static int bgmac_dma_init(struct bgmac *bgmac)
{
struct bgmac_dma_ring *ring;
int i, err;
for (i = 0; i < BGMAC_MAX_TX_RINGS; i++) {
ring = &bgmac->tx_ring[i];
if (!ring->unaligned)
bgmac_dma_tx_enable(bgmac, ring);
bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_TX_RINGLO,
lower_32_bits(ring->dma_base));
bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_TX_RINGHI,
upper_32_bits(ring->dma_base));
if (ring->unaligned)
bgmac_dma_tx_enable(bgmac, ring);
ring->start = 0;
ring->end = 0; /* Points the slot that should *not* be read */
}
for (i = 0; i < BGMAC_MAX_RX_RINGS; i++) {
int j;
ring = &bgmac->rx_ring[i];
if (!ring->unaligned)
bgmac_dma_rx_enable(bgmac, ring);
bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_RINGLO,
lower_32_bits(ring->dma_base));
bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_RINGHI,
upper_32_bits(ring->dma_base));
if (ring->unaligned)
bgmac_dma_rx_enable(bgmac, ring);
ring->start = 0;
ring->end = 0;
for (j = 0; j < BGMAC_RX_RING_SLOTS; j++) {
err = bgmac_dma_rx_skb_for_slot(bgmac, &ring->slots[j]);
if (err)
goto error;
bgmac_dma_rx_setup_desc(bgmac, ring, j);
}
bgmac_dma_rx_update_index(bgmac, ring);
}
return 0;
error:
bgmac_dma_cleanup(bgmac);
return err;
}
static int bgmac_dma_alloc(struct bgmac *bgmac)
{
struct device *dma_dev = bgmac->core->dma_dev;
struct bgmac_dma_ring *ring;
static const u16 ring_base[] = { BGMAC_DMA_BASE0, BGMAC_DMA_BASE1,
BGMAC_DMA_BASE2, BGMAC_DMA_BASE3, };
int size; /* ring size: different for Tx and Rx */
int err;
int i;
BUILD_BUG_ON(BGMAC_MAX_TX_RINGS > ARRAY_SIZE(ring_base));
BUILD_BUG_ON(BGMAC_MAX_RX_RINGS > ARRAY_SIZE(ring_base));
if (!(bcma_aread32(bgmac->core, BCMA_IOST) & BCMA_IOST_DMA64)) {
bgmac_err(bgmac, "Core does not report 64-bit DMA\n");
return -ENOTSUPP;
}
for (i = 0; i < BGMAC_MAX_TX_RINGS; i++) {
ring = &bgmac->tx_ring[i];
ring->num_slots = BGMAC_TX_RING_SLOTS;
ring->mmio_base = ring_base[i];
/* Alloc ring of descriptors */
size = ring->num_slots * sizeof(struct bgmac_dma_desc);
ring->cpu_base = dma_zalloc_coherent(dma_dev, size,
&ring->dma_base,
GFP_KERNEL);
if (!ring->cpu_base) {
bgmac_err(bgmac, "Allocation of TX ring 0x%X failed\n",
ring->mmio_base);
goto err_dma_free;
}
if (ring->dma_base & 0xC0000000)
bgmac_warn(bgmac, "DMA address using 0xC0000000 bit(s), it may need translation trick\n");
ring->unaligned = bgmac_dma_unaligned(bgmac, ring,
BGMAC_DMA_RING_TX);
if (ring->unaligned)
ring->index_base = lower_32_bits(ring->dma_base);
else
ring->index_base = 0;
/* No need to alloc TX slots yet */
}
for (i = 0; i < BGMAC_MAX_RX_RINGS; i++) {
int j;
ring = &bgmac->rx_ring[i];
ring->num_slots = BGMAC_RX_RING_SLOTS;
ring->mmio_base = ring_base[i];
/* Alloc ring of descriptors */
size = ring->num_slots * sizeof(struct bgmac_dma_desc);
ring->cpu_base = dma_zalloc_coherent(dma_dev, size,
&ring->dma_base,
GFP_KERNEL);
if (!ring->cpu_base) {
bgmac_err(bgmac, "Allocation of RX ring 0x%X failed\n",
ring->mmio_base);
err = -ENOMEM;
goto err_dma_free;
}
if (ring->dma_base & 0xC0000000)
bgmac_warn(bgmac, "DMA address using 0xC0000000 bit(s), it may need translation trick\n");
ring->unaligned = bgmac_dma_unaligned(bgmac, ring,
BGMAC_DMA_RING_RX);
if (ring->unaligned)
ring->index_base = lower_32_bits(ring->dma_base);
else
ring->index_base = 0;
/* Alloc RX slots */
for (j = 0; j < ring->num_slots; j++) {
err = bgmac_dma_rx_skb_for_slot(bgmac, &ring->slots[j]);
if (err) {
bgmac_err(bgmac, "Can't allocate skb for slot in RX ring\n");
goto err_dma_free;
}
}
}
return 0;
err_dma_free:
bgmac_dma_free(bgmac);
return -ENOMEM;
}
static int bgmac_dma_rx_read(struct bgmac *bgmac, struct bgmac_dma_ring *ring,
int weight)
{
u32 end_slot;
int handled = 0;
end_slot = bgmac_read(bgmac, ring->mmio_base + BGMAC_DMA_RX_STATUS);
end_slot &= BGMAC_DMA_RX_STATDPTR;
end_slot -= ring->index_base;
end_slot &= BGMAC_DMA_RX_STATDPTR;
