dmaengine: idxd: add char driver to expose submission portal to userland
Create a char device region that will allow acquisition of user portals in
order to allow applications to submit DMA operations. A char device will be
created per work queue that gets exposed. The workqueue type "user"
is used to mark a work queue for user char device. For example if the
workqueue 0 of DSA device 0 is marked for char device, then a device node
of /dev/dsa/wq0.0 will be created.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/157965026985.73301.976523230037106742.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
diff --git a/drivers/dma/idxd/submit.c b/drivers/dma/idxd/submit.c
index e16cab3..45a0c58 100644
--- a/drivers/dma/idxd/submit.c
+++ b/drivers/dma/idxd/submit.c
@@ -69,17 +69,19 @@ int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
{
struct idxd_device *idxd = wq->idxd;
int vec = desc->hw->int_handle;
+ void __iomem *portal;
if (idxd->state != IDXD_DEV_ENABLED)
return -EIO;
+ portal = wq->dportal + idxd_get_wq_portal_offset(IDXD_PORTAL_UNLIMITED);
/*
* The wmb() flushes writes to coherent DMA data before possibly
* triggering a DMA read. The wmb() is necessary even on UP because
* the recipient is a device.
*/
wmb();
- iosubmit_cmds512(wq->dportal, desc->hw, 1);
+ iosubmit_cmds512(portal, desc->hw, 1);
/*
* Pending the descriptor to the lockless list for the irq_entry