int cpdma_chan_stop(struct cpdma_chan *chan)
{
struct cpdma_ctlr *ctlr = chan->ctlr;
struct cpdma_desc_pool *pool = ctlr->pool;
unsigned long flags;
int ret;
unsigned long timeout;
spin_lock_irqsave(&chan->lock, flags);
if (chan->state != CPDMA_STATE_ACTIVE) {
spin_unlock_irqrestore(&chan->lock, flags);
return -EINVAL;
}
chan->state = CPDMA_STATE_TEARDOWN;
dma_reg_write(ctlr, chan->int_clear, chan->mask);
/* trigger teardown */
dma_reg_write(ctlr, chan->td, chan_linear(chan));
/* wait for teardown complete */
timeout = jiffies + HZ/10; /* 100 msec */
while (time_before(jiffies, timeout)) {
u32 cp = chan_read(chan, cp);
if ((cp & CPDMA_TEARDOWN_VALUE) == CPDMA_TEARDOWN_VALUE)
break;
cpu_relax();
}
WARN_ON(!time_before(jiffies, timeout));
chan_write(chan, cp, CPDMA_TEARDOWN_VALUE);
/* handle completed packets */
spin_unlock_irqrestore(&chan->lock, flags);
do {
ret = __cpdma_chan_process(chan);
if (ret < 0)
break;
} while ((ret & CPDMA_DESC_TD_COMPLETE) == 0);
spin_lock_irqsave(&chan->lock, flags);
/* remaining packets haven't been tx/rx'ed, clean them up */
while (chan->head) {
struct cpdma_desc __iomem *desc = chan->head;
dma_addr_t next_dma;
next_dma = desc_read(desc, hw_next);
chan->head = desc_from_phys(pool, next_dma);
chan->count--;
chan->stats.teardown_dequeue++;
/* issue callback without locks held */
spin_unlock_irqrestore(&chan->lock, flags);
__cpdma_chan_free(chan, desc, 0, -ENOSYS);
spin_lock_irqsave(&chan->lock, flags);
}
chan->state = CPDMA_STATE_IDLE;
spin_unlock_irqrestore(&chan->lock, flags);
return 0;
}
static int __cpdma_chan_process(struct cpdma_chan *chan)
{
struct cpdma_ctlr *ctlr = chan->ctlr;
struct cpdma_desc __iomem *desc;
int status, outlen;
int cb_status = 0;
struct cpdma_desc_pool *pool = ctlr->pool;
dma_addr_t desc_dma;
unsigned long flags;
spin_lock_irqsave(&chan->lock, flags);
desc = chan->head;
if (!desc) {
chan->stats.empty_dequeue++;
status = -ENOENT;
goto unlock_ret;
}
desc_dma = desc_phys(pool, desc);
status = __raw_readl(&desc->hw_mode);
outlen = status & 0x7ff;
if (status & CPDMA_DESC_OWNER) {
chan->stats.busy_dequeue++;
status = -EBUSY;
goto unlock_ret;
}
if (status & CPDMA_DESC_PASS_CRC)
outlen -= CPDMA_DESC_CRC_LEN;
status = status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE |
CPDMA_DESC_PORT_MASK);
chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
chan_write(chan, cp, desc_dma);
chan->count--;
chan->stats.good_dequeue++;
if (status & CPDMA_DESC_EOQ) {
chan->stats.requeue++;
chan_write(chan, hdp, desc_phys(pool, chan->head));
}
spin_unlock_irqrestore(&chan->lock, flags);
if (unlikely(status & CPDMA_DESC_TD_COMPLETE))
cb_status = -ENOSYS;
else
cb_status = status;
__cpdma_chan_free(chan, desc, outlen, cb_status);
return status;
unlock_ret:
spin_unlock_irqrestore(&chan->lock, flags);
return status;
}
static int __cpdma_chan_process(struct cpdma_chan *chan)
{
struct cpdma_ctlr *ctlr = chan->ctlr;
struct cpdma_desc __iomem *desc;
int status, outlen;
struct cpdma_desc_pool *pool = ctlr->pool;
dma_addr_t desc_dma;
rtdm_lockctx_t context;
//rtdm_printk("__cpdma_chan_process(%x)\n", chan);
rtdm_lock_get_irqsave(&chan->lock, context);
desc = chan->head;
if (!desc) {
chan->stats.empty_dequeue++;
status = -ENOENT;
goto unlock_ret;
}
desc_dma = desc_phys(pool, desc);
status = __raw_readl(&desc->hw_mode);
outlen = status & 0x7ff;
if (status & CPDMA_DESC_OWNER) {
chan->stats.busy_dequeue++;
status = -EBUSY;
goto unlock_ret;
}
status = status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE);
chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
chan_write(chan, cp, desc_dma);
chan->count--;
chan->stats.good_dequeue++;
if (status & CPDMA_DESC_EOQ) {
chan->stats.requeue++;
chan_write(chan, hdp, desc_phys(pool, chan->head));
}
rtdm_lock_put_irqrestore(&chan->lock, context);
__cpdma_chan_free(chan, desc, outlen, status);
return status;
unlock_ret:
rtdm_lock_put_irqrestore(&chan->lock, context);
return status;
}
static int __cpdma_chan_process(struct cpdma_chan *chan)
{
struct cpdma_ctlr *ctlr = chan->ctlr;
struct cpdma_desc __iomem *desc;
u32 status, outlen;
struct cpdma_desc_pool *pool = ctlr->pool;
dma_addr_t desc_dma;
unsigned long flags;
spin_lock_irqsave(&chan->lock, flags);
desc = chan->head;
if (!desc) {
chan->stats.empty_dequeue++;
status = -ENOENT;
goto unlock_ret;
}
desc_dma = desc_phys(pool, desc);
status = __raw_readl(&desc->hw_mode);
outlen = status & 0x7ff;
if (status & CPDMA_DESC_OWNER) {
chan->stats.busy_dequeue++;
status = -EBUSY;
goto unlock_ret;
}
status = status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE);
chan->head = desc_from_phys(pool, desc_read(desc, sw_next));
chan_write(chan, cp, desc_dma);
chan->count--;
chan->stats.good_dequeue++;
if ((status & CPDMA_DESC_EOQ) && (chan->head) && (!(status & CPDMA_DESC_TD_COMPLETE))) {
chan->stats.requeue++;
chan_write(chan, hdp, desc_phys(pool, chan->head));
}
spin_unlock_irqrestore(&chan->lock, flags);
__cpdma_chan_free(chan, desc, outlen, (int)status);
return status;
unlock_ret:
spin_unlock_irqrestore(&chan->lock, flags);
return status;
}