caif-hsi: Making read and writes asynchronous.

Some platforms do not allow to put HSI block into low-power
mode when FIFO is not empty. The patch flushes (by reading)
FIFO at wake down sequence. Asynchronous read and write is
implemented for that. As a side effect this will also greatly
improve performance.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Daniel Martensson 2011-10-13 11:29:25 +00:00 committed by David S. Miller
parent 73033c987a
commit 687b13e98a
2 changed files with 147 additions and 145 deletions

View file

@ -145,7 +145,7 @@ static int cfhsi_flush_fifo(struct cfhsi *cfhsi)
}
ret = 5 * HZ;
wait_event_interruptible_timeout(cfhsi->flush_fifo_wait,
ret = wait_event_interruptible_timeout(cfhsi->flush_fifo_wait,
!test_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits), ret);
if (ret < 0) {
@ -272,16 +272,13 @@ static int cfhsi_tx_frm(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
return CFHSI_DESC_SZ + pld_len;
}
static void cfhsi_tx_done_work(struct work_struct *work)
static void cfhsi_tx_done(struct cfhsi *cfhsi)
{
struct cfhsi *cfhsi = NULL;
struct cfhsi_desc *desc = NULL;
int len = 0;
int res;
cfhsi = container_of(work, struct cfhsi, tx_done_work);
dev_dbg(&cfhsi->ndev->dev, "%s.\n",
__func__);
dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__);
if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
return;
@ -343,11 +340,11 @@ static void cfhsi_tx_done_cb(struct cfhsi_drv *drv)
if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
return;
queue_work(cfhsi->wq, &cfhsi->tx_done_work);
cfhsi_tx_done(cfhsi);
}
static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi,
bool *dump)
{
int xfer_sz = 0;
int nfrms = 0;
@ -358,6 +355,7 @@ static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
(desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
dev_err(&cfhsi->ndev->dev, "%s: Invalid descriptor.\n",
__func__);
*dump = true;
return 0;
}
@ -365,7 +363,7 @@ static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
if (desc->offset) {
struct sk_buff *skb;
u8 *dst = NULL;
int len = 0, retries = 0;
int len = 0;
pfrm = ((u8 *)desc) + desc->offset;
/* Remove offset padding. */
@ -378,24 +376,11 @@ static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
/* Allocate SKB (OK even in IRQ context). */
skb = alloc_skb(len + 1, GFP_KERNEL);
while (!skb) {
retries++;
schedule_timeout(1);
skb = alloc_skb(len + 1, GFP_KERNEL);
if (skb) {
printk(KERN_WARNING "%s: slept for %u "
"before getting memory\n",
__func__, retries);
break;
}
if (retries > HZ) {
printk(KERN_ERR "%s: slept for 1HZ and "
"did not get memory\n",
__func__);
cfhsi->ndev->stats.rx_dropped++;
goto drop_frame;
}
skb = alloc_skb(len + 1, GFP_ATOMIC);
if (!skb) {
dev_err(&cfhsi->ndev->dev, "%s: Out of memory !\n",
__func__);
return -ENOMEM;
}
caif_assert(skb != NULL);
@ -421,7 +406,6 @@ static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
cfhsi->ndev->stats.rx_bytes += len;
}
drop_frame:
/* Calculate transfer length. */
plen = desc->cffrm_len;
while (nfrms < CFHSI_MAX_PKTS && *plen) {
@ -439,12 +423,13 @@ static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
"%s: Invalid payload len: %d, ignored.\n",
__func__, xfer_sz);
xfer_sz = 0;
*dump = true;
}
return xfer_sz;
