Reduce send overhead by grouping FIFO writes into fewer transfers.
Individual transfers on a slow bus (e.g., tcan4x5x) have high fixed
costs, so fewer transfers means higher throughput.
Signed-off-by: Matt Kline <mkline@xxxxxxxxxxx>
---
drivers/net/can/m_can/m_can.c | 52 ++++++++++++--------------
drivers/net/can/m_can/m_can.h | 2 +-
drivers/net/can/m_can/m_can_pci.c | 5 ++-
drivers/net/can/m_can/m_can_platform.c | 5 ++-
drivers/net/can/m_can/tcan4x5x-core.c | 4 +-
5 files changed, 33 insertions(+), 35 deletions(-)
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 0defdb33a7c0..7ed52e3fd006 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -302,7 +302,7 @@ enum m_can_reg {
/* Message RAM Elements */
#define M_CAN_FIFO_ID 0x0
#define M_CAN_FIFO_DLC 0x4
-#define M_CAN_FIFO_DATA(n) (0x8 + ((n) << 2))
+#define M_CAN_FIFO_DATA 0x8
/* Rx Buffer Element */
/* R0 */
@@ -356,18 +356,20 @@ static void m_can_fifo_read(struct m_can_classdev *cdev,
}
static void m_can_fifo_write(struct m_can_classdev *cdev,
- u32 fpi, unsigned int offset, u32 val)
+ u32 fpi, unsigned int offset, const void *val, size_t val_count)
{
u32 addr_offset = cdev->mcfg[MRAM_TXB].off + fpi * TXB_ELEMENT_SIZE +
offset;
+ int result;
- cdev->ops->write_fifo(cdev, addr_offset, val);
+ result = cdev->ops->write_fifo(cdev, addr_offset, val, val_count);
+ WARN_ON(result != 0);
}
static inline void m_can_fifo_write_no_off(struct m_can_classdev *cdev,
u32 fpi, u32 val)
{
- cdev->ops->write_fifo(cdev, fpi, val);
+ cdev->ops->write_fifo(cdev, fpi, &val, 1);
}
static u32 m_can_txe_fifo_read(struct m_can_classdev *cdev, u32 fgi, u32 offset)
@@ -531,7 +533,7 @@ static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
if (dlc & RX_BUF_BRS)
cf->flags |= CANFD_BRS;
- m_can_fifo_read(cdev, fgi, M_CAN_FIFO_DATA(0), cf->data, DIV_ROUND_UP(cf->len, 4));
+ m_can_fifo_read(cdev, fgi, M_CAN_FIFO_DATA, cf->data, DIV_ROUND_UP(cf->len, 4));
}
/* acknowledge rx fifo 0 */
@@ -1564,8 +1566,8 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
struct net_device *dev = cdev->net;
struct sk_buff *skb = cdev->tx_skb;
u32 id, cccr, fdflags;
- int i;
int putidx;
+ u32 id_and_dlc[2];
cdev->tx_skb = NULL;
@@ -1581,18 +1583,16 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
if (cf->can_id & CAN_RTR_FLAG)
id |= TX_BUF_RTR;
+ id_and_dlc[0] = id;
+
if (cdev->version == 30) {
netif_stop_queue(dev);
- /* message ram configuration */
- m_can_fifo_write(cdev, 0, M_CAN_FIFO_ID, id);
- m_can_fifo_write(cdev, 0, M_CAN_FIFO_DLC,
- can_fd_len2dlc(cf->len) << 16);
+ id_and_dlc[1] = can_fd_len2dlc(cf->len) << 16;
- for (i = 0; i < cf->len; i += 4)
- m_can_fifo_write(cdev, 0,
- M_CAN_FIFO_DATA(i / 4),
- *(u32 *)(cf->data + i));
+ /* Write the frame ID, DLC, and payload to the FIFO element. */
+ m_can_fifo_write(cdev, 0, M_CAN_FIFO_ID, id_and_dlc, ARRAY_SIZE(id_and_dlc));
+ m_can_fifo_write(cdev, 0, M_CAN_FIFO_DATA, cf->data, DIV_ROUND_UP(cf->len, 4));
can_put_echo_skb(skb, dev, 0, 0);
@@ -1636,8 +1636,11 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
/* get put index for frame */
putidx = ((m_can_read(cdev, M_CAN_TXFQS) & TXFQS_TFQPI_MASK)
>> TXFQS_TFQPI_SHIFT);
- /* Write ID Field to FIFO Element */
- m_can_fifo_write(cdev, putidx, M_CAN_FIFO_ID, id);
+
+ /* Construct the DLC Field, with CAN-FD configuration.
+ * Use the put index of fifo as message the marker,
+ * used in the TX interrupt for sending the correct echo frame.
