lkml.org 
[lkml]   [2021]   [Mar]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 5.10 337/663] iommu: Move iotlb_sync_map out from __iommu_map
Hi!

> [ Upstream commit d8c1df02ac7f2c802a9b2afc0f5c888c4217f1d5 ]
>
> In the end of __iommu_map, It alway call iotlb_sync_map.
>
> This patch moves iotlb_sync_map out from __iommu_map since it is
> unnecessary to call this for each sg segment especially iotlb_sync_map
> is flush tlb all currently. Add a little helper _iommu_map for this.

> Signed-off-by: Sasha Levin <sashal@kernel.org>

AFAICT this is slight performance optimalization, not a bugfix. It
actually introduces a bug, fixed by the next patch. I'd preffer not to
have it in stable.

Best regards,
Pavel

> @@ -2421,18 +2418,31 @@ static int __iommu_map(struct iommu_domain *domain, unsigned long iova,
>
> +static int _iommu_map(struct iommu_domain *domain, unsigned long iova,
> + phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
> +{
> + const struct iommu_ops *ops = domain->ops;
> + int ret;
> +
> + ret = __iommu_map(domain, iova, paddr, size, prot, GFP_KERNEL);
> + if (ret == 0 && ops->iotlb_sync_map)
> + ops->iotlb_sync_map(domain);
> +
> + return ret;
> +}

--
http://www.livejournal.com/~pavelmachek
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2021-03-04 09:47    [W:1.509 / U:0.472 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site