can: c_can: Store dlc private

We can avoid the HW access in TX cleanup path for retrieving the DLC
of the sent package if we store the DLC in a private array.

Ideally this should be handled in the can_echo_skb functions, but I
leave that exercise to the CAN folks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 8ea1379a398be7b74c64827338108c37aeecdba8..1e75223d614f159622af392ecd15540f87a01fa8 100644 (file)
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -145,33 +145,6 @@
 #define IF_RX                  0
 #define IF_TX                  1
 
-/*
- * IFx register masks:
- * allow easy operation on 16-bit registers when the
- * argument is 32-bit instead
- */
-#define IFX_WRITE_LOW_16BIT(x) ((x) & 0xFFFF)
-#define IFX_WRITE_HIGH_16BIT(x)        (((x) & 0xFFFF0000) >> 16)
-
-/* message object split */
-#define C_CAN_NO_OF_OBJECTS    32
-#define C_CAN_MSG_OBJ_RX_NUM   16
-#define C_CAN_MSG_OBJ_TX_NUM   16
-
-#define C_CAN_MSG_OBJ_RX_FIRST 1
-#define C_CAN_MSG_OBJ_RX_LAST  (C_CAN_MSG_OBJ_RX_FIRST + \
-                               C_CAN_MSG_OBJ_RX_NUM - 1)
-
-#define C_CAN_MSG_OBJ_TX_FIRST (C_CAN_MSG_OBJ_RX_LAST + 1)
-#define C_CAN_MSG_OBJ_TX_LAST  (C_CAN_MSG_OBJ_TX_FIRST + \
-                               C_CAN_MSG_OBJ_TX_NUM - 1)
-
-#define C_CAN_MSG_OBJ_RX_SPLIT 9
-#define C_CAN_MSG_RX_LOW_LAST  (C_CAN_MSG_OBJ_RX_SPLIT - 1)
-
-#define C_CAN_NEXT_MSG_OBJ_MASK        (C_CAN_MSG_OBJ_TX_NUM - 1)
-#define RECEIVE_OBJECT_BITS    0x0000ffff
-
 /* status interrupt */
 #define STATUS_INTERRUPT       0x8000
 
@@ -537,6 +510,7 @@ static netdev_tx_t c_can_start_xmit(struct sk_buff *skb,
 
        /* prepare message object for transmission */
        c_can_write_msg_object(dev, IF_TX, frame, msg_obj_no);
+       priv->dlc[msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST] = frame->can_dlc;
        can_put_echo_skb(skb, dev, msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST);
 
        /*

diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
index 5097c802a61eb1f65fca1abe3ece9b4742f7daaf..faa8404162b397e4bd589c0b7b665c2f6ab1e4e4 100644 (file)
--- a/drivers/net/can/c_can/c_can.h
+++ b/drivers/net/can/c_can/c_can.h
@@ -22,6 +22,33 @@
 #ifndef C_CAN_H
 #define C_CAN_H
 
+/*
+ * IFx register masks:
+ * allow easy operation on 16-bit registers when the
+ * argument is 32-bit instead
+ */
+#define IFX_WRITE_LOW_16BIT(x) ((x) & 0xFFFF)
+#define IFX_WRITE_HIGH_16BIT(x)        (((x) & 0xFFFF0000) >> 16)
+
+/* message object split */
+#define C_CAN_NO_OF_OBJECTS    32
+#define C_CAN_MSG_OBJ_RX_NUM   16
+#define C_CAN_MSG_OBJ_TX_NUM   16
+
+#define C_CAN_MSG_OBJ_RX_FIRST 1
+#define C_CAN_MSG_OBJ_RX_LAST  (C_CAN_MSG_OBJ_RX_FIRST + \
+                               C_CAN_MSG_OBJ_RX_NUM - 1)
+
+#define C_CAN_MSG_OBJ_TX_FIRST (C_CAN_MSG_OBJ_RX_LAST + 1)
+#define C_CAN_MSG_OBJ_TX_LAST  (C_CAN_MSG_OBJ_TX_FIRST + \
+                               C_CAN_MSG_OBJ_TX_NUM - 1)
+
+#define C_CAN_MSG_OBJ_RX_SPLIT 9
+#define C_CAN_MSG_RX_LOW_LAST  (C_CAN_MSG_OBJ_RX_SPLIT - 1)
+
+#define C_CAN_NEXT_MSG_OBJ_MASK        (C_CAN_MSG_OBJ_TX_NUM - 1)
+#define RECEIVE_OBJECT_BITS    0x0000ffff
+
 enum reg {
        C_CAN_CTRL_REG = 0,
        C_CAN_CTRL_EX_REG,
@@ -173,6 +200,7 @@ struct c_can_priv {
        u32 __iomem *raminit_ctrlreg;
        unsigned int instance;
        void (*raminit) (const struct c_can_priv *priv, bool enable);
+       u32 dlc[C_CAN_MSG_OBJ_TX_NUM];
 };
 
 struct net_device *alloc_c_can_dev(void);