RDMA/efa: CQ notifications

This patch adds support for CQ notifications through the standard verbs
api.

In order to achieve that, a new event queue (EQ) object is introduced,
which is in charge of reporting completion events to the driver.  On
driver load, EQs are allocated and their affinity is set to a single
cpu. When a user app creates a CQ with a completion channel, the
completion vector number is converted to a EQ number, which is in charge
of reporting the CQ events.

In addition, the CQ creation admin command now returns an offset for the
CQ doorbell, which is mapped to the userspace provider and is used to arm
the CQ when requested by the user.

The EQs use a single doorbell (located on the registers BAR), which
encodes the EQ number and arm as part of the doorbell value.  The EQs are
polled by the driver on each new EQE, and arm it when the poll is
completed.

Link: https://lore.kernel.org/r/20211003105605.29222-1-galpress@amazon.com
Reviewed-by: Firas JahJah <firasj@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

1 files changed, 17 insertions, 2 deletions

diff --git a/drivers/infiniband/hw/efa/efa.h b/drivers/infiniband/hw/efa/efa.h
index 87b1dadeb7fe..e0c9ba4c70f4 100644
--- a/drivers/infiniband/hw/efa/efa.h
+++ b/drivers/infiniband/hw/efa/efa.h
@@ -20,14 +20,14 @@
 
 #define EFA_IRQNAME_SIZE        40
 
-/* 1 for AENQ + ADMIN */
-#define EFA_NUM_MSIX_VEC                  1
 #define EFA_MGMNT_MSIX_VEC_IDX            0
+#define EFA_COMP_EQS_VEC_BASE             1
 
 struct efa_irq {
 	irq_handler_t handler;
 	void *data;
 	u32 irqn;
+	u32 vector;
 	cpumask_t affinity_hint_mask;
 	char name[EFA_IRQNAME_SIZE];
 };
@@ -61,6 +61,13 @@ struct efa_dev {
 	struct efa_irq admin_irq;
 
 	struct efa_stats stats;
+
+	/* Array of completion EQs */
+	struct efa_eq *eqs;
+	unsigned int neqs;
+
+	/* Only stores CQs with interrupts enabled */
+	struct xarray cqs_xa;
 };
 
 struct efa_ucontext {
@@ -84,8 +91,11 @@ struct efa_cq {
 	dma_addr_t dma_addr;
 	void *cpu_addr;
 	struct rdma_user_mmap_entry *mmap_entry;
+	struct rdma_user_mmap_entry *db_mmap_entry;
 	size_t size;
 	u16 cq_idx;
+	/* NULL when no interrupts requested */
+	struct efa_eq *eq;
 };
 
 struct efa_qp {
@@ -116,6 +126,11 @@ struct efa_ah {
 	u8 id[EFA_GID_SIZE];
 };
 
+struct efa_eq {
+	struct efa_com_eq eeq;
+	struct efa_irq irq;
+};
+
 int efa_query_device(struct ib_device *ibdev,
 		     struct ib_device_attr *props,
 		     struct ib_udata *udata);