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NET: sa11x0-ir: containerize DMA data
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Both the transmit and receive DMA store identical data: the skb, dma
address, and the dma registers.  Move this data into its own data
structure.  The following replacements were used:

	rxskb -> dma_rx.skb
	rxbuf_dma -> dma_rx.dma
	rxdma -> dma_rx.regs

	txskb -> dma_tx.skb
	txbuf_dma -> dma_tx.dma
	txdma -> dma_tx.regs

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Russell King committed Feb 9, 2012
1 parent e556fdb commit 885767c
Showing 1 changed file with 48 additions and 46 deletions.
94 changes: 48 additions & 46 deletions drivers/net/irda/sa1100_ir.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -43,6 +43,12 @@ static int power_level = 3;
static int tx_lpm;
static int max_rate = 4000000;

struct sa1100_buf {
struct sk_buff *skb;
dma_addr_t dma;
dma_regs_t *regs;
};

struct sa1100_irda {
unsigned char hscr0;
unsigned char utcr4;
Expand All @@ -52,12 +58,8 @@ struct sa1100_irda {
int speed;
int newspeed;

struct sk_buff *txskb;
struct sk_buff *rxskb;
dma_addr_t txbuf_dma;
dma_addr_t rxbuf_dma;
dma_regs_t *txdma;
dma_regs_t *rxdma;
struct sa1100_buf dma_rx;
struct sa1100_buf dma_tx;

struct device *dev;
struct irda_platform_data *pdata;
Expand All @@ -77,11 +79,11 @@ struct sa1100_irda {
*/
static int sa1100_irda_rx_alloc(struct sa1100_irda *si)
{
if (si->rxskb)
if (si->dma_rx.skb)
return 0;

si->rxskb = alloc_skb(HPSIR_MAX_RXLEN + 1, GFP_ATOMIC);
if (!si->rxskb) {
si->dma_rx.skb = alloc_skb(HPSIR_MAX_RXLEN + 1, GFP_ATOMIC);
if (!si->dma_rx.skb) {
printk(KERN_ERR "sa1100_ir: out of memory for RX SKB\n");
return -ENOMEM;
}
Expand All @@ -90,13 +92,13 @@ static int sa1100_irda_rx_alloc(struct sa1100_irda *si)
* Align any IP headers that may be contained
* within the frame.
*/
skb_reserve(si->rxskb, 1);
skb_reserve(si->dma_rx.skb, 1);

si->rxbuf_dma = dma_map_single(si->dev, si->rxskb->data,
si->dma_rx.dma = dma_map_single(si->dev, si->dma_rx.skb->data,
HPSIR_MAX_RXLEN,
DMA_FROM_DEVICE);
if (dma_mapping_error(si->dev, si->rxbuf_dma)) {
dev_kfree_skb_any(si->rxskb);
if (dma_mapping_error(si->dev, si->dma_rx.dma)) {
dev_kfree_skb_any(si->dma_rx.skb);
return -ENOMEM;
}

Expand All @@ -109,7 +111,7 @@ static int sa1100_irda_rx_alloc(struct sa1100_irda *si)
*/
static void sa1100_irda_rx_dma_start(struct sa1100_irda *si)
{
if (!si->rxskb) {
if (!si->dma_rx.skb) {
printk(KERN_ERR "sa1100_ir: rx buffer went missing\n");
return;
}
Expand All @@ -122,8 +124,8 @@ static void sa1100_irda_rx_dma_start(struct sa1100_irda *si)
/*
* Enable the DMA, receiver and receive interrupt.
*/
sa1100_clear_dma(si->rxdma);
sa1100_start_dma(si->rxdma, si->rxbuf_dma, HPSIR_MAX_RXLEN);
sa1100_clear_dma(si->dma_rx.regs);
sa1100_start_dma(si->dma_rx.regs, si->dma_rx.dma, HPSIR_MAX_RXLEN);
Ser2HSCR0 = si->hscr0 | HSCR0_HSSP | HSCR0_RXE;
}

