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Message-ID: <50dc2f47f2c9f94fce78583568830a66af49307d.1303896567.git.viresh.kumar@st.com>
Date: Wed, 27 Apr 2011 15:06:44 +0530
From: Viresh Kumar <viresh.kumar@...com>
To: <vinod.koul@...el.com>, <dan.j.williams@...el.com>
Cc: <linux-kernel@...r.kernel.org>, <armando.visconti@...com>,
<shiraz.hashim@...com>, <linux-arm-kernel@...ts.infradead.org>,
<viresh.linux@...il.com>, Viresh Kumar <viresh.kumar@...com>
Subject: [PATCH V3 2/7] dmaengine/dw_dmac: Replace spin_lock* with irqsave variants
dmaengine routines can be called from interrupt context and with interrupts
disabled. Whereas spin_unlock_bh can't be called from such contexts. So this
patch converts all spin_*_bh routines to irqsave variants.
Also, spin_lock() used in tasklet is converted to irqsave variants, as tasklet
can be interrupted, and dma requests from such interruptions may also call
spin_lock.
Signed-off-by: Viresh Kumar <viresh.kumar@...com>
---
drivers/dma/dw_dmac.c | 82 +++++++++++++++++++++++++++++-------------------
1 files changed, 49 insertions(+), 33 deletions(-)
diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index b8985af..b6dfc39 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -93,8 +93,9 @@ static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc)
struct dw_desc *desc, *_desc;
struct dw_desc *ret = NULL;
unsigned int i = 0;
+ unsigned long flags;
- spin_lock_bh(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) {
if (async_tx_test_ack(&desc->txd)) {
list_del(&desc->desc_node);
@@ -104,7 +105,7 @@ static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc)
dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc);
i++;
}
- spin_unlock_bh(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i);
@@ -130,12 +131,14 @@ static void dwc_sync_desc_for_cpu(struct dw_dma_chan *dwc, struct dw_desc *desc)
*/
static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
{
+ unsigned long flags;
+
if (desc) {
struct dw_desc *child;
dwc_sync_desc_for_cpu(dwc, desc);
- spin_lock_bh(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
list_for_each_entry(child, &desc->tx_list, desc_node)
dev_vdbg(chan2dev(&dwc->chan),
"moving child desc %p to freelist\n",
@@ -143,7 +146,7 @@ static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
list_splice_init(&desc->tx_list, &dwc->free_list);
dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc);
list_add(&desc->desc_node, &dwc->free_list);
- spin_unlock_bh(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
}
}
@@ -407,6 +410,8 @@ EXPORT_SYMBOL(dw_dma_get_dst_addr);
static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
u32 status_block, u32 status_err, u32 status_xfer)
{
+ unsigned long flags;
+
if (status_block & dwc->mask) {
void (*callback)(void *param);
void *callback_param;
@@ -418,9 +423,9 @@ static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
callback = dwc->cdesc->period_callback;
callback_param = dwc->cdesc->period_callback_param;
if (callback) {
- spin_unlock(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
callback(callback_param);
- spin_lock(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
}
}
@@ -470,6 +475,7 @@ static void dw_dma_tasklet(unsigned long data)
u32 status_block;
u32 status_xfer;
u32 status_err;
+ unsigned long flags;
int i;
status_block = dma_readl(dw, RAW.BLOCK);
@@ -481,7 +487,7 @@ static void dw_dma_tasklet(unsigned long data)
for (i = 0; i < dw->dma.chancnt; i++) {
dwc = &dw->chan[i];
- spin_lock(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
if (test_bit(DW_DMA_IS_CYCLIC, &dwc->flags))
dwc_handle_cyclic(dw, dwc, status_block, status_err,
status_xfer);
@@ -489,7 +495,7 @@ static void dw_dma_tasklet(unsigned long data)
dwc_handle_error(dw, dwc);
else if ((status_block | status_xfer) & (1 << i))
dwc_scan_descriptors(dw, dwc);
- spin_unlock(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
}
/*
@@ -544,8 +550,9 @@ static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
struct dw_desc *desc = txd_to_dw_desc(tx);
struct dw_dma_chan *dwc = to_dw_dma_chan(tx->chan);
dma_cookie_t cookie;
+ unsigned long flags;
- spin_lock_bh(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
cookie = dwc_assign_cookie(dwc, desc);
/*
@@ -565,7 +572,7 @@ static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
list_add_tail(&desc->desc_node, &dwc->queue);
}
- spin_unlock_bh(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
return cookie;
}
@@ -804,6 +811,7 @@ static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma *dw = to_dw_dma(chan->device);
struct dw_desc *desc, *_desc;
+ unsigned long flags;
LIST_HEAD(list);
/* Only supports DMA_TERMINATE_ALL */
@@ -816,7 +824,7 @@ static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
* channel. We still have to poll the channel enable bit due
* to AHB/HSB limitations.
*/
- spin_lock_bh(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
channel_clear_bit(dw, CH_EN, dwc->mask);
@@ -831,7 +839,7 @@ static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
list_for_each_entry_safe(desc, _desc, &list, desc_node)
dwc_descriptor_complete(dwc, desc);
- spin_unlock_bh(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
return 0;
}
@@ -845,15 +853,16 @@ dwc_tx_status(struct dma_chan *chan,
dma_cookie_t last_used;
dma_cookie_t last_complete;
int ret;
+ unsigned long flags;
last_complete = dwc->completed;
last_used = chan->cookie;
ret = dma_async_is_complete(cookie, last_complete, last_used);
if (ret != DMA_SUCCESS) {
- spin_lock_bh(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
- spin_unlock_bh(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
last_complete = dwc->completed;
last_used = chan->cookie;
@@ -869,11 +878,12 @@ dwc_tx_status(struct dma_chan *chan,
static void dwc_issue_pending(struct dma_chan *chan)
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
+ unsigned long flags;
- spin_lock_bh(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
if (!list_empty(&dwc->queue))
dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
- spin_unlock_bh(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
}
static int dwc_alloc_chan_resources(struct dma_chan *chan)
@@ -885,6 +895,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
int i;
u32 cfghi;
u32 cfglo;
+ unsigned long flags;
dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
@@ -922,16 +933,16 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
* doesn't mean what you think it means), and status writeback.
