[PATCH] net: macb: Add 64 bit addressing support for GEM

From: Harini Katakam
Date: Tue Aug 09 2016 - 04:22:47 EST


This patch adds support for 64 bit addressing and BDs.
-> Enable 64 bit addressing in DMACFG register.
-> Set DMA mask when design config register shows support for 64 bit addr.
-> Add new BD words for higher address when 64 bit DMA support is present.
-> Add and update TBQPH and RBQPH for MSB of BD pointers.
-> Change extraction and updation of buffer addresses to use
64 bit address.
-> In gem_rx extract address in one place insted of two and use a
separate flag for RXUSED.

Signed-off-by: Harini Katakam <harinik@xxxxxxxxxx>
---
drivers/net/ethernet/cadence/macb.c | 62 ++++++++++++++++++++++++++++++-------
drivers/net/ethernet/cadence/macb.h | 10 ++++++
2 files changed, 61 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
index 89c0cfa..6b797e3 100644
--- a/drivers/net/ethernet/cadence/macb.c
+++ b/drivers/net/ethernet/cadence/macb.c
@@ -541,6 +541,14 @@ static void macb_tx_unmap(struct macb *bp, struct macb_tx_skb *tx_skb)
}
}

+static inline void macb_set_addr(struct macb_dma_desc *desc, dma_addr_t addr)
+{
+ desc->addr = (u32)addr;
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+ desc->addrh = (u32)(addr >> 32);
+#endif
+}
+
static void macb_tx_error_task(struct work_struct *work)
{
struct macb_queue *queue = container_of(work, struct macb_queue,
@@ -621,14 +629,17 @@ static void macb_tx_error_task(struct work_struct *work)

/* Set end of TX queue */
desc = macb_tx_desc(queue, 0);
- desc->addr = 0;
+ macb_set_addr(desc, 0);
desc->ctrl = MACB_BIT(TX_USED);

/* Make descriptor updates visible to hardware */
wmb();

/* Reinitialize the TX desc queue */
- queue_writel(queue, TBQP, queue->tx_ring_dma);
+ queue_writel(queue, TBQP, (u32)(queue->tx_ring_dma));
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+ queue_writel(queue, TBQPH, (u32)(queue->tx_ring_dma >> 32));
+#endif
/* Make TX ring reflect state of hardware */
queue->tx_head = 0;
queue->tx_tail = 0;
@@ -750,7 +761,7 @@ static void gem_rx_refill(struct macb *bp)

if (entry == RX_RING_SIZE - 1)
paddr |= MACB_BIT(RX_WRAP);
- bp->rx_ring[entry].addr = paddr;
+ macb_set_addr(&(bp->rx_ring[entry]), paddr);
bp->rx_ring[entry].ctrl = 0;

/* properly align Ethernet header */
@@ -798,7 +809,9 @@ static int gem_rx(struct macb *bp, int budget)
int count = 0;

while (count < budget) {
- u32 addr, ctrl;
+ u32 ctrl;
+ dma_addr_t addr;
+ bool rxused;

entry = macb_rx_ring_wrap(bp->rx_tail);
desc = &bp->rx_ring[entry];
@@ -806,10 +819,14 @@ static int gem_rx(struct macb *bp, int budget)
/* Make hw descriptor updates visible to CPU */
rmb();

- addr = desc->addr;
+ rxused = (desc->addr & MACB_BIT(RX_USED)) ? true : false;
+ addr = MACB_BF(RX_WADDR, MACB_BFEXT(RX_WADDR, desc->addr));
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+ addr |= ((u64)(desc->addrh) << 32);
+#endif
ctrl = desc->ctrl;

- if (!(addr & MACB_BIT(RX_USED)))
+ if (!rxused)
break;

bp->rx_tail++;
@@ -835,7 +852,6 @@ static int gem_rx(struct macb *bp, int budget)
netdev_vdbg(bp->dev, "gem_rx %u (len %u)\n", entry, len);

skb_put(skb, len);
- addr = MACB_BF(RX_WADDR, MACB_BFEXT(RX_WADDR, addr));
dma_unmap_single(&bp->pdev->dev, addr,
bp->rx_buffer_size, DMA_FROM_DEVICE);

@@ -1299,7 +1315,7 @@ static unsigned int macb_tx_map(struct macb *bp,
ctrl |= MACB_BIT(TX_WRAP);

