net/macb: increase RX buffer size for GEM

Macb Ethernet controller requires a RX buffer of 128 bytes. It is highly sub-optimal for Gigabit-capable GEM that is able to use a bigger DMA buffer. Change this constant and associated macros with data stored in the private structure. RX DMA buffer size has to be multiple of 64 bytes as indicated in DMA Configuration Register specification. Signed-off-by: Ramon Fried <rfried.dev@gmail.com> Acked-by: Joe Hershberger <joe.hershberger@ni.com>

net/macb: increase RX buffer size for GEM
Macb Ethernet controller requires a RX buffer of 128 bytes. It is highly sub-optimal for Gigabit-capable GEM that is able to use a bigger DMA buffer. Change this constant and associated macros with data stored in the private structure. RX DMA buffer size has to be multiple of 64 bytes as indicated in DMA Configuration Register specification. Signed-off-by: Ramon Fried <rfried.dev@gmail.com> Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Ramon Fried · Joe Hershberger · Eric Lee · Eric Lee · Eric Lee · Eric Lee
1 parent 9c29580720
Showing 1 changed file with 23 additions and 8 deletions Side-by-side Diff
drivers/net/macb.c
@@ -45,10 +45,17 @@
  
 DECLARE_GLOBAL_DATA_PTR;
  
-#define MACB_RX_BUFFER_SIZE		4096
-#define MACB_RX_RING_SIZE		(MACB_RX_BUFFER_SIZE / 128)
+/*
+ * These buffer sizes must be power of 2 and divisible
+ * by RX_BUFFER_MULTIPLE
+ */
+#define MACB_RX_BUFFER_SIZE		128
+#define GEM_RX_BUFFER_SIZE		2048
 #define RX_BUFFER_MULTIPLE		64
+
+#define MACB_RX_RING_SIZE		32
 #define MACB_TX_RING_SIZE		16
+
 #define MACB_TX_TIMEOUT		1000
 #define MACB_AUTONEG_TIMEOUT	5000000
  
@@ -95,6 +102,7 @@
 	void			*tx_buffer;
 	struct macb_dma_desc	*rx_ring;
 	struct macb_dma_desc	*tx_ring;
+	size_t			rx_buffer_size;
  
 	unsigned long		rx_buffer_dma;
 	unsigned long		rx_ring_dma;
  
@@ -395,15 +403,16 @@
 		}
  
 		if (status & MACB_BIT(RX_EOF)) {
-			buffer = macb->rx_buffer + 128 * macb->rx_tail;
+			buffer = macb->rx_buffer +
+				macb->rx_buffer_size * macb->rx_tail;
 			length = status & RXBUF_FRMLEN_MASK;
  
 			macb_invalidate_rx_buffer(macb);
 			if (macb->wrapped) {
 				unsigned int headlen, taillen;
  
-				headlen = 128 * (MACB_RX_RING_SIZE
-						 - macb->rx_tail);
+				headlen = macb->rx_buffer_size *
+					(MACB_RX_RING_SIZE - macb->rx_tail);
 				taillen = length - headlen;
 				memcpy((void *)net_rx_packets[0],
 				       buffer, headlen);
@@ -703,7 +712,7 @@
 	u32 buffer_size;
 	u32 dmacfg;
  
-	buffer_size = 128 / RX_BUFFER_MULTIPLE;
+	buffer_size = macb->rx_buffer_size / RX_BUFFER_MULTIPLE;
 	dmacfg = gem_readl(macb, DMACFG) & ~GEM_BF(RXBS, -1L);
 	dmacfg |= GEM_BF(RXBS, buffer_size);
  
@@ -748,7 +757,7 @@
 			paddr |= MACB_BIT(RX_WRAP);
 		macb->rx_ring[i].addr = paddr;
 		macb->rx_ring[i].ctrl = 0;
-		paddr += 128;
+		paddr += macb->rx_buffer_size;
 	}
 	macb_flush_ring_desc(macb, RX);
 	macb_flush_rx_buffer(macb);
  
@@ -959,8 +968,14 @@
 	int id = 0;	/* This is not used by functions we call */
 	u32 ncfgr;
  
