From: Dave Jiang <dave.jiang@intel.com>
To: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
vkoul@kernel.org
Cc: dan.j.williams@intel.com, tony.luck@intel.com,
jing.lin@intel.com, ashok.raj@intel.com,
sanjay.k.kumar@intel.com, megha.dey@intel.com,
jacob.jun.pan@intel.com, yi.l.liu@intel.com, axboe@kernel.dk,
akpm@linux-foundation.org, tglx@linutronix.de, mingo@redhat.com,
bp@alien8.de, fenghua.yu@intel.com, hpa@zytor.com
Subject: [PATCH RFC v2 03/14] dmaengine: add new dma device registration
Date: Thu, 12 Dec 2019 11:24:28 -0700 [thread overview]
Message-ID: <157617506831.42350.5972817923465724195.stgit@djiang5-desk3.ch.intel.com> (raw)
In-Reply-To: <157617487798.42350.4471714981643413895.stgit@djiang5-desk3.ch.intel.com>
Add a new device registration call in order to allow dynamic registration
of channels. __dma_async_device_register() will only register the DMA
device. The channel registration is done separately.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
drivers/dma/dmaengine.c | 106 ++++++++++++++++++++++++++++-------------------
1 file changed, 63 insertions(+), 43 deletions(-)
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index a20ab568b637..3c74402f1c34 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -149,10 +149,8 @@ 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)) {
- ida_free(&dma_ida, chan_dev->dev_id);
+ if (atomic_dec_and_test(chan_dev->idr_ref))
kfree(chan_dev->idr_ref);
- }
kfree(chan_dev);
}
@@ -950,8 +948,23 @@ static int __dma_async_device_channel_register(struct dma_device *device,
chan->client_count = 0;
device->chancnt = chan->chan_id + 1;
+ if (dmaengine_ref_count &&
+ !dma_has_cap(DMA_PRIVATE, device->cap_mask)) {
+ if (dma_chan_get(chan) == -ENODEV) {
+ /*
+ * Note we can only get here for the first
+ * channel as the remaining channels are
+ * guaranteed to get a reference.
+ */
+ rc = -ENODEV;
+ goto chan_get_err;
+ }
+ }
+
return 0;
+ chan_get_err:
+ device_unregister(&chan->dev->device);
err_out:
free_percpu(chan->local);
kfree(chan->dev);
@@ -981,6 +994,8 @@ static void __dma_async_device_channel_unregister(struct dma_device *device,
"%s called while %d clients hold a reference\n",
__func__, chan->client_count);
mutex_lock(&dma_list_mutex);
+ list_del(&chan->device_node);
+ device->chancnt--;
chan->dev->chan = NULL;
mutex_unlock(&dma_list_mutex);
device_unregister(&chan->dev->device);
@@ -995,13 +1010,53 @@ void dma_async_device_channel_unregister(struct dma_device *device,
}
EXPORT_SYMBOL_GPL(dma_async_device_channel_unregister);
+/**
+ * __dma_async_device_register - registers DMA devices found.
+ * Core function that registers a DMA device.
