[14/30] net: eepro100: Add cache management

Add cache invalidation and flushes wherever the DMA descriptors are
written or read, otherwise this driver cannot work reliably on any
systems where caches are enabled.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
---
 drivers/net/eepro100.c | 65 +++++++++++++++++++++++++++++-------------
 1 file changed, 45 insertions(+), 20 deletions(-)

On Sat, May 23, 2020 at 7:43 PM Marek Vasut <marek.vasut@gmail.com> wrote:
>
> Add cache invalidation and flushes wherever the DMA descriptors are
> written or read, otherwise this driver cannot work reliably on any
> systems where caches are enabled.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
> ---
>  drivers/net/eepro100.c | 65 +++++++++++++++++++++++++++++-------------
>  1 file changed, 45 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/net/eepro100.c b/drivers/net/eepro100.c
> index 03ba9a41a5..89bfcfba0a 100644
> --- a/drivers/net/eepro100.c
> +++ b/drivers/net/eepro100.c
> @@ -5,6 +5,7 @@
>   */
>
>  #include <common.h>
> +#include <cpu_func.h>
>  #include <malloc.h>
>  #include <net.h>
>  #include <netdev.h>
> @@ -459,6 +460,9 @@ static int eepro100_txcmd_send(struct eth_device *dev,
>         u16 rstat;
>         int i = 0;
>
> +       flush_dcache_range((unsigned long)desc,
> +                          (unsigned long)desc + sizeof(*desc));
> +
>         if (!wait_for_eepro100(dev))
>                 return -ETIMEDOUT;
>
> @@ -466,6 +470,8 @@ static int eepro100_txcmd_send(struct eth_device *dev,
>         OUTW(dev, SCB_M | CU_START, SCB_CMD);
>
>         while (true) {
> +               invalidate_dcache_range((unsigned long)desc,
> +                                       (unsigned long)desc + sizeof(*desc));
>                 rstat = le16_to_cpu(desc->status);
>                 if (rstat & CONFIG_SYS_STATUS_C)
>                         break;
> @@ -476,6 +482,8 @@ static int eepro100_txcmd_send(struct eth_device *dev,
>                 }
>         }
>
> +       invalidate_dcache_range((unsigned long)desc,
> +                               (unsigned long)desc + sizeof(*desc));
>         rstat = le16_to_cpu(desc->status);
>
>         if (!(rstat & CONFIG_SYS_STATUS_OK)) {
> @@ -523,6 +531,7 @@ static int eepro100_init(struct eth_device *dev, bd_t *bis)
>                 goto done;
>         }
>
> +       /* RX ring cache was already flushed in init_rx_ring() */
>         OUTL(dev, phys_to_bus((u32)&rx_ring[rx_next]), SCB_POINTER);
>         OUTW(dev, SCB_M | RUC_START, SCB_CMD);
>
> @@ -573,6 +582,7 @@ done:
>
>  static int eepro100_send(struct eth_device *dev, void *packet, int length)
>  {
> +       struct eepro100_txfd *desc;
>         int ret, status = -1;
>         int tx_cur;
>
> @@ -584,17 +594,15 @@ static int eepro100_send(struct eth_device *dev, void *packet, int length)
>         tx_cur = tx_next;
>         tx_next = (tx_next + 1) % NUM_TX_DESC;
>
> -       tx_ring[tx_cur].command = cpu_to_le16(TXCB_CMD_TRANSMIT | TXCB_CMD_SF |
> -                                             TXCB_CMD_S | TXCB_CMD_EL);
> -       tx_ring[tx_cur].status = 0;
> -       tx_ring[tx_cur].count = cpu_to_le32 (tx_threshold);
> -       tx_ring[tx_cur].link =
> -               cpu_to_le32 (phys_to_bus((u32)&tx_ring[tx_next]));
> -       tx_ring[tx_cur].tx_desc_addr =
> -               cpu_to_le32 (phys_to_bus((u32)&tx_ring[tx_cur].tx_buf_addr0));
> -       tx_ring[tx_cur].tx_buf_addr0 =
> -               cpu_to_le32 (phys_to_bus((u_long)packet));
> -       tx_ring[tx_cur].tx_buf_size0 = cpu_to_le32 (length);
> +       desc = &tx_ring[tx_cur];
> +       desc->command = cpu_to_le16(TXCB_CMD_TRANSMIT | TXCB_CMD_SF |
> +                                   TXCB_CMD_S | TXCB_CMD_EL);
> +       desc->status = 0;
> +       desc->count = cpu_to_le32(tx_threshold);
> +       desc->link = cpu_to_le32(phys_to_bus((u32)&tx_ring[tx_next]));
> +       desc->tx_desc_addr = cpu_to_le32(phys_to_bus((u32)&desc->tx_buf_addr0));
