net: rtl8169: Improve cache maintenance

Instead of directly calling the low-level invalidate_dcache_range() and
flush_cache() functions, provide thin wrappers that take into account
alignment requirements.

While at it, fix a case where the cache was flushed but should have been
invalidated, two cases where the buffer data was flushed instead of the
descriptor and a missing cache invalidation before reading the packet
data that the NIC just wrote to memory.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Patch: 276474

diff --git a/drivers/net/rtl8169.c b/drivers/net/rtl8169.c
index 290c9887c013105b96576be0cc8dec37acb0e28f..c47485a969cd1d009ed33bb0f5f641345649eb4c 100644 (file)
--- a/drivers/net/rtl8169.c
+++ b/drivers/net/rtl8169.c
@@ -395,6 +395,50 @@ match:
        return 0;
 }
 
+/*
+ * Cache maintenance functions. These are simple wrappers around the more
+ * general purpose flush_cache() and invalidate_dcache_range() functions.
+ */
+
+static void rtl_inval_rx_desc(struct RxDesc *desc)
+{
+       unsigned long start = (unsigned long)desc & ~(ARCH_DMA_MINALIGN - 1);
+       unsigned long end = ALIGN(start + sizeof(*desc), ARCH_DMA_MINALIGN);
+
+       invalidate_dcache_range(start, end);
+}
+
+static void rtl_flush_rx_desc(struct RxDesc *desc)
+{
+       flush_cache((unsigned long)desc, sizeof(*desc));
+}
+
+static void rtl_inval_tx_desc(struct TxDesc *desc)
+{
+       unsigned long start = (unsigned long)desc & ~(ARCH_DMA_MINALIGN - 1);
+       unsigned long end = ALIGN(start + sizeof(*desc), ARCH_DMA_MINALIGN);
+
+       invalidate_dcache_range(start, end);
+}
+
+static void rtl_flush_tx_desc(struct TxDesc *desc)
+{
+       flush_cache((unsigned long)desc, sizeof(*desc));
+}
+
+static void rtl_inval_buffer(void *buf, size_t size)
+{
+       unsigned long start = (unsigned long)buf & ~(ARCH_DMA_MINALIGN - 1);
+       unsigned long end = ALIGN(start + size, ARCH_DMA_MINALIGN);
+
+       invalidate_dcache_range(start, end);
+}
+
+static void rtl_flush_buffer(void *buf, size_t size)
+{
+       flush_cache((unsigned long)buf, size);
+}
+
 /**************************************************************************
 RECV - Receive a frame
 ***************************************************************************/
@@ -412,14 +456,16 @@ static int rtl_recv(struct eth_device *dev)
        ioaddr = dev->iobase;
 
        cur_rx = tpc->cur_rx;
-       flush_cache((unsigned long)&tpc->RxDescArray[cur_rx],
-                       sizeof(struct RxDesc));
+
+       rtl_inval_rx_desc(&tpc->RxDescArray[cur_rx]);
+
        if ((le32_to_cpu(tpc->RxDescArray[cur_rx].status) & OWNbit) == 0) {
                if (!(le32_to_cpu(tpc->RxDescArray[cur_rx].status) & RxRES)) {
                        unsigned char rxdata[RX_BUF_LEN];
                        length = (int) (le32_to_cpu(tpc->RxDescArray[cur_rx].
                                                status) & 0x00001FFF) - 4;
 
+                       rtl_inval_buffer(tpc->RxBufferRing[cur_rx], length);
                        memcpy(rxdata, tpc->RxBufferRing[cur_rx], length);
                        NetReceive(rxdata, length);
 
@@ -431,8 +477,7 @@ static int rtl_recv(struct eth_device *dev)
                                        cpu_to_le32(OWNbit + RX_BUF_SIZE);
                        tpc->RxDescArray[cur_rx].buf_addr =
                                cpu_to_le32(bus_to_phys(tpc->RxBufferRing[cur_rx]));
-                       flush_cache((unsigned long)tpc->RxBufferRing[cur_rx],
-                                       RX_BUF_SIZE);
+                       rtl_flush_rx_desc(&tpc->RxDescArray[cur_rx]);
                } else {
                        puts("Error Rx");
                }
@@ -474,7 +519,7 @@ static int rtl_send(struct eth_device *dev, void *packet, int length)
        /* point to the current txb incase multiple tx_rings are used */
        ptxb = tpc->Tx_skbuff[entry * MAX_ETH_FRAME_SIZE];
        memcpy(ptxb, (char *)packet, (int)length);
-       flush_cache((unsigned long)ptxb, length);
+       rtl_flush_buffer(ptxb, length);
 
        while (len < ETH_ZLEN)
                ptxb[len++] = '\0';
@@ -490,13 +535,13 @@ static int rtl_send(struct eth_device *dev, void *packet, int length)
                        cpu_to_le32((OWNbit | EORbit | FSbit | LSbit) |
                                    ((len > ETH_ZLEN) ? len : ETH_ZLEN));
        }
+       rtl_flush_tx_desc(&tpc->TxDescArray[entry]);
        RTL_W8(TxPoll, 0x40);   /* set polling bit */
 
        tpc->cur_tx++;
        to = currticks() + TX_TIMEOUT;
        do {
-               flush_cache((unsigned long)&tpc->TxDescArray[entry],
-                               sizeof(struct TxDesc));
+               rtl_inval_tx_desc(&tpc->TxDescArray[entry]);
        } while ((le32_to_cpu(tpc->TxDescArray[entry].status) & OWNbit)
                                && (currticks() < to)); /* wait */
 
@@ -639,7 +684,7 @@ static void rtl8169_init_ring(struct eth_device *dev)
                tpc->RxBufferRing[i] = &rxb[i * RX_BUF_SIZE];
                tpc->RxDescArray[i].buf_addr =
                        cpu_to_le32(bus_to_phys(tpc->RxBufferRing[i]));
-               flush_cache((unsigned long)tpc->RxBufferRing[i], RX_BUF_SIZE);
+               rtl_flush_rx_desc(&tpc->RxDescArray[i]);
        }
 
 #ifdef DEBUG_RTL8169