lkml.org 
[lkml]   [2017]   [Jul]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 2/5] iommu/arm-smmu: add IOMMU_CAP_BYPASS to the ARM SMMU driver
From
Date
On 19/07/17 10:33, Anup Patel wrote:
> The ARM SMMUv1 and SMMUv2 support bypassing transactions for
> which domain is not configured. The patch adds corresponding
> IOMMU capability to advertise this fact.
>
> Signed-off-by: Anup Patel <anup.patel@broadcom.com>
> