[PATCH v2 00/10] dmaengine: idxd: Memory leak and FLR fixes

[PATCH v2 00/10] dmaengine: idxd: Memory leak and FLR fixes

[Vinicius Costa Gomes]

Hi,

During testing some not so happy code paths in a debugging (lockdep,
kmemleak, etc) kernel, found a few issues.

There's still a crash that happens when doing a PCI unbind, but I
don't have a patch at this time.

Cheers,

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
Changes in v2:
- Fixed messing up the definition of FLR (Function Level
  Reset) (Nathan Lynch)
- Simplified callers of idxd_device_config(), moved a common check,
  and locking to inside the function (Dave Jiang);
- For idxd DMA backend, ->terminate_all() now flushes all pending
  descriptors (Dave Jiang);
- For idxd DMA backend, ->device_synchronize() now waits for submitted
  operations to finish (Dave Jiang);
- Link to v1: https://lore.kernel.org/r/20250804-idxd-fix-flr-on-kernel-queues-v3-v1-0-4e020fbf52c1@intel.com

---
Vinicius Costa Gomes (10):
      dmaengine: idxd: Fix lockdep warnings when calling idxd_device_config()
      dmaengine: idxd: Fix crash when the event log is disabled
      dmaengine: idxd: Fix possible invalid memory access after FLR
      dmaengine: idxd: Flush kernel workqueues on Function Level Reset
      dmaengine: idxd: Flush all pending descriptors
      dmaengine: idxd: Wait for submitted operations on .device_synchronize()
      dmaengine: idxd: Fix not releasing workqueue on .release()
      dmaengine: idxd: Fix memory leak when a wq is reset
      dmaengine: idxd: Fix freeing the allocated ida too late
      dmaengine: idxd: Fix leaking event log memory

 drivers/dma/idxd/cdev.c   |  8 ++++----
 drivers/dma/idxd/device.c | 43 +++++++++++++++++++++++++++++--------------
 drivers/dma/idxd/dma.c    | 18 ++++++++++++++++++
 drivers/dma/idxd/idxd.h   |  1 +
 drivers/dma/idxd/init.c   | 14 +++++++-------
 drivers/dma/idxd/irq.c    | 16 ++++++++++++++++
 drivers/dma/idxd/sysfs.c  |  1 +
 7 files changed, 76 insertions(+), 25 deletions(-)
---
base-commit: 1daede86fef9e9890c5781541ad4934c776858c5
change-id: 20250804-idxd-fix-flr-on-kernel-queues-v3-13f37abd7178

Best regards,
--  
Vinicius

[PATCH v2 01/10] dmaengine: idxd: Fix lockdep warnings when calling idxd_device_config()

[Vinicius Costa Gomes]

Move the check for IDXD_FLAG_CONFIGURABLE and the locking to "inside"
idxd_device_config(), as this is common to all callers, and the one
that wasn't holding the lock was an error (that was causing the
lockdep warning).

Suggested-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 drivers/dma/idxd/device.c | 17 +++++++----------
 drivers/dma/idxd/init.c   | 10 ++++------
 2 files changed, 11 insertions(+), 16 deletions(-)

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 5cf419fe6b46..ac41889e4fe1 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -1107,7 +1107,11 @@ int idxd_device_config(struct idxd_device *idxd)
 {
 	int rc;
 
-	lockdep_assert_held(&idxd->dev_lock);
+	guard(spinlock)(&idxd->dev_lock);
+
+	if (!test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
+		return 0;
+
 	rc = idxd_wqs_setup(idxd);
 	if (rc < 0)
 		return rc;
@@ -1434,11 +1438,7 @@ int idxd_drv_enable_wq(struct idxd_wq *wq)
 		}
 	}
 
-	rc = 0;
-	spin_lock(&idxd->dev_lock);
-	if (test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
-		rc = idxd_device_config(idxd);
-	spin_unlock(&idxd->dev_lock);
+	rc = idxd_device_config(idxd);
 	if (rc < 0) {
 		dev_dbg(dev, "Writing wq %d config failed: %d\n", wq->id, rc);
 		goto err;
@@ -1534,10 +1534,7 @@ int idxd_device_drv_probe(struct idxd_dev *idxd_dev)
 	}
 
