[PATCH RFC wireless-next 1/3] wifi: b43: set the DMA burst and prefetch bits of core revisions 40 and 42

[Andreas Wendleder <gonsolo@gmail.com>]

The DMA engines of the core revisions 40 and 42 (BCM4352, BCM4360) need
the burst length and prefetch bits of the TX and RX control words that the
vendor driver sets (0x03780040 and 0x036c0000). Without them the engine
moves about 6 MB/s and every link tops out near 50 Mbit/s.

Add b43_is_ac_core() for these core revisions.
Signed-off-by: Andreas Wendleder <gonsolo@gmail.com>
---
 drivers/net/wireless/broadcom/b43/b43.h | 6 ++++++
 drivers/net/wireless/broadcom/b43/dma.c | 4 ++++
 drivers/net/wireless/broadcom/b43/dma.h | 2 ++
 3 files changed, 12 insertions(+)

diff --git a/drivers/net/wireless/broadcom/b43/b43.h b/drivers/net/wireless/broadcom/b43/b43.h
index e1e8083..80b299b 100644
--- a/drivers/net/wireless/broadcom/b43/b43.h
+++ b/drivers/net/wireless/broadcom/b43/b43.h
@@ -1001,6 +1001,12 @@ static inline enum nl80211_band b43_current_band(struct b43_wl *wl)
 	return wl->hw->conf.chandef.chan->band;
 }
 
+/* MAC core of the BCM4352 and BCM4360 (core revisions 40 and 42). */
+static inline bool b43_is_ac_core(struct b43_wldev *dev)
+{
+	return dev->dev->core_rev == 40 || dev->dev->core_rev == 42;
+}
+
 static inline int b43_bus_may_powerdown(struct b43_wldev *wldev)
 {
 	return wldev->dev->bus_may_powerdown(wldev->dev);
diff --git a/drivers/net/wireless/broadcom/b43/dma.c b/drivers/net/wireless/broadcom/b43/dma.c
index 5e1b30a..5f968b0 100644
--- a/drivers/net/wireless/broadcom/b43/dma.c
+++ b/drivers/net/wireless/broadcom/b43/dma.c
@@ -691,6 +691,8 @@ static int dmacontroller_setup(struct b43_dmaring *ring)
 			    & B43_DMA64_TXADDREXT_MASK;
 			if (!parity)
 				value |= B43_DMA64_TXPARITYDISABLE;
+			if (b43_is_ac_core(ring->dev))
+				value |= B43_DMA64_TXCTL_AC;
 			if (ring->dev->dma.ptr_is_addr) {
 				ring->ptr_base = lower_32_bits(ring->dmabase);
 				value |= b43_dma_read(ring, B43_DMA64_TXCTL) &
@@ -733,6 +735,8 @@ static int dmacontroller_setup(struct b43_dmaring *ring)
 			    & B43_DMA64_RXADDREXT_MASK;
 			if (!parity)
 				value |= B43_DMA64_RXPARITYDISABLE;
+			if (b43_is_ac_core(ring->dev))
+				value |= B43_DMA64_RXCTL_AC;
 			if (ring->dev->dma.ptr_is_addr) {
 				ring->ptr_base = lower_32_bits(ring->dmabase);
 				value |= b43_dma_read(ring, B43_DMA64_RXCTL) &
diff --git a/drivers/net/wireless/broadcom/b43/dma.h b/drivers/net/wireless/broadcom/b43/dma.h
index eddc882..14de4cb 100644
--- a/drivers/net/wireless/broadcom/b43/dma.h
+++ b/drivers/net/wireless/broadcom/b43/dma.h
@@ -91,6 +91,7 @@ struct b43_dmadesc32 {
 #define		B43_DMA64_TXADDREXT_MASK		0x00030000
 #define		B43_DMA64_TXADDREXT_SHIFT		16
 #define B43_DMA64_TXCTL_KEEP				0x03FC00C0
+#define B43_DMA64_TXCTL_AC				0x03780040
 #define B43_DMA64_TXINDEX				0x04
 #define B43_DMA64_TXRINGLO				0x08
 #define B43_DMA64_TXRINGHI				0x0C
@@ -120,6 +121,7 @@ struct b43_dmadesc32 {
 #define		B43_DMA64_RXADDREXT_MASK		0x00030000
 #define		B43_DMA64_RXADDREXT_SHIFT		16
 #define B43_DMA64_RXCTL_KEEP				0x03FC0000
+#define B43_DMA64_RXCTL_AC				0x036c0000
 #define B43_DMA64_RXINDEX				0x24
 #define B43_DMA64_RXRINGLO				0x28
 #define B43_DMA64_RXRINGHI				0x2C