diff options
| author | Matthew Wilcox <mawilcox@microsoft.com> | 2016-12-15 17:57:51 +0100 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2017-01-02 05:16:32 +0100 |
| commit | adc064cd9f6ee7a8b426955e6a28191abc9d0e8e (patch) | |
| tree | a2f5fe47fdecf0c5edbaa8a64c3e3c6cad8bd661 /drivers/dma/dmaengine.c | |
| parent | Linux 4.10-rc2 (diff) | |
| download | linux-adc064cd9f6ee7a8b426955e6a28191abc9d0e8e.tar.xz linux-adc064cd9f6ee7a8b426955e6a28191abc9d0e8e.zip | |
dmaengine: Convert ID allocation to an IDA
dmaengine currently uses an IDR to allocate DMA IDs, but it only needs
to know whether IDs are in use or not; the ID to pointer functionality
of the IDR is unused. That means it can use the more space-efficient IDA.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/dmaengine.c')
| -rw-r--r-- | drivers/dma/dmaengine.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 6b535262ac5d..24e0221fd66d 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -65,7 +65,7 @@ #include <linux/mempool.h> static DEFINE_MUTEX(dma_list_mutex); -static DEFINE_IDR(dma_idr); +static DEFINE_IDA(dma_ida); static LIST_HEAD(dma_device_list); static long dmaengine_ref_count; @@ -162,7 +162,7 @@ static void chan_dev_release(struct device *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); + ida_remove(&dma_ida, chan_dev->dev_id); mutex_unlock(&dma_list_mutex); kfree(chan_dev->idr_ref); } @@ -898,14 +898,15 @@ static int get_dma_id(struct dma_device *device) { int rc; - mutex_lock(&dma_list_mutex); - - rc = idr_alloc(&dma_idr, NULL, 0, 0, GFP_KERNEL); - if (rc >= 0) - device->dev_id = rc; + do { + if (!ida_pre_get(&dma_ida, GFP_KERNEL)) + return -ENOMEM; + mutex_lock(&dma_list_mutex); + rc = ida_get_new(&dma_ida, &device->dev_id); + mutex_unlock(&dma_list_mutex); + } while (rc == -EAGAIN); - mutex_unlock(&dma_list_mutex); - return rc < 0 ? rc : 0; + return rc; } /** @@ -1035,7 +1036,7 @@ err_out: /* if we never registered a channel just release the idr */ if (atomic_read(idr_ref) == 0) { mutex_lock(&dma_list_mutex); - idr_remove(&dma_idr, device->dev_id); + ida_remove(&dma_ida, device->dev_id); mutex_unlock(&dma_list_mutex); kfree(idr_ref); return rc; |