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ftgmac100: Remove tx descriptor accessors
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Directly access the fields when needed. The accessors add clutter
not clarity and in some cases cause unnecessary read-modify-write
type access on the slow (uncached) descriptor memory.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Benjamin Herrenschmidt authored and David S. Miller committed Apr 10, 2017
1 parent 6db7470 commit 52c0cae
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Showing 2 changed files with 69 additions and 114 deletions.
175 changes: 65 additions & 110 deletions drivers/net/ethernet/faraday/ftgmac100.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -468,77 +468,13 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
return true;
}

static bool ftgmac100_txdes_owned_by_dma(struct ftgmac100_txdes *txdes)
static u32 ftgmac100_base_tx_ctlstat(struct ftgmac100 *priv,
unsigned int index)
{
return txdes->txdes0 & cpu_to_le32(FTGMAC100_TXDES0_TXDMA_OWN);
}

static void ftgmac100_txdes_set_dma_own(struct ftgmac100_txdes *txdes)
{
txdes->txdes0 |= cpu_to_le32(FTGMAC100_TXDES0_TXDMA_OWN);
}

static void ftgmac100_txdes_set_end_of_ring(const struct ftgmac100 *priv,
struct ftgmac100_txdes *txdes)
{
txdes->txdes0 |= cpu_to_le32(priv->txdes0_edotr_mask);
}

static void ftgmac100_txdes_set_first_segment(struct ftgmac100_txdes *txdes)
{
txdes->txdes0 |= cpu_to_le32(FTGMAC100_TXDES0_FTS);
}

static inline bool ftgmac100_txdes_get_first_segment(struct ftgmac100_txdes *txdes)
{
return (txdes->txdes0 & cpu_to_le32(FTGMAC100_TXDES0_FTS)) != 0;
}

static void ftgmac100_txdes_set_last_segment(struct ftgmac100_txdes *txdes)
{
txdes->txdes0 |= cpu_to_le32(FTGMAC100_TXDES0_LTS);
}

static inline bool ftgmac100_txdes_get_last_segment(struct ftgmac100_txdes *txdes)
{
return (txdes->txdes0 & cpu_to_le32(FTGMAC100_TXDES0_LTS)) != 0;
}

static void ftgmac100_txdes_set_buffer_size(struct ftgmac100_txdes *txdes,
unsigned int len)
{
txdes->txdes0 |= cpu_to_le32(FTGMAC100_TXDES0_TXBUF_SIZE(len));
}

static inline unsigned int ftgmac100_txdes_get_buffer_size(struct ftgmac100_txdes *txdes)
{
return FTGMAC100_TXDES0_TXBUF_SIZE(cpu_to_le32(txdes->txdes0));
}

static void ftgmac100_txdes_set_tcpcs(struct ftgmac100_txdes *txdes)
{
txdes->txdes1 |= cpu_to_le32(FTGMAC100_TXDES1_TCP_CHKSUM);
}

static void ftgmac100_txdes_set_udpcs(struct ftgmac100_txdes *txdes)
{
txdes->txdes1 |= cpu_to_le32(FTGMAC100_TXDES1_UDP_CHKSUM);
}

static void ftgmac100_txdes_set_ipcs(struct ftgmac100_txdes *txdes)
{
txdes->txdes1 |= cpu_to_le32(FTGMAC100_TXDES1_IP_CHKSUM);
}

static void ftgmac100_txdes_set_dma_addr(struct ftgmac100_txdes *txdes,
dma_addr_t addr)
{
txdes->txdes3 = cpu_to_le32(addr);
}

static dma_addr_t ftgmac100_txdes_get_dma_addr(struct ftgmac100_txdes *txdes)
{
return (dma_addr_t)le32_to_cpu(txdes->txdes3);
if (index == (TX_QUEUE_ENTRIES - 1))
return priv->txdes0_edotr_mask;
else
return 0;
}

static int ftgmac100_next_tx_pointer(int pointer)
Expand Down Expand Up @@ -566,29 +502,24 @@ static bool ftgmac100_tx_buf_cleanable(struct ftgmac100 *priv)
static void ftgmac100_free_tx_packet(struct ftgmac100 *priv,
unsigned int pointer,
struct sk_buff *skb,
struct ftgmac100_txdes *txdes)
struct ftgmac100_txdes *txdes,
u32 ctl_stat)
{
dma_addr_t map = ftgmac100_txdes_get_dma_addr(txdes);
dma_addr_t map = le32_to_cpu(txdes->txdes3);
size_t len;

if (ftgmac100_txdes_get_first_segment(txdes)) {
dma_unmap_single(priv->dev, map, skb_headlen(skb),
DMA_TO_DEVICE);
if (ctl_stat & FTGMAC100_TXDES0_FTS) {
len = skb_headlen(skb);
dma_unmap_single(priv->dev, map, len, DMA_TO_DEVICE);
} else {
dma_unmap_page(priv->dev, map,
ftgmac100_txdes_get_buffer_size(txdes),
DMA_TO_DEVICE);
len = FTGMAC100_TXDES0_TXBUF_SIZE(ctl_stat);
dma_unmap_page(priv->dev, map, len, DMA_TO_DEVICE);
}

if (ftgmac100_txdes_get_last_segment(txdes))
/* Free SKB on last segment */
if (ctl_stat & FTGMAC100_TXDES0_LTS)
dev_kfree_skb(skb);
priv->tx_skbs[pointer] = NULL;

