can: mcp251xfd: ring: add support for runtime configurable RX/TX ring parameters

This patch adds runtime configurable RX and TX ring parameters via
ethtool to the driver.

Link: https://lore.kernel.org/20220313083640.501791-8-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-ethtool.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ethtool.c
index 4131185..8825195 100644 (file)
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-ethtool.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ethtool.c
@@ -9,6 +9,7 @@
 #include <linux/ethtool.h>
 
 #include "mcp251xfd.h"
+#include "mcp251xfd-ram.h"
 
 static void
 mcp251xfd_ring_get_ringparam(struct net_device *ndev,
@@ -17,19 +18,51 @@ mcp251xfd_ring_get_ringparam(struct net_device *ndev,
                             struct netlink_ext_ack *extack)
 {
        const struct mcp251xfd_priv *priv = netdev_priv(ndev);
+       const bool fd_mode = mcp251xfd_is_fd_mode(priv);
+       struct can_ram_layout layout;
 
-       ring->rx_max_pending = MCP251XFD_RX_OBJ_NUM_MAX;
-       ring->tx_max_pending = MCP251XFD_TX_OBJ_NUM_MAX;
+       can_ram_get_layout(&layout, &mcp251xfd_ram_config, NULL, NULL, fd_mode);
+       ring->rx_max_pending = layout.max_rx;
+       ring->tx_max_pending = layout.max_tx;
 
        ring->rx_pending = priv->rx_obj_num;
        ring->tx_pending = priv->tx->obj_num;
 }
 
+static int
+mcp251xfd_ring_set_ringparam(struct net_device *ndev,
+                            struct ethtool_ringparam *ring,
+                            struct kernel_ethtool_ringparam *kernel_ring,
+                            struct netlink_ext_ack *extack)
+{
+       struct mcp251xfd_priv *priv = netdev_priv(ndev);
+       const bool fd_mode = mcp251xfd_is_fd_mode(priv);
+       struct can_ram_layout layout;
+
+       can_ram_get_layout(&layout, &mcp251xfd_ram_config, ring, NULL, fd_mode);
+       if ((layout.cur_rx != priv->rx_obj_num ||
+            layout.cur_tx != priv->tx->obj_num) &&
+           netif_running(ndev))
+               return -EBUSY;
+
+       priv->rx_obj_num = layout.cur_rx;
+       priv->tx->obj_num = layout.cur_tx;
+
+       return 0;
+}
+
 static const struct ethtool_ops mcp251xfd_ethtool_ops = {
        .get_ringparam = mcp251xfd_ring_get_ringparam,
+       .set_ringparam = mcp251xfd_ring_set_ringparam,
 };
 
 void mcp251xfd_ethtool_init(struct mcp251xfd_priv *priv)
 {
+       struct can_ram_layout layout;
+
        priv->ndev->ethtool_ops = &mcp251xfd_ethtool_ops;
+
+       can_ram_get_layout(&layout, &mcp251xfd_ram_config, NULL, NULL, false);
+       priv->rx_obj_num = layout.default_rx;
+       priv->tx->obj_num = layout.default_tx;
 }

diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c
index bb0e342..2ff4d4e 100644 (file)
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c
@@ -15,6 +15,7 @@
 #include <asm/unaligned.h>
 
 #include "mcp251xfd.h"
+#include "mcp251xfd-ram.h"
 
 static inline u8
 mcp251xfd_cmd_prepare_write_reg(const struct mcp251xfd_priv *priv,
@@ -285,33 +286,63 @@ void mcp251xfd_ring_free(struct mcp251xfd_priv *priv)
        }
 }
 
+const struct can_ram_config mcp251xfd_ram_config = {
+       .rx = {
+               .size[CAN_RAM_MODE_CAN] = sizeof(struct mcp251xfd_hw_rx_obj_can),
+               .size[CAN_RAM_MODE_CANFD] = sizeof(struct mcp251xfd_hw_rx_obj_canfd),
+               .min = MCP251XFD_RX_OBJ_NUM_MIN,
+               .max = MCP251XFD_RX_OBJ_NUM_MAX,
+               .def[CAN_RAM_MODE_CAN] = CAN_RAM_NUM_MAX,
+               .def[CAN_RAM_MODE_CANFD] = CAN_RAM_NUM_MAX,
+               .fifo_num = MCP251XFD_FIFO_RX_NUM,
+               .fifo_depth_min = MCP251XFD_RX_FIFO_DEPTH_MIN,
+       },
+       .tx = {
+               .size[CAN_RAM_MODE_CAN] = sizeof(struct mcp251xfd_hw_tef_obj) +
+                       sizeof(struct mcp251xfd_hw_tx_obj_can),
+               .size[CAN_RAM_MODE_CANFD] = sizeof(struct mcp251xfd_hw_tef_obj) +
+                       sizeof(struct mcp251xfd_hw_tx_obj_canfd),
+               .min = MCP251XFD_TX_OBJ_NUM_MIN,
+               .max = MCP251XFD_TX_OBJ_NUM_MAX,
+               .def[CAN_RAM_MODE_CAN] = MCP251XFD_TX_OBJ_NUM_CAN_DEFAULT,
+               .def[CAN_RAM_MODE_CANFD] = MCP251XFD_TX_OBJ_NUM_CANFD_DEFAULT,
+               .fifo_num = MCP251XFD_FIFO_TX_NUM,
+               .fifo_depth_min = MCP251XFD_TX_FIFO_DEPTH_MIN,
+       },
+       .size = MCP251XFD_RAM_SIZE,
+       .fifo_depth = MCP251XFD_FIFO_DEPTH,
+};
+
 int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv)
 {
-       struct mcp251xfd_tx_ring *tx_ring;
+       const bool fd_mode = mcp251xfd_is_fd_mode(priv);
+       struct mcp251xfd_tx_ring *tx_ring = priv->tx;
        struct mcp251xfd_rx_ring *rx_ring;
-       u8 tef_obj_size, tx_obj_size, rx_obj_size;
-       u8 tx_obj_num;
+       u8 tx_obj_size, rx_obj_size;
        u8 rem, i;
 
