aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--include/linux/msi.h27
-rw-r--r--kernel/irq/msi.c70
2 files changed, 75 insertions, 22 deletions
diff --git a/include/linux/msi.h b/include/linux/msi.h
index a65cc47d0610..0180534b5428 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -241,6 +241,10 @@ struct msi_domain_info;
* @msi_finish: Optional callback to finalize the allocation
* @set_desc: Set the msi descriptor for an interrupt
* @handle_error: Optional error handler if the allocation fails
+ * @domain_alloc_irqs: Optional function to override the default allocation
+ * function.
+ * @domain_free_irqs: Optional function to override the default free
+ * function.
*
* @get_hwirq, @msi_init and @msi_free are callbacks used by
* msi_create_irq_domain() and related interfaces
@@ -248,6 +252,22 @@ struct msi_domain_info;
* @msi_check, @msi_prepare, @msi_finish, @set_desc and @handle_error
* are callbacks used by msi_domain_alloc_irqs() and related
* interfaces which are based on msi_desc.
+ *
+ * @domain_alloc_irqs, @domain_free_irqs can be used to override the
+ * default allocation/free functions (__msi_domain_alloc/free_irqs). This
+ * is initially for a wrapper around XENs seperate MSI universe which can't
+ * be wrapped into the regular irq domains concepts by mere mortals. This
+ * allows to universally use msi_domain_alloc/free_irqs without having to
+ * special case XEN all over the place.
+ *
+ * Contrary to other operations @domain_alloc_irqs and @domain_free_irqs
+ * are set to the default implementation if NULL and even when
+ * MSI_FLAG_USE_DEF_DOM_OPS is not set to avoid breaking existing users and
+ * because these callbacks are obviously mandatory.
+ *
+ * This is NOT meant to be abused, but it can be useful to build wrappers
+ * for specialized MSI irq domains which need extra work before and after
+ * calling __msi_domain_alloc_irqs()/__msi_domain_free_irqs().
*/
struct msi_domain_ops {
irq_hw_number_t (*get_hwirq)(struct msi_domain_info *info,
@@ -270,6 +290,10 @@ struct msi_domain_ops {
struct msi_desc *desc);
int (*handle_error)(struct irq_domain *domain,
struct msi_desc *desc, int error);
+ int (*domain_alloc_irqs)(struct irq_domain *domain,
+ struct device *dev, int nvec);
+ void (*domain_free_irqs)(struct irq_domain *domain,
+ struct device *dev);
};
/**
@@ -327,8 +351,11 @@ int msi_domain_set_affinity(struct irq_data *data, const struct cpumask *mask,
struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode,
struct msi_domain_info *info,
struct irq_domain *parent);
+int __msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
+ int nvec);
int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
int nvec);
+void __msi_domain_free_irqs(struct irq_domain *domain, struct device *dev);
void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev);
struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain);
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 616b9583cfbb..2c0c4d6d0f83 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -229,11 +229,13 @@ static int msi_domain_ops_check(struct irq_domain *domain,
}
static struct msi_domain_ops msi_domain_ops_default = {
- .get_hwirq = msi_domain_ops_get_hwirq,
- .msi_init = msi_domain_ops_init,
- .msi_check = msi_domain_ops_check,
- .msi_prepare = msi_domain_ops_prepare,
- .set_desc = msi_domain_ops_set_desc,
+ .get_hwirq = msi_domain_ops_get_hwirq,
+ .msi_init = msi_domain_ops_init,
+ .msi_check = msi_domain_ops_check,
+ .msi_prepare = msi_domain_ops_prepare,
+ .set_desc = msi_domain_ops_set_desc,
+ .domain_alloc_irqs = __msi_domain_alloc_irqs,
+ .domain_free_irqs = __msi_domain_free_irqs,
};
static void msi_domain_update_dom_ops(struct msi_domain_info *info)
@@ -245,6 +247,14 @@ static void msi_domain_update_dom_ops(struct msi_domain_info *info)
return;
}
+ if (ops->domain_alloc_irqs == NULL)
+ ops->domain_alloc_irqs = msi_domain_ops_default.domain_alloc_irqs;
+ if (ops->domain_free_irqs == NULL)
+ ops->domain_free_irqs = msi_domain_ops_default.domain_free_irqs;
+
+ if (!(info->flags & MSI_FLAG_USE_DEF_DOM_OPS))
+ return;
+
if (ops->get_hwirq == NULL)
ops->get_hwirq = msi_domain_ops_default.get_hwirq;
if (ops->msi_init == NULL)
@@ -278,8 +288,7 @@ struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode,
{
struct irq_domain *domain;
- if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
- msi_domain_update_dom_ops(info);
+ msi_domain_update_dom_ops(info);
if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
msi_domain_update_chip_ops(info);
@@ -386,17 +395,8 @@ static bool msi_check_reservation_mode(struct irq_domain *domain,
return desc->msi_attrib.is_msix || desc->msi_attrib.maskbit;
}
-/**
- * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain
- * @domain: The domain to allocate from
- * @dev: Pointer to device struct of the device for which the interrupts
- * are allocated
- * @nvec: The number of interrupts to allocate
- *
- * Returns 0 on success or an error code.
- */
-int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
- int nvec)
+int __msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
+ int nvec)
{
struct msi_domain_info *info = domain->host_data;
struct msi_domain_ops *ops = info->ops;
@@ -490,12 +490,24 @@ cleanup:
}
/**
- * msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated tp @dev
- * @domain: The domain to managing the interrupts
+ * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain
+ * @domain: The domain to allocate from
* @dev: Pointer to device struct of the device for which the interrupts
- * are free
+ * are allocated
+ * @nvec: The number of interrupts to allocate
+ *
+ * Returns 0 on success or an error code.
*/
-void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
+int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev,
+ int nvec)
+{
+ struct msi_domain_info *info = domain->host_data;
+ struct msi_domain_ops *ops = info->ops;
+
+ return ops->domain_alloc_irqs(domain, dev, nvec);
+}
+
+void __msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
{
struct msi_desc *desc;
@@ -513,6 +525,20 @@ void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
}
/**
+ * __msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated tp @dev
+ * @domain: The domain to managing the interrupts
+ * @dev: Pointer to device struct of the device for which the interrupts
+ * are free
+ */
+void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
+{
+ struct msi_domain_info *info = domain->host_data;
+ struct msi_domain_ops *ops = info->ops;
+
+ return ops->domain_free_irqs(domain, dev);
+}
+
+/**
* msi_get_domain_info - Get the MSI interrupt domain info for @domain
* @domain: The interrupt domain to retrieve data from
*