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141 lines
5.2 KiB
Diff
141 lines
5.2 KiB
Diff
bgmac: implement unaligned addressing for DMA rings that support it
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This is important patch for new devices that support unaligned
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addressing. That devices suffer from the backward-compatibility bug in
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DMA engine. In theory we should be able to use old mechanism, but in
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practice DMA address seems to be randomly copied into status register
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when hardware reaches end of a ring. This breaks reading slot number
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from status register and we can't use DMA anymore.
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Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
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--- a/drivers/net/ethernet/broadcom/bgmac.c
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+++ b/drivers/net/ethernet/broadcom/bgmac.c
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@@ -157,6 +157,7 @@ static netdev_tx_t bgmac_dma_tx_add(stru
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if (++ring->end >= BGMAC_TX_RING_SLOTS)
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ring->end = 0;
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bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_TX_INDEX,
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+ ring->index_base +
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ring->end * sizeof(struct bgmac_dma_desc));
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/* Always keep one slot free to allow detecting bugged calls. */
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@@ -181,6 +182,8 @@ static void bgmac_dma_tx_free(struct bgm
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/* The last slot that hardware didn't consume yet */
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empty_slot = bgmac_read(bgmac, ring->mmio_base + BGMAC_DMA_TX_STATUS);
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empty_slot &= BGMAC_DMA_TX_STATDPTR;
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+ empty_slot -= ring->index_base;
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+ empty_slot &= BGMAC_DMA_TX_STATDPTR;
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empty_slot /= sizeof(struct bgmac_dma_desc);
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while (ring->start != empty_slot) {
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@@ -274,6 +277,8 @@ static int bgmac_dma_rx_read(struct bgma
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end_slot = bgmac_read(bgmac, ring->mmio_base + BGMAC_DMA_RX_STATUS);
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end_slot &= BGMAC_DMA_RX_STATDPTR;
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+ end_slot -= ring->index_base;
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+ end_slot &= BGMAC_DMA_RX_STATDPTR;
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end_slot /= sizeof(struct bgmac_dma_desc);
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ring->end = end_slot;
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@@ -418,9 +423,6 @@ static int bgmac_dma_alloc(struct bgmac
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ring = &bgmac->tx_ring[i];
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ring->num_slots = BGMAC_TX_RING_SLOTS;
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ring->mmio_base = ring_base[i];
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- if (bgmac_dma_unaligned(bgmac, ring, BGMAC_DMA_RING_TX))
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- bgmac_warn(bgmac, "TX on ring 0x%X supports unaligned addressing but this feature is not implemented\n",
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- ring->mmio_base);
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/* Alloc ring of descriptors */
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size = ring->num_slots * sizeof(struct bgmac_dma_desc);
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@@ -435,6 +437,13 @@ static int bgmac_dma_alloc(struct bgmac
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if (ring->dma_base & 0xC0000000)
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bgmac_warn(bgmac, "DMA address using 0xC0000000 bit(s), it may need translation trick\n");
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+ ring->unaligned = bgmac_dma_unaligned(bgmac, ring,
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+ BGMAC_DMA_RING_TX);
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+ if (ring->unaligned)
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+ ring->index_base = lower_32_bits(ring->dma_base);
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+ else
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+ ring->index_base = 0;
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+
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/* No need to alloc TX slots yet */
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}
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@@ -444,9 +453,6 @@ static int bgmac_dma_alloc(struct bgmac
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ring = &bgmac->rx_ring[i];
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ring->num_slots = BGMAC_RX_RING_SLOTS;
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ring->mmio_base = ring_base[i];
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- if (bgmac_dma_unaligned(bgmac, ring, BGMAC_DMA_RING_RX))
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- bgmac_warn(bgmac, "RX on ring 0x%X supports unaligned addressing but this feature is not implemented\n",
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- ring->mmio_base);
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/* Alloc ring of descriptors */
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size = ring->num_slots * sizeof(struct bgmac_dma_desc);
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@@ -462,6 +468,13 @@ static int bgmac_dma_alloc(struct bgmac
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if (ring->dma_base & 0xC0000000)
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bgmac_warn(bgmac, "DMA address using 0xC0000000 bit(s), it may need translation trick\n");
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+ ring->unaligned = bgmac_dma_unaligned(bgmac, ring,
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+ BGMAC_DMA_RING_RX);
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+ if (ring->unaligned)
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+ ring->index_base = lower_32_bits(ring->dma_base);
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+ else
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+ ring->index_base = 0;
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+
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/* Alloc RX slots */
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for (j = 0; j < ring->num_slots; j++) {
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err = bgmac_dma_rx_skb_for_slot(bgmac, &ring->slots[j]);
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@@ -489,12 +502,14 @@ static void bgmac_dma_init(struct bgmac
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for (i = 0; i < BGMAC_MAX_TX_RINGS; i++) {
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ring = &bgmac->tx_ring[i];
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- /* We don't implement unaligned addressing, so enable first */
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- bgmac_dma_tx_enable(bgmac, ring);
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+ if (!ring->unaligned)
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+ bgmac_dma_tx_enable(bgmac, ring);
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bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_TX_RINGLO,
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lower_32_bits(ring->dma_base));
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bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_TX_RINGHI,
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upper_32_bits(ring->dma_base));
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+ if (ring->unaligned)
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+ bgmac_dma_tx_enable(bgmac, ring);
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ring->start = 0;
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ring->end = 0; /* Points the slot that should *not* be read */
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@@ -505,12 +520,14 @@ static void bgmac_dma_init(struct bgmac
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ring = &bgmac->rx_ring[i];
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- /* We don't implement unaligned addressing, so enable first */
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- bgmac_dma_rx_enable(bgmac, ring);
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+ if (!ring->unaligned)
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+ bgmac_dma_rx_enable(bgmac, ring);
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bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_RINGLO,
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lower_32_bits(ring->dma_base));
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bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_RINGHI,
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upper_32_bits(ring->dma_base));
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+ if (ring->unaligned)
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+ bgmac_dma_rx_enable(bgmac, ring);
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for (j = 0, dma_desc = ring->cpu_base; j < ring->num_slots;
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j++, dma_desc++) {
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@@ -531,6 +548,7 @@ static void bgmac_dma_init(struct bgmac
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}
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bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_INDEX,
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+ ring->index_base +
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ring->num_slots * sizeof(struct bgmac_dma_desc));
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ring->start = 0;
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--- a/drivers/net/ethernet/broadcom/bgmac.h
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+++ b/drivers/net/ethernet/broadcom/bgmac.h
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@@ -384,6 +384,8 @@ struct bgmac_dma_ring {
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u16 mmio_base;
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struct bgmac_dma_desc *cpu_base;
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dma_addr_t dma_base;
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+ u32 index_base; /* Used for unaligned rings only, otherwise 0 */
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+ bool unaligned;
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struct bgmac_slot_info slots[BGMAC_RX_RING_SLOTS];
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};
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