-       tef_obj_size = sizeof(struct mcp251xfd_hw_tef_obj);
-       if (mcp251xfd_is_fd_mode(priv)) {
-               tx_obj_num = MCP251XFD_TX_OBJ_NUM_CANFD_DEFAULT;
+       /* switching from CAN-2.0 to CAN-FD mode or vice versa */
+       if (fd_mode != test_bit(MCP251XFD_FLAGS_FD_MODE, priv->flags)) {
+               struct can_ram_layout layout;
+
+               can_ram_get_layout(&layout, &mcp251xfd_ram_config, NULL, NULL, fd_mode);
+               priv->rx_obj_num = layout.default_rx;
+               tx_ring->obj_num = layout.default_tx;
+       }
+
+       if (fd_mode) {
                tx_obj_size = sizeof(struct mcp251xfd_hw_tx_obj_canfd);
                rx_obj_size = sizeof(struct mcp251xfd_hw_rx_obj_canfd);
+               set_bit(MCP251XFD_FLAGS_FD_MODE, priv->flags);
        } else {
-               tx_obj_num = MCP251XFD_TX_OBJ_NUM_CAN_DEFAULT;
                tx_obj_size = sizeof(struct mcp251xfd_hw_tx_obj_can);
                rx_obj_size = sizeof(struct mcp251xfd_hw_rx_obj_can);
+               clear_bit(MCP251XFD_FLAGS_FD_MODE, priv->flags);
        }
 
-       priv->rx_obj_num = 0;
-
-       tx_ring = priv->tx;
-       tx_ring->obj_num = tx_obj_num;
        tx_ring->obj_size = tx_obj_size;
 
-       rem = (MCP251XFD_RAM_SIZE - tx_obj_num *
-              (tef_obj_size + tx_obj_size)) / rx_obj_size;
+       rem = priv->rx_obj_num;
        for (i = 0; i < ARRAY_SIZE(priv->rx) && rem; i++) {
                u8 rx_obj_num;
 
@@ -319,8 +350,6 @@ int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv)
                                   MCP251XFD_FIFO_DEPTH);
                rem -= rx_obj_num;
 
-               priv->rx_obj_num += rx_obj_num;
-
                rx_ring = kzalloc(sizeof(*rx_ring) + rx_obj_size * rx_obj_num,
                                  GFP_KERNEL);
                if (!rx_ring) {

diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
index b1cc8d1..c61df20 100644 (file)
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
@@ -582,6 +582,12 @@ struct mcp251xfd_devtype_data {
        u32 quirks;
 };
 
+enum mcp251xfd_flags {
+       MCP251XFD_FLAGS_FD_MODE,
+
+       __MCP251XFD_FLAGS_SIZE__
+};
+
 struct mcp251xfd_priv {
        struct can_priv can;
        struct can_rx_offload offload;
@@ -607,6 +613,8 @@ struct mcp251xfd_priv {
        struct mcp251xfd_rx_ring *rx[MCP251XFD_FIFO_RX_NUM];
        struct mcp251xfd_tx_ring tx[MCP251XFD_FIFO_TX_NUM];
 
+       DECLARE_BITMAP(flags, __MCP251XFD_FLAGS_SIZE__);
+
        u8 rx_ring_num;
        u8 rx_obj_num;
 
@@ -892,6 +900,7 @@ u16 mcp251xfd_crc16_compute2(const void *cmd, size_t cmd_size,
 u16 mcp251xfd_crc16_compute(const void *data, size_t data_size);
 void mcp251xfd_ethtool_init(struct mcp251xfd_priv *priv);
 int mcp251xfd_regmap_init(struct mcp251xfd_priv *priv);
+extern const struct can_ram_config mcp251xfd_ram_config;
 int mcp251xfd_ring_init(struct mcp251xfd_priv *priv);
 void mcp251xfd_ring_free(struct mcp251xfd_priv *priv);
 int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv);