qed: Prevent a possible deadlock during driver load and unload

The MFW manages an internal lock to prevent concurrent hardware
(de)initialization of different PFs.
This, together with the busy-waiting for the MFW's responses for commands,
might lead to a deadlock during concurrent load or unload of PFs.
This patch adds the option to sleep within the busy-waiting, and uses it
for the (un)load requests (which are not sent from an interrupt context) to
prevent the possible deadlock.

Signed-off-by: Tomer Tayar <Tomer.Tayar@cavium.com>
Signed-off-by: Ariel Elior <Ariel.Elior@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 8 deletions

diff --git a/drivers/net/ethernet/qlogic/qed/qed_mcp.h b/drivers/net/ethernet/qlogic/qed/qed_mcp.h
index 047976d5c6e9..b9d3ecf7aad6 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_mcp.h
+++ b/drivers/net/ethernet/qlogic/qed/qed_mcp.h
@@ -660,14 +660,19 @@ struct qed_mcp_info {
 };
 
 struct qed_mcp_mb_params {
-	u32			cmd;
-	u32			param;
-	void			*p_data_src;
-	u8			data_src_size;
-	void			*p_data_dst;
-	u8			data_dst_size;
-	u32			mcp_resp;
-	u32			mcp_param;
+	u32 cmd;
+	u32 param;
+	void *p_data_src;
+	void *p_data_dst;
+	u8 data_src_size;
+	u8 data_dst_size;
+	u32 mcp_resp;
+	u32 mcp_param;
+	u32 flags;
+#define QED_MB_FLAG_CAN_SLEEP	(0x1 << 0)
+#define QED_MB_FLAGS_IS_SET(params, flag) \
+	({ typeof(params) __params = (params); \
+	   (__params && (__params->flags & QED_MB_FLAG_ ## flag)); })
 };
 
 struct qed_drv_tlv_hdr {