[PATCH 3/6] net: calxedaxgmac: use relaxed i/o accessors in rx and tx paths

Rob Herring
2012-10-12T15:15:42Z

The standard readl/writel accessors involve a spinlock and cache sync
operation on ARM platforms with an outer cache. Only DMA triggering
accesses need this, so use the relaxed variants instead.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
drivers/net/ethernet/calxeda/Kconfig | 2 +-
drivers/net/ethernet/calxeda/xgmac.c | 12 ++++++------
2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/calxeda/Kconfig b/drivers/net/ethernet/calxeda/Kconfig
index aba435c..6a4ddf6 100644
--- a/drivers/net/ethernet/calxeda/Kconfig
+++ b/drivers/net/ethernet/calxeda/Kconfig
@@ -1,6 +1,6 @@
config NET_CALXEDA_XGMAC
tristate "Calxeda 1G/10G XGMAC Ethernet driver"
- depends on HAS_IOMEM
+ depends on HAS_IOMEM && ARM
select CRC32
help
This is the driver for the XGMAC Ethernet IP block found on Calxeda
diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index 728fcef..117839e 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -1203,7 +1203,7 @@ static int xgmac_poll(struct napi_struct *napi, int budget)

if (work_done < budget) {
napi_complete(napi);
- writel(DMA_INTR_DEFAULT_MASK, priv->base + XGMAC_DMA_INTR_ENA);
+ writel_relaxed(DMA_INTR_DEFAULT_MASK, priv->base + XGMAC_DMA_INTR_ENA);
}
return work_done;
}
@@ -1348,7 +1348,7 @@ static irqreturn_t xgmac_pmt_interrupt(int irq, void *dev_id)
struct xgmac_priv *priv = netdev_priv(dev);
void __iomem *ioaddr = priv->base;

- intr_status = readl(ioaddr + XGMAC_INT_STAT);
+ intr_status = readl_relaxed(ioaddr + XGMAC_INT_STAT);
if (intr_status & XGMAC_INT_STAT_PMT) {
netdev_dbg(priv->dev, "received Magic frame\n");
/* clear the PMT bits 5 and 6 by reading the PMT */
@@ -1366,9 +1366,9 @@ static irqreturn_t xgmac_interrupt(int irq, void *dev_id)
struct xgmac_extra_stats *x = &priv->xstats;

/* read the status register (CSR5) */
- intr_status = readl(priv->base + XGMAC_DMA_STATUS);
- intr_status &= readl(priv->base + XGMAC_DMA_INTR_ENA);
- writel(intr_status, priv->base + XGMAC_DMA_STATUS);
+ intr_status = readl_relaxed(priv->base + XGMAC_DMA_STATUS);
+ intr_status &= readl_relaxed(priv->base + XGMAC_DMA_INTR_ENA);
+ writel_relaxed(intr_status, priv->base + XGMAC_DMA_STATUS);

/* It displays the DMA process states (CSR5 register) */
/* ABNORMAL interrupts */
@@ -1404,7 +1404,7 @@ static irqreturn_t xgmac_interrupt(int irq, void *dev_id)

/* TX/RX NORMAL interrupts */
if (intr_status & (DMA_STATUS_RI | DMA_STATUS_TU)) {
- writel(DMA_INTR_ABNORMAL, priv->base + XGMAC_DMA_INTR_ENA);
+ writel_relaxed(DMA_INTR_ABNORMAL, priv->base + XGMAC_DMA_INTR_ENA);
napi_schedule(&priv->napi);
}

--
1.7.9.5