}
static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi,
bool *dump)
{
int rx_sz = 0;
int nfrms = 0;
@ -456,21 +441,33 @@ static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
(desc->offset > CFHSI_MAX_EMB_FRM_SZ))) {
dev_err(&cfhsi->ndev->dev, "%s: Invalid descriptor.\n",
__func__);
*dump = true;
return -EINVAL;
}
/* Set frame pointer to start of payload. */
pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
plen = desc->cffrm_len;
/* Skip already processed frames. */
while (nfrms < cfhsi->rx_state.nfrms) {
pfrm += *plen;
rx_sz += *plen;
plen++;
nfrms++;
}
/* Parse payload. */
while (nfrms < CFHSI_MAX_PKTS && *plen) {
struct sk_buff *skb;
u8 *dst = NULL;
u8 *pcffrm = NULL;
int len = 0, retries = 0;
int len = 0;
if (WARN_ON(desc->cffrm_len[nfrms] > CFHSI_MAX_PAYLOAD_SZ)) {
dev_err(&cfhsi->ndev->dev, "%s: Invalid payload.\n",
__func__);
*dump = true;
return -EINVAL;
}
@ -483,24 +480,12 @@ static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
len += 2; /* Add FCS fields. */
/* Allocate SKB (OK even in IRQ context). */
skb = alloc_skb(len + 1, GFP_KERNEL);
while (!skb) {
retries++;
schedule_timeout(1);
skb = alloc_skb(len + 1, GFP_KERNEL);
if (skb) {
printk(KERN_WARNING "%s: slept for %u "
"before getting memory\n",
__func__, retries);
break;
}
if (retries > HZ) {
printk(KERN_ERR "%s: slept for 1HZ "
"and did not get memory\n",
__func__);
cfhsi->ndev->stats.rx_dropped++;
goto drop_frame;
}
skb = alloc_skb(len + 1, GFP_ATOMIC);
if (!skb) {
dev_err(&cfhsi->ndev->dev, "%s: Out of memory !\n",
__func__);
cfhsi->rx_state.nfrms = nfrms;
return -ENOMEM;
}
caif_assert(skb != NULL);
@ -524,7 +509,6 @@ static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
cfhsi->ndev->stats.rx_packets++;
cfhsi->ndev->stats.rx_bytes += len;
drop_frame:
pfrm += *plen;
rx_sz += *plen;
plen++;
@ -534,18 +518,16 @@ static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
return rx_sz;
}
static void cfhsi_rx_done_work(struct work_struct *work)
static void cfhsi_rx_done(struct cfhsi *cfhsi)
{
int res;
int desc_pld_len = 0;
struct cfhsi *cfhsi = NULL;
struct cfhsi_desc *desc = NULL;
bool dump = false;
cfhsi = container_of(work, struct cfhsi, rx_done_work);
desc = (struct cfhsi_desc *)cfhsi->rx_buf;
dev_dbg(&cfhsi->ndev->dev, "%s: Kick timer if pending.\n",
__func__);
dev_dbg(&cfhsi->ndev->dev, "%s\n", __func__);
if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
return;
@ -555,21 +537,33 @@ static void cfhsi_rx_done_work(struct work_struct *work)
mod_timer_pending(&cfhsi->timer, jiffies + CFHSI_INACTIVITY_TOUT);
spin_unlock_bh(&cfhsi->lock);
if (cfhsi->rx_state == CFHSI_RX_STATE_DESC) {
desc_pld_len = cfhsi_rx_desc(desc, cfhsi);
if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
desc_pld_len = cfhsi_rx_desc(desc, cfhsi, &dump);
if (desc_pld_len == -ENOMEM)
goto restart;
} else {
int pld_len;
pld_len = cfhsi_rx_pld(desc, cfhsi);
if (!cfhsi->rx_state.piggy_desc) {
pld_len = cfhsi_rx_pld(desc, cfhsi, &dump);
if (pld_len == -ENOMEM)
goto restart;
cfhsi->rx_state.pld_len = pld_len;
} else {
pld_len = cfhsi->rx_state.pld_len;
}
if ((pld_len > 0) && (desc->header & CFHSI_PIGGY_DESC)) {
struct cfhsi_desc *piggy_desc;
piggy_desc = (struct cfhsi_desc *)
(desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ +
pld_len);
cfhsi->rx_state.piggy_desc = true;
/* Extract piggy-backed descriptor. */
desc_pld_len = cfhsi_rx_desc(piggy_desc, cfhsi);
desc_pld_len = cfhsi_rx_desc(piggy_desc, cfhsi, &dump);
if (desc_pld_len == -ENOMEM)
goto restart;
/*
* Copy needed information from the piggy-backed
@ -580,16 +574,24 @@ static void cfhsi_rx_done_work(struct work_struct *work)
}
}
if (unlikely(dump)) {
size_t rx_offset = cfhsi->rx_ptr - cfhsi->rx_buf;
dev_err(&cfhsi->ndev->dev, "%s: RX offset: %u.\n",
__func__, (unsigned) rx_offset);
print_hex_dump_bytes("--> ", DUMP_PREFIX_NONE,
cfhsi->rx_buf, cfhsi->rx_len + rx_offset);
}
memset(&cfhsi->rx_state, 0, sizeof(cfhsi->rx_state));
if (desc_pld_len) {
cfhsi->rx_state = CFHSI_RX_STATE_PAYLOAD;
cfhsi->rx_state.state = CFHSI_RX_STATE_PAYLOAD;
cfhsi->rx_ptr = cfhsi->rx_buf + CFHSI_DESC_SZ;
cfhsi->rx_len = desc_pld_len;
} else {
cfhsi->rx_state = CFHSI_RX_STATE_DESC;
cfhsi->rx_state.state = CFHSI_RX_STATE_DESC;
cfhsi->rx_ptr = cfhsi->rx_buf;
cfhsi->rx_len = CFHSI_DESC_SZ;
}
clear_bit(CFHSI_PENDING_RX, &cfhsi->bits);
if (test_bit(CFHSI_AWAKE, &cfhsi->bits)) {
/* Set up new transfer. */
@ -604,6 +606,26 @@ static void cfhsi_rx_done_work(struct work_struct *work)
cfhsi->ndev->stats.rx_dropped++;
}
}
return;
restart:
if (++cfhsi->rx_state.retries > CFHSI_MAX_RX_RETRIES) {
dev_err(&cfhsi->ndev->dev, "%s: No memory available "
"in %d iterations.\n",
__func__, CFHSI_MAX_RX_RETRIES);
BUG();
}
mod_timer(&cfhsi->rx_slowpath_timer, jiffies + 1);
}
static void cfhsi_rx_slowpath(unsigned long arg)
{
struct cfhsi *cfhsi = (struct cfhsi *)arg;
dev_dbg(&cfhsi->ndev->dev, "%s.\n",
__func__);
cfhsi_rx_done(cfhsi);
}
static void cfhsi_rx_done_cb(struct cfhsi_drv *drv)
@ -617,12 +639,10 @@ static void cfhsi_rx_done_cb(struct cfhsi_drv *drv)
if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
return;
set_bit(CFHSI_PENDING_RX, &cfhsi->bits);
if (test_and_clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits))
wake_up_interruptible(&cfhsi->flush_fifo_wait);
else
queue_work(cfhsi->wq, &cfhsi->rx_done_work);
cfhsi_rx_done(cfhsi);
}
static void cfhsi_wake_up(struct work_struct *work)
@ -651,9 +671,9 @@ static void cfhsi_wake_up(struct work_struct *work)
__func__);
/* Wait for acknowledge. */
ret = CFHSI_WAKEUP_TOUT;
wait_event_interruptible_timeout(cfhsi->wake_up_wait,
test_bit(CFHSI_WAKE_UP_ACK,
ret = CFHSI_WAKE_TOUT;
ret = wait_event_interruptible_timeout(cfhsi->wake_up_wait,
test_and_clear_bit(CFHSI_WAKE_UP_ACK,
&cfhsi->bits), ret);
if (unlikely(ret < 0)) {
/* Interrupted by signal. */
@ -678,16 +698,11 @@ static void cfhsi_wake_up(struct work_struct *work)
clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
/* Resume read operation. */
if (!test_bit(CFHSI_PENDING_RX, &cfhsi->bits)) {
dev_dbg(&cfhsi->ndev->dev, "%s: Start RX.\n",
__func__);
res = cfhsi->dev->cfhsi_rx(cfhsi->rx_ptr,
cfhsi->rx_len, cfhsi->dev);
if (WARN_ON(res < 0)) {
dev_err(&cfhsi->ndev->dev, "%s: RX error %d.\n",
__func__, res);
}
}
dev_dbg(&cfhsi->ndev->dev, "%s: Start RX.\n", __func__);
res = cfhsi->dev->cfhsi_rx(cfhsi->rx_ptr, cfhsi->rx_len, cfhsi->dev);
if (WARN_ON(res < 0))
dev_err(&cfhsi->ndev->dev, "%s: RX err %d.\n", __func__, res);
