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p54pci: rx tasklet refactoring
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This patch moves the all of p54pci's receiver code out of the
bloated interrupt handler routine and into a less critical tasklet.

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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Christian Lamparter authored and John W. Linville committed Aug 29, 2008
1 parent 84df3ed commit 7262d59
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Showing 2 changed files with 168 additions and 84 deletions.
242 changes: 161 additions & 81 deletions drivers/net/wireless/p54/p54pci.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@
* Linux device driver for PCI based Prism54
*
* Copyright (c) 2006, Michael Wu <flamingice@sourmilk.net>
* Copyright (c) 2008, Christian Lamparter <chunkeey@web.de>
*
* Based on the islsm (softmac prism54) driver, which is:
* Copyright 2004-2006 Jean-Baptiste Note <jean-baptiste.note@m4x.org>, et al.
Expand Down Expand Up @@ -237,20 +238,22 @@ static int p54p_read_eeprom(struct ieee80211_hw *dev)
return err;
}

static void p54p_refill_rx_ring(struct ieee80211_hw *dev)
static void p54p_refill_rx_ring(struct ieee80211_hw *dev,
int ring_index, struct p54p_desc *ring, u32 ring_limit,
struct sk_buff **rx_buf)
{
struct p54p_priv *priv = dev->priv;
struct p54p_ring_control *ring_control = priv->ring_control;
u32 limit, host_idx, idx;
u32 limit, idx, i;

host_idx = le32_to_cpu(ring_control->host_idx[0]);
limit = host_idx;
limit -= le32_to_cpu(ring_control->device_idx[0]);
limit = ARRAY_SIZE(ring_control->rx_data) - limit;
idx = le32_to_cpu(ring_control->host_idx[ring_index]);
limit = idx;
limit -= le32_to_cpu(ring_control->device_idx[ring_index]);
limit = ring_limit - limit;

idx = host_idx % ARRAY_SIZE(ring_control->rx_data);
i = idx % ring_limit;
while (limit-- > 1) {
struct p54p_desc *desc = &ring_control->rx_data[idx];
struct p54p_desc *desc = &ring[i];

if (!desc->host_addr) {
struct sk_buff *skb;
Expand All @@ -267,16 +270,106 @@ static void p54p_refill_rx_ring(struct ieee80211_hw *dev)
desc->device_addr = 0; // FIXME: necessary?
desc->len = cpu_to_le16(MAX_RX_SIZE);
desc->flags = 0;
priv->rx_buf[idx] = skb;
rx_buf[i] = skb;
}

i++;
idx++;
host_idx++;
idx %= ARRAY_SIZE(ring_control->rx_data);
i %= ring_limit;
}

wmb();
ring_control->host_idx[0] = cpu_to_le32(host_idx);
ring_control->host_idx[ring_index] = cpu_to_le32(idx);
}

static void p54p_check_rx_ring(struct ieee80211_hw *dev, u32 *index,
int ring_index, struct p54p_desc *ring, u32 ring_limit,
struct sk_buff **rx_buf)
{
struct p54p_priv *priv = dev->priv;
struct p54p_ring_control *ring_control = priv->ring_control;
struct p54p_desc *desc;
u32 idx, i;

i = (*index) % ring_limit;
(*index) = idx = le32_to_cpu(ring_control->device_idx[ring_index]);
idx %= ring_limit;
while (i != idx) {
u16 len;
struct sk_buff *skb;
desc = &ring[i];
len = le16_to_cpu(desc->len);
skb = rx_buf[i];

if (!skb)
continue;

skb_put(skb, len);

if (p54_rx(dev, skb)) {
pci_unmap_single(priv->pdev,
le32_to_cpu(desc->host_addr),
MAX_RX_SIZE, PCI_DMA_FROMDEVICE);
rx_buf[i] = NULL;
desc->host_addr = 0;
} else {
skb_trim(skb, 0);
desc->len = cpu_to_le16(MAX_RX_SIZE);
}

i++;
i %= ring_limit;
}

p54p_refill_rx_ring(dev, ring_index, ring, ring_limit, rx_buf);
}

/* caller must hold priv->lock */
static void p54p_check_tx_ring(struct ieee80211_hw *dev, u32 *index,
int ring_index, struct p54p_desc *ring, u32 ring_limit,
void **tx_buf)
{
struct p54p_priv *priv = dev->priv;
struct p54p_ring_control *ring_control = priv->ring_control;
struct p54p_desc *desc;
u32 idx, i;

i = (*index) % ring_limit;
(*index) = idx = le32_to_cpu(ring_control->device_idx[1]);
idx %= ring_limit;

while (i != idx) {
desc = &ring[i];
kfree(tx_buf[i]);
tx_buf[i] = NULL;

