Re: [PATCH v4 19/19] iommu: Remove detach_dev callback

From: Baolu Lu
Date: Thu Jan 05 2023 - 01:42:10 EST


On 2023/1/4 21:22, Jason Gunthorpe wrote:
On Wed, Jan 04, 2023 at 08:57:25PM +0800, Lu Baolu wrote:
The detach_dev callback of domain ops is not called in the IOMMU core.
Remove this callback to avoid dead code. The trace event for detaching
domain from device is removed accordingly.

Signed-off-by: Lu Baolu<baolu.lu@xxxxxxxxxxxxxxx>
---
include/linux/iommu.h | 2 --
include/trace/events/iommu.h | 7 -------
drivers/iommu/iommu-traces.c | 1 -
drivers/iommu/iommu.c | 29 +++++------------------------
4 files changed, 5 insertions(+), 34 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 0d10566b3cb2..a8063f26ff69 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -299,7 +299,6 @@ struct iommu_ops {
* * EBUSY - device is attached to a domain and cannot be changed
* * ENODEV - device specific errors, not able to be attached
* * <others> - treated as ENODEV by the caller. Use is discouraged
- * @detach_dev: detach an iommu domain from a device
* @set_dev_pasid: set an iommu domain to a pasid of device
* @map: map a physically contiguous memory region to an iommu domain
* @map_pages: map a physically contiguous set of pages of the same size to
@@ -320,7 +319,6 @@ struct iommu_ops {
*/
struct iommu_domain_ops {
int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
- void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
int (*set_dev_pasid)(struct iommu_domain *domain, struct device *dev,
ioasid_t pasid);
diff --git a/include/trace/events/iommu.h b/include/trace/events/iommu.h
index 29096fe12623..70743db1fb75 100644
--- a/include/trace/events/iommu.h
+++ b/include/trace/events/iommu.h
@@ -76,13 +76,6 @@ DEFINE_EVENT(iommu_device_event, attach_device_to_domain,
TP_ARGS(dev)
);
-DEFINE_EVENT(iommu_device_event, detach_device_from_domain,
-
- TP_PROTO(struct device *dev),
-
- TP_ARGS(dev)
-);
-
did you want to add a trace for the set_platform_dma_ops in the
earlier patch?

If necessary, we can add such a trace event. But I do hope to further
evolve the iommu drivers that need this callback. Finally, we should
remove it totally.

--
Best regards,
baolu