+	if (macb_is_gem(macb))
+		macb->rx_buffer_size = GEM_RX_BUFFER_SIZE;
+	else
+		macb->rx_buffer_size = MACB_RX_BUFFER_SIZE;
+
 	/* TODO: we need check the rx/tx_ring_dma is dcache line aligned */
-	macb->rx_buffer = dma_alloc_coherent(MACB_RX_BUFFER_SIZE,
+	macb->rx_buffer = dma_alloc_coherent(macb->rx_buffer_size *
+					     MACB_RX_RING_SIZE,
 					     &macb->rx_buffer_dma);
 	macb->rx_ring = dma_alloc_coherent(MACB_RX_DMA_DESC_SIZE,
 					   &macb->rx_ring_dma);
...	...	@@ -45,10 +45,17 @@
45	45
46	46	DECLARE_GLOBAL_DATA_PTR;
47	47
48		-#define MACB_RX_BUFFER_SIZE 4096
49		-#define MACB_RX_RING_SIZE (MACB_RX_BUFFER_SIZE / 128)
	48	+/*
	49	+ * These buffer sizes must be power of 2 and divisible
	50	+ * by RX_BUFFER_MULTIPLE
	51	+ */
	52	+#define MACB_RX_BUFFER_SIZE 128
	53	+#define GEM_RX_BUFFER_SIZE 2048
50	54	#define RX_BUFFER_MULTIPLE 64
	55	+
	56	+#define MACB_RX_RING_SIZE 32
51	57	#define MACB_TX_RING_SIZE 16
	58	+
52	59	#define MACB_TX_TIMEOUT 1000
53	60	#define MACB_AUTONEG_TIMEOUT 5000000
54	61
...	...	@@ -95,6 +102,7 @@
95	102	void *tx_buffer;
96	103	struct macb_dma_desc *rx_ring;
97	104	struct macb_dma_desc *tx_ring;
	105	+ size_t rx_buffer_size;
98	106
99	107	unsigned long rx_buffer_dma;
100	108	unsigned long rx_ring_dma;
101	109
...	...	@@ -395,15 +403,16 @@
395	403	}
396	404
397	405	if (status & MACB_BIT(RX_EOF)) {
398		- buffer = macb->rx_buffer + 128 * macb->rx_tail;
	406	+ buffer = macb->rx_buffer +
	407	+ macb->rx_buffer_size * macb->rx_tail;
399	408	length = status & RXBUF_FRMLEN_MASK;
400	409
401	410	macb_invalidate_rx_buffer(macb);
402	411	if (macb->wrapped) {
403	412	unsigned int headlen, taillen;
404	413
405		- headlen = 128 * (MACB_RX_RING_SIZE
406		- - macb->rx_tail);
	414	+ headlen = macb->rx_buffer_size *
	415	+ (MACB_RX_RING_SIZE - macb->rx_tail);
407	416	taillen = length - headlen;
408	417	memcpy((void *)net_rx_packets[0],
409	418	buffer, headlen);
...	...	@@ -703,7 +712,7 @@
703	712	u32 buffer_size;
704	713	u32 dmacfg;
705	714
706		- buffer_size = 128 / RX_BUFFER_MULTIPLE;
	715	+ buffer_size = macb->rx_buffer_size / RX_BUFFER_MULTIPLE;
707	716	dmacfg = gem_readl(macb, DMACFG) & ~GEM_BF(RXBS, -1L);
708	717	dmacfg \|= GEM_BF(RXBS, buffer_size);
709	718
...	...	@@ -748,7 +757,7 @@
748	757	paddr \|= MACB_BIT(RX_WRAP);
749	758	macb->rx_ring[i].addr = paddr;
750	759	macb->rx_ring[i].ctrl = 0;
751		- paddr += 128;
	760	+ paddr += macb->rx_buffer_size;
752	761	}
753	762	macb_flush_ring_desc(macb, RX);
754	763	macb_flush_rx_buffer(macb);
755	764
...	...	@@ -959,8 +968,14 @@
959	968	int id = 0; /* This is not used by functions we call */
960	969	u32 ncfgr;
961	970
	971	+ if (macb_is_gem(macb))
	972	+ macb->rx_buffer_size = GEM_RX_BUFFER_SIZE;
	973	+ else
	974	+ macb->rx_buffer_size = MACB_RX_BUFFER_SIZE;
	975	+
962	976	/* TODO: we need check the rx/tx_ring_dma is dcache line aligned */
963		- macb->rx_buffer = dma_alloc_coherent(MACB_RX_BUFFER_SIZE,
	977	+ macb->rx_buffer = dma_alloc_coherent(macb->rx_buffer_size *
	978	+ MACB_RX_RING_SIZE,
964	979	&macb->rx_buffer_dma);
965	980	macb->rx_ring = dma_alloc_coherent(MACB_RX_DMA_DESC_SIZE,
966	981	&macb->rx_ring_dma);