+ * @device: &dma_device
+ */
+static int __dma_async_device_register(struct dma_device *device)
+{
+ struct dma_chan *chan;
+ int rc, i = 0;
+
+ if (!device)
+ return -ENODEV;
+
+ /* Validate device routines */
+ if (!device->dev) {
+ pr_err("DMA device must have valid dev\n");
+ return -EIO;
+ }
+
+ rc = get_dma_id(device);
+ if (rc != 0)
+ return rc;
+
+ /* represent channels in sysfs. Probably want devs too */
+ list_for_each_entry(chan, &device->channels, device_node) {
+ rc = __dma_async_device_channel_register(device, chan, i++);
+ if (rc < 0)
+ return rc;
+ }
+
+ mutex_lock(&dma_list_mutex);
+ list_add_tail_rcu(&device->global_node, &dma_device_list);
+ if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
+ device->privatecnt++; /* Always private */
+ dma_channel_rebalance();
+ mutex_unlock(&dma_list_mutex);
+
+ return 0;
+}
+
/**
* dma_async_device_register - registers DMA devices found
* @device: &dma_device
*/
int dma_async_device_register(struct dma_device *device)
{
- int rc, i = 0;
+ int rc;
struct dma_chan* chan;
if (!device)
@@ -1094,45 +1149,9 @@ 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);
- rc = get_dma_id(device);
+ rc = __dma_async_device_register(device);
if (rc != 0)
- return rc;
-
- /* represent channels in sysfs. Probably want devs too */
- list_for_each_entry(chan, &device->channels, device_node) {
- rc = __dma_async_device_channel_register(device, chan, i++);
- if (rc < 0)
- goto err_out;
- }
-
- if (!device->chancnt) {
- dev_err(device->dev, "%s: device has no channels!\n", __func__);
- rc = -ENODEV;
goto err_out;
- }
-
- mutex_lock(&dma_list_mutex);
- /* take references on public channels */
- if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask))
- list_for_each_entry(chan, &device->channels, device_node) {
- /* if clients are already waiting for channels we need
- * to take references on their behalf
- */
- if (dma_chan_get(chan) == -ENODEV) {
- /* note we can only get here for the first
- * channel as the remaining channels are
- * guaranteed to get a reference
- */
- rc = -ENODEV;
- mutex_unlock(&dma_list_mutex);
- goto err_out;
- }
- }
- list_add_tail_rcu(&device->global_node, &dma_device_list);
- if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
- device->privatecnt++; /* Always private */
- dma_channel_rebalance();
- mutex_unlock(&dma_list_mutex);
return 0;
@@ -1165,15 +1184,16 @@ EXPORT_SYMBOL(dma_async_device_register);
*/
void dma_async_device_unregister(struct dma_device *device)
{
- struct dma_chan *chan;
+ struct dma_chan *chan, *n;
mutex_lock(&dma_list_mutex);
list_del_rcu(&device->global_node);
dma_channel_rebalance();
mutex_unlock(&dma_list_mutex);
- list_for_each_entry(chan, &device->channels, device_node)
+ list_for_each_entry_safe(chan, n, &device->channels, device_node)
__dma_async_device_channel_unregister(device, chan);
+ ida_free(&dma_ida, device->dev_id);
}
EXPORT_SYMBOL(dma_async_device_unregister);
next prev parent reply other threads:[~2019-12-12 18:24 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-12 18:24 [PATCH RFC v2 00/14] idxd driver for Intel Data Streaming Accelerator Dave Jiang
2019-12-12 18:24 ` [PATCH RFC v2 01/14] x86/asm: add iosubmit_cmds512() based on movdir64b CPU instruction Dave Jiang
2019-12-12 18:24 ` [PATCH RFC v2 02/14] dmaengine: break out channel registration Dave Jiang
2019-12-12 18:24 ` Dave Jiang [this message]
2019-12-12 18:24 ` [PATCH RFC v2 04/14] mm: create common code from request allocation based from blk-mq code Dave Jiang
2019-12-13 0:43 ` Andrew Morton
2019-12-13 22:06 ` Dave Jiang
2019-12-12 18:24 ` [PATCH RFC v2 05/14] dmaengine: add dma_request support functions Dave Jiang
2019-12-12 18:24 ` [PATCH RFC v2 06/14] dmaengine: add dma request submit and completion path support Dave Jiang
2019-12-12 18:24 ` [PATCH RFC v2 07/14] dmaengine: update dmatest to support dma request Dave Jiang
2019-12-12 18:24 ` [PATCH RFC v2 08/14] dmaengine: idxd: Init and probe for Intel data accelerators Dave Jiang
2019-12-12 18:25 ` [PATCH RFC v2 09/14] dmaengine: idxd: add configuration component of driver Dave Jiang
2019-12-12 18:25 ` [PATCH RFC v2 10/14] dmaengine: idxd: add descriptor manipulation routines Dave Jiang
2019-12-12 18:25 ` [PATCH RFC v2 11/14] dmaengine: idxd: connect idxd to dmaengine subsystem Dave Jiang
2019-12-12 18:25 ` [PATCH RFC v2 12/14] dmaengine: request submit optimization Dave Jiang
2019-12-12 18:25 ` [PATCH RFC v2 13/14] dmaengine: idxd: add char driver to expose submission portal to userland Dave Jiang
2019-12-12 18:25 ` [PATCH RFC v2 14/14] dmaengine: idxd: add sysfs ABI for idxd driver Dave Jiang
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