[PATCH 6.12] dmaengine: Add missing cleanup on module unload

[PATCH 6.12] dmaengine: Add missing cleanup on module unload

[Guenter Roeck]

Upstream commit b7cb9a034305 ("dmaengine: idxd: Fix refcount underflow
on module unload") fixes a refcount underflow by replacing the call to
idxd_cleanup() in the remove function with direct cleanup calls. That works
fine upstream. However, upstream removed support for IOMMU_DEV_FEAT_IOPF,
which is still supported in v6.12.y. The backport of commit b7cb9a034305
into v6.12.y misses the call to disable it. This results in a warning
backtrace when unloading and reloading the module.

WARNING: CPU: 0 PID: 665849 at drivers/pci/ats.c:337 pci_reset_pri+0x4c/0x60
...
RIP: 0010:pci_reset_pri+0xa7/0x130

Add the missing cleanup call to fix the problem.

Fixes: ce81905bec91 ("dmaengine: idxd: Fix refcount underflow on module unload")
Cc: Yi Sun <yi.sun@intel.com>
Cc: Shuai Xue <xueshuai@linux.alibaba.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Cc: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
The problem fixed with this patch only affects v6.12.y.

 drivers/dma/idxd/init.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 74a83203181d..e55136bb525e 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -923,6 +923,8 @@ static void idxd_remove(struct pci_dev *pdev)
 	idxd_cleanup_interrupts(idxd);
 	if (device_pasid_enabled(idxd))
 		idxd_disable_system_pasid(idxd);
+	if (device_user_pasid_enabled(idxd))
+		idxd_disable_sva(idxd->pdev);
 	pci_iounmap(pdev, idxd->reg_base);
 	put_device(idxd_confdev(idxd));
 	pci_disable_device(pdev);
-- 
2.45.2

Re: [PATCH 6.12] dmaengine: Add missing cleanup on module unload

[Vinicius Costa Gomes]

Guenter Roeck <linux@roeck-us.net> writes:

> Upstream commit b7cb9a034305 ("dmaengine: idxd: Fix refcount underflow
> on module unload") fixes a refcount underflow by replacing the call to
> idxd_cleanup() in the remove function with direct cleanup calls. That works
> fine upstream. However, upstream removed support for IOMMU_DEV_FEAT_IOPF,
> which is still supported in v6.12.y. The backport of commit b7cb9a034305
> into v6.12.y misses the call to disable it. This results in a warning
> backtrace when unloading and reloading the module.
>
> WARNING: CPU: 0 PID: 665849 at drivers/pci/ats.c:337 pci_reset_pri+0x4c/0x60
> ...
> RIP: 0010:pci_reset_pri+0xa7/0x130
>
> Add the missing cleanup call to fix the problem.
>
> Fixes: ce81905bec91 ("dmaengine: idxd: Fix refcount underflow on module unload")
> Cc: Yi Sun <yi.sun@intel.com>
> Cc: Shuai Xue <xueshuai@linux.alibaba.com>
> Cc: Dave Jiang <dave.jiang@intel.com>
> Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com>
> Cc: Vinod Koul <vkoul@kernel.org>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
> The problem fixed with this patch only affects v6.12.y.
>

Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>


Cheers,
-- 
Vinicius