From 96cec17d3cd22ca2251d6f7946409933a231ce6f Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Mon, 15 Sep 2014 01:05:23 +0200 Subject: 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 Cc: Chin Liang See Cc: Dinh Nguyen Cc: Albert Aribaud Cc: Tom Rini Cc: Wolfgang Denk Cc: Pavel Machek Cc: Joe Hershberger Acked-by: Pavel Machek Acked-by: Chin Liang See --- drivers/net/designware.c | 48 +++++++++++++++++++++++------------------------- 1 file changed, 23 insertions(+), 25 deletions(-) (limited to 'drivers') diff --git a/drivers/net/designware.c b/drivers/net/designware.c index aaf146d444d..9ded8950b83 100644 --- 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) -- cgit v1.2.3