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ftgmac100: Remove rx 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 6, 2017
1 parent 027f426 commit 4ca2415
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Showing 2 changed files with 53 additions and 115 deletions.
152 changes: 41 additions & 111 deletions drivers/net/ethernet/faraday/ftgmac100.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -278,92 +278,6 @@ static void ftgmac100_stop_hw(struct ftgmac100 *priv)
iowrite32(0, priv->base + FTGMAC100_OFFSET_MACCR);
}

static bool ftgmac100_rxdes_first_segment(struct ftgmac100_rxdes *rxdes)
{
return rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_FRS);
}

static bool ftgmac100_rxdes_last_segment(struct ftgmac100_rxdes *rxdes)
{
return rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_LRS);
}

static bool ftgmac100_rxdes_packet_ready(struct ftgmac100_rxdes *rxdes)
{
return rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_RXPKT_RDY);
}

#define RXDES0_ANY_ERROR ( \
FTGMAC100_RXDES0_RX_ERR | \
FTGMAC100_RXDES0_CRC_ERR | \
FTGMAC100_RXDES0_FTL | \
FTGMAC100_RXDES0_RUNT | \
FTGMAC100_RXDES0_RX_ODD_NB)

static inline bool ftgmac100_rxdes_any_error(struct ftgmac100_rxdes *rxdes)
{
return rxdes->rxdes0 & cpu_to_le32(RXDES0_ANY_ERROR);
}

static bool ftgmac100_rxdes_rx_error(struct ftgmac100_rxdes *rxdes)
{
return rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_RX_ERR);
}

static bool ftgmac100_rxdes_crc_error(struct ftgmac100_rxdes *rxdes)
{
return rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_CRC_ERR);
}

static bool ftgmac100_rxdes_frame_too_long(struct ftgmac100_rxdes *rxdes)
{
return rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_FTL);
}

static bool ftgmac100_rxdes_runt(struct ftgmac100_rxdes *rxdes)
{
return rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_RUNT);
}

static bool ftgmac100_rxdes_odd_nibble(struct ftgmac100_rxdes *rxdes)
{
return rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_RX_ODD_NB);
}

static unsigned int ftgmac100_rxdes_data_length(struct ftgmac100_rxdes *rxdes)
{
return le32_to_cpu(rxdes->rxdes0) & FTGMAC100_RXDES0_VDBC;
}

static bool ftgmac100_rxdes_multicast(struct ftgmac100_rxdes *rxdes)
{
return rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_MULTICAST);
}

static void ftgmac100_rxdes_set_end_of_ring(const struct ftgmac100 *priv,
struct ftgmac100_rxdes *rxdes)
{
rxdes->rxdes0 |= cpu_to_le32(priv->rxdes0_edorr_mask);
}

static void ftgmac100_rxdes_set_dma_addr(struct ftgmac100_rxdes *rxdes,
dma_addr_t addr)
{
rxdes->rxdes3 = cpu_to_le32(addr);
}

static dma_addr_t ftgmac100_rxdes_get_dma_addr(struct ftgmac100_rxdes *rxdes)
{
return le32_to_cpu(rxdes->rxdes3);
}

static inline bool ftgmac100_rxdes_csum_err(struct ftgmac100_rxdes *rxdes)
{
return !!(rxdes->rxdes1 & cpu_to_le32(FTGMAC100_RXDES1_TCP_CHKSUM_ERR |
FTGMAC100_RXDES1_UDP_CHKSUM_ERR |
FTGMAC100_RXDES1_IP_CHKSUM_ERR));
}

static int ftgmac100_alloc_rx_buf(struct ftgmac100 *priv, unsigned int entry,
struct ftgmac100_rxdes *rxdes, gfp_t gfp)
{
Expand Down Expand Up @@ -395,13 +309,16 @@ static int ftgmac100_alloc_rx_buf(struct ftgmac100 *priv, unsigned int entry,
priv->rx_skbs[entry] = skb;

/* Store DMA address into RX desc */
ftgmac100_rxdes_set_dma_addr(rxdes, map);
rxdes->rxdes3 = cpu_to_le32(map);

/* Ensure the above is ordered vs clearing the OWN bit */
dma_wmb();

