On Fri, Apr 4, 2014 at 7:33 PM, Alex Williamson <[email protected]> wrote: > On Fri, 2014-04-04 at 11:12 +0530, Ritesh Harjani wrote: >> Hi All, >> >> Please find the below patch and let me know your suggestions on this. >> >> With this patch iommu groups can be linked and iommu driver will >> get to know which all iommu groups belongs to a particular iommu device. >> >> >> >> Each iommu device might have multiple iommu groups, >> with each group populated with many devices. With >> this configuration, iommu driver may require a list >> of iommu groups belonging to each iommu device. >> >> Add list_head struct entry in iommu_group. >> >> Signed-off-by: Ritesh Harjani <[email protected]> >> --- >> drivers/iommu/iommu.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >> index e5555fc..70588dc 100644 >> --- a/drivers/iommu/iommu.c >> +++ b/drivers/iommu/iommu.c >> @@ -36,6 +36,10 @@ static struct ida iommu_group_ida; >> static struct mutex iommu_group_mutex; >> >> struct iommu_group { >> + struct list_head list; /* lower level iommu driver structure >> + * may require list of iommu groups >> + * belonging to that iommu device. >> + */ > > > To have a list would require locking to manage that list, but you seem > to imply that the iommu driver would be managing this list... but there > might be multiple iommu drivers in a single system. Groups are > currently independent of each other by design, trying to manage them in > a list defeats that.
HOW ?? > There is also no example provided here of why we > would need or even want to do this. Thanks, Say multiple groups are linked to one iommu device. Each iommu_group maintains one iommu_data specific to their group. Now, if iommu driver of a iommu device wants to query all the iommu groups and thus all devices which belongs to this iommu hardware, then in that it will be nice if iommu_group struct provides a list_entry ? Thanks Ritesh > > Alex > >> struct kobject kobj; >> struct kobject *devices_kobj; >> struct list_head devices; >> -- >> 1.8.1.3 > > > _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
