[net-next v4 1/5] net: stmmac: Add HDMA mapping for dw25gmac support

[jitendra.vegiraju at broadcom.com]

From: Jitendra Vegiraju <jitendra.vegiraju at broadcom.com>

Add hdma configuration support in include/linux/stmmac.h file.
The hdma configuration includes mapping of virtual DMAs to physical DMAs.
Define a new data structure stmmac_hdma_cfg to provide the mapping.

Signed-off-by: Jitendra Vegiraju <jitendra.vegiraju at broadcom.com>
---
 include/linux/stmmac.h | 50 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index 338991c08f00..1775bd2b7c14 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -89,6 +89,55 @@ struct stmmac_mdio_bus_data {
 	bool needs_reset;
 };
 
+/* DW25GMAC Hyper-DMA Overview
+ * Hyper-DMA allows support for large number of Virtual DMA(VDMA)
+ * channels using a smaller set of physical DMA channels(PDMA).
+ * This is supported by the  mapping of VDMAs to Traffic Class (TC)
+ * and PDMA to TC in each traffic direction as shown below.
+ *
+ *        VDMAs            Traffic Class      PDMA
+ *       +--------+          +------+         +-----------+
+ *       |VDMA0   |--------->| TC0  |-------->|PDMA0/TXQ0 |
+ *TX     +--------+   |----->+------+         +-----------+
+ *Host=> +--------+   |      +------+         +-----------+ => MAC
+ *SW     |VDMA1   |---+      | TC1  |    +--->|PDMA1/TXQ1 |
+ *       +--------+          +------+    |    +-----------+
+ *       +--------+          +------+----+    +-----------+
+ *       |VDMA2   |--------->| TC2  |-------->|PDMA2/TXQ1 |
+ *       +--------+          +------+         +-----------+
+ *            .                 .                 .
+ *       +--------+          +------+         +-----------+
+ *       |VDMAn-1 |--------->| TCx-1|-------->|PDMAm/TXQm |
+ *       +--------+          +------+         +-----------+
+ *
+ *       +------+          +------+         +------+
+ *       |PDMA0 |--------->| TC0  |-------->|VDMA0 |
+ *       +------+   |----->+------+         +------+
+ *MAC => +------+   |      +------+         +------+
+ *RXQs   |PDMA1 |---+      | TC1  |    +--->|VDMA1 |  => Host
+ *       +------+          +------+    |    +------+
+ *            .                 .                 .
+ */
+
+#define STMMAC_DW25GMAC_MAX_NUM_TX_VDMA		128
+#define STMMAC_DW25GMAC_MAX_NUM_RX_VDMA		128
+
+#define STMMAC_DW25GMAC_MAX_NUM_TX_PDMA		8
+#define STMMAC_DW25GMAC_MAX_NUM_RX_PDMA		10
+
+#define STMMAC_DW25GMAC_MAX_TC			8
+
+/* Hyper-DMA mapping configuration
+ * Traffic Class associated with each VDMA/PDMA mapping
+ * is stored in corresponding array entry.
+ */
+struct stmmac_hdma_cfg {
+	u8 tvdma_tc[STMMAC_DW25GMAC_MAX_NUM_TX_VDMA];
+	u8 rvdma_tc[STMMAC_DW25GMAC_MAX_NUM_RX_VDMA];
+	u8 tpdma_tc[STMMAC_DW25GMAC_MAX_NUM_TX_PDMA];
+	u8 rpdma_tc[STMMAC_DW25GMAC_MAX_NUM_RX_PDMA];
+};
+
 struct stmmac_dma_cfg {
 	int pbl;
 	int txpbl;
@@ -101,6 +150,7 @@ struct stmmac_dma_cfg {
 	bool multi_msi_en;
 	bool dche;
 	bool atds;
+	struct stmmac_hdma_cfg *hdma_cfg;
 };
 
 #define AXI_BLEN	7
-- 
2.34.1