5 files changed, 44 insertions, 0 deletions

diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c
index 1e2c0d9f1df7..f02a85974e49 100644
--- a/drivers/misc/cxl/api.c
+++ b/drivers/misc/cxl/api.c
@@ -97,6 +97,21 @@ static irq_hw_number_t cxl_find_afu_irq(struct cxl_context *ctx, int num)
 	return 0;
 }
 
+int _cxl_next_msi_hwirq(struct pci_dev *pdev, struct cxl_context **ctx, int *afu_irq)
+{
+	if (*ctx == NULL || *afu_irq == 0) {
+		*afu_irq = 1;
+		*ctx = cxl_get_context(pdev);
+	} else {
+		(*afu_irq)++;
+		if (*afu_irq > cxl_get_max_irqs_per_process(pdev)) {
+			*ctx = list_next_entry(*ctx, extra_irq_contexts);
+			*afu_irq = 1;
+		}
+	}
+	return cxl_find_afu_irq(*ctx, *afu_irq);
+}
+/* Exported via cxl_base */
 
 int cxl_set_priv(struct cxl_context *ctx, void *priv)
 {
diff --git a/drivers/misc/cxl/base.c b/drivers/misc/cxl/base.c
index e1e80cb99ad9..fe90f895bb10 100644
--- a/drivers/misc/cxl/base.c
+++ b/drivers/misc/cxl/base.c
@@ -141,6 +141,23 @@ void cxl_pci_disable_device(struct pci_dev *dev)
 }
 EXPORT_SYMBOL_GPL(cxl_pci_disable_device);
 
+int cxl_next_msi_hwirq(struct pci_dev *pdev, struct cxl_context **ctx, int *afu_irq)
+{
+	int ret;
+	struct cxl_calls *calls;
+
+	calls = cxl_calls_get();
+	if (!calls)
+		return -EBUSY;
+
+	ret = calls->cxl_next_msi_hwirq(pdev, ctx, afu_irq);
+
+	cxl_calls_put(calls);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cxl_next_msi_hwirq);
+
 static int __init cxl_base_init(void)
 {
 	struct device_node *np;
diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c
index edbb99e93114..2616cddbbb33 100644
--- a/drivers/misc/cxl/context.c
+++ b/drivers/misc/cxl/context.c
@@ -68,6 +68,7 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master,
 	ctx->pending_afu_err = false;
 
 	INIT_LIST_HEAD(&ctx->irq_names);
+	INIT_LIST_HEAD(&ctx->extra_irq_contexts);
 
 	/*
 	 * When we have to destroy all contexts in cxl_context_detach_all() we
diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h
index b81f476a2b9f..73b9a55aa35b 100644
--- a/drivers/misc/cxl/cxl.h
+++ b/drivers/misc/cxl/cxl.h
@@ -537,6 +537,14 @@ struct cxl_context {
 	atomic_t afu_driver_events;
 
 	struct rcu_head rcu;
+
+	/*
+	 * Only used when more interrupts are allocated via
+	 * pci_enable_msix_range than are supported in the default context, to
+	 * use additional contexts to overcome the limitation. i.e. Mellanox
+	 * CX4 only:
+	 */
+	struct list_head extra_irq_contexts;
 };
 
 struct cxl_service_layer_ops {
@@ -722,11 +730,13 @@ ssize_t cxl_pci_afu_read_err_buffer(struct cxl_afu *afu, char *buf,
 /* Internal functions wrapped in cxl_base to allow PHB to call them */
 bool _cxl_pci_associate_default_context(struct pci_dev *dev, struct cxl_afu *afu);
 void _cxl_pci_disable_device(struct pci_dev *dev);
+int _cxl_next_msi_hwirq(struct pci_dev *pdev, struct cxl_context **ctx, int *afu_irq);
 
 struct cxl_calls {
 	void (*cxl_slbia)(struct mm_struct *mm);
 	bool (*cxl_pci_associate_default_context)(struct pci_dev *dev, struct cxl_afu *afu);
 	void (*cxl_pci_disable_device)(struct pci_dev *dev);
+	int (*cxl_next_msi_hwirq)(struct pci_dev *pdev, struct cxl_context **ctx, int *afu_irq);
 
 	struct module *owner;
 };
diff --git a/drivers/misc/cxl/main.c b/drivers/misc/cxl/main.c
index 4e5474b00b28..66fac713e7ad 100644
--- a/drivers/misc/cxl/main.c
+++ b/drivers/misc/cxl/main.c
@@ -112,6 +112,7 @@ static struct cxl_calls cxl_calls = {
 	.cxl_slbia = cxl_slbia_core,
 	.cxl_pci_associate_default_context = _cxl_pci_associate_default_context,
 	.cxl_pci_disable_device = _cxl_pci_disable_device,
+	.cxl_next_msi_hwirq = _cxl_next_msi_hwirq,
 	.owner = THIS_MODULE,
 };