diff options
| -rw-r--r-- | drivers/dma/dmaengine.c | 27 | ||||
| -rw-r--r-- | include/linux/dmaengine.h | 4 |
2 files changed, 29 insertions, 2 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 93c4c9ac8997..dd43410c1019 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -57,10 +57,12 @@ #include <linux/mutex.h> #include <linux/jiffies.h> #include <linux/rculist.h> +#include <linux/idr.h> static DEFINE_MUTEX(dma_list_mutex); static LIST_HEAD(dma_device_list); static long dmaengine_ref_count; +static struct idr dma_idr; /* --- sysfs implementation --- */ @@ -147,6 +149,12 @@ static void chan_dev_release(struct device *dev) struct dma_chan_dev *chan_dev; chan_dev = container_of(dev, typeof(*chan_dev), device); + if (atomic_dec_and_test(chan_dev->idr_ref)) { + mutex_lock(&dma_list_mutex); + idr_remove(&dma_idr, chan_dev->dev_id); + mutex_unlock(&dma_list_mutex); + kfree(chan_dev->idr_ref); + } kfree(chan_dev); } @@ -611,9 +619,9 @@ EXPORT_SYMBOL(dmaengine_put); */ int dma_async_device_register(struct dma_device *device) { - static int id; int chancnt = 0, rc; struct dma_chan* chan; + atomic_t *idr_ref; if (!device) return -ENODEV; @@ -640,9 +648,20 @@ int dma_async_device_register(struct dma_device *device) BUG_ON(!device->device_issue_pending); BUG_ON(!device->dev); + idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL); + if (!idr_ref) + return -ENOMEM; + atomic_set(idr_ref, 0); + idr_retry: + if (!idr_pre_get(&dma_idr, GFP_KERNEL)) + return -ENOMEM; mutex_lock(&dma_list_mutex); - device->dev_id = id++; + rc = idr_get_new(&dma_idr, NULL, &device->dev_id); mutex_unlock(&dma_list_mutex); + if (rc == -EAGAIN) + goto idr_retry; + else if (rc != 0) + return rc; /* represent channels in sysfs. Probably want devs too */ list_for_each_entry(chan, &device->channels, device_node) { @@ -659,6 +678,9 @@ int dma_async_device_register(struct dma_device *device) chan->dev->device.class = &dma_devclass; chan->dev->device.parent = device->dev; chan->dev->chan = chan; + chan->dev->idr_ref = idr_ref; + chan->dev->dev_id = device->dev_id; + atomic_inc(idr_ref); dev_set_name(&chan->dev->device, "dma%dchan%d", device->dev_id, chan->chan_id); @@ -971,6 +993,7 @@ EXPORT_SYMBOL_GPL(dma_run_dependencies); static int __init dma_bus_init(void) { + idr_init(&dma_idr); mutex_init(&dma_list_mutex); return class_register(&dma_devclass); } diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index d6b6bff355f4..64dea2ab326c 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -140,10 +140,14 @@ struct dma_chan { * struct dma_chan_dev - relate sysfs device node to backing channel device * @chan - driver channel device * @device - sysfs device + * @dev_id - parent dma_device dev_id + * @idr_ref - reference count to gate release of dma_device dev_id */ struct dma_chan_dev { struct dma_chan *chan; struct device device; + int dev_id; + atomic_t *idr_ref; }; static inline const char *dma_chan_name(struct dma_chan *chan) |