> +       desc->tx_buf_addr0 = cpu_to_le32(phys_to_bus((u_long)packet));
> +       desc->tx_buf_size0 = cpu_to_le32(length);
>
>         ret = eepro100_txcmd_send(dev, &tx_ring[tx_cur]);
>         if (ret) {
> @@ -612,14 +620,18 @@ done:
>
>  static int eepro100_recv(struct eth_device *dev)
>  {
> -       u16 status, stat;
> +       struct eepro100_rxfd *desc;
>         int rx_prev, length = 0;
> +       u16 status, stat;
>
>         stat = INW(dev, SCB_STATUS);
>         OUTW(dev, stat & SCB_STATUS_RNR, SCB_STATUS);
>
>         for (;;) {
> -               status = le16_to_cpu(rx_ring[rx_next].status);
> +               desc = &rx_ring[rx_next];
> +               invalidate_dcache_range((unsigned long)desc,
> +                                       (unsigned long)desc + sizeof(*desc));
> +               status = le16_to_cpu(desc->status);
>
>                 if (!(status & RFD_STATUS_C))
>                         break;
> @@ -627,22 +639,26 @@ static int eepro100_recv(struct eth_device *dev)
>                 /* Valid frame status. */
>                 if ((status & RFD_STATUS_OK)) {
>                         /* A valid frame received. */
> -                       length = le32_to_cpu(rx_ring[rx_next].count) & 0x3fff;
> +                       length = le32_to_cpu(desc->count) & 0x3fff;
>
>                         /* Pass the packet up to the protocol layers. */
> -                       net_process_received_packet((u8 *)rx_ring[rx_next].data,
> -                                                   length);
> +                       net_process_received_packet((u8 *)desc->data, length);
>                 } else {
>                         /* There was an error. */
>                         printf("RX error status = 0x%08X\n", status);
>                 }
>
> -               rx_ring[rx_next].control = cpu_to_le16 (RFD_CONTROL_S);
> -               rx_ring[rx_next].status = 0;
> -               rx_ring[rx_next].count = cpu_to_le32 (PKTSIZE_ALIGN << 16);
> +               desc->control = cpu_to_le16(RFD_CONTROL_S);
> +               desc->status = 0;
> +               desc->count = cpu_to_le32(PKTSIZE_ALIGN << 16);
> +               flush_dcache_range((unsigned long)desc,
> +                                  (unsigned long)desc + sizeof(*desc));
>
>                 rx_prev = (rx_next + NUM_RX_DESC - 1) % NUM_RX_DESC;
> -               rx_ring[rx_prev].control = 0;
> +               desc = &rx_ring[rx_prev];
> +               desc->control = 0;
> +               flush_dcache_range((unsigned long)desc,
> +                                  (unsigned long)desc + sizeof(*desc));
>
>                 /* Update entry information. */
>                 rx_next = (rx_next + 1) % NUM_RX_DESC;
> @@ -659,6 +675,7 @@ static int eepro100_recv(struct eth_device *dev)
>                         goto done;
>                 }
>
> +               /* RX ring cache was already flushed in init_rx_ring() */
>                 OUTL(dev, phys_to_bus((u32)&rx_ring[rx_next]), SCB_POINTER);
>                 OUTW(dev, SCB_M | RUC_START, SCB_CMD);
>         }
> @@ -744,6 +761,10 @@ static void init_rx_ring(struct eth_device *dev)
>                 rx_ring[i].count = cpu_to_le32(PKTSIZE_ALIGN << 16);
>         }
>
> +       flush_dcache_range((unsigned long)rx_ring,
> +                          (unsigned long)rx_ring +
> +                          (sizeof(*rx_ring) * NUM_RX_DESC));
> +
>         rx_next = 0;
>  }
>
> @@ -752,6 +773,10 @@ static void purge_tx_ring(struct eth_device *dev)
>         tx_next = 0;
>         tx_threshold = 0x01208000;
>         memset(tx_ring, 0, sizeof(*tx_ring) * NUM_TX_DESC);
> +
> +       flush_dcache_range((unsigned long)tx_ring,
> +                          (unsigned long)tx_ring +
> +                          (sizeof(*tx_ring) * NUM_TX_DESC));
>  }
>
>  static void read_hw_addr(struct eth_device *dev, bd_t *bis)
> --
> 2.25.1
>
Reviewed-By: Ramon Fried <rfried.dev@gmail.com>