/* Clear power up acknowledment. */
clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
@ -726,50 +741,29 @@ static void cfhsi_wake_up(struct work_struct *work)
"%s: Failed to create HSI frame: %d.\n",
__func__, len);
}
}
static void cfhsi_wake_down(struct work_struct *work)
{
long ret;
struct cfhsi *cfhsi = NULL;
size_t fifo_occupancy;
size_t fifo_occupancy = 0;
int retry = CFHSI_WAKE_TOUT;
cfhsi = container_of(work, struct cfhsi, wake_down_work);
dev_dbg(&cfhsi->ndev->dev, "%s.\n",
__func__);
dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__);
if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
return;
/* Check if there is something in FIFO. */
if (WARN_ON(cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
&fifo_occupancy)))
fifo_occupancy = 0;
if (fifo_occupancy) {
dev_dbg(&cfhsi->ndev->dev,
"%s: %u words in RX FIFO, restart timer.\n",
__func__, (unsigned) fifo_occupancy);
spin_lock_bh(&cfhsi->lock);
mod_timer(&cfhsi->timer,
jiffies + CFHSI_INACTIVITY_TOUT);
spin_unlock_bh(&cfhsi->lock);
return;
}
/* Cancel pending RX requests */
cfhsi->dev->cfhsi_rx_cancel(cfhsi->dev);
/* Deactivate wake line. */
cfhsi->dev->cfhsi_wake_down(cfhsi->dev);
/* Wait for acknowledge. */
ret = CFHSI_WAKEUP_TOUT;
ret = CFHSI_WAKE_TOUT;
ret = wait_event_interruptible_timeout(cfhsi->wake_down_wait,
test_bit(CFHSI_WAKE_DOWN_ACK,
&cfhsi->bits),
ret);
test_and_clear_bit(CFHSI_WAKE_DOWN_ACK,
&cfhsi->bits), ret);
if (ret < 0) {
/* Interrupted by signal. */
dev_info(&cfhsi->ndev->dev, "%s: Signalled: %ld.\n",
@ -777,28 +771,31 @@ static void cfhsi_wake_down(struct work_struct *work)
return;
} else if (!ret) {
/* Timeout */
dev_err(&cfhsi->ndev->dev, "%s: Timeout.\n",
__func__);
dev_err(&cfhsi->ndev->dev, "%s: Timeout.\n", __func__);
}
/* Clear power down acknowledment. */
clear_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
/* Check FIFO occupancy. */
while (retry) {
WARN_ON(cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
&fifo_occupancy));
if (!fifo_occupancy)
break;
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(1);
retry--;
}
if (!retry)
dev_err(&cfhsi->ndev->dev, "%s: FIFO Timeout.\n", __func__);
/* Clear AWAKE condition. */
clear_bit(CFHSI_AWAKE, &cfhsi->bits);
/* Check if there is something in FIFO. */
if (WARN_ON(cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
&fifo_occupancy)))
fifo_occupancy = 0;
/* Cancel pending RX requests. */
cfhsi->dev->cfhsi_rx_cancel(cfhsi->dev);
if (fifo_occupancy) {
dev_dbg(&cfhsi->ndev->dev,
"%s: %u words in RX FIFO, wakeup forced.\n",
__func__, (unsigned) fifo_occupancy);
if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
queue_work(cfhsi->wq, &cfhsi->wake_up_work);
} else
dev_dbg(&cfhsi->ndev->dev, "%s: Done.\n",
__func__);
}
static void cfhsi_wake_up_cb(struct cfhsi_drv *drv)
@ -874,11 +871,7 @@ static int cfhsi_xmit(struct sk_buff *skb, struct net_device *dev)
}
/* Delete inactivity timer if started. */
#ifdef CONFIG_SMP
timer_active = del_timer_sync(&cfhsi->timer);
#else
timer_active = del_timer(&cfhsi->timer);
#endif /* CONFIG_SMP */
spin_unlock_bh(&cfhsi->lock);
@ -962,7 +955,7 @@ int cfhsi_probe(struct platform_device *pdev)
/* Initialize state vaiables. */
cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