 	/* Device configuration */
-	spin_lock(&idxd->dev_lock);
-	if (test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
-		rc = idxd_device_config(idxd);
-	spin_unlock(&idxd->dev_lock);
+	rc = idxd_device_config(idxd);
 	if (rc < 0)
 		return -ENXIO;
 
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index f98aa41fa42e..c25bd0595561 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -1092,12 +1092,10 @@ static void idxd_reset_done(struct pci_dev *pdev)
 	idxd_device_config_restore(idxd, idxd->idxd_saved);
 
 	/* Re-configure IDXD device if allowed. */
-	if (test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags)) {
-		rc = idxd_device_config(idxd);
-		if (rc < 0) {
-			dev_err(dev, "HALT: %s config fails\n", idxd_name);
-			goto out;
-		}
+	rc = idxd_device_config(idxd);
+	if (rc < 0) {
+		dev_err(dev, "HALT: %s config fails\n", idxd_name);
+		goto out;
 	}
 
 	/* Bind IDXD device to driver. */

-- 
2.50.1

[PATCH v2 02/10] dmaengine: idxd: Fix crash when the event log is disabled

[Vinicius Costa Gomes]

If reporting errors to the event log is not supported by the hardware,
and an error that causes Function Level Reset (FLR) is received, the
driver will try to restore the event log even if it was not allocated.

Also, only try to free the event log if it was properly allocated.

Fixes: 6078a315aec1 ("dmaengine: idxd: Add idxd_device_config_save() and idxd_device_config_restore() helpers")
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 drivers/dma/idxd/device.c | 3 +++
 drivers/dma/idxd/init.c   | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index ac41889e4fe1..02bda8868e24 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -815,6 +815,9 @@ static void idxd_device_evl_free(struct idxd_device *idxd)
 	struct device *dev = &idxd->pdev->dev;
 	struct idxd_evl *evl = idxd->evl;
 
+	if (!evl)
+		return;
+
 	gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
 	if (!gencfg.evl_en)
 		return;
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index c25bd0595561..e9fe5471f722 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -961,7 +961,8 @@ static void idxd_device_config_restore(struct idxd_device *idxd,
 
 	idxd->rdbuf_limit = idxd_saved->saved_idxd.rdbuf_limit;
 
-	idxd->evl->size = saved_evl->size;
+	if (idxd->evl)
+		idxd->evl->size = saved_evl->size;
 
 	for (i = 0; i < idxd->max_groups; i++) {
 		struct idxd_group *saved_group, *group;

-- 
2.50.1

[PATCH v2 03/10] dmaengine: idxd: Fix possible invalid memory access after FLR

[Vinicius Costa Gomes]

In the case that the first Function Level Reset (FLR) concludes
correctly, but in the second FLR the scratch area for the saved
configuration cannot be allocated, it's possible for a invalid memory
access to happen.

Always set the deallocated scratch area to NULL after FLR completes.

Fixes: 98d187a98903 ("dmaengine: idxd: Enable Function Level Reset (FLR) for halt")
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 drivers/dma/idxd/init.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index e9fe5471f722..a5f4c80bf7a6 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -1134,6 +1134,7 @@ static void idxd_reset_done(struct pci_dev *pdev)
 	}
 out:
 	kfree(idxd->idxd_saved);
+	idxd->idxd_saved = NULL;
 }
 
 static const struct pci_error_handlers idxd_error_handler = {

-- 
2.50.1

[PATCH v2 04/10] dmaengine: idxd: Flush kernel workqueues on Function Level Reset

[Vinicius Costa Gomes]

When a Function Level Reset (FLR) happens, terminate the pending
descriptors that were issued by in-kernel users and disable the
interrupts associated with those. They will be re-enabled after FLR
finishes.

