dmaengine: shdma: protect against the IRQ handler
The IRQ handler of the shdma driver accesses common hardware registers,
that are also accessed from other contexts. Therefore access to them
has to be performed with interrupts disabled, not only with disabled
bottom halves.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
(cherry picked from commit b4dae6e1adaedc9c343b5f00332312d649600bdc)
Signed-off-by: Simon Horman <horms@verge.net.au>
diff --git a/drivers/dma/shdma.c b/drivers/dma/shdma.c
index 7f49235..e7bb747 100644
--- a/drivers/dma/shdma.c
+++ b/drivers/dma/shdma.c
@@ -265,8 +265,9 @@
struct sh_dmae_chan *sh_chan = to_sh_chan(tx->chan);
dma_async_tx_callback callback = tx->callback;
dma_cookie_t cookie;
+ unsigned long flags;
- spin_lock_bh(&sh_chan->desc_lock);
+ spin_lock_irqsave(&sh_chan->desc_lock, flags);
cookie = sh_chan->common.cookie;
cookie++;
@@ -302,7 +303,7 @@
tx->cookie, &last->async_tx, sh_chan->id,
desc->hw.sar, desc->hw.tcr, desc->hw.dar);
- spin_unlock_bh(&sh_chan->desc_lock);
+ spin_unlock_irqrestore(&sh_chan->desc_lock, flags);
return cookie;
}
@@ -374,24 +375,18 @@
dmae_init(sh_chan);
}
- spin_lock_bh(&sh_chan->desc_lock);
while (sh_chan->descs_allocated < NR_DESCS_PER_CHANNEL) {
- spin_unlock_bh(&sh_chan->desc_lock);
desc = kzalloc(sizeof(struct sh_desc), GFP_KERNEL);
- if (!desc) {
- spin_lock_bh(&sh_chan->desc_lock);
+ if (!desc)
break;
- }
dma_async_tx_descriptor_init(&desc->async_tx,
&sh_chan->common);
desc->async_tx.tx_submit = sh_dmae_tx_submit;
desc->mark = DESC_IDLE;
- spin_lock_bh(&sh_chan->desc_lock);
list_add(&desc->node, &sh_chan->ld_free);
sh_chan->descs_allocated++;
}
- spin_unlock_bh(&sh_chan->desc_lock);
if (!sh_chan->descs_allocated) {
ret = -ENOMEM;
@@ -405,6 +400,7 @@
clear_bit(param->slave_id, sh_dmae_slave_used);
etestused:
efindslave:
+ chan->private = NULL;
pm_runtime_put(sh_chan->dev);
return ret;
}
@@ -437,12 +433,12 @@
chan->private = NULL;
}
- spin_lock_bh(&sh_chan->desc_lock);
+ spin_lock_irq(&sh_chan->desc_lock);
list_splice_init(&sh_chan->ld_free, &list);
sh_chan->descs_allocated = 0;
- spin_unlock_bh(&sh_chan->desc_lock);
+ spin_unlock_irq(&sh_chan->desc_lock);
if (descs > 0)
pm_runtime_put(sh_chan->dev);
@@ -534,6 +530,7 @@
struct sh_desc *first = NULL, *new = NULL /* compiler... */;
LIST_HEAD(tx_list);
int chunks = 0;
+ unsigned long irq_flags;
int i;
if (!sg_len)
@@ -544,7 +541,7 @@
(SH_DMA_TCR_MAX + 1);
/* Have to lock the whole loop to protect against concurrent release */
- spin_lock_bh(&sh_chan->desc_lock);
+ spin_lock_irqsave(&sh_chan->desc_lock, irq_flags);
/*
* Chaining:
@@ -590,7 +587,7 @@
/* Put them back on the free list, so, they don't get lost */
list_splice_tail(&tx_list, &sh_chan->ld_free);
- spin_unlock_bh(&sh_chan->desc_lock);
+ spin_unlock_irqrestore(&sh_chan->desc_lock, irq_flags);
return &first->async_tx;
@@ -599,7 +596,7 @@
