Messages in this thread | | | Subject | Re: [PATCH v6 07/33] iommu: Avoid reallocate default domain for a group | From | Robin Murphy <> | Date | Fri, 29 Jan 2021 00:03:57 +0000 |
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On 2021-01-28 21:14, Will Deacon wrote: > On Thu, Jan 28, 2021 at 09:10:20PM +0000, Will Deacon wrote: >> On Wed, Jan 27, 2021 at 05:39:16PM +0800, Yong Wu wrote: >>> On Tue, 2021-01-26 at 22:23 +0000, Will Deacon wrote: >>>> On Mon, Jan 11, 2021 at 07:18:48PM +0800, Yong Wu wrote: >>>>> If group->default_domain exists, avoid reallocate it. >>>>> >>>>> In some iommu drivers, there may be several devices share a group. Avoid >>>>> realloc the default domain for this case. >>>>> >>>>> Signed-off-by: Yong Wu <yong.wu@mediatek.com> >>>>> --- >>>>> drivers/iommu/iommu.c | 3 ++- >>>>> 1 file changed, 2 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >>>>> index 3d099a31ddca..f4b87e6abe80 100644 >>>>> --- a/drivers/iommu/iommu.c >>>>> +++ b/drivers/iommu/iommu.c >>>>> @@ -266,7 +266,8 @@ int iommu_probe_device(struct device *dev) >>>>> * support default domains, so the return value is not yet >>>>> * checked. >>>>> */ >>>>> - iommu_alloc_default_domain(group, dev); >>>>> + if (!group->default_domain) >>>>> + iommu_alloc_default_domain(group, dev); >>>> >>>> I don't really get what this achieves, since iommu_alloc_default_domain() >>>> looks like this: >>>> >>>> static int iommu_alloc_default_domain(struct iommu_group *group, >>>> struct device *dev) >>>> { >>>> unsigned int type; >>>> >>>> if (group->default_domain) >>>> return 0; >>>> >>>> ... >>>> >>>> in which case, it should be fine? >>> >>> oh. sorry, I overlooked this. the current code is enough. >>> I will remove this patch. and send the next version in this week. >>> Thanks very much. >> >> Actually, looking at this again, if we're dropping this patch and patch 6 >> just needs the kfree() moving about, then there's no need to repost. The >> issue that Robin and Paul are discussing can be handled separately.
FWIW patch #6 gets dropped as well now, since Rob has applied the standalone fix (89c7cb1608ac).
Robin.
> Argh, except that this version of the patches doesn't apply :) > > So after all that, please go ahead and post a v7 ASAP based on this branch: > > https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=for-joerg/mtk > > Will >
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