On 29.11.23 10:54, Steffen Trumtrar wrote:
> Instead of directly reading from memory addresses and inserting
> sw barriers to be sure that the compiler will not move loads/stores
> behind this point, just use proper volatile writel/readl accesses.
>
> Signed-off-by: Steffen Trumtrar <s.trumtrar@xxxxxxxxxxxxxx>
> ---
> drivers/net/macb.c | 52 +++++++++++++++++++++-------------------------------
> 1 file changed, 21 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/net/macb.c b/drivers/net/macb.c
> index 55498c9e84..8a2d898d10 100644
> --- a/drivers/net/macb.c
> +++ b/drivers/net/macb.c
> @@ -119,17 +119,15 @@ static int macb_send(struct eth_device *edev, void *packet,
> macb->tx_head++;
> }
>
> - macb->tx_ring[tx_head].ctrl = ctrl;
> - macb->tx_ring[tx_head].addr = (ulong)packet;
> - barrier();
> + writel(ctrl, &macb->tx_ring[tx_head].ctrl);
> + writel((ulong)packet, &macb->tx_ring[tx_head].addr);
> dma_sync_single_for_device(macb->dev, (unsigned long)packet, length, DMA_TO_DEVICE);
> macb_writel(macb, NCR, MACB_BIT(TE) | MACB_BIT(RE) | MACB_BIT(TSTART));
>
> start = get_time_ns();
> ret = -ETIMEDOUT;
> do {
> - barrier();
> - ctrl = macb->tx_ring[0].ctrl;
> + ctrl = readl(&macb->tx_ring[0].ctrl);
> if (ctrl & MACB_BIT(TX_USED)) {
> ret = 0;
> break;
> @@ -154,18 +152,17 @@ static void reclaim_rx_buffers(struct macb_device *macb,
>
> i = macb->rx_tail;
> while (i > new_tail) {
> - macb->rx_ring[i].addr &= ~MACB_BIT(RX_USED);
> + clrbits_le32(&macb->rx_ring[i].addr, MACB_BIT(RX_USED));
> i++;
> if (i > macb->rx_ring_size)
> i = 0;
> }
>
> while (i < new_tail) {
> - macb->rx_ring[i].addr &= ~MACB_BIT(RX_USED);
> + clrbits_le32(&macb->rx_ring[i].addr, MACB_BIT(RX_USED));
> i++;
> }
>
> - barrier();
> macb->rx_tail = new_tail;
> }
>
> @@ -176,15 +173,11 @@ static int gem_recv(struct eth_device *edev)
> u32 status;
>
> for (;;) {
> - barrier();
> - if (!(macb->rx_ring[macb->rx_tail].addr & MACB_BIT(RX_USED)))
> + if (!(readl(&macb->rx_ring[macb->rx_tail].addr) & MACB_BIT(RX_USED)))
> return -1;
>
> - barrier();
> - status = macb->rx_ring[macb->rx_tail].ctrl;
> + status = readl(&macb->rx_ring[macb->rx_tail].ctrl);
> length = MACB_BFEXT(RX_FRMLEN, status);
> - macb->rx_ring[macb->rx_tail].addr &= ~MACB_BIT(RX_USED);
> - barrier();
> dma_sync_single_for_cpu(macb->dev,
> macb->rx_buffer_phys + macb->rx_buffer_size * macb->rx_tail,
> length, DMA_FROM_DEVICE);
> @@ -192,6 +185,7 @@ static int gem_recv(struct eth_device *edev)
> dma_sync_single_for_device(macb->dev,
> macb->rx_buffer_phys + macb->rx_buffer_size * macb->rx_tail,
> length, DMA_FROM_DEVICE);
> + clrbits_le32(&macb->rx_ring[macb->rx_tail].addr, MACB_BIT(RX_USED));
This short be in the previous hunk, shouldn't it?