Expand All @@ -144,7 +146,7 @@ static int sa1100_irda_set_speed(struct sa1100_irda *si, int speed)
* Stop the receive DMA.
*/
if (IS_FIR(si))
sa1100_stop_dma(si->rxdma);
sa1100_stop_dma(si->dma_rx.regs);

local_irq_save(flags);

Expand Down Expand Up @@ -280,8 +282,8 @@ static void sa1100_irda_shutdown(struct sa1100_irda *si)
/*
* Stop all DMA activity.
*/
sa1100_stop_dma(si->rxdma);
sa1100_stop_dma(si->txdma);
sa1100_stop_dma(si->dma_rx.regs);
sa1100_stop_dma(si->dma_tx.regs);

/* Disable the port. */
Ser2UTCR3 = 0;
Expand Down Expand Up @@ -460,7 +462,7 @@ static void sa1100_irda_hpsir_irq(struct net_device *dev)

static void sa1100_irda_fir_error(struct sa1100_irda *si, struct net_device *dev)
{
struct sk_buff *skb = si->rxskb;
struct sk_buff *skb = si->dma_rx.skb;
dma_addr_t dma_addr;
unsigned int len, stat, data;

Expand All @@ -472,11 +474,11 @@ static void sa1100_irda_fir_error(struct sa1100_irda *si, struct net_device *dev
/*
* Get the current data position.
*/
dma_addr = sa1100_get_dma_pos(si->rxdma);
len = dma_addr - si->rxbuf_dma;
dma_addr = sa1100_get_dma_pos(si->dma_rx.regs);
len = dma_addr - si->dma_rx.dma;
if (len > HPSIR_MAX_RXLEN)
len = HPSIR_MAX_RXLEN;
dma_unmap_single(si->dev, si->rxbuf_dma, len, DMA_FROM_DEVICE);
dma_unmap_single(si->dev, si->dma_rx.dma, len, DMA_FROM_DEVICE);

do {
/*
Expand Down Expand Up @@ -504,7 +506,7 @@ static void sa1100_irda_fir_error(struct sa1100_irda *si, struct net_device *dev
} while (Ser2HSSR0 & HSSR0_EIF);

if (stat & HSSR1_EOF) {
si->rxskb = NULL;
si->dma_rx.skb = NULL;

skb_put(skb, len);
skb->dev = dev;
Expand All @@ -524,7 +526,7 @@ static void sa1100_irda_fir_error(struct sa1100_irda *si, struct net_device *dev
* Remap the buffer - it was previously mapped, and we
* hope that this succeeds.
*/
si->rxbuf_dma = dma_map_single(si->dev, si->rxskb->data,
si->dma_rx.dma = dma_map_single(si->dev, si->dma_rx.skb->data,
HPSIR_MAX_RXLEN,
DMA_FROM_DEVICE);
}
Expand All @@ -543,7 +545,7 @@ static void sa1100_irda_fir_irq(struct net_device *dev)
/*
* Stop RX DMA
*/
sa1100_stop_dma(si->rxdma);
sa1100_stop_dma(si->dma_rx.regs);

/*
* Framing error - we throw away the packet completely.
Expand Down Expand Up @@ -600,9 +602,9 @@ static void sa1100_irda_txdma_irq(void *id)
{
struct net_device *dev = id;
struct sa1100_irda *si = netdev_priv(dev);
struct sk_buff *skb = si->txskb;
struct sk_buff *skb = si->dma_tx.skb;

si->txskb = NULL;
si->dma_tx.skb = NULL;

/*
* Wait for the transmission to complete. Unfortunately,
Expand All @@ -620,7 +622,7 @@ static void sa1100_irda_txdma_irq(void *id)

