2008-08-24 20:27:36

by Christian Lamparter

[permalink] [raw]
Subject: [PATCH] p54pci: rx tasklet refactoring

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 <[email protected]>
---
linux-next material as well
---
diff -Nurp a/drivers/net/wireless/p54/p54pci.c b/drivers/net/wireless/p54/p54pci.c
--- a/drivers/net/wireless/p54/p54pci.c 2008-08-24 02:13:44.000000000 +0200
+++ b/drivers/net/wireless/p54/p54pci.c 2008-08-24 22:05:06.000000000 +0200
@@ -3,6 +3,7 @@
* Linux device driver for PCI based Prism54
*
* Copyright (c) 2006, Michael Wu <[email protected]>
+ * Copyright (c) 2008, Christian Lamparter <[email protected]>
*
* Based on the islsm (softmac prism54) driver, which is:
* Copyright 2004-2006 Jean-Baptiste Note <[email protected]>, et al.
@@ -237,20 +238,22 @@ static int p54p_read_eeprom(struct ieee8
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;
@@ -267,16 +270,106 @@ static void p54p_refill_rx_ring(struct i
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)
@@ -298,65 +391,18 @@ static irqreturn_t p54p_interrupt(int ir
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;
- }
+ p54p_check_tx_ring(dev, &priv->tx_idx_mgmt,
+ 3, ring_control->tx_mgmt,
+ ARRAY_SIZE(ring_control->tx_mgmt),
+ priv->tx_buf_mgmt);
+
+ p54p_check_tx_ring(dev, &priv->tx_idx_data,
+ 1, ring_control->tx_data,
+ ARRAY_SIZE(ring_control->tx_data),
+ priv->tx_buf_data);

- pci_unmap_single(priv->pdev, le32_to_cpu(desc->host_addr),
- le16_to_cpu(desc->len), PCI_DMA_TODEVICE);
+ tasklet_schedule(&priv->rx_tasklet);

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

@@ -392,7 +438,7 @@ static void p54p_tx(struct ieee80211_hw
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);

@@ -420,8 +466,14 @@ static int p54p_open(struct ieee80211_hw
}

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);

@@ -465,6 +517,8 @@ static void p54p_stop(struct ieee80211_h
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);
@@ -473,26 +527,51 @@ static void p54p_stop(struct ieee80211_h

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_data[i]);
+ priv->rx_buf_data[i] = NULL;
+ }
+
+ 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[i]);
- priv->rx_buf[i] = NULL;
+ kfree_skb(priv->rx_buf_mgmt[i]);
+ priv->rx_buf_mgmt[i] = NULL;
}

- for (i = 0; i < ARRAY_SIZE(priv->tx_buf); i++) {
+ 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[i]);
- priv->tx_buf[i] = NULL;
+ kfree(priv->tx_buf_data[i]);
+ priv->tx_buf_data[i] = NULL;
}

- memset(ring_control, 0, sizeof(ring_control));
+ 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_mgmt[i]);
+ priv->tx_buf_mgmt[i] = NULL;
+ }
+
+ memset(ring_control, 0, sizeof(*ring_control));
}

static int __devinit p54p_probe(struct pci_dev *pdev,
@@ -585,6 +664,7 @@ static int __devinit p54p_probe(struct p
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) {
diff -Nurp a/drivers/net/wireless/p54/p54pci.h b/drivers/net/wireless/p54/p54pci.h
--- a/drivers/net/wireless/p54/p54pci.h 2008-08-24 02:13:44.000000000 +0200
+++ b/drivers/net/wireless/p54/p54pci.h 2008-08-24 21:52:29.000000000 +0200
@@ -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;
};