[PATCH for-next] RDMA/efa: Expose device P2P DMA support via device query

[Yonatan Nachum <ynachum@amazon.com>]

Expose device P2P DMA support using the query device verbs.
If the device support P2P DMA, it can DMA directly to and from a peer
PCIe device

Reviewed-by: Michael Margolin <mrgolin@amazon.com>
Reviewed-by: Yehuda Yitschak <yehuday@amazon.com>
Signed-off-by: Yonatan Nachum <ynachum@amazon.com>
---
 drivers/infiniband/hw/efa/efa_admin_cmds_defs.h | 10 +++++++++-
 drivers/infiniband/hw/efa/efa_verbs.c           |  3 +++
 include/uapi/rdma/efa-abi.h                     |  1 +
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/efa/efa_admin_cmds_defs.h b/drivers/infiniband/hw/efa/efa_admin_cmds_defs.h
index ad34ea5da6b0..097b3303f3e9 100644
--- a/drivers/infiniband/hw/efa/efa_admin_cmds_defs.h
+++ b/drivers/infiniband/hw/efa/efa_admin_cmds_defs.h
@@ -725,7 +725,11 @@ struct efa_admin_feature_device_attr_desc {
 	 *    on TX queues
 	 * 4 : unsolicited_write_recv - If set, unsolicited
 	 *    write with imm. receive is supported
-	 * 31:5 : reserved - MBZ
+	 * 5 : event_counters - If set, event counters are
+	 *    supported
+	 * 6 : p2p_dma - If set the device can DMA directly
+	 *    to and from a peer PCIe device
+	 * 31:7 : reserved - MBZ
 	 */
 	u32 device_caps;
 
@@ -1132,6 +1136,10 @@ struct efa_admin_host_info {
 #define EFA_ADMIN_FEATURE_DEVICE_ATTR_DESC_DATA_POLLING_128_MASK BIT(2)
 #define EFA_ADMIN_FEATURE_DEVICE_ATTR_DESC_RDMA_WRITE_MASK  BIT(3)
 #define EFA_ADMIN_FEATURE_DEVICE_ATTR_DESC_UNSOLICITED_WRITE_RECV_MASK BIT(4)
+#define EFA_ADMIN_FEATURE_DEVICE_ATTR_DESC_EVENT_COUNTERS_SHIFT 5
+#define EFA_ADMIN_FEATURE_DEVICE_ATTR_DESC_EVENT_COUNTERS_MASK BIT(5)
+#define EFA_ADMIN_FEATURE_DEVICE_ATTR_DESC_P2P_DMA_SHIFT    6
+#define EFA_ADMIN_FEATURE_DEVICE_ATTR_DESC_P2P_DMA_MASK     BIT(6)
 
 /* create_eq_cmd */
 #define EFA_ADMIN_CREATE_EQ_CMD_ENTRY_SIZE_WORDS_MASK       GENMASK(4, 0)
diff --git a/drivers/infiniband/hw/efa/efa_verbs.c b/drivers/infiniband/hw/efa/efa_verbs.c
index 7bd0838ebc99..b16f470f7d30 100644
--- a/drivers/infiniband/hw/efa/efa_verbs.c
+++ b/drivers/infiniband/hw/efa/efa_verbs.c
@@ -270,6 +270,9 @@ int efa_query_device(struct ib_device *ibdev,
 		if (EFA_DEV_CAP(dev, UNSOLICITED_WRITE_RECV))
 			resp.device_caps |= EFA_QUERY_DEVICE_CAPS_UNSOLICITED_WRITE_RECV;
 
+		if (EFA_DEV_CAP(dev, P2P_DMA))
+			resp.device_caps |= EFA_QUERY_DEVICE_CAPS_P2P_DMA;
+
 		if (dev->neqs)
 			resp.device_caps |= EFA_QUERY_DEVICE_CAPS_CQ_NOTIFICATIONS;
 
diff --git a/include/uapi/rdma/efa-abi.h b/include/uapi/rdma/efa-abi.h
index d5c18f8de182..d19cb59d822d 100644
--- a/include/uapi/rdma/efa-abi.h
+++ b/include/uapi/rdma/efa-abi.h
@@ -133,6 +133,7 @@ enum {
 	EFA_QUERY_DEVICE_CAPS_RDMA_WRITE = 1 << 5,
 	EFA_QUERY_DEVICE_CAPS_UNSOLICITED_WRITE_RECV = 1 << 6,
 	EFA_QUERY_DEVICE_CAPS_CQ_WITH_EXT_MEM = 1 << 7,
+	EFA_QUERY_DEVICE_CAPS_P2P_DMA = 1 << 8,
 };
 
 struct efa_ibv_ex_query_device_resp {
-- 
2.50.1