[U-Boot] [PATCH 1/2] e1000: Implement dcache support

Tim Harvey
2014-08-08T14:41:38Z

From: Marek Vasut <marex@denx.de>

Implement proper support for cache flushing and invalidation into the
Intel e1000 NIC driver.

Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Tim Harvey <tharvey@gateworks.com>
---
drivers/net/e1000.c | 71 ++++++++++++++++++++++++++++++++++++-----------------
1 file changed, 49 insertions(+), 22 deletions(-)

diff --git a/drivers/net/e1000.c b/drivers/net/e1000.c
index 9d9b259..0441a4f 100644
--- a/drivers/net/e1000.c
+++ b/drivers/net/e1000.c
@@ -41,12 +41,12 @@ tested on both gig copper and gig fiber boards

/* NIC specific static variables go here */

-static char tx_pool[128 + 16];
-static char rx_pool[128 + 16];
-static char packet[2096];
+/* Intel i210 needs the DMA descriptor rings aligned to 128b */
+#define E1000_BUFFER_ALIGN 128

-static struct e1000_tx_desc *tx_base;
-static struct e1000_rx_desc *rx_base;
+DEFINE_ALIGN_BUFFER(struct e1000_tx_desc, tx_base, 16, E1000_BUFFER_ALIGN);
+DEFINE_ALIGN_BUFFER(struct e1000_rx_desc, rx_base, 16, E1000_BUFFER_ALIGN);
+DEFINE_ALIGN_BUFFER(unsigned char, packet, 4096, E1000_BUFFER_ALIGN);

static int tx_tail;
static int rx_tail, rx_last;
@@ -4803,12 +4803,25 @@ void
fill_rx(struct e1000_hw *hw)
{
struct e1000_rx_desc *rd;
+ uint32_t flush_start, flush_end;

rx_last = rx_tail;
rd = rx_base + rx_tail;
rx_tail = (rx_tail + 1) % 8;
memset(rd, 0, 16);
- rd->buffer_addr = cpu_to_le64((u32) & packet);
+ rd->buffer_addr = cpu_to_le64((u32)packet);
+
+ /*
+ * Make sure there are no stale data in WB over this area, which
+ * might get written into the memory while the e1000 also writes
+ * into the same memory area.
+ */
+ invalidate_dcache_range((u32)packet, (u32)packet + 4096);
+ /* Dump the DMA descriptor into RAM. */
+ flush_start = ((u32)rd) & ~(ARCH_DMA_MINALIGN - 1);
+ flush_end = flush_start + roundup(sizeof(*rd), ARCH_DMA_MINALIGN);
+ flush_dcache_range(flush_start, flush_end);
+
E1000_WRITE_REG(hw, RDT, rx_tail);
}

@@ -4822,17 +4835,10 @@ fill_rx(struct e1000_hw *hw)
static void
e1000_configure_tx(struct e1000_hw *hw)
{
- unsigned long ptr;
unsigned long tctl;
unsigned long tipg, tarc;
uint32_t ipgr1, ipgr2;

- ptr = (u32) tx_pool;
- if (ptr & 0xf)
- ptr = (ptr + 0x10) & (~0xf);
-
- tx_base = (typeof(tx_base)) ptr;
-
E1000_WRITE_REG(hw, TDBAL, (u32) tx_base);
E1000_WRITE_REG(hw, TDBAH, 0);

@@ -4941,7 +4947,6 @@ e1000_setup_rctl(struct e1000_hw *hw)
static void
e1000_configure_rx(struct e1000_hw *hw)
{
- unsigned long ptr;
unsigned long rctl, ctrl_ext;
rx_tail = 0;
/* make sure receives are disabled while setting up the descriptors */
@@ -4963,10 +4968,6 @@ e1000_configure_rx(struct e1000_hw *hw)
E1000_WRITE_FLUSH(hw);
}
/* Setup the Base and Length of the Rx Descriptor Ring */
- ptr = (u32) rx_pool;
- if (ptr & 0xf)
- ptr = (ptr + 0x10) & (~0xf);
- rx_base = (typeof(rx_base)) ptr;
E1000_WRITE_REG(hw, RDBAL, (u32) rx_base);
E1000_WRITE_REG(hw, RDBAH, 0);

@@ -4989,12 +4990,25 @@ e1000_poll(struct eth_device *nic)
{
struct e1000_hw *hw = nic->priv;
struct e1000_rx_desc *rd;
+ uint32_t inval_start, inval_end;
+ uint32_t len;
+
/* return true if there's an ethernet packet ready to read */
rd = rx_base + rx_last;
+
+ /* Re-load the descriptor from RAM. */
+ inval_start = ((u32)rd) & ~(ARCH_DMA_MINALIGN - 1);
+ inval_end = inval_start + roundup(sizeof(*rd), ARCH_DMA_MINALIGN);
+ invalidate_dcache_range(inval_start, inval_end);
+
if (!(le32_to_cpu(rd->status)) & E1000_RXD_STAT_DD)
return 0;
/*DEBUGOUT("recv: packet len=%d \n", rd->length); */
- NetReceive((uchar *)packet, le32_to_cpu(rd->length));
+ /* Packet received, make sure the data are re-loaded from RAM. */
+ len = le32_to_cpu(rd->length);
+ invalidate_dcache_range((u32)packet,
+ (u32)packet + roundup(len, ARCH_DMA_MINALIGN));
+ NetReceive((uchar *)packet, len);
fill_rx(hw);
return 1;
}
@@ -5002,12 +5016,13 @@ e1000_poll(struct eth_device *nic)
/**************************************************************************
TRANSMIT - Transmit a frame
***************************************************************************/
-static int e1000_transmit(struct eth_device *nic, void *packet, int length)
+static int e1000_transmit(struct eth_device *nic, void *txpacket, int length)
{
- void *nv_packet = (void *)packet;
+ void *nv_packet = (void *)txpacket;
struct e1000_hw *hw = nic->priv;
struct e1000_tx_desc *txp;
int i = 0;
+ uint32_t flush_start, flush_end;

txp = tx_base + tx_tail;
tx_tail = (tx_tail + 1) % 8;
@@ -5015,10 +5030,22 @@ static int e1000_transmit(struct eth_device *nic, void *packet, int length)
txp->buffer_addr = cpu_to_le64(virt_to_bus(hw->pdev, nv_packet));
txp->lower.data = cpu_to_le32(hw->txd_cmd | length);
txp->upper.data = 0;
+
+ /* Dump the packet into RAM so e1000 can pick them. */
+ flush_dcache_range((u32)nv_packet,
+ (u32)nv_packet + roundup(length, ARCH_DMA_MINALIGN));
+ /* Dump the descriptor into RAM as well. */
+ flush_start = ((u32)txp) & ~(ARCH_DMA_MINALIGN - 1);
+ flush_end = flush_start + roundup(sizeof(*txp), ARCH_DMA_MINALIGN);
+ flush_dcache_range(flush_start, flush_end);
+
E1000_WRITE_REG(hw, TDT, tx_tail);

E1000_WRITE_FLUSH(hw);
- while (!(le32_to_cpu(txp->upper.data) & E1000_TXD_STAT_DD)) {
+ while (1) {
+ invalidate_dcache_range(flush_start, flush_end);
+ if (le32_to_cpu(txp->upper.data) & E1000_TXD_STAT_DD)
+ break;
if (i++ > TOUT_LOOP) {
DEBUGOUT("e1000: tx timeout\n");
return 0;
--
1.8.3.2