+ */
/* get CAN FD configuration of frame */
fdflags = 0;
@@ -1646,21 +1649,14 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
if (cf->flags & CANFD_BRS)
fdflags |= TX_BUF_BRS;
}
-
- /* Construct DLC Field. Also contains CAN-FD configuration
- * use put index of fifo as message marker
- * it is used in TX interrupt for
- * sending the correct echo frame
- */
- m_can_fifo_write(cdev, putidx, M_CAN_FIFO_DLC,
- ((putidx << TX_BUF_MM_SHIFT) &
+ id_and_dlc[1] = ((putidx << TX_BUF_MM_SHIFT) &
TX_BUF_MM_MASK) |
(can_fd_len2dlc(cf->len) << 16) |
- fdflags | TX_BUF_EFC);
+ fdflags | TX_BUF_EFC;
- for (i = 0; i < cf->len; i += 4)
- m_can_fifo_write(cdev, putidx, M_CAN_FIFO_DATA(i / 4),
- *(u32 *)(cf->data + i));
+ /* Write the frame ID, DLC, and payload to the FIFO element. */
+ m_can_fifo_write(cdev, putidx, M_CAN_FIFO_ID, id_and_dlc, ARRAY_SIZE(id_and_dlc));
+ m_can_fifo_write(cdev, 0, M_CAN_FIFO_DATA, cf->data, DIV_ROUND_UP(cf->len, 4));
/* Push loopback echo.
* Will be looped back on TX interrupt based on message marker
diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h
index 2571ec1efec4..edf2477b064f 100644
--- a/drivers/net/can/m_can/m_can.h
+++ b/drivers/net/can/m_can/m_can.h
@@ -66,7 +66,7 @@ struct m_can_ops {
int (*write_reg)(struct m_can_classdev *cdev, int reg, int val);
int (*read_fifo)(struct m_can_classdev *cdev, int addr_offset, void *val, size_t val_count);
int (*write_fifo)(struct m_can_classdev *cdev, int addr_offset,
- int val);
+ const void *val, size_t val_count);
int (*init)(struct m_can_classdev *cdev);
};
diff --git a/drivers/net/can/m_can/m_can_pci.c b/drivers/net/can/m_can/m_can_pci.c
index 11614a635796..89cc3d41e952 100644
--- a/drivers/net/can/m_can/m_can_pci.c
+++ b/drivers/net/can/m_can/m_can_pci.c
@@ -57,11 +57,12 @@ static int iomap_write_reg(struct m_can_classdev *cdev, int reg, int val)
return 0;
}
-static int iomap_write_fifo(struct m_can_classdev *cdev, int offset, int val)
+static int iomap_write_fifo(struct m_can_classdev *cdev, int offset,
+ const void *val, size_t val_count)
{
struct m_can_pci_priv *priv = cdev_to_priv(cdev);
- writel(val, priv->base + offset);
+ iowrite32_rep(priv->base + offset, val, val_count);
return 0;
}
diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
index 94c82dd39076..40e5351c7f74 100644
--- a/drivers/net/can/m_can/m_can_platform.c
+++ b/drivers/net/can/m_can/m_can_platform.c
@@ -46,11 +46,12 @@ static int iomap_write_reg(struct m_can_classdev *cdev, int reg, int val)
return 0;
}
-static int iomap_write_fifo(struct m_can_classdev *cdev, int offset, int val)
+static int iomap_write_fifo(struct m_can_classdev *cdev, int offset,
+ const void *val, size_t val_count)
{
struct m_can_plat_priv *priv = cdev_to_priv(cdev);
- writel(val, priv->mram_base + offset);
+ iowrite32_rep(priv->base + offset, val, val_count);
return 0;
}
diff --git a/drivers/net/can/m_can/tcan4x5x-core.c b/drivers/net/can/m_can/tcan4x5x-core.c
index 4f77b1dbd492..89d2009c895b 100644
--- a/drivers/net/can/m_can/tcan4x5x-core.c
+++ b/drivers/net/can/m_can/tcan4x5x-core.c
@@ -170,11 +170,11 @@ static int tcan4x5x_write_reg(struct m_can_classdev *cdev, int reg, int val)
}
static int tcan4x5x_write_fifo(struct m_can_classdev *cdev,
- int addr_offset, int val)
+ int addr_offset, const void *val, size_t val_count)
{
struct tcan4x5x_priv *priv = cdev_to_priv(cdev);
- return regmap_write(priv->regmap, TCAN4X5X_MRAM_START + addr_offset, val);
+ return regmap_bulk_write(priv->regmap, TCAN4X5X_MRAM_START + addr_offset, val, val_count);
}
static int tcan4x5x_power_enable(struct regulator *reg, int enable)
--
2.31.1
