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SubjectRe: [PATCH] net: macb: Add 64 bit addressing support for GEM
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Le 09/08/2016 à 09:45, Harini Katakam a écrit :
> 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@xilinx.com>

Even if I do understand the focus on efficiency for the use of ifdef's
in the code, I suspect that it's not very clean and adds a lot of
readability issues to it.

So, is there a common pattern for this kind of 32/64 bits drivers? Is
someone able to advice Harini for this?

Bye,

> ---
> 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;
>


--
Nicolas Ferre

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