realtek: eth: rename ring steering bits

A network interface card (NIC) hardware ring of the Realtek Otto switch
SoCs is nothing more than a list of pointers to the ring headers. I.E.

address | content   | comment
--------+-----------+------------------------
x + 0   | pointer 0 | points to ring header 0
x + 4   | pointer 1 | points to ring header 1
...
x + 4*n | pointer n | points to ring header n

Headers must be 4 byte aligend. So the lower two bits of the pointers
are unused. Hardware designers desided to give them special meanings.

- Bit 0: Owner of this ring entry, 1 = hardware, 0 = software
- Bit 1: Wrap, 1 = last ring pointer, 0 = normal ring pointer

The driver uses constant defines with slightly confusing naming. Replace
OWN_CPU with OWN_HW to make clear what it is about. Align prefix and
make the defines bitmasks for better readability.

Link: https://github.com/openwrt/openwrt/pull/23676
Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>

diff --git a/target/linux/realtek/files-6.18/drivers/net/ethernet/rtl838x_eth.c b/target/linux/realtek/files-6.18/drivers/net/ethernet/rtl838x_eth.c
index bd9b9365a3ac8a96c41e78356d3635336cbc9709..06fe6f7ed05b5c258f9e9e8ec4378c6ee57ca55a 100644 (file)
--- a/target/linux/realtek/files-6.18/drivers/net/ethernet/rtl838x_eth.c
+++ b/target/linux/realtek/files-6.18/drivers/net/ethernet/rtl838x_eth.c
@@ -26,8 +26,10 @@
 
 #include "rtl838x_eth.h"
 
+#define RING_OWN_HW                    BIT(0)
+#define RING_WRAP                      BIT(1)
+
 #define RTETH_SKB_HEADROOM             (NET_SKB_PAD + NET_IP_ALIGN)
-#define RTETH_OWN_CPU                  1
 #define RTETH_RX_RING_SIZE             128
 #define RTETH_RX_RINGS                 2
 #define RTETH_TX_RING_SIZE             16
@@ -39,7 +41,6 @@
 #define RX_TRUNCATE_EN_93XX            BIT(6)
 #define RX_TRUNCATE_EN_83XX            BIT(4)
 #define TX_PAD_EN_838X                 BIT(5)
-#define WRAP                           0x2
 #define RING_BUFFER                    1600
 
 /* Define page pool that holds 2KB fragments in 4KB pages and has 8 safety pages */
@@ -681,10 +682,10 @@ static int rteth_setup_ring_buffer(struct rteth_ctrl *ctrl)
                                                   sizeof(struct rteth_rx) * r +
                                                   offsetof(struct rteth_rx, packet) +
                                                   sizeof(struct rteth_packet) * i +
-                                                  RTETH_OWN_CPU;
+                                                  RING_OWN_HW;
                }
 
-               ctrl->rx_data[r].ring[RTETH_RX_RING_SIZE - 1] |= WRAP;
+               ctrl->rx_data[r].ring[RTETH_RX_RING_SIZE - 1] |= RING_WRAP;
                ctrl->rx_data[r].slot = 0;
        }
 
@@ -697,7 +698,7 @@ static int rteth_setup_ring_buffer(struct rteth_ctrl *ctrl)
                                                   sizeof(struct rteth_packet) * i;
                }
 
-               ctrl->tx_data[r].ring[RTETH_TX_RING_SIZE - 1] |= WRAP;
+               ctrl->tx_data[r].ring[RTETH_TX_RING_SIZE - 1] |= RING_WRAP;
                ctrl->tx_data[r].slot = 0;
        }
 
@@ -714,7 +715,8 @@ static void rteth_839x_setup_notify_ring_buffer(struct rteth_ctrl *ctrl)
        struct notify_b *b = ctrl->membase;
 
        for (int i = 0; i < NOTIFY_BLOCKS; i++)
-               b->ring[i] = KSEG1ADDR(&b->blocks[i]) | 1 | (i == (NOTIFY_BLOCKS - 1) ? WRAP : 0);
+               b->ring[i] = KSEG1ADDR(&b->blocks[i]) | RING_OWN_HW;
+       b->ring[NOTIFY_BLOCKS - 1] |= RING_WRAP;
 
        regmap_write(ctrl->map, RTL839X_DMA_IF_NBUF_BASE_DESC_ADDR_CTRL, (u32)b->ring);
        regmap_update_bits(ctrl->map, RTL839X_L2_NOTIFICATION_CTRL, 0x3ff << 2, 100 << 2);
@@ -1031,7 +1033,7 @@ static int rteth_start_xmit(struct sk_buff *skb, struct net_device *dev)
        packet = &ctrl->tx_data[ring].packet[slot];
        packet_dma = ctrl->tx_data[ring].ring[slot];
 
-       if (unlikely(packet_dma & RTETH_OWN_CPU)) {
+       if (unlikely(packet_dma & RING_OWN_HW)) {
                netif_stop_subqueue(dev, ring);
                if (net_ratelimit())
                        netdev_warn(dev, "tx ring %d busy, waiting for slot %d\n", ring, slot);
@@ -1061,7 +1063,7 @@ static int rteth_start_xmit(struct sk_buff *skb, struct net_device *dev)
        packet->len = len;
        packet->skb = skb;
        dma_wmb();
-       ctrl->tx_data[ring].ring[slot] = packet_dma | RTETH_OWN_CPU;
+       ctrl->tx_data[ring].ring[slot] = packet_dma | RING_OWN_HW;
        ctrl->tx_data[ring].slot = (slot + 1) % RTETH_TX_RING_SIZE;
        wmb();
 
@@ -1103,7 +1105,7 @@ static int rteth_hw_receive(struct net_device *dev, int ring, int budget)
                packet_dma = ctrl->rx_data[ring].ring[slot];
                rmb();
 
-               if (packet_dma & RTETH_OWN_CPU)
+               if (packet_dma & RING_OWN_HW)
                        break;
 
                packet = &ctrl->rx_data[ring].packet[slot];
@@ -1170,7 +1172,7 @@ static int rteth_hw_receive(struct net_device *dev, int ring, int budget)
 
 recycle:
                dma_wmb();
-               ctrl->rx_data[ring].ring[slot] = packet_dma | RTETH_OWN_CPU;
+               ctrl->rx_data[ring].ring[slot] = packet_dma | RING_OWN_HW;
                ctrl->rx_data[ring].slot = (slot + 1) % RTETH_RX_RING_SIZE;
                work_done++;
        }