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dma: mmp_pdma: add protect when alloc/free phy channels 

In mmp pdma, phy channels are allocated/freed dynamically
and frequently. But no proper protection is added.
Conflict will happen when multi-users are requesting phy
channels at the same time. Use spinlock to protect.

Signed-off-by: Xiang Wang <wangx@marvell.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
hifive-unleashed-5.1
Xiang Wang 2013-06-18 14:55:58 +08:00 committed by Vinod Koul
parent 337ae47c2d
commit 027f28b7bb
1 changed files with 26 additions and 16 deletions
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42
drivers/dma/mmp_pdma.c
View File

@ -121,6 +121,7 @@ struct mmp_pdma_device {
struct device *dev;
struct dma_device device;
struct mmp_pdma_phy *phy;
spinlock_t phy_lock; /* protect alloc/free phy channels */
};
#define tx_to_mmp_pdma_desc(tx) container_of(tx, struct mmp_pdma_desc_sw, async_tx)
@ -219,6 +220,7 @@ static struct mmp_pdma_phy *lookup_phy(struct mmp_pdma_chan *pchan)
int prio, i;
struct mmp_pdma_device *pdev = to_mmp_pdma_dev(pchan->chan.device);
struct mmp_pdma_phy *phy;
unsigned long flags;
/*
* dma channel priorities
@ -227,6 +229,8 @@ static struct mmp_pdma_phy *lookup_phy(struct mmp_pdma_chan *pchan)
* ch 8 - 11, 24 - 27 <--> (2)
* ch 12 - 15, 28 - 31 <--> (3)
*/
spin_lock_irqsave(&pdev->phy_lock, flags);
for (prio = 0; prio <= (((pdev->dma_channels - 1) & 0xf) >> 2); prio++) {
for (i = 0; i < pdev->dma_channels; i++) {
if (prio != ((i & 0xf) >> 2))
@ -234,14 +238,30 @@ static struct mmp_pdma_phy *lookup_phy(struct mmp_pdma_chan *pchan)
phy = &pdev->phy[i];
if (!phy->vchan) {
phy->vchan = pchan;
spin_unlock_irqrestore(&pdev->phy_lock, flags);
return phy;
}
}
}
spin_unlock_irqrestore(&pdev->phy_lock, flags);
return NULL;
}
static void mmp_pdma_free_phy(struct mmp_pdma_chan *pchan)
{
struct mmp_pdma_device *pdev = to_mmp_pdma_dev(pchan->chan.device);
unsigned long flags;
if (!pchan->phy)
return;
spin_lock_irqsave(&pdev->phy_lock, flags);
pchan->phy->vchan = NULL;
pchan->phy = NULL;
spin_unlock_irqrestore(&pdev->phy_lock, flags);
}
/* desc->tx_list ==> pending list */
static void append_pending_queue(struct mmp_pdma_chan *chan,
struct mmp_pdma_desc_sw *desc)
@ -277,10 +297,7 @@ static void start_pending_queue(struct mmp_pdma_chan *chan)
if (list_empty(&chan->chain_pending)) {
/* chance to re-fetch phy channel with higher prio */
if (chan->phy) {
chan->phy->vchan = NULL;
chan->phy = NULL;
}
mmp_pdma_free_phy(chan);
dev_dbg(chan->dev, "no pending list\n");
return;
}
@ -377,10 +394,7 @@ static int mmp_pdma_alloc_chan_resources(struct dma_chan *dchan)
dev_err(chan->dev, "unable to allocate descriptor pool\n");
return -ENOMEM;
}
if (chan->phy) {
chan->phy->vchan = NULL;
chan->phy = NULL;
}
mmp_pdma_free_phy(chan);
chan->idle = true;
chan->dev_addr = 0;
return 1;
@ -411,10 +425,7 @@ static void mmp_pdma_free_chan_resources(struct dma_chan *dchan)
chan->desc_pool = NULL;
chan->idle = true;
chan->dev_addr = 0;
if (chan->phy) {
chan->phy->vchan = NULL;
chan->phy = NULL;
}
mmp_pdma_free_phy(chan);
return;
}
@ -581,10 +592,7 @@ static int mmp_pdma_control(struct dma_chan *dchan, enum dma_ctrl_cmd cmd,
switch (cmd) {
case DMA_TERMINATE_ALL:
disable_chan(chan->phy);
if (chan->phy) {
chan->phy->vchan = NULL;
chan->phy = NULL;
}
mmp_pdma_free_phy(chan);
spin_lock_irqsave(&chan->desc_lock, flags);
mmp_pdma_free_desc_list(chan, &chan->chain_pending);
mmp_pdma_free_desc_list(chan, &chan->chain_running);
@ -769,6 +777,8 @@ static int mmp_pdma_probe(struct platform_device *op)
return -ENOMEM;
pdev->dev = &op->dev;
spin_lock_init(&pdev->phy_lock);
iores = platform_get_resource(op, IORESOURCE_MEM, 0);
if (!iores)
return -EINVAL;