*/
- spin_lock_bh(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
i = dwc->descs_allocated;
while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
- spin_unlock_bh(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
desc = kzalloc(sizeof(struct dw_desc), GFP_KERNEL);
if (!desc) {
dev_info(chan2dev(chan),
"only allocated %d descriptors\n", i);
- spin_lock_bh(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
break;
}
@@ -943,7 +954,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
sizeof(desc->lli), DMA_TO_DEVICE);
dwc_desc_put(dwc, desc);
- spin_lock_bh(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
i = ++dwc->descs_allocated;
}
@@ -952,7 +963,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
channel_set_bit(dw, MASK.BLOCK, dwc->mask);
channel_set_bit(dw, MASK.ERROR, dwc->mask);
- spin_unlock_bh(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
dev_dbg(chan2dev(chan),
"alloc_chan_resources allocated %d descriptors\n", i);
@@ -965,6 +976,7 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma *dw = to_dw_dma(chan->device);
struct dw_desc *desc, *_desc;
+ unsigned long flags;
LIST_HEAD(list);
dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n",
@@ -975,7 +987,7 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
BUG_ON(!list_empty(&dwc->queue));
BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask);
- spin_lock_bh(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
list_splice_init(&dwc->free_list, &list);
dwc->descs_allocated = 0;
@@ -984,7 +996,7 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
channel_clear_bit(dw, MASK.BLOCK, dwc->mask);
channel_clear_bit(dw, MASK.ERROR, dwc->mask);
- spin_unlock_bh(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
list_for_each_entry_safe(desc, _desc, &list, desc_node) {
dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc);
@@ -1009,13 +1021,14 @@ int dw_dma_cyclic_start(struct dma_chan *chan)
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma *dw = to_dw_dma(dwc->chan.device);
+ unsigned long flags;
if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
dev_err(chan2dev(&dwc->chan), "missing prep for cyclic DMA\n");
return -ENODEV;
}
- spin_lock(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
/* assert channel is idle */
if (dma_readl(dw, CH_EN) & dwc->mask) {
@@ -1028,7 +1041,7 @@ int dw_dma_cyclic_start(struct dma_chan *chan)
channel_readl(dwc, LLP),
channel_readl(dwc, CTL_HI),
channel_readl(dwc, CTL_LO));
- spin_unlock(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
return -EBUSY;
}
@@ -1043,7 +1056,7 @@ int dw_dma_cyclic_start(struct dma_chan *chan)
channel_set_bit(dw, CH_EN, dwc->mask);
- spin_unlock(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
return 0;
}
@@ -1059,14 +1072,15 @@ void dw_dma_cyclic_stop(struct dma_chan *chan)
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma *dw = to_dw_dma(dwc->chan.device);
+ unsigned long flags;
- spin_lock(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
channel_clear_bit(dw, CH_EN, dwc->mask);
while (dma_readl(dw, CH_EN) & dwc->mask)
cpu_relax();
- spin_unlock(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
}
EXPORT_SYMBOL(dw_dma_cyclic_stop);
@@ -1095,17 +1109,18 @@ struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
unsigned int reg_width;
unsigned int periods;
unsigned int i;
+ unsigned long flags;
- spin_lock_bh(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
if (!list_empty(&dwc->queue) || !list_empty(&dwc->active_list)) {
- spin_unlock_bh(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
dev_dbg(chan2dev(&dwc->chan),
"queue and/or active list are not empty\n");
return ERR_PTR(-EBUSY);
}
was_cyclic = test_and_set_bit(DW_DMA_IS_CYCLIC, &dwc->flags);
- spin_unlock_bh(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
if (was_cyclic) {
dev_dbg(chan2dev(&dwc->chan),
"channel already prepared for cyclic DMA\n");
@@ -1219,13 +1234,14 @@ void dw_dma_cyclic_free(struct dma_chan *chan)
struct dw_dma *dw = to_dw_dma(dwc->chan.device);
struct dw_cyclic_desc *cdesc = dwc->cdesc;
int i;
+ unsigned long flags;
dev_dbg(chan2dev(&dwc->chan), "cyclic free\n");
if (!cdesc)
return;
- spin_lock_bh(&dwc->lock);
+ spin_lock_irqsave(&dwc->lock, flags);
channel_clear_bit(dw, CH_EN, dwc->mask);
while (dma_readl(dw, CH_EN) & dwc->mask)
@@ -1235,7 +1251,7 @@ void dw_dma_cyclic_free(struct dma_chan *chan)
dma_writel(dw, CLEAR.ERROR, dwc->mask);
dma_writel(dw, CLEAR.XFER, dwc->mask);
- spin_unlock_bh(&dwc->lock);
+ spin_unlock_irqrestore(&dwc->lock, flags);
for (i = 0; i < cdesc->periods; i++)
dwc_desc_put(dwc, cdesc->desc[i]);
--
1.7.3.4
--
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