idxd_wq_flush_desc() is declared on idxd.h because it's going to be
used in by the DMA backend in a future patch.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 drivers/dma/idxd/device.c | 20 ++++++++++++++++++++
 drivers/dma/idxd/idxd.h   |  1 +
 drivers/dma/idxd/irq.c    | 16 ++++++++++++++++
 3 files changed, 37 insertions(+)

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 02bda8868e24..c62808e30417 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -1319,6 +1319,11 @@ void idxd_wq_free_irq(struct idxd_wq *wq)
 
 	free_irq(ie->vector, ie);
 	idxd_flush_pending_descs(ie);
+
+	/* The interrupt might have been already released by FLR */
+	if (ie->int_handle == INVALID_INT_HANDLE)
+		return;
+
 	if (idxd->request_int_handles)
 		idxd_device_release_int_handle(idxd, ie->int_handle, IDXD_IRQ_MSIX);
 	idxd_device_clear_perm_entry(idxd, ie);
@@ -1327,6 +1332,21 @@ void idxd_wq_free_irq(struct idxd_wq *wq)
 	ie->pasid = IOMMU_PASID_INVALID;
 }
 
+void idxd_wq_flush_descs(struct idxd_wq *wq)
+{
+	struct idxd_irq_entry *ie = &wq->ie;
+	struct idxd_device *idxd = wq->idxd;
+
+	if (wq->state != IDXD_WQ_ENABLED || wq->type != IDXD_WQT_KERNEL)
+		return;
+
+	idxd_flush_pending_descs(ie);
+	if (idxd->request_int_handles)
+		idxd_device_release_int_handle(idxd, ie->int_handle, IDXD_IRQ_MSIX);
+	idxd_device_clear_perm_entry(idxd, ie);
+	ie->int_handle = INVALID_INT_HANDLE;
+}
+
 int idxd_wq_request_irq(struct idxd_wq *wq)
 {
 	struct idxd_device *idxd = wq->idxd;
diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index 74e6695881e6..fb7f570e002b 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -784,6 +784,7 @@ void idxd_wq_quiesce(struct idxd_wq *wq);
 int idxd_wq_init_percpu_ref(struct idxd_wq *wq);
 void idxd_wq_free_irq(struct idxd_wq *wq);
 int idxd_wq_request_irq(struct idxd_wq *wq);
+void idxd_wq_flush_descs(struct idxd_wq *wq);
 
 /* submission */
 int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc);
diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c
index 1107db3ce0a3..8d0eaf5029fa 100644
--- a/drivers/dma/idxd/irq.c
+++ b/drivers/dma/idxd/irq.c
@@ -397,6 +397,17 @@ static void idxd_device_flr(struct work_struct *work)
 		dev_err(&idxd->pdev->dev, "FLR failed\n");
 }
 
+static void idxd_wqs_flush_descs(struct idxd_device *idxd)
+{
+	int i;
+
+	for (i = 0; i < idxd->max_wqs; i++) {
+		struct idxd_wq *wq = idxd->wqs[i];
+
+		idxd_wq_flush_descs(wq);
+	}
+}
+
 static irqreturn_t idxd_halt(struct idxd_device *idxd)
 {
 	union gensts_reg gensts;
@@ -415,6 +426,11 @@ static irqreturn_t idxd_halt(struct idxd_device *idxd)
 		} else if (gensts.reset_type == IDXD_DEVICE_RESET_FLR) {
 			idxd->state = IDXD_DEV_HALTED;
 			idxd_mask_error_interrupts(idxd);
+			/* Flush all pending descriptors, and disable
+			 * interrupts, they will be re-enabled when FLR
+			 * concludes.
+			 */
+			idxd_wqs_flush_descs(idxd);
 			dev_dbg(&idxd->pdev->dev,
 				"idxd halted, doing FLR. After FLR, configs are restored\n");
 			INIT_WORK(&idxd->work, idxd_device_flr);

-- 
2.50.1

[PATCH v2 05/10] dmaengine: idxd: Flush all pending descriptors

[Vinicius Costa Gomes]

When used as a dmaengine, the DMA "core" might ask the driver to
terminate all pending requests, when that happens, flush all pending
descriptors.