pci_unmap_single(priv->pdev, le32_to_cpu(desc->host_addr),
le16_to_cpu(desc->len), PCI_DMA_TODEVICE);

desc->host_addr = 0;
desc->device_addr = 0;
desc->len = 0;
desc->flags = 0;

i++;
i %= ring_limit;
}
}

static void p54p_rx_tasklet(unsigned long dev_id)
{
struct ieee80211_hw *dev = (struct ieee80211_hw *)dev_id;
struct p54p_priv *priv = dev->priv;
struct p54p_ring_control *ring_control = priv->ring_control;

p54p_check_rx_ring(dev, &priv->rx_idx_mgmt, 2, ring_control->rx_mgmt,
ARRAY_SIZE(ring_control->rx_mgmt), priv->rx_buf_mgmt);

p54p_check_rx_ring(dev, &priv->rx_idx_data, 0, ring_control->rx_data,
ARRAY_SIZE(ring_control->rx_data), priv->rx_buf_data);

wmb();
P54P_WRITE(dev_int, cpu_to_le32(ISL38XX_DEV_INT_UPDATE));
}

static irqreturn_t p54p_interrupt(int irq, void *dev_id)
Expand All @@ -298,65 +391,18 @@ static irqreturn_t p54p_interrupt(int irq, void *dev_id)
reg &= P54P_READ(int_enable);

if (reg & cpu_to_le32(ISL38XX_INT_IDENT_UPDATE)) {
struct p54p_desc *desc;
u32 idx, i;
i = priv->tx_idx;
i %= ARRAY_SIZE(ring_control->tx_data);
priv->tx_idx = idx = le32_to_cpu(ring_control->device_idx[1]);
idx %= ARRAY_SIZE(ring_control->tx_data);

while (i != idx) {
desc = &ring_control->tx_data[i];
if (priv->tx_buf[i]) {
kfree(priv->tx_buf[i]);
priv->tx_buf[i] = NULL;
}

pci_unmap_single(priv->pdev, le32_to_cpu(desc->host_addr),
le16_to_cpu(desc->len), PCI_DMA_TODEVICE);
p54p_check_tx_ring(dev, &priv->tx_idx_mgmt,
3, ring_control->tx_mgmt,
ARRAY_SIZE(ring_control->tx_mgmt),
priv->tx_buf_mgmt);

desc->host_addr = 0;
desc->device_addr = 0;
desc->len = 0;
desc->flags = 0;
p54p_check_tx_ring(dev, &priv->tx_idx_data,
1, ring_control->tx_data,
ARRAY_SIZE(ring_control->tx_data),
priv->tx_buf_data);

i++;
i %= ARRAY_SIZE(ring_control->tx_data);
}

i = priv->rx_idx;
i %= ARRAY_SIZE(ring_control->rx_data);
priv->rx_idx = idx = le32_to_cpu(ring_control->device_idx[0]);
idx %= ARRAY_SIZE(ring_control->rx_data);
while (i != idx) {
u16 len;
struct sk_buff *skb;
desc = &ring_control->rx_data[i];
len = le16_to_cpu(desc->len);
skb = priv->rx_buf[i];

skb_put(skb, len);

if (p54_rx(dev, skb)) {
pci_unmap_single(priv->pdev,
le32_to_cpu(desc->host_addr),
MAX_RX_SIZE, PCI_DMA_FROMDEVICE);

priv->rx_buf[i] = NULL;
desc->host_addr = 0;
} else {
skb_trim(skb, 0);
desc->len = cpu_to_le16(MAX_RX_SIZE);
}

i++;
i %= ARRAY_SIZE(ring_control->rx_data);
}
tasklet_schedule(&priv->rx_tasklet);

p54p_refill_rx_ring(dev);

wmb();
P54P_WRITE(dev_int, cpu_to_le32(ISL38XX_DEV_INT_UPDATE));
} else if (reg & cpu_to_le32(ISL38XX_INT_IDENT_INIT))
complete(&priv->boot_comp);

Expand Down Expand Up @@ -392,7 +438,7 @@ static void p54p_tx(struct ieee80211_hw *dev, struct p54_control_hdr *data,
ring_control->host_idx[1] = cpu_to_le32(idx + 1);

if (free_on_tx)
priv->tx_buf[i] = data;
priv->tx_buf_data[i] = data;

spin_unlock_irqrestore(&priv->lock, flags);

Expand Down Expand Up @@ -420,8 +466,14 @@ static int p54p_open(struct ieee80211_hw *dev)
}

memset(priv->ring_control, 0, sizeof(*priv->ring_control));
priv->rx_idx = priv->tx_idx = 0;
p54p_refill_rx_ring(dev);
priv->rx_idx_data = priv->tx_idx_data = 0;
priv->rx_idx_mgmt = priv->tx_idx_mgmt = 0;

p54p_refill_rx_ring(dev, 0, priv->ring_control->rx_data,
ARRAY_SIZE(priv->ring_control->rx_data), priv->rx_buf_data);

p54p_refill_rx_ring(dev, 2, priv->ring_control->rx_mgmt,
ARRAY_SIZE(priv->ring_control->rx_mgmt), priv->rx_buf_mgmt);

p54p_upload_firmware(dev);