new->mark = DESC_IDLE;
list_splice(&tx_list, &sh_chan->ld_free);
- spin_unlock_bh(&sh_chan->desc_lock);
+ spin_unlock_irqrestore(&sh_chan->desc_lock, irq_flags);
return NULL;
}
@@ -661,6 +658,7 @@
unsigned long arg)
{
struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
+ unsigned long flags;
/* Only supports DMA_TERMINATE_ALL */
if (cmd != DMA_TERMINATE_ALL)
@@ -669,7 +667,7 @@
if (!chan)
return -EINVAL;
- spin_lock_bh(&sh_chan->desc_lock);
+ spin_lock_irqsave(&sh_chan->desc_lock, flags);
dmae_halt(sh_chan);
if (!list_empty(&sh_chan->ld_queue)) {
@@ -680,7 +678,7 @@
sh_chan->xmit_shift;
}
- spin_unlock_bh(&sh_chan->desc_lock);
+ spin_unlock_irqrestore(&sh_chan->desc_lock, flags);
sh_dmae_chan_ld_cleanup(sh_chan, true);
@@ -695,8 +693,9 @@
dma_cookie_t cookie = 0;
dma_async_tx_callback callback = NULL;
void *param = NULL;
+ unsigned long flags;
- spin_lock_bh(&sh_chan->desc_lock);
+ spin_lock_irqsave(&sh_chan->desc_lock, flags);
list_for_each_entry_safe(desc, _desc, &sh_chan->ld_queue, node) {
struct dma_async_tx_descriptor *tx = &desc->async_tx;
@@ -773,7 +772,7 @@
*/
sh_chan->completed_cookie = sh_chan->common.cookie;
- spin_unlock_bh(&sh_chan->desc_lock);
+ spin_unlock_irqrestore(&sh_chan->desc_lock, flags);
if (callback)
callback(param);
@@ -796,10 +795,12 @@
{
struct sh_desc *desc;
- spin_lock_bh(&sh_chan->desc_lock);
+ spin_lock_irq(&sh_chan->desc_lock);
/* DMA work check */
- if (dmae_is_busy(sh_chan))
- goto sh_chan_xfer_ld_queue_end;
+ if (dmae_is_busy(sh_chan)) {
+ spin_unlock_irq(&sh_chan->desc_lock);
+ return;
+ }
/* Find the first not transferred descriptor */
list_for_each_entry(desc, &sh_chan->ld_queue, node)
@@ -813,8 +814,7 @@
break;
}
-sh_chan_xfer_ld_queue_end:
- spin_unlock_bh(&sh_chan->desc_lock);
+ spin_unlock_irq(&sh_chan->desc_lock);
}
static void sh_dmae_memcpy_issue_pending(struct dma_chan *chan)
@@ -831,6 +831,7 @@
dma_cookie_t last_used;
dma_cookie_t last_complete;
enum dma_status status;
+ unsigned long flags;
sh_dmae_chan_ld_cleanup(sh_chan, false);
@@ -841,7 +842,7 @@
BUG_ON(last_complete < 0);
dma_set_tx_state(txstate, last_complete, last_used, 0);
- spin_lock_bh(&sh_chan->desc_lock);
+ spin_lock_irqsave(&sh_chan->desc_lock, flags);
status = dma_async_is_complete(cookie, last_complete, last_used);
@@ -859,7 +860,7 @@
}
}
- spin_unlock_bh(&sh_chan->desc_lock);
+ spin_unlock_irqrestore(&sh_chan->desc_lock, flags);
return status;
}
@@ -952,7 +953,7 @@
u32 sar_buf = sh_dmae_readl(sh_chan, SAR);
u32 dar_buf = sh_dmae_readl(sh_chan, DAR);
- spin_lock(&sh_chan->desc_lock);
+ spin_lock_irq(&sh_chan->desc_lock);
list_for_each_entry(desc, &sh_chan->ld_queue, node) {
if (desc->mark == DESC_SUBMITTED &&
((desc->direction == DMA_FROM_DEVICE &&
@@ -965,7 +966,7 @@
break;
}
}
- spin_unlock(&sh_chan->desc_lock);
+ spin_unlock_irq(&sh_chan->desc_lock);
/* Next desc */
sh_chan_xfer_ld_queue(sh_chan);