In this context, flush means removing the requests from the pending
lists, so even if they are completed after, the user is not notified.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 drivers/dma/idxd/dma.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/dma/idxd/dma.c b/drivers/dma/idxd/dma.c
index dbecd699237e..e4f9788aa635 100644
--- a/drivers/dma/idxd/dma.c
+++ b/drivers/dma/idxd/dma.c
@@ -194,6 +194,15 @@ static void idxd_dma_release(struct dma_device *device)
 	kfree(idxd_dma);
 }
 
+static int idxd_dma_terminate_all(struct dma_chan *c)
+{
+	struct idxd_wq *wq = to_idxd_wq(c);
+
+	idxd_wq_flush_descs(wq);
+
+	return 0;
+}
+
 int idxd_register_dma_device(struct idxd_device *idxd)
 {
 	struct idxd_dma_dev *idxd_dma;
@@ -224,6 +233,7 @@ int idxd_register_dma_device(struct idxd_device *idxd)
 	dma->device_issue_pending = idxd_dma_issue_pending;
 	dma->device_alloc_chan_resources = idxd_dma_alloc_chan_resources;
 	dma->device_free_chan_resources = idxd_dma_free_chan_resources;
+	dma->device_terminate_all = idxd_dma_terminate_all;
 
 	rc = dma_async_device_register(dma);
 	if (rc < 0) {

-- 
2.50.1

[PATCH v2 06/10] dmaengine: idxd: Wait for submitted operations on .device_synchronize()

[Vinicius Costa Gomes]

When the dmaengine "core" asks the driver to synchronize, send a Drain
operation to the device workqueue, which will wait for the already
submitted operations to finish.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 drivers/dma/idxd/dma.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/dma/idxd/dma.c b/drivers/dma/idxd/dma.c
index e4f9788aa635..9937b671f637 100644
--- a/drivers/dma/idxd/dma.c
+++ b/drivers/dma/idxd/dma.c
@@ -203,6 +203,13 @@ static int idxd_dma_terminate_all(struct dma_chan *c)
 	return 0;
 }
 
+static void idxd_dma_synchronize(struct dma_chan *c)
+{
+	struct idxd_wq *wq = to_idxd_wq(c);
+
+	idxd_wq_drain(wq);
+}
+
 int idxd_register_dma_device(struct idxd_device *idxd)
 {
 	struct idxd_dma_dev *idxd_dma;
@@ -234,6 +241,7 @@ int idxd_register_dma_device(struct idxd_device *idxd)
 	dma->device_alloc_chan_resources = idxd_dma_alloc_chan_resources;
 	dma->device_free_chan_resources = idxd_dma_free_chan_resources;
 	dma->device_terminate_all = idxd_dma_terminate_all;
+	dma->device_synchronize = idxd_dma_synchronize;
 
 	rc = dma_async_device_register(dma);
 	if (rc < 0) {

-- 
2.50.1

[PATCH v2 07/10] dmaengine: idxd: Fix not releasing workqueue on .release()

[Vinicius Costa Gomes]

The workqueue associated with an DSA/IAA device is not released when
the object is freed.

Fixes: 47c16ac27d4c ("dmaengine: idxd: fix idxd conf_dev 'struct device' lifetime")
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 drivers/dma/idxd/sysfs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 9f0701021af0..cdd7a59140d9 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -1812,6 +1812,7 @@ static void idxd_conf_device_release(struct device *dev)
 {
 	struct idxd_device *idxd = confdev_to_idxd(dev);
 
+	destroy_workqueue(idxd->wq);
 	kfree(idxd->groups);
 	bitmap_free(idxd->wq_enable_map);
 	kfree(idxd->wqs);

-- 
2.50.1

[PATCH v2 08/10] dmaengine: idxd: Fix memory leak when a wq is reset

[Vinicius Costa Gomes]

idxd_wq_disable_cleanup() which is called from the reset path for a
workqueue, sets the wq type to NONE, which for other parts of the
driver mean that the wq is empty (all its resources were released).

