[PATCH] net/macb: GEM DMA configuration register update

From: Nicolas Ferre
Date: Fri Nov 23 2012 - 08:48:54 EST


Add information to the DMA Configuration Register to
maximize system performance:
- rx/tx packet buffer full memory size
- allow possibility to use INCR16 if supported

Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
---
drivers/net/ethernet/cadence/macb.c | 10 ++++++++--
drivers/net/ethernet/cadence/macb.h | 11 +++++++++++
2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
index cc6e593..6a59bce 100644
--- a/drivers/net/ethernet/cadence/macb.c
+++ b/drivers/net/ethernet/cadence/macb.c
@@ -1033,8 +1033,12 @@ static u32 macb_dbw(struct macb *bp)
}

/*
- * Configure the receive DMA engine to use the correct receive buffer size.
- * This is a configurable parameter for GEM.
+ * Configure the receive DMA engine
+ * - use the correct receive buffer size
+ * - set the possibility to use INCR16 bursts
+ * (if not supported by FIFO, it will fallback to default)
+ * - set both rx/tx packet buffers to full memory size
+ * These are configurable parameters for GEM.
*/
static void macb_configure_dma(struct macb *bp)
{
@@ -1043,6 +1047,8 @@ static void macb_configure_dma(struct macb *bp)
if (macb_is_gem(bp)) {
dmacfg = gem_readl(bp, DMACFG) & ~GEM_BF(RXBS, -1L);
dmacfg |= GEM_BF(RXBS, RX_BUFFER_SIZE / 64);
+ dmacfg |= GEM_BF(FBLDO, 16);
+ dmacfg |= GEM_BIT(TXPBMS) | GEM_BF(RXBMS, -1L);
gem_writel(bp, DMACFG, dmacfg);
}
}
diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index 4414421..570908b 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -171,8 +171,19 @@
#define GEM_DBW128 2

/* Bitfields in DMACFG. */
+#define GEM_FBLDO_OFFSET 0
+#define GEM_FBLDO_SIZE 5
+#define GEM_RXBMS_OFFSET 8
+#define GEM_RXBMS_SIZE 2
+#define GEM_TXPBMS_OFFSET 10
+#define GEM_TXPBMS_SIZE 1
+#define GEM_TXCOEN_OFFSET 11
+#define GEM_TXCOEN_SIZE 1
#define GEM_RXBS_OFFSET 16
#define GEM_RXBS_SIZE 8
+#define GEM_DDRP_OFFSET 24
+#define GEM_DDRP_SIZE 1
+

/* Bitfields in NSR */
#define MACB_NSR_LINK_OFFSET 0
--
1.8.0

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