/* Clean rxdes0 (which resets own bit) */
rxdes->rxdes0 &= cpu_to_le32(priv->rxdes0_edorr_mask);
/* Clean status (which resets own bit) */
if (entry == (RX_QUEUE_ENTRIES - 1))
rxdes->rxdes0 = cpu_to_le32(priv->rxdes0_edorr_mask);
else
rxdes->rxdes0 = 0;

return 0;
}
Expand All @@ -411,20 +328,19 @@ static int ftgmac100_next_rx_pointer(int pointer)
return (pointer + 1) & (RX_QUEUE_ENTRIES - 1);
}

static void ftgmac100_rx_packet_error(struct ftgmac100 *priv,
struct ftgmac100_rxdes *rxdes)
static void ftgmac100_rx_packet_error(struct ftgmac100 *priv, u32 status)
{
struct net_device *netdev = priv->netdev;

if (ftgmac100_rxdes_rx_error(rxdes))
if (status & FTGMAC100_RXDES0_RX_ERR)
netdev->stats.rx_errors++;

if (ftgmac100_rxdes_crc_error(rxdes))
if (status & FTGMAC100_RXDES0_CRC_ERR)
netdev->stats.rx_crc_errors++;

if (ftgmac100_rxdes_frame_too_long(rxdes) ||
ftgmac100_rxdes_runt(rxdes) ||
ftgmac100_rxdes_odd_nibble(rxdes))
if (status & (FTGMAC100_RXDES0_FTL |
FTGMAC100_RXDES0_RUNT |
FTGMAC100_RXDES0_RX_ODD_NB))
netdev->stats.rx_length_errors++;
}

Expand All @@ -434,27 +350,31 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
struct ftgmac100_rxdes *rxdes;
struct sk_buff *skb;
unsigned int pointer, size;
u32 status;
dma_addr_t map;

/* Grab next RX descriptor */
pointer = priv->rx_pointer;
rxdes = &priv->descs->rxdes[pointer];

/* Grab descriptor status */
status = le32_to_cpu(rxdes->rxdes0);

/* Do we have a packet ? */
if (!ftgmac100_rxdes_packet_ready(rxdes))
if (!(status & FTGMAC100_RXDES0_RXPKT_RDY))
return false;

/* Order subsequent reads with the test for the ready bit */
dma_rmb();

/* We don't cope with fragmented RX packets */
if (unlikely(!ftgmac100_rxdes_first_segment(rxdes) ||
!ftgmac100_rxdes_last_segment(rxdes)))
if (unlikely(!(status & FTGMAC100_RXDES0_FRS) ||
!(status & FTGMAC100_RXDES0_LRS)))
goto drop;

/* Any error (other than csum offload) flagged ? */
if (unlikely(ftgmac100_rxdes_any_error(rxdes))) {
ftgmac100_rx_packet_error(priv, rxdes);
if (unlikely(status & RXDES0_ANY_ERROR)) {
ftgmac100_rx_packet_error(priv, status);
goto drop;
}

Expand All @@ -467,7 +387,7 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
goto drop;
}

if (unlikely(ftgmac100_rxdes_multicast(rxdes)))
if (unlikely(status & FTGMAC100_RXDES0_MULTICAST))
netdev->stats.multicast++;

/* If the HW found checksum errors, bounce it to software.
Expand All @@ -489,11 +409,12 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)
}

/* Grab received size annd transfer to skb */
size = ftgmac100_rxdes_data_length(rxdes);
size = status & FTGMAC100_RXDES0_VDBC;
skb_put(skb, size);

/* Tear down DMA mapping, do necessary cache management */
map = ftgmac100_rxdes_get_dma_addr(rxdes);
map = le32_to_cpu(rxdes->rxdes3);

#if defined(CONFIG_ARM) && !defined(CONFIG_ARM_DMA_USE_IOMMU)
/* When we don't have an iommu, we can save cycles by not
* invalidating the cache for the part of the packet that
Expand Down Expand Up @@ -525,7 +446,7 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)

drop:
/* Clean rxdes0 (which resets own bit) */
rxdes->rxdes0 &= cpu_to_le32(priv->rxdes0_edorr_mask);
rxdes->rxdes0 = cpu_to_le32(status & priv->rxdes0_edorr_mask);
priv->rx_pointer = ftgmac100_next_rx_pointer(pointer);
netdev->stats.rx_dropped++;
return true;
Expand Down Expand Up @@ -747,7 +668,7 @@ static void ftgmac100_free_buffers(struct ftgmac100 *priv)
for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
struct ftgmac100_rxdes *rxdes = &priv->descs->rxdes[i];
struct sk_buff *skb = priv->rx_skbs[i];
dma_addr_t map = ftgmac100_rxdes_get_dma_addr(rxdes);
dma_addr_t map = le32_to_cpu(rxdes->rxdes3);

