summaryrefslogtreecommitdiffstats
path: root/drivers/dma
diff options
context:
space:
mode:
authorDave Jiang <dave.jiang@intel.com>2020-01-21 16:43:47 -0700
committerVinod Koul <vkoul@kernel.org>2020-01-24 11:18:45 +0530
commitd2fb0a0438384fee08a418025f743913020033ce (patch)
tree30b137754d9e648f44238010d6f95d9b7e283fdb /drivers/dma
parent232bb01bb8ad2f88aefbd88b0d3fe3f9a253502b (diff)
downloadlinux-d2fb0a0438384fee08a418025f743913020033ce.tar.bz2
dmaengine: break out channel registration
In preparation for dynamic channel registration, the code segment that does the channel registration is broken out to its own function. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/157965022778.73301.8929944324898985438.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/dmaengine.c135
1 files changed, 81 insertions, 54 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 7550dbdf5488..2daf2ee9bebd 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -926,6 +926,79 @@ static int get_dma_id(struct dma_device *device)
return 0;
}
+static int __dma_async_device_channel_register(struct dma_device *device,
+ struct dma_chan *chan,
+ int chan_id)
+{
+ int rc = 0;
+ int chancnt = device->chancnt;
+ atomic_t *idr_ref;
+ struct dma_chan *tchan;
+
+ tchan = list_first_entry_or_null(&device->channels,
+ struct dma_chan, device_node);
+ if (tchan->dev) {
+ idr_ref = tchan->dev->idr_ref;
+ } else {
+ idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL);
+ if (!idr_ref)
+ return -ENOMEM;
+ atomic_set(idr_ref, 0);
+ }
+
+ chan->local = alloc_percpu(typeof(*chan->local));
+ if (!chan->local)
+ goto err_out;
+ chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);
+ if (!chan->dev) {
+ free_percpu(chan->local);
+ chan->local = NULL;
+ goto err_out;
+ }
+
+ /*
+ * When the chan_id is a negative value, we are dynamically adding
+ * the channel. Otherwise we are static enumerating.
+ */
+ chan->chan_id = chan_id < 0 ? chancnt : chan_id;
+ 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);
+
+ rc = device_register(&chan->dev->device);
+ if (rc)
+ goto err_out;
+ chan->client_count = 0;
+ device->chancnt = chan->chan_id + 1;
+
+ return 0;
+
+ err_out:
+ free_percpu(chan->local);
+ kfree(chan->dev);
+ if (atomic_dec_return(idr_ref) == 0)
+ kfree(idr_ref);
+ return rc;
+}
+
+static void __dma_async_device_channel_unregister(struct dma_device *device,
+ struct dma_chan *chan)
+{
+ WARN_ONCE(!device->device_release && chan->client_count,
+ "%s called while %d clients hold a reference\n",
+ __func__, chan->client_count);
+ mutex_lock(&dma_list_mutex);
+ chan->dev->chan = NULL;
+ mutex_unlock(&dma_list_mutex);
+ device_unregister(&chan->dev->device);
+ free_percpu(chan->local);
+}
+
/**
* dma_async_device_register - registers DMA devices found
* @device: &dma_device
@@ -936,9 +1009,8 @@ static int get_dma_id(struct dma_device *device)
*/
int dma_async_device_register(struct dma_device *device)
{
- int chancnt = 0, rc;
+ int rc, i = 0;
struct dma_chan* chan;
- atomic_t *idr_ref;
if (!device)
return -ENODEV;
@@ -1038,59 +1110,23 @@ int dma_async_device_register(struct dma_device *device)
if (device_has_all_tx_types(device))
dma_cap_set(DMA_ASYNC_TX, device->cap_mask);
- idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL);
- if (!idr_ref)
- return -ENOMEM;
rc = get_dma_id(device);
- if (rc != 0) {
- kfree(idr_ref);
+ if (rc != 0)
return rc;
- }
-
- atomic_set(idr_ref, 0);
/* represent channels in sysfs. Probably want devs too */
list_for_each_entry(chan, &device->channels, device_node) {
- rc = -ENOMEM;
- chan->local = alloc_percpu(typeof(*chan->local));
- if (chan->local == NULL)
+ rc = __dma_async_device_channel_register(device, chan, i++);
+ if (rc < 0)
goto err_out;
- chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);
- if (chan->dev == NULL) {
- free_percpu(chan->local);
- chan->local = NULL;
- goto err_out;
- }
-
- chan->chan_id = chancnt++;
- 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);
-
- rc = device_register(&chan->dev->device);
- if (rc) {
- free_percpu(chan->local);
- chan->local = NULL;
- kfree(chan->dev);
- atomic_dec(idr_ref);
- goto err_out;
- }
- chan->client_count = 0;
}
- if (!chancnt) {
+ if (!device->chancnt) {
dev_err(device->dev, "%s: device has no channels!\n", __func__);
rc = -ENODEV;
goto err_out;
}
- device->chancnt = chancnt;
-
mutex_lock(&dma_list_mutex);
/* take references on public channels */
if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask))
@@ -1118,9 +1154,8 @@ int dma_async_device_register(struct dma_device *device)
err_out:
/* if we never registered a channel just release the idr */
- if (atomic_read(idr_ref) == 0) {
+ if (!device->chancnt) {
ida_free(&dma_ida, device->dev_id);
- kfree(idr_ref);
return rc;
}
@@ -1148,16 +1183,8 @@ void dma_async_device_unregister(struct dma_device *device)
{
struct dma_chan *chan;
- list_for_each_entry(chan, &device->channels, device_node) {
- WARN_ONCE(!device->device_release && chan->client_count,
- "%s called while %d clients hold a reference\n",
- __func__, chan->client_count);
- mutex_lock(&dma_list_mutex);
- chan->dev->chan = NULL;
- mutex_unlock(&dma_list_mutex);
- device_unregister(&chan->dev->device);
- free_percpu(chan->local);
- }
+ list_for_each_entry(chan, &device->channels, device_node)
+ __dma_async_device_channel_unregister(device, chan);
mutex_lock(&dma_list_mutex);
/*