Only set the wq type to NONE after its resources are released.

Fixes: da32b28c95a7 ("dmaengine: idxd: cleanup workqueue config after disabling")
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 drivers/dma/idxd/device.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index c62808e30417..ddce262853b0 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -174,6 +174,7 @@ void idxd_wq_free_resources(struct idxd_wq *wq)
 	free_descs(wq);
 	dma_free_coherent(dev, wq->compls_size, wq->compls, wq->compls_addr);
 	sbitmap_queue_free(&wq->sbq);
+	wq->type = IDXD_WQT_NONE;
 }
 EXPORT_SYMBOL_NS_GPL(idxd_wq_free_resources, "IDXD");
 
@@ -367,7 +368,6 @@ static void idxd_wq_disable_cleanup(struct idxd_wq *wq)
 	lockdep_assert_held(&wq->wq_lock);
 	wq->state = IDXD_WQ_DISABLED;
 	memset(wq->wqcfg, 0, idxd->wqcfg_size);
-	wq->type = IDXD_WQT_NONE;
 	wq->threshold = 0;
 	wq->priority = 0;
 	wq->enqcmds_retries = IDXD_ENQCMDS_RETRIES;
@@ -1536,7 +1536,6 @@ void idxd_drv_disable_wq(struct idxd_wq *wq)
 	idxd_wq_reset(wq);
 	idxd_wq_free_resources(wq);
 	percpu_ref_exit(&wq->wq_active);
-	wq->type = IDXD_WQT_NONE;
 	wq->client_count = 0;
 }
 EXPORT_SYMBOL_NS_GPL(idxd_drv_disable_wq, "IDXD");

-- 
2.50.1

[PATCH v2 09/10] dmaengine: idxd: Fix freeing the allocated ida too late

[Vinicius Costa Gomes]

It can happen that when the cdev .release() is called, the driver
already called ida_destroy(). Move ida_free() to the _del() path.

We see with DEBUG_KOBJECT_RELEASE enabled and forcing an early PCI
unbind.

Fixes: 04922b7445a1 ("dmaengine: idxd: fix cdev setup and free device lifetime issues")
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 drivers/dma/idxd/cdev.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c
index 7e4715f92773..4105688cf3f0 100644
--- a/drivers/dma/idxd/cdev.c
+++ b/drivers/dma/idxd/cdev.c
@@ -158,11 +158,7 @@ static const struct device_type idxd_cdev_file_type = {
 static void idxd_cdev_dev_release(struct device *dev)
 {
 	struct idxd_cdev *idxd_cdev = dev_to_cdev(dev);
-	struct idxd_cdev_context *cdev_ctx;
-	struct idxd_wq *wq = idxd_cdev->wq;
 
-	cdev_ctx = &ictx[wq->idxd->data->type];
-	ida_free(&cdev_ctx->minor_ida, idxd_cdev->minor);
 	kfree(idxd_cdev);
 }
 
@@ -582,11 +578,15 @@ int idxd_wq_add_cdev(struct idxd_wq *wq)
 
 void idxd_wq_del_cdev(struct idxd_wq *wq)
 {
+	struct idxd_cdev_context *cdev_ctx;
 	struct idxd_cdev *idxd_cdev;
 
 	idxd_cdev = wq->idxd_cdev;
 	wq->idxd_cdev = NULL;
 	cdev_device_del(&idxd_cdev->cdev, cdev_dev(idxd_cdev));
+
+	cdev_ctx = &ictx[wq->idxd->data->type];
+	ida_free(&cdev_ctx->minor_ida, idxd_cdev->minor);
 	put_device(cdev_dev(idxd_cdev));
 }
 

-- 
2.50.1

[PATCH v2 10/10] dmaengine: idxd: Fix leaking event log memory

[Vinicius Costa Gomes]

During the device remove process, the device is reset, causing the
configuration registers to go back to their default state, which is
zero. As the driver is checking if the event log support was enabled
before deallocating, it will fail if a reset happened before.