/* Set TX buffer descriptor */
- desc->addr = tx_skb->mapping;
+ macb_set_addr(desc, tx_skb->mapping);
/* desc->addr must be visible to hardware before clearing
* 'TX_USED' bit in desc->ctrl.
*/
@@ -1422,6 +1438,9 @@ static void gem_free_rx_buffers(struct macb *bp)

desc = &bp->rx_ring[i];
addr = MACB_BF(RX_WADDR, MACB_BFEXT(RX_WADDR, desc->addr));
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+ addr |= ((u64)(desc->addrh) << 32);
+#endif
dma_unmap_single(&bp->pdev->dev, addr, bp->rx_buffer_size,
DMA_FROM_DEVICE);
dev_kfree_skb_any(skb);
@@ -1547,7 +1566,7 @@ static void gem_init_rings(struct macb *bp)

for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
for (i = 0; i < TX_RING_SIZE; i++) {
- queue->tx_ring[i].addr = 0;
+ macb_set_addr(&(queue->tx_ring[i]), 0);
queue->tx_ring[i].ctrl = MACB_BIT(TX_USED);
}
queue->tx_ring[TX_RING_SIZE - 1].ctrl |= MACB_BIT(TX_WRAP);
@@ -1694,6 +1713,10 @@ static void macb_configure_dma(struct macb *bp)
dmacfg |= GEM_BIT(TXCOEN);
else
dmacfg &= ~GEM_BIT(TXCOEN);
+
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+ dmacfg |= GEM_BIT(ADDR64);
+#endif
netdev_dbg(bp->dev, "Cadence configure DMA with 0x%08x\n",
dmacfg);
gem_writel(bp, DMACFG, dmacfg);
@@ -1739,9 +1762,15 @@ static void macb_init_hw(struct macb *bp)
macb_configure_dma(bp);

/* Initialize TX and RX buffers */
- macb_writel(bp, RBQP, bp->rx_ring_dma);
+ macb_writel(bp, RBQP, (u32)(bp->rx_ring_dma));
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+ macb_writel(bp, RBQPH, (u32)(bp->rx_ring_dma >> 32));
+#endif
for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
- queue_writel(queue, TBQP, queue->tx_ring_dma);
+ queue_writel(queue, TBQP, (u32)(queue->tx_ring_dma));
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+ queue_writel(queue, TBQPH, (u32)(queue->tx_ring_dma >> 32));
+#endif

/* Enable interrupts */
queue_writel(queue, IER,
@@ -2379,6 +2408,9 @@ static int macb_init(struct platform_device *pdev)
queue->IDR = GEM_IDR(hw_q - 1);
queue->IMR = GEM_IMR(hw_q - 1);
queue->TBQP = GEM_TBQP(hw_q - 1);
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+ queue->TBQPH = GEM_TBQPH(hw_q -1);
+#endif
} else {
/* queue0 uses legacy registers */
queue->ISR = MACB_ISR;
@@ -2386,6 +2418,9 @@ static int macb_init(struct platform_device *pdev)
queue->IDR = MACB_IDR;
queue->IMR = MACB_IMR;
queue->TBQP = MACB_TBQP;
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+ queue->TBQPH = MACB_TBQPH;
+#endif
}

/* get irq: here we use the linux queue index, not the hardware
@@ -2935,6 +2970,11 @@ static int macb_probe(struct platform_device *pdev)
bp->wol |= MACB_WOL_HAS_MAGIC_PACKET;
device_init_wakeup(&pdev->dev, bp->wol & MACB_WOL_HAS_MAGIC_PACKET);

+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+ if (GEM_BFEXT(DBWDEF, gem_readl(bp, DCFG1)) > GEM_DBW32)
+ dma_set_mask(&pdev->dev, DMA_BIT_MASK(44));
+#endif
+
spin_lock_init(&bp->lock);

/* setup capabilities */
diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index b6fcf10..aa3aeec 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -66,6 +66,8 @@
#define MACB_USRIO 0x00c0
#define MACB_WOL 0x00c4
#define MACB_MID 0x00fc
+#define MACB_TBQPH 0x04C8
+#define MACB_RBQPH 0x04D4

/* GEM register offsets. */
#define GEM_NCFGR 0x0004 /* Network Config */
@@ -139,6 +141,7 @@

#define GEM_ISR(hw_q) (0x0400 + ((hw_q) << 2))
#define GEM_TBQP(hw_q) (0x0440 + ((hw_q) << 2))
+#define GEM_TBQPH(hw_q) (0x04C8)
#define GEM_RBQP(hw_q) (0x0480 + ((hw_q) << 2))
#define GEM_IER(hw_q) (0x0600 + ((hw_q) << 2))
#define GEM_IDR(hw_q) (0x0620 + ((hw_q) << 2))
@@ -249,6 +252,8 @@
#define GEM_RXBS_SIZE 8
#define GEM_DDRP_OFFSET 24 /* disc_when_no_ahb */
#define GEM_DDRP_SIZE 1
+#define GEM_ADDR64_OFFSET 30 /* Address bus width - 64b or 32b */
+#define GEM_ADDR64_SIZE 1


/* Bitfields in NSR */
@@ -474,6 +479,10 @@
struct macb_dma_desc {
u32 addr;
u32 ctrl;
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
+ u32 addrh;
+ u32 resvd;
+#endif
};

/* DMA descriptor bitfields */
@@ -777,6 +786,7 @@ struct macb_queue {
unsigned int IDR;
unsigned int IMR;
unsigned int TBQP;
+ unsigned int TBQPH;

unsigned int tx_head, tx_tail;
struct macb_dma_desc *tx_ring;
--
2.7.4