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Commit 3f7832c2 authored by Timur Tabi's avatar Timur Tabi Committed by David S. Miller
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Revert "net: qcom/emac: enforce DMA address restrictions" 



This reverts commit df1ec1b9.

It turns out that memory allocated via dma_alloc_coherent is always
aligned to the size of the buffer, so there's no way the RRD and RFD
can ever be in separate 32-bit regions.

Signed-off-by: default avatarTimur Tabi <timur@codeaurora.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 437d2762

drivers/net/ethernet/qualcomm/emac/emac-mac.c

+15 −24
Original line number Diff line number Diff line
@@ -734,11 +734,6 @@ static int emac_rx_descs_alloc(struct emac_adapter *adpt) 
	rx_q->rrd.size = rx_q->rrd.count * (adpt->rrd_size * 4);

	rx_q->rfd.size = rx_q->rfd.count * (adpt->rfd_size * 4);



	/* Check if the RRD and RFD are aligned properly, and if not, adjust. */

	if (upper_32_bits(ring_header->dma_addr) !=

	    upper_32_bits(ring_header->dma_addr + ALIGN(rx_q->rrd.size, 8)))

		ring_header->used = ALIGN(rx_q->rrd.size, 8);



	rx_q->rrd.dma_addr = ring_header->dma_addr + ring_header->used;

	rx_q->rrd.v_addr   = ring_header->v_addr + ring_header->used;

	ring_header->used += ALIGN(rx_q->rrd.size, 8);
@@ -772,18 +767,11 @@ int emac_mac_rx_tx_rings_alloc_all(struct emac_adapter *adpt) 


	/* Ring DMA buffer. Each ring may need up to 8 bytes for alignment,

	 * hence the additional padding bytes are allocated.

	 *

	 * Also double the memory allocated for the RRD so that we can

	 * re-align it if necessary.  The EMAC has a restriction that the

	 * upper 32 bits of the base addresses for the RFD and RRD rings

	 * must be the same.  It is extremely unlikely that this is not the

	 * case, since the rings are only a few KB in size.  However, we

	 * need to check for this anyway, and if the two rings are not

	 * compliant, then we re-align.

	 */

	ring_header->size = ALIGN(num_tx_descs * (adpt->tpd_size * 4), 8) +

			    ALIGN(num_rx_descs * (adpt->rfd_size * 4), 8) +

			    ALIGN(num_rx_descs * (adpt->rrd_size * 4), 8) * 2;

	ring_header->size = num_tx_descs * (adpt->tpd_size * 4) +

			    num_rx_descs * (adpt->rfd_size * 4) +

			    num_rx_descs * (adpt->rrd_size * 4) +

			    8 + 2 * 8; /* 8 byte per one Tx and two Rx rings */



	ring_header->used = 0;

	ring_header->v_addr = dma_zalloc_coherent(dev, ring_header->size,
@@ -792,23 +780,26 @@ int emac_mac_rx_tx_rings_alloc_all(struct emac_adapter *adpt) 
	if (!ring_header->v_addr)

		return -ENOMEM;



	ret = emac_rx_descs_alloc(adpt);

	if (ret) {

		netdev_err(adpt->netdev, "error: Rx Queue alloc failed\n");

		goto err_alloc_rx;

	}

	ring_header->used = ALIGN(ring_header->dma_addr, 8) -

							ring_header->dma_addr;



	ret = emac_tx_q_desc_alloc(adpt, &adpt->tx_q);

	if (ret) {

		netdev_err(adpt->netdev, "transmit queue allocation failed\n");

		netdev_err(adpt->netdev, "error: Tx Queue alloc failed\n");

		goto err_alloc_tx;

	}



	ret = emac_rx_descs_alloc(adpt);

	if (ret) {

		netdev_err(adpt->netdev, "error: Rx Queue alloc failed\n");

		goto err_alloc_rx;

	}



	return 0;



err_alloc_tx:

	emac_rx_q_bufs_free(adpt);

err_alloc_rx:

	emac_tx_q_bufs_free(adpt);

err_alloc_tx:

	dma_free_coherent(dev, ring_header->size,

			  ring_header->v_addr, ring_header->dma_addr);