net: dwc: Make the cache handling less cryptic

Add a few new variables to make the cache handling less cryptic.
Add a variable for DMA and DATA descriptor start and end, so the
correctness of the code is easier to inspect.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chin Liang See <clsee@altera.com>
Cc: Dinh Nguyen <dinguyen@altera.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Tom Rini <trini@ti.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Pavel Machek <pavel@denx.de>
Cc: Joe Hershberger <joe.hershberger@gmail.com>
Acked-by: Pavel Machek <pavel@denx.de>
Acked-by: Chin Liang See <clsee@altera.com>

diff --git a/drivers/net/designware.c b/drivers/net/designware.c
index aaf146d444d4e166e651988af8d18934e15dd4c4..9ded8950b83d22aa6021ed8e81ee4141e6d85a23 100644 (file)
--- a/drivers/net/designware.c
+++ b/drivers/net/designware.c
@@ -279,19 +279,21 @@ static int dw_eth_send(struct eth_device *dev, void *packet, int length)
        struct eth_dma_regs *dma_p = priv->dma_regs_p;
        u32 desc_num = priv->tx_currdescnum;
        struct dmamacdescr *desc_p = &priv->tx_mac_descrtable[desc_num];
-
+       uint32_t desc_start = (uint32_t)desc_p;
+       uint32_t desc_end = desc_start +
+               roundup(sizeof(*desc_p), ARCH_DMA_MINALIGN);
+       uint32_t data_start = (uint32_t)desc_p->dmamac_addr;
+       uint32_t data_end = data_start +
+               roundup(length, ARCH_DMA_MINALIGN);
        /*
         * Strictly we only need to invalidate the "txrx_status" field
         * for the following check, but on some platforms we cannot
-        * invalidate only 4 bytes, so roundup to
-        * ARCH_DMA_MINALIGN. This is safe because the individual
-        * descriptors in the array are each aligned to
-        * ARCH_DMA_MINALIGN.
+        * invalidate only 4 bytes, so we flush the entire descriptor,
+        * which is 16 bytes in total. This is safe because the
+        * individual descriptors in the array are each aligned to
+        * ARCH_DMA_MINALIGN and padded appropriately.
         */
-       invalidate_dcache_range(
-               (unsigned long)desc_p,
-               (unsigned long)desc_p +
-               roundup(sizeof(desc_p->txrx_status), ARCH_DMA_MINALIGN));
+       invalidate_dcache_range(desc_start, desc_end);
 
        /* Check if the descriptor is owned by CPU */
        if (desc_p->txrx_status & DESC_TXSTS_OWNBYDMA) {
@@ -299,12 +301,10 @@ static int dw_eth_send(struct eth_device *dev, void *packet, int length)
                return -1;
        }
 
-       memcpy((void *)desc_p->dmamac_addr, packet, length);
+       memcpy(desc_p->dmamac_addr, packet, length);
 
        /* Flush data to be sent */
-       flush_dcache_range((unsigned long)desc_p->dmamac_addr,
-                          (unsigned long)desc_p->dmamac_addr +
-                          roundup(length, ARCH_DMA_MINALIGN));
+       flush_dcache_range(data_start, data_end);
 
 #if defined(CONFIG_DW_ALTDESCRIPTOR)
        desc_p->txrx_status |= DESC_TXSTS_TXFIRST | DESC_TXSTS_TXLAST;
@@ -322,8 +322,7 @@ static int dw_eth_send(struct eth_device *dev, void *packet, int length)
 #endif
 
        /* Flush modified buffer descriptor */
-       flush_dcache_range((unsigned long)desc_p,
-                          (unsigned long)desc_p + sizeof(struct dmamacdescr));
+       flush_dcache_range(desc_start, desc_end);
 
        /* Test the wrap-around condition. */
        if (++desc_num >= CONFIG_TX_DESCR_NUM)
@@ -343,11 +342,14 @@ static int dw_eth_recv(struct eth_device *dev)
        u32 status, desc_num = priv->rx_currdescnum;
        struct dmamacdescr *desc_p = &priv->rx_mac_descrtable[desc_num];
        int length = 0;
+       uint32_t desc_start = (uint32_t)desc_p;
+       uint32_t desc_end = desc_start +
+               roundup(sizeof(*desc_p), ARCH_DMA_MINALIGN);
+       uint32_t data_start = (uint32_t)desc_p->dmamac_addr;
+       uint32_t data_end;
 
        /* Invalidate entire buffer descriptor */
-       invalidate_dcache_range((unsigned long)desc_p,
-                               (unsigned long)desc_p +
-                               sizeof(struct dmamacdescr));
+       invalidate_dcache_range(desc_start, desc_end);
 
        status = desc_p->txrx_status;
 
@@ -358,9 +360,8 @@ static int dw_eth_recv(struct eth_device *dev)
                         DESC_RXSTS_FRMLENSHFT;
 
                /* Invalidate received data */
-               invalidate_dcache_range((unsigned long)desc_p->dmamac_addr,
-                                       (unsigned long)desc_p->dmamac_addr +
-                                       roundup(length, ARCH_DMA_MINALIGN));
+               data_end = data_start + roundup(length, ARCH_DMA_MINALIGN);
+               invalidate_dcache_range(data_start, data_end);
 
                NetReceive(desc_p->dmamac_addr, length);
 
@@ -371,10 +372,7 @@ static int dw_eth_recv(struct eth_device *dev)
                desc_p->txrx_status |= DESC_RXSTS_OWNBYDMA;
 
                /* Flush only status field - others weren't changed */
-               flush_dcache_range((unsigned long)&desc_p->txrx_status,
-                                  (unsigned long)&desc_p->txrx_status +
-                                       roundup(sizeof(desc_p->txrx_status),
-                                               ARCH_DMA_MINALIGN));
+               flush_dcache_range(desc_start, desc_end);
 
                /* Test the wrap-around condition. */
                if (++desc_num >= CONFIG_RX_DESCR_NUM)