if (!skb)
continue;
Expand Down Expand Up @@ -806,15 +727,17 @@ static int ftgmac100_alloc_rings(struct ftgmac100 *priv)

static void ftgmac100_init_rings(struct ftgmac100 *priv)
{
struct ftgmac100_rxdes *rxdes;
int i;

/* Initialize RX ring */
for (i = 0; i < RX_QUEUE_ENTRIES; i++) {
struct ftgmac100_rxdes *rxdes = &priv->descs->rxdes[i];
ftgmac100_rxdes_set_dma_addr(rxdes, priv->rx_scratch_dma);
rxdes = &priv->descs->rxdes[i];
rxdes->rxdes0 = 0;
rxdes->rxdes3 = cpu_to_le32(priv->rx_scratch_dma);
}
ftgmac100_rxdes_set_end_of_ring(priv, &priv->descs->rxdes[i - 1]);
/* Mark the end of the ring */
rxdes->rxdes0 |= cpu_to_le32(priv->rxdes0_edorr_mask);

/* Initialize TX ring */
for (i = 0; i < TX_QUEUE_ENTRIES; i++)
Expand Down Expand Up @@ -1030,6 +953,14 @@ static irqreturn_t ftgmac100_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}

static bool ftgmac100_check_rx(struct ftgmac100 *priv)
{
struct ftgmac100_rxdes *rxdes = &priv->descs->rxdes[priv->rx_pointer];

/* Do we have a packet ? */
return !!(rxdes->rxdes0 & cpu_to_le32(FTGMAC100_RXDES0_RXPKT_RDY));
}

static int ftgmac100_poll(struct napi_struct *napi, int budget)
{
struct ftgmac100 *priv = container_of(napi, struct ftgmac100, napi);
Expand Down Expand Up @@ -1069,8 +1000,7 @@ static int ftgmac100_poll(struct napi_struct *napi, int budget)
*/
iowrite32(FTGMAC100_INT_RXTX,
priv->base + FTGMAC100_OFFSET_ISR);
if (ftgmac100_rxdes_packet_ready
(ftgmac100_current_rxdes(priv)) || priv->tx_pending)
if (ftgmac100_check_rx(priv) || priv->tx_pending)
return budget;

/* deschedule NAPI */
Expand Down
16 changes: 12 additions & 4 deletions drivers/net/ethernet/faraday/ftgmac100.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -227,10 +227,10 @@ struct ftgmac100_txdes {
* Receive descriptor, aligned to 16 bytes
*/
struct ftgmac100_rxdes {
unsigned int rxdes0;
unsigned int rxdes1;
unsigned int rxdes2; /* not used by HW */
unsigned int rxdes3; /* RXBUF_BADR */
__le32 rxdes0; /* Control & status bits */
__le32 rxdes1; /* Checksum and vlan status */
__le32 rxdes2; /* length/type on AST2500 */
__le32 rxdes3; /* DMA buffer address */
} __attribute__ ((aligned(16)));

#define FTGMAC100_RXDES0_VDBC 0x3fff
Expand All @@ -248,6 +248,14 @@ struct ftgmac100_rxdes {
#define FTGMAC100_RXDES0_FRS (1 << 29)
#define FTGMAC100_RXDES0_RXPKT_RDY (1 << 31)

/* Errors we care about for dropping packets */
#define RXDES0_ANY_ERROR ( \
FTGMAC100_RXDES0_RX_ERR | \
FTGMAC100_RXDES0_CRC_ERR | \
FTGMAC100_RXDES0_FTL | \
FTGMAC100_RXDES0_RUNT | \
FTGMAC100_RXDES0_RX_ODD_NB)

#define FTGMAC100_RXDES1_VLANTAG_CI 0xffff
#define FTGMAC100_RXDES1_PROT_MASK (0x3 << 20)
#define FTGMAC100_RXDES1_PROT_NONIP (0x0 << 20)
Expand Down

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