cfhsi->rx_state = CFHSI_RX_STATE_DESC;
cfhsi->rx_state.state = CFHSI_RX_STATE_DESC;
/* Set flow info */
cfhsi->flow_off_sent = 0;
@ -1012,15 +1005,12 @@ int cfhsi_probe(struct platform_device *pdev)
/* Initialize the work queues. */
INIT_WORK(&cfhsi->wake_up_work, cfhsi_wake_up);
INIT_WORK(&cfhsi->wake_down_work, cfhsi_wake_down);
INIT_WORK(&cfhsi->rx_done_work, cfhsi_rx_done_work);
INIT_WORK(&cfhsi->tx_done_work, cfhsi_tx_done_work);
/* Clear all bit fields. */
clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
clear_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
clear_bit(CFHSI_AWAKE, &cfhsi->bits);
clear_bit(CFHSI_PENDING_RX, &cfhsi->bits);
/* Create work thread. */
cfhsi->wq = create_singlethread_workqueue(pdev->name);
@ -1040,6 +1030,10 @@ int cfhsi_probe(struct platform_device *pdev)
init_timer(&cfhsi->timer);
cfhsi->timer.data = (unsigned long)cfhsi;
cfhsi->timer.function = cfhsi_inactivity_tout;
/* Setup the slowpath RX timer. */
init_timer(&cfhsi->rx_slowpath_timer);
cfhsi->rx_slowpath_timer.data = (unsigned long)cfhsi;
cfhsi->rx_slowpath_timer.function = cfhsi_rx_slowpath;
/* Add CAIF HSI device to list. */
spin_lock(&cfhsi_list_lock);
@ -1110,12 +1104,9 @@ static void cfhsi_shutdown(struct cfhsi *cfhsi, bool remove_platform_dev)
/* Flush workqueue */
flush_workqueue(cfhsi->wq);
/* Delete timer if pending */
#ifdef CONFIG_SMP
/* Delete timers if pending */
del_timer_sync(&cfhsi->timer);
#else
del_timer(&cfhsi->timer);
#endif /* CONFIG_SMP */
del_timer_sync(&cfhsi->rx_slowpath_timer);
/* Cancel pending RX request (if any) */
cfhsi->dev->cfhsi_rx_cancel(cfhsi->dev);

View file

@ -75,18 +75,21 @@ struct cfhsi_desc {
#define CFHSI_WAKE_UP_ACK 1
#define CFHSI_WAKE_DOWN_ACK 2
#define CFHSI_AWAKE 3
#define CFHSI_PENDING_RX 4
#define CFHSI_SHUTDOWN 6
#define CFHSI_FLUSH_FIFO 7
#define CFHSI_WAKELOCK_HELD 4
#define CFHSI_SHUTDOWN 5
#define CFHSI_FLUSH_FIFO 6
#ifndef CFHSI_INACTIVITY_TOUT
#define CFHSI_INACTIVITY_TOUT (1 * HZ)
#endif /* CFHSI_INACTIVITY_TOUT */
#ifndef CFHSI_WAKEUP_TOUT
#define CFHSI_WAKEUP_TOUT (3 * HZ)
#endif /* CFHSI_WAKEUP_TOUT */
#ifndef CFHSI_WAKE_TOUT
#define CFHSI_WAKE_TOUT (3 * HZ)
#endif /* CFHSI_WAKE_TOUT */
#ifndef CFHSI_MAX_RX_RETRIES
#define CFHSI_MAX_RX_RETRIES (10 * HZ)
#endif
/* Structure implemented by the CAIF HSI driver. */
struct cfhsi_drv {
@ -109,6 +112,15 @@ struct cfhsi_dev {
struct cfhsi_drv *drv;
};
/* Structure holds status of received CAIF frames processing */
struct cfhsi_rx_state {
int state;
int nfrms;
int pld_len;
int retries;
bool piggy_desc;
};
/* Structure implemented by CAIF HSI drivers. */
struct cfhsi {
struct caif_dev_common cfdev;
@ -118,7 +130,7 @@ struct cfhsi {
struct cfhsi_drv drv;
struct cfhsi_dev *dev;
int tx_state;
int rx_state;
struct cfhsi_rx_state rx_state;
int rx_len;
u8 *rx_ptr;
u8 *tx_buf;
@ -130,13 +142,12 @@ struct cfhsi {
struct list_head list;
struct work_struct wake_up_work;
struct work_struct wake_down_work;
struct work_struct rx_done_work;
struct work_struct tx_done_work;
struct workqueue_struct *wq;
wait_queue_head_t wake_up_wait;
wait_queue_head_t wake_down_wait;
wait_queue_head_t flush_fifo_wait;
struct timer_list timer;
struct timer_list rx_slowpath_timer;
unsigned long bits;
};