end_slot /= sizeof(struct bgmac_dma_desc);
while (ring->start != end_slot) {
struct device *dma_dev = bgmac->core->dma_dev;
struct bgmac_slot_info *slot = &ring->slots[ring->start];
struct bgmac_rx_header *rx = slot->buf + BGMAC_RX_BUF_OFFSET;
struct sk_buff *skb;
void *buf = slot->buf;
dma_addr_t dma_addr = slot->dma_addr;
u16 len, flags;
do {
/* Prepare new skb as replacement */
if (bgmac_dma_rx_skb_for_slot(bgmac, slot)) {
bgmac_dma_rx_poison_buf(dma_dev, slot);
break;
}
/* Unmap buffer to make it accessible to the CPU */
dma_unmap_single(dma_dev, dma_addr,
BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
/* Get info from the header */
len = le16_to_cpu(rx->len);
flags = le16_to_cpu(rx->flags);
/* Check for poison and drop or pass the packet */
if (len == 0xdead && flags == 0xbeef) {
bgmac_err(bgmac, "Found poisoned packet at slot %d, DMA issue!\n",
ring->start);
put_page(virt_to_head_page(buf));
break;
}
if (len > BGMAC_RX_ALLOC_SIZE) {
bgmac_err(bgmac, "Found oversized packet at slot %d, DMA issue!\n",
ring->start);
put_page(virt_to_head_page(buf));
break;
}
/* Omit CRC. */
len -= ETH_FCS_LEN;
skb = build_skb(buf, BGMAC_RX_ALLOC_SIZE);
if (unlikely(!skb)) {
bgmac_err(bgmac, "build_skb failed\n");
put_page(virt_to_head_page(buf));
break;
}
skb_put(skb, BGMAC_RX_FRAME_OFFSET +
BGMAC_RX_BUF_OFFSET + len);
skb_pull(skb, BGMAC_RX_FRAME_OFFSET +
BGMAC_RX_BUF_OFFSET);
skb_checksum_none_assert(skb);
skb->protocol = eth_type_trans(skb, bgmac->net_dev);
napi_gro_receive(&bgmac->napi, skb);
handled++;
} while (0);
bgmac_dma_rx_setup_desc(bgmac, ring, ring->start);
if (++ring->start >= BGMAC_RX_RING_SLOTS)
ring->start = 0;
if (handled >= weight) /* Should never be greater */
break;
}
bgmac_dma_rx_update_index(bgmac, ring);
return handled;
}
static int bgmac_dma_rx_read(struct bgmac *bgmac, struct bgmac_dma_ring *ring,
int weight)
{
u32 end_slot;
int handled = 0;
end_slot = bgmac_read(bgmac, ring->mmio_base + BGMAC_DMA_RX_STATUS);
end_slot &= BGMAC_DMA_RX_STATDPTR;
end_slot -= ring->index_base;
end_slot &= BGMAC_DMA_RX_STATDPTR;
end_slot /= sizeof(struct bgmac_dma_desc);
ring->end = end_slot;
while (ring->start != ring->end) {
struct device *dma_dev = bgmac->core->dma_dev;
struct bgmac_slot_info *slot = &ring->slots[ring->start];
struct sk_buff *skb = slot->skb;
struct bgmac_rx_header *rx;
u16 len, flags;
/* Unmap buffer to make it accessible to the CPU */
dma_sync_single_for_cpu(dma_dev, slot->dma_addr,
BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
/* Get info from the header */
rx = (struct bgmac_rx_header *)skb->data;
len = le16_to_cpu(rx->len);
flags = le16_to_cpu(rx->flags);
do {
dma_addr_t old_dma_addr = slot->dma_addr;
int err;
/* Check for poison and drop or pass the packet */
if (len == 0xdead && flags == 0xbeef) {
bgmac_err(bgmac, "Found poisoned packet at slot %d, DMA issue!\n",
ring->start);
dma_sync_single_for_device(dma_dev,
slot->dma_addr,
BGMAC_RX_BUF_SIZE,
DMA_FROM_DEVICE);
break;
}
/* Omit CRC. */
len -= ETH_FCS_LEN;
/* Prepare new skb as replacement */
err = bgmac_dma_rx_skb_for_slot(bgmac, slot);
if (err) {
/* Poison the old skb */
rx->len = cpu_to_le16(0xdead);
rx->flags = cpu_to_le16(0xbeef);
dma_sync_single_for_device(dma_dev,
slot->dma_addr,
BGMAC_RX_BUF_SIZE,
DMA_FROM_DEVICE);
break;
}
bgmac_dma_rx_setup_desc(bgmac, ring, ring->start);
/* Unmap old skb, we'll pass it to the netfif */
dma_unmap_single(dma_dev, old_dma_addr,
BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
skb_put(skb, BGMAC_RX_FRAME_OFFSET + len);
skb_pull(skb, BGMAC_RX_FRAME_OFFSET);
skb_checksum_none_assert(skb);
skb->protocol = eth_type_trans(skb, bgmac->net_dev);
netif_receive_skb(skb);
handled++;
} while (0);
if (++ring->start >= BGMAC_RX_RING_SLOTS)
ring->start = 0;
if (handled >= weight) /* Should never be greater */
break;
}
return handled;
}