/* Clear txdes0 except end of ring bit, clear txdes1 as we
* only "OR" into it, leave 2 and 3 alone as 2 is unused
* and 3 will be overwritten entirely
*/
txdes->txdes0 &= cpu_to_le32(priv->txdes0_edotr_mask);
txdes->txdes1 = 0;
}

static bool ftgmac100_tx_complete_packet(struct ftgmac100 *priv)
Expand All @@ -597,17 +528,20 @@ static bool ftgmac100_tx_complete_packet(struct ftgmac100 *priv)
struct ftgmac100_txdes *txdes;
struct sk_buff *skb;
unsigned int pointer;
u32 ctl_stat;

pointer = priv->tx_clean_pointer;
txdes = &priv->descs->txdes[pointer];

if (ftgmac100_txdes_owned_by_dma(txdes))
ctl_stat = le32_to_cpu(txdes->txdes0);
if (ctl_stat & FTGMAC100_TXDES0_TXDMA_OWN)
return false;

skb = priv->tx_skbs[pointer];
netdev->stats.tx_packets++;
netdev->stats.tx_bytes += skb->len;
ftgmac100_free_tx_packet(priv, pointer, skb, txdes);
ftgmac100_free_tx_packet(priv, pointer, skb, txdes, ctl_stat);
txdes->txdes0 = cpu_to_le32(ctl_stat & priv->txdes0_edotr_mask);

priv->tx_clean_pointer = ftgmac100_next_tx_pointer(pointer);

Expand Down Expand Up @@ -644,6 +578,7 @@ static int ftgmac100_hard_start_xmit(struct sk_buff *skb,
struct ftgmac100 *priv = netdev_priv(netdev);
struct ftgmac100_txdes *txdes, *first;
unsigned int pointer, nfrags, len, i, j;
u32 f_ctl_stat, ctl_stat, csum_vlan;
dma_addr_t map;

/* The HW doesn't pad small frames */
Expand Down Expand Up @@ -679,26 +614,34 @@ static int ftgmac100_hard_start_xmit(struct sk_buff *skb,
pointer = priv->tx_pointer;
txdes = first = &priv->descs->txdes[pointer];

/* Setup it up with the packet head. We don't set the OWN bit yet. */
/* Setup it up with the packet head. Don't write the head to the
* ring just yet
*/
priv->tx_skbs[pointer] = skb;
ftgmac100_txdes_set_dma_addr(txdes, map);
ftgmac100_txdes_set_buffer_size(txdes, len);
ftgmac100_txdes_set_first_segment(txdes);
f_ctl_stat = ftgmac100_base_tx_ctlstat(priv, pointer);
f_ctl_stat |= FTGMAC100_TXDES0_TXDMA_OWN;
f_ctl_stat |= FTGMAC100_TXDES0_TXBUF_SIZE(len);
f_ctl_stat |= FTGMAC100_TXDES0_FTS;
if (nfrags == 0)
f_ctl_stat |= FTGMAC100_TXDES0_LTS;
txdes->txdes3 = cpu_to_le32(map);

/* Setup HW checksumming */
csum_vlan = 0;
if (skb->ip_summed == CHECKSUM_PARTIAL) {
__be16 protocol = skb->protocol;

if (protocol == cpu_to_be16(ETH_P_IP)) {
u8 ip_proto = ip_hdr(skb)->protocol;

ftgmac100_txdes_set_ipcs(txdes);
csum_vlan |= FTGMAC100_TXDES1_IP_CHKSUM;
if (ip_proto == IPPROTO_TCP)
ftgmac100_txdes_set_tcpcs(txdes);
csum_vlan |= FTGMAC100_TXDES1_TCP_CHKSUM;
else if (ip_proto == IPPROTO_UDP)
ftgmac100_txdes_set_udpcs(txdes);
csum_vlan |= FTGMAC100_TXDES1_UDP_CHKSUM;
}
}
txdes->txdes1 = cpu_to_le32(csum_vlan);