Do not check if the support was enabled, the check for 'idxd->evl'
being valid (only allocated if the HW capability is available) is
enough.

Fixes: 244da66cda35 ("dmaengine: idxd: setup event log configuration")
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
 drivers/dma/idxd/device.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index ddce262853b0..0cf1425e9a7c 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -818,10 +818,6 @@ static void idxd_device_evl_free(struct idxd_device *idxd)
 	if (!evl)
 		return;
 
-	gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
-	if (!gencfg.evl_en)
-		return;
-
 	mutex_lock(&evl->lock);
 	gencfg.evl_en = 0;
 	iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);

-- 
2.50.1

Re: [PATCH v2 01/10] dmaengine: idxd: Fix lockdep warnings when calling idxd_device_config()

[Dave Jiang]

On 8/21/25 3:59 PM, Vinicius Costa Gomes wrote:
> Move the check for IDXD_FLAG_CONFIGURABLE and the locking to "inside"
> idxd_device_config(), as this is common to all callers, and the one
> that wasn't holding the lock was an error (that was causing the
> lockdep warning).
> 
> Suggested-by: Dave Jiang <dave.jiang@intel.com>
> Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  drivers/dma/idxd/device.c | 17 +++++++----------
>  drivers/dma/idxd/init.c   | 10 ++++------
>  2 files changed, 11 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
> index 5cf419fe6b46..ac41889e4fe1 100644
> --- a/drivers/dma/idxd/device.c
> +++ b/drivers/dma/idxd/device.c
> @@ -1107,7 +1107,11 @@ int idxd_device_config(struct idxd_device *idxd)
>  {
>  	int rc;
>  
> -	lockdep_assert_held(&idxd->dev_lock);
> +	guard(spinlock)(&idxd->dev_lock);
> +
> +	if (!test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
> +		return 0;
> +
>  	rc = idxd_wqs_setup(idxd);
>  	if (rc < 0)
>  		return rc;
> @@ -1434,11 +1438,7 @@ int idxd_drv_enable_wq(struct idxd_wq *wq)
>  		}
>  	}
>  
> -	rc = 0;
> -	spin_lock(&idxd->dev_lock);
> -	if (test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
> -		rc = idxd_device_config(idxd);
> -	spin_unlock(&idxd->dev_lock);
> +	rc = idxd_device_config(idxd);
>  	if (rc < 0) {
>  		dev_dbg(dev, "Writing wq %d config failed: %d\n", wq->id, rc);
>  		goto err;
> @@ -1534,10 +1534,7 @@ int idxd_device_drv_probe(struct idxd_dev *idxd_dev)
>  	}
>  
>  	/* Device configuration */
> -	spin_lock(&idxd->dev_lock);
> -	if (test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags))
> -		rc = idxd_device_config(idxd);
> -	spin_unlock(&idxd->dev_lock);
> +	rc = idxd_device_config(idxd);
>  	if (rc < 0)
>  		return -ENXIO;
>  
> diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
> index f98aa41fa42e..c25bd0595561 100644
> --- a/drivers/dma/idxd/init.c
> +++ b/drivers/dma/idxd/init.c
> @@ -1092,12 +1092,10 @@ static void idxd_reset_done(struct pci_dev *pdev)
>  	idxd_device_config_restore(idxd, idxd->idxd_saved);
>  
>  	/* Re-configure IDXD device if allowed. */
> -	if (test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags)) {
> -		rc = idxd_device_config(idxd);
> -		if (rc < 0) {
> -			dev_err(dev, "HALT: %s config fails\n", idxd_name);
> -			goto out;
> -		}
> +	rc = idxd_device_config(idxd);
> +	if (rc < 0) {
> +		dev_err(dev, "HALT: %s config fails\n", idxd_name);
> +		goto out;
>  	}
>  
>  	/* Bind IDXD device to driver. */
> 

Re: [PATCH v2 04/10] dmaengine: idxd: Flush kernel workqueues on Function Level Reset

[Dave Jiang]