/*
* Do we need to change speed? Note that we're lazy
* here - we don't free the old rxskb. We don't need
* here - we don't free the old dma_rx.skb. We don't need
* to allocate a buffer either.
*/
if (si->newspeed) {
Expand All @@ -638,7 +640,7 @@ static void sa1100_irda_txdma_irq(void *id)
* Account and free the packet.
*/
if (skb) {
dma_unmap_single(si->dev, si->txbuf_dma, skb->len, DMA_TO_DEVICE);
dma_unmap_single(si->dev, si->dma_tx.dma, skb->len, DMA_TO_DEVICE);
dev->stats.tx_packets ++;
dev->stats.tx_bytes += skb->len;
dev_kfree_skb_irq(skb);
Expand Down Expand Up @@ -698,22 +700,22 @@ static int sa1100_irda_hard_xmit(struct sk_buff *skb, struct net_device *dev)
/*
* We must not be transmitting...
*/
BUG_ON(si->txskb);
BUG_ON(si->dma_tx.skb);

netif_stop_queue(dev);

si->txskb = skb;
si->txbuf_dma = dma_map_single(si->dev, skb->data,
si->dma_tx.skb = skb;
si->dma_tx.dma = dma_map_single(si->dev, skb->data,
skb->len, DMA_TO_DEVICE);
if (dma_mapping_error(si->dev, si->txbuf_dma)) {
si->txskb = NULL;
if (dma_mapping_error(si->dev, si->dma_tx.dma)) {
si->dma_tx.skb = NULL;
netif_wake_queue(dev);
dev->stats.tx_dropped++;
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}

sa1100_start_dma(si->txdma, si->txbuf_dma, skb->len);
sa1100_start_dma(si->dma_tx.regs, si->dma_tx.dma, skb->len);

/*
* If we have a mean turn-around time, impose the specified
Expand Down Expand Up @@ -785,12 +787,12 @@ static int sa1100_irda_start(struct net_device *dev)
goto err_irq;

err = sa1100_request_dma(DMA_Ser2HSSPRd, "IrDA receive",
NULL, NULL, &si->rxdma);
NULL, NULL, &si->dma_rx.regs);
if (err)
goto err_rx_dma;

err = sa1100_request_dma(DMA_Ser2HSSPWr, "IrDA transmit",
sa1100_irda_txdma_irq, dev, &si->txdma);
sa1100_irda_txdma_irq, dev, &si->dma_tx.regs);
if (err)
goto err_tx_dma;

Expand Down Expand Up @@ -827,9 +829,9 @@ static int sa1100_irda_start(struct net_device *dev)
si->open = 0;
sa1100_irda_shutdown(si);
err_startup:
sa1100_free_dma(si->txdma);
sa1100_free_dma(si->dma_tx.regs);
err_tx_dma:
sa1100_free_dma(si->rxdma);
sa1100_free_dma(si->dma_rx.regs);
err_rx_dma:
free_irq(dev->irq, dev);
err_irq:
Expand All @@ -847,11 +849,11 @@ static int sa1100_irda_stop(struct net_device *dev)
* If we have been doing DMA receive, make sure we
* tidy that up cleanly.
*/
if (si->rxskb) {
dma_unmap_single(si->dev, si->rxbuf_dma, HPSIR_MAX_RXLEN,
if (si->dma_rx.skb) {
dma_unmap_single(si->dev, si->dma_rx.dma, HPSIR_MAX_RXLEN,
DMA_FROM_DEVICE);
dev_kfree_skb(si->rxskb);
si->rxskb = NULL;
dev_kfree_skb(si->dma_rx.skb);
si->dma_rx.skb = NULL;
}

/* Stop IrLAP */
Expand All @@ -866,8 +868,8 @@ static int sa1100_irda_stop(struct net_device *dev)
/*
* Free resources
*/
sa1100_free_dma(si->txdma);
sa1100_free_dma(si->rxdma);
sa1100_free_dma(si->dma_tx.regs);
sa1100_free_dma(si->dma_rx.regs);
free_irq(dev->irq, dev);

sa1100_set_power(si, 0);
Expand Down

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