/* Next descriptor */
pointer = ftgmac100_next_tx_pointer(pointer);
Expand All @@ -718,20 +661,24 @@ static int ftgmac100_hard_start_xmit(struct sk_buff *skb,
/* Setup descriptor */
priv->tx_skbs[pointer] = skb;
txdes = &priv->descs->txdes[pointer];
ftgmac100_txdes_set_dma_addr(txdes, map);
ftgmac100_txdes_set_buffer_size(txdes, len);
ftgmac100_txdes_set_dma_own(txdes);
ctl_stat = ftgmac100_base_tx_ctlstat(priv, pointer);
ctl_stat |= FTGMAC100_TXDES0_TXDMA_OWN;
ctl_stat |= FTGMAC100_TXDES0_TXBUF_SIZE(len);
if (i == (nfrags - 1))
ctl_stat |= FTGMAC100_TXDES0_LTS;
txdes->txdes0 = cpu_to_le32(ctl_stat);
txdes->txdes1 = 0;
txdes->txdes3 = cpu_to_le32(map);

/* Next one */
pointer = ftgmac100_next_tx_pointer(pointer);
}

/* Tag last fragment */
ftgmac100_txdes_set_last_segment(txdes);

/* Order the previous packet and descriptor udpates
* before setting the OWN bit.
* before setting the OWN bit on the first descriptor.
*/
dma_wmb();
ftgmac100_txdes_set_dma_own(first);
first->txdes0 = cpu_to_le32(f_ctl_stat);

/* Update next TX pointer */
priv->tx_pointer = pointer;
Expand All @@ -758,13 +705,16 @@ static int ftgmac100_hard_start_xmit(struct sk_buff *skb,

/* Free head */
pointer = priv->tx_pointer;
ftgmac100_free_tx_packet(priv, pointer, skb, first);
ftgmac100_free_tx_packet(priv, pointer, skb, first, f_ctl_stat);
first->txdes0 = cpu_to_le32(f_ctl_stat & priv->txdes0_edotr_mask);

/* Then all fragments */
for (j = 0; j < i; j++) {
pointer = ftgmac100_next_tx_pointer(pointer);
txdes = &priv->descs->txdes[pointer];
ftgmac100_free_tx_packet(priv, pointer, skb, txdes);
ctl_stat = le32_to_cpu(txdes->txdes0);
ftgmac100_free_tx_packet(priv, pointer, skb, txdes, ctl_stat);
txdes->txdes0 = cpu_to_le32(ctl_stat & priv->txdes0_edotr_mask);
}

/* This cannot be reached if we successfully mapped the
Expand Down Expand Up @@ -802,8 +752,10 @@ static void ftgmac100_free_buffers(struct ftgmac100 *priv)
struct ftgmac100_txdes *txdes = &priv->descs->txdes[i];
struct sk_buff *skb = priv->tx_skbs[i];

if (skb)
ftgmac100_free_tx_packet(priv, i, skb, txdes);
if (!skb)
continue;
ftgmac100_free_tx_packet(priv, i, skb, txdes,
le32_to_cpu(txdes->txdes0));
}
}

Expand Down Expand Up @@ -843,6 +795,7 @@ static int ftgmac100_alloc_rings(struct ftgmac100 *priv)
static void ftgmac100_init_rings(struct ftgmac100 *priv)
{
struct ftgmac100_rxdes *rxdes;
struct ftgmac100_txdes *txdes;
int i;

/* Initialize RX ring */
Expand All @@ -855,9 +808,11 @@ static void ftgmac100_init_rings(struct ftgmac100 *priv)
rxdes->rxdes0 |= cpu_to_le32(priv->rxdes0_edorr_mask);

/* Initialize TX ring */
for (i = 0; i < TX_QUEUE_ENTRIES; i++)
priv->descs->txdes[i].txdes0 = 0;
ftgmac100_txdes_set_end_of_ring(priv, &priv->descs->txdes[i -1]);
for (i = 0; i < TX_QUEUE_ENTRIES; i++) {
txdes = &priv->descs->txdes[i];
txdes->txdes0 = 0;
}
txdes->txdes0 |= cpu_to_le32(priv->txdes0_edotr_mask);
}

static int ftgmac100_alloc_rx_buffers(struct ftgmac100 *priv)
Expand Down
8 changes: 4 additions & 4 deletions drivers/net/ethernet/faraday/ftgmac100.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -202,10 +202,10 @@
* Transmit descriptor, aligned to 16 bytes
*/
struct ftgmac100_txdes {
unsigned int txdes0;
unsigned int txdes1;
unsigned int txdes2; /* not used by HW */
unsigned int txdes3; /* TXBUF_BADR */
__le32 txdes0; /* Control & status bits */
__le32 txdes1; /* Irq, checksum and vlan control */
__le32 txdes2; /* Reserved */
__le32 txdes3; /* DMA buffer address */
} __attribute__ ((aligned(16)));

#define FTGMAC100_TXDES0_TXBUF_SIZE(x) ((x) & 0x3fff)
Expand Down

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