On 8/21/25 3:59 PM, Vinicius Costa Gomes wrote:
> When a Function Level Reset (FLR) happens, terminate the pending
> descriptors that were issued by in-kernel users and disable the
> interrupts associated with those. They will be re-enabled after FLR
> finishes.
> 
> idxd_wq_flush_desc() is declared on idxd.h because it's going to be
> used in by the DMA backend in a future patch.
> 
> Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  drivers/dma/idxd/device.c | 20 ++++++++++++++++++++
>  drivers/dma/idxd/idxd.h   |  1 +
>  drivers/dma/idxd/irq.c    | 16 ++++++++++++++++
>  3 files changed, 37 insertions(+)
> 
> diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
> index 02bda8868e24..c62808e30417 100644
> --- a/drivers/dma/idxd/device.c
> +++ b/drivers/dma/idxd/device.c
> @@ -1319,6 +1319,11 @@ void idxd_wq_free_irq(struct idxd_wq *wq)
>  
>  	free_irq(ie->vector, ie);
>  	idxd_flush_pending_descs(ie);
> +
> +	/* The interrupt might have been already released by FLR */
> +	if (ie->int_handle == INVALID_INT_HANDLE)
> +		return;
> +
>  	if (idxd->request_int_handles)
>  		idxd_device_release_int_handle(idxd, ie->int_handle, IDXD_IRQ_MSIX);
>  	idxd_device_clear_perm_entry(idxd, ie);
> @@ -1327,6 +1332,21 @@ void idxd_wq_free_irq(struct idxd_wq *wq)
>  	ie->pasid = IOMMU_PASID_INVALID;
>  }
>  
> +void idxd_wq_flush_descs(struct idxd_wq *wq)
> +{
> +	struct idxd_irq_entry *ie = &wq->ie;
> +	struct idxd_device *idxd = wq->idxd;
> +
> +	if (wq->state != IDXD_WQ_ENABLED || wq->type != IDXD_WQT_KERNEL)
> +		return;
> +
> +	idxd_flush_pending_descs(ie);
> +	if (idxd->request_int_handles)
> +		idxd_device_release_int_handle(idxd, ie->int_handle, IDXD_IRQ_MSIX);
> +	idxd_device_clear_perm_entry(idxd, ie);
> +	ie->int_handle = INVALID_INT_HANDLE;
> +}
> +
>  int idxd_wq_request_irq(struct idxd_wq *wq)
>  {
>  	struct idxd_device *idxd = wq->idxd;
> diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
> index 74e6695881e6..fb7f570e002b 100644
> --- a/drivers/dma/idxd/idxd.h
> +++ b/drivers/dma/idxd/idxd.h
> @@ -784,6 +784,7 @@ void idxd_wq_quiesce(struct idxd_wq *wq);
>  int idxd_wq_init_percpu_ref(struct idxd_wq *wq);
>  void idxd_wq_free_irq(struct idxd_wq *wq);
>  int idxd_wq_request_irq(struct idxd_wq *wq);
> +void idxd_wq_flush_descs(struct idxd_wq *wq);
>  
>  /* submission */
>  int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc);
> diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c
> index 1107db3ce0a3..8d0eaf5029fa 100644
> --- a/drivers/dma/idxd/irq.c
> +++ b/drivers/dma/idxd/irq.c
> @@ -397,6 +397,17 @@ static void idxd_device_flr(struct work_struct *work)
>  		dev_err(&idxd->pdev->dev, "FLR failed\n");
>  }
>  
> +static void idxd_wqs_flush_descs(struct idxd_device *idxd)
> +{
> +	int i;
> +
> +	for (i = 0; i < idxd->max_wqs; i++) {
> +		struct idxd_wq *wq = idxd->wqs[i];
> +
> +		idxd_wq_flush_descs(wq);
> +	}
> +}
> +
>  static irqreturn_t idxd_halt(struct idxd_device *idxd)
>  {
>  	union gensts_reg gensts;
> @@ -415,6 +426,11 @@ static irqreturn_t idxd_halt(struct idxd_device *idxd)
>  		} else if (gensts.reset_type == IDXD_DEVICE_RESET_FLR) {
>  			idxd->state = IDXD_DEV_HALTED;
>  			idxd_mask_error_interrupts(idxd);
> +			/* Flush all pending descriptors, and disable
> +			 * interrupts, they will be re-enabled when FLR
> +			 * concludes.
> +			 */
> +			idxd_wqs_flush_descs(idxd);
>  			dev_dbg(&idxd->pdev->dev,
>  				"idxd halted, doing FLR. After FLR, configs are restored\n");
>  			INIT_WORK(&idxd->work, idxd_device_flr);
> 

