irqs(domain, -1, desc->nvec_used,