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dmaengine: add a release for dma class devices and dependent infrastructure

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Resolves:
WARNING: at drivers/base/core.c:122 device_release+0x4d/0x52()
Device 'dma0chan0' does not have a release() function, it is broken and must be fixed.

The dma_chan_dev object is introduced to gear-match sysfs kobject and
dmaengine channel lifetimes.  When a channel is removed access to the
sysfs entries return -ENODEV until the kobject can be released.

The bulk of the change is updates to existing code to handle the extra
layer of indirection between a dma_chan and its struct device.

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams
2009-01-06 11:38:21 -07:00
parent 4fac7fa57c
commit 41d5e59c12
5 changed files with 157 additions and 75 deletions
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106
drivers/dma/dmaengine.c
View File

@@ -64,36 +64,75 @@ static long dmaengine_ref_count;
/* --- sysfs implementation --- */
/**
* dev_to_dma_chan - convert a device pointer to the its sysfs container object
* @dev - device node
*
* Must be called under dma_list_mutex
*/
static struct dma_chan *dev_to_dma_chan(struct device *dev)
{
struct dma_chan_dev *chan_dev;
chan_dev = container_of(dev, typeof(*chan_dev), device);
return chan_dev->chan;
}
static ssize_t show_memcpy_count(struct device *dev, struct device_attribute *attr, char *buf)
{
struct dma_chan *chan = to_dma_chan(dev);
struct dma_chan *chan;
unsigned long count = 0;
int i;
int err;
for_each_possible_cpu(i)
count += per_cpu_ptr(chan->local, i)->memcpy_count;
mutex_lock(&dma_list_mutex);
chan = dev_to_dma_chan(dev);
if (chan) {
for_each_possible_cpu(i)
count += per_cpu_ptr(chan->local, i)->memcpy_count;
err = sprintf(buf, "%lu\n", count);
} else
err = -ENODEV;
mutex_unlock(&dma_list_mutex);
return sprintf(buf, "%lu\n", count);
return err;
}
static ssize_t show_bytes_transferred(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct dma_chan *chan = to_dma_chan(dev);
struct dma_chan *chan;
unsigned long count = 0;
int i;
int err;
for_each_possible_cpu(i)
count += per_cpu_ptr(chan->local, i)->bytes_transferred;
mutex_lock(&dma_list_mutex);
chan = dev_to_dma_chan(dev);
if (chan) {
for_each_possible_cpu(i)
count += per_cpu_ptr(chan->local, i)->bytes_transferred;
err = sprintf(buf, "%lu\n", count);
} else
err = -ENODEV;
mutex_unlock(&dma_list_mutex);
return sprintf(buf, "%lu\n", count);
return err;
}
static ssize_t show_in_use(struct device *dev, struct device_attribute *attr, char *buf)
{
struct dma_chan *chan = to_dma_chan(dev);
struct dma_chan *chan;
int err;
return sprintf(buf, "%d\n", chan->client_count);
mutex_lock(&dma_list_mutex);
chan = dev_to_dma_chan(dev);
if (chan)
err = sprintf(buf, "%d\n", chan->client_count);
else
err = -ENODEV;
mutex_unlock(&dma_list_mutex);
return err;
}
static struct device_attribute dma_attrs[] = {
@@ -103,9 +142,18 @@ static struct device_attribute dma_attrs[] = {
__ATTR_NULL
};
static void chan_dev_release(struct device *dev)
{
struct dma_chan_dev *chan_dev;
chan_dev = container_of(dev, typeof(*chan_dev), device);
kfree(chan_dev);
}
static struct class dma_devclass = {
.name = "dma",
.dev_attrs = dma_attrs,
.dev_release = chan_dev_release,
};
/* --- client and device registration --- */
@@ -420,7 +468,7 @@ static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_devic
list_for_each_entry(chan, &dev->channels, device_node) {
if (chan->client_count) {
pr_debug("%s: %s busy\n",
__func__, dev_name(&chan->dev));
__func__, dma_chan_name(chan));
continue;
}
ret = chan;
@@ -466,22 +514,22 @@ struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, v
if (err == -ENODEV) {
pr_debug("%s: %s module removed\n", __func__,
dev_name(&chan->dev));
dma_chan_name(chan));
list_del_rcu(&device->global_node);
} else if (err)
pr_err("dmaengine: failed to get %s: (%d)\n",
dev_name(&chan->dev), err);
dma_chan_name(chan), err);
else
break;
} else
pr_debug("%s: %s filter said false\n",
__func__, dev_name(&chan->dev));
__func__, dma_chan_name(chan));
chan = NULL;
}
mutex_unlock(&dma_list_mutex);
pr_debug("%s: %s (%s)\n", __func__, chan ? "success" : "fail",
chan ? dev_name(&chan->dev) : NULL);
chan ? dma_chan_name(chan) : NULL);
return chan;
}
@@ -521,7 +569,7 @@ void dmaengine_get(void)
break;
} else if (err)
pr_err("dmaengine: failed to get %s: (%d)\n",
dev_name(&chan->dev), err);
dma_chan_name(chan), err);
}
}
@@ -601,14 +649,20 @@ int dma_async_device_register(struct dma_device *device)
chan->local = alloc_percpu(typeof(*chan->local));
if (chan->local == NULL)
continue;
chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);
if (chan->dev == NULL) {
free_percpu(chan->local);
continue;
}
chan->chan_id = chancnt++;
chan->dev.class = &dma_devclass;
chan->dev.parent = device->dev;
dev_set_name(&chan->dev, "dma%dchan%d",
chan->dev->device.class = &dma_devclass;
chan->dev->device.parent = device->dev;
chan->dev->chan = chan;
dev_set_name(&chan->dev->device, "dma%dchan%d",
device->dev_id, chan->chan_id);
rc = device_register(&chan->dev);
rc = device_register(&chan->dev->device);
if (rc) {
free_percpu(chan->local);
chan->local = NULL;
@@ -645,7 +699,10 @@ err_out:
list_for_each_entry(chan, &device->channels, device_node) {
if (chan->local == NULL)
continue;
device_unregister(&chan->dev);
mutex_lock(&dma_list_mutex);
chan->dev->chan = NULL;
mutex_unlock(&dma_list_mutex);
device_unregister(&chan->dev->device);
free_percpu(chan->local);
}
return rc;
@@ -672,7 +729,10 @@ void dma_async_device_unregister(struct dma_device *device)
WARN_ONCE(chan->client_count,
"%s called while %d clients hold a reference\n",
__func__, chan->client_count);
device_unregister(&chan->dev);
mutex_lock(&dma_list_mutex);
chan->dev->chan = NULL;
mutex_unlock(&dma_list_mutex);
device_unregister(&chan->dev->device);
}
}
EXPORT_SYMBOL(dma_async_device_unregister);
@@ -845,7 +905,7 @@ dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
return DMA_SUCCESS;
WARN_ONCE(tx->parent, "%s: speculatively walking dependency chain for"
" %s\n", __func__, dev_name(&tx->chan->dev));
" %s\n", __func__, dma_chan_name(tx->chan));
/* poll through the dependency chain, return when tx is complete */
do {