Re: [PATCH v2 05/10] dmaengine: idxd: Flush all pending descriptors

[Dave Jiang]

On 8/21/25 3:59 PM, Vinicius Costa Gomes wrote:
> When used as a dmaengine, the DMA "core" might ask the driver to
> terminate all pending requests, when that happens, flush all pending
> descriptors.
> 
> In this context, flush means removing the requests from the pending
> lists, so even if they are completed after, the user is not notified.
> 
> Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  drivers/dma/idxd/dma.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/dma/idxd/dma.c b/drivers/dma/idxd/dma.c
> index dbecd699237e..e4f9788aa635 100644
> --- a/drivers/dma/idxd/dma.c
> +++ b/drivers/dma/idxd/dma.c
> @@ -194,6 +194,15 @@ static void idxd_dma_release(struct dma_device *device)
>  	kfree(idxd_dma);
>  }
>  
> +static int idxd_dma_terminate_all(struct dma_chan *c)
> +{
> +	struct idxd_wq *wq = to_idxd_wq(c);
> +
> +	idxd_wq_flush_descs(wq);
> +
> +	return 0;
> +}
> +
>  int idxd_register_dma_device(struct idxd_device *idxd)
>  {
>  	struct idxd_dma_dev *idxd_dma;
> @@ -224,6 +233,7 @@ int idxd_register_dma_device(struct idxd_device *idxd)
>  	dma->device_issue_pending = idxd_dma_issue_pending;
>  	dma->device_alloc_chan_resources = idxd_dma_alloc_chan_resources;
>  	dma->device_free_chan_resources = idxd_dma_free_chan_resources;
> +	dma->device_terminate_all = idxd_dma_terminate_all;
>  
>  	rc = dma_async_device_register(dma);
>  	if (rc < 0) {
> 

Re: [PATCH v2 06/10] dmaengine: idxd: Wait for submitted operations on .device_synchronize()

[Dave Jiang]

On 8/21/25 3:59 PM, Vinicius Costa Gomes wrote:
> When the dmaengine "core" asks the driver to synchronize, send a Drain
> operation to the device workqueue, which will wait for the already
> submitted operations to finish.
> 
> Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  drivers/dma/idxd/dma.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/dma/idxd/dma.c b/drivers/dma/idxd/dma.c
> index e4f9788aa635..9937b671f637 100644
> --- a/drivers/dma/idxd/dma.c
> +++ b/drivers/dma/idxd/dma.c
> @@ -203,6 +203,13 @@ static int idxd_dma_terminate_all(struct dma_chan *c)
>  	return 0;
>  }
>  
> +static void idxd_dma_synchronize(struct dma_chan *c)
> +{
> +	struct idxd_wq *wq = to_idxd_wq(c);
> +
> +	idxd_wq_drain(wq);
> +}
> +
>  int idxd_register_dma_device(struct idxd_device *idxd)
>  {
>  	struct idxd_dma_dev *idxd_dma;
> @@ -234,6 +241,7 @@ int idxd_register_dma_device(struct idxd_device *idxd)
>  	dma->device_alloc_chan_resources = idxd_dma_alloc_chan_resources;
>  	dma->device_free_chan_resources = idxd_dma_free_chan_resources;
>  	dma->device_terminate_all = idxd_dma_terminate_all;
> +	dma->device_synchronize = idxd_dma_synchronize;
>  
>  	rc = dma_async_device_register(dma);
>  	if (rc < 0) {
>