>
> macb->rx_tail++;
> if (macb->rx_tail >= macb->rx_ring_size)
> @@ -210,12 +204,10 @@ static int macb_recv(struct eth_device *edev)
> u32 status;
>
> for (;;) {
> - barrier();
> - if (!(macb->rx_ring[rx_tail].addr & MACB_BIT(RX_USED)))
> + if (!(readl(&macb->rx_ring[rx_tail].addr) & MACB_BIT(RX_USED)))
> return -1;
>
> - barrier();
> - status = macb->rx_ring[rx_tail].ctrl;
> + status = readl(&macb->rx_ring[rx_tail].ctrl);
> if (status & MACB_BIT(RX_SOF)) {
> if (rx_tail != macb->rx_tail)
> reclaim_rx_buffers(macb, rx_tail);
> @@ -256,7 +248,6 @@ static int macb_recv(struct eth_device *edev)
> length,
> DMA_FROM_DEVICE);
> }
> - barrier();
> if (++rx_tail >= macb->rx_ring_size)
> rx_tail = 0;
> reclaim_rx_buffers(macb, rx_tail);
> @@ -376,9 +367,9 @@ static int gmac_init_dummy_tx_queues(struct macb_device *macb)
> if (queue_mask & (1 << i))
> num_queues++;
>
> - macb->gem_q1_descs[0].addr = 0;
> - macb->gem_q1_descs[0].ctrl = MACB_BIT(TX_WRAP) |
> - MACB_BIT(TX_LAST) | MACB_BIT(TX_USED);
> + writel(0, &macb->gem_q1_descs[0].addr);
> + writel(MACB_BIT(TX_WRAP) | MACB_BIT(TX_LAST) | MACB_BIT(TX_USED),
> + &macb->gem_q1_descs[0].ctrl);
>
> for (i = 1; i < num_queues; i++)
> gem_writel_queue_TBQP(macb, (ulong)macb->gem_q1_descs, i - 1);
> @@ -404,17 +395,17 @@ static int macb_init(struct macb_device *macb)
> /* initialize DMA descriptors */
> paddr = (ulong)macb->rx_buffer;
> for (i = 0; i < macb->rx_ring_size; i++) {
> - macb->rx_ring[i].addr = paddr;
> - macb->rx_ring[i].ctrl = 0;
> + writel(paddr, &macb->rx_ring[i].addr);
> + writel(0, &macb->rx_ring[i].ctrl);
> paddr += macb->rx_buffer_size;
> }
> - macb->rx_ring[macb->rx_ring_size - 1].addr |= MACB_BIT(RX_WRAP);
> + setbits_le32(&macb->rx_ring[macb->rx_ring_size - 1].addr, MACB_BIT(RX_WRAP));
>
> for (i = 0; i < TX_RING_SIZE; i++) {
> - macb->tx_ring[i].addr = 0;
> - macb->tx_ring[i].ctrl = MACB_BIT(TX_USED);
> + writel(0, &macb->tx_ring[i].addr);
> + writel(MACB_BIT(TX_USED), &macb->tx_ring[i].ctrl);
> }
> - macb->tx_ring[TX_RING_SIZE - 1].addr |= MACB_BIT(TX_WRAP);
> + setbits_le32(&macb->tx_ring[TX_RING_SIZE - 1].addr, MACB_BIT(TX_WRAP));
>
> macb->rx_tail = macb->tx_head = 0;
>
> @@ -427,9 +418,8 @@ static int macb_init(struct macb_device *macb)
> gmac_init_dummy_tx_queues(macb);
>
> /* Disable the second priority rx queue */
> - macb->gem_q1_descs[1].addr = MACB_BIT(RX_USED) |
> - MACB_BIT(RX_WRAP);
> - macb->gem_q1_descs[1].ctrl = 0;
> + writel(MACB_BIT(RX_USED) | MACB_BIT(RX_WRAP), &macb->gem_q1_descs[1].addr);
> + writel(0, &macb->gem_q1_descs[1].ctrl);
>
> gem_writel(macb, RQ1, (ulong)&macb->gem_q1_descs[1]);
> }
>
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