Expand Down Expand Up @@ -465,6 +517,8 @@ static void p54p_stop(struct ieee80211_hw *dev)
unsigned int i;
struct p54p_desc *desc;

tasklet_kill(&priv->rx_tasklet);

P54P_WRITE(int_enable, cpu_to_le32(0));
P54P_READ(int_enable);
udelay(10);
Expand All @@ -473,26 +527,51 @@ static void p54p_stop(struct ieee80211_hw *dev)

P54P_WRITE(dev_int, cpu_to_le32(ISL38XX_DEV_INT_RESET));

for (i = 0; i < ARRAY_SIZE(priv->rx_buf); i++) {
for (i = 0; i < ARRAY_SIZE(priv->rx_buf_data); i++) {
desc = &ring_control->rx_data[i];
if (desc->host_addr)
pci_unmap_single(priv->pdev, le32_to_cpu(desc->host_addr),
pci_unmap_single(priv->pdev,
le32_to_cpu(desc->host_addr),
MAX_RX_SIZE, PCI_DMA_FROMDEVICE);
kfree_skb(priv->rx_buf[i]);
priv->rx_buf[i] = NULL;
kfree_skb(priv->rx_buf_data[i]);
priv->rx_buf_data[i] = NULL;
}

for (i = 0; i < ARRAY_SIZE(priv->tx_buf); i++) {
for (i = 0; i < ARRAY_SIZE(priv->rx_buf_mgmt); i++) {
desc = &ring_control->rx_mgmt[i];
if (desc->host_addr)
pci_unmap_single(priv->pdev,
le32_to_cpu(desc->host_addr),
MAX_RX_SIZE, PCI_DMA_FROMDEVICE);
kfree_skb(priv->rx_buf_mgmt[i]);
priv->rx_buf_mgmt[i] = NULL;
}

for (i = 0; i < ARRAY_SIZE(priv->tx_buf_data); i++) {
desc = &ring_control->tx_data[i];
if (desc->host_addr)
pci_unmap_single(priv->pdev, le32_to_cpu(desc->host_addr),
le16_to_cpu(desc->len), PCI_DMA_TODEVICE);
pci_unmap_single(priv->pdev,
le32_to_cpu(desc->host_addr),
le16_to_cpu(desc->len),
PCI_DMA_TODEVICE);

kfree(priv->tx_buf_data[i]);
priv->tx_buf_data[i] = NULL;
}

for (i = 0; i < ARRAY_SIZE(priv->tx_buf_mgmt); i++) {
desc = &ring_control->tx_mgmt[i];
if (desc->host_addr)
pci_unmap_single(priv->pdev,
le32_to_cpu(desc->host_addr),
le16_to_cpu(desc->len),
PCI_DMA_TODEVICE);

kfree(priv->tx_buf[i]);
priv->tx_buf[i] = NULL;
kfree(priv->tx_buf_mgmt[i]);
priv->tx_buf_mgmt[i] = NULL;
}

memset(ring_control, 0, sizeof(ring_control));
memset(ring_control, 0, sizeof(*ring_control));
}

static int __devinit p54p_probe(struct pci_dev *pdev,
Expand Down Expand Up @@ -585,6 +664,7 @@ static int __devinit p54p_probe(struct pci_dev *pdev,
priv->common.tx = p54p_tx;

spin_lock_init(&priv->lock);
tasklet_init(&priv->rx_tasklet, p54p_rx_tasklet, (unsigned long)dev);

err = ieee80211_register_hw(dev);
if (err) {
Expand Down
10 changes: 7 additions & 3 deletions drivers/net/wireless/p54/p54pci.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -92,13 +92,17 @@ struct p54p_priv {
struct p54_common common;
struct pci_dev *pdev;
struct p54p_csr __iomem *map;
struct tasklet_struct rx_tasklet;

spinlock_t lock;
struct p54p_ring_control *ring_control;
dma_addr_t ring_control_dma;
u32 rx_idx, tx_idx;
struct sk_buff *rx_buf[8];
void *tx_buf[32];
u32 rx_idx_data, tx_idx_data;
u32 rx_idx_mgmt, tx_idx_mgmt;
struct sk_buff *rx_buf_data[8];
struct sk_buff *rx_buf_mgmt[4];
void *tx_buf_data[32];
void *tx_buf_mgmt[4];
struct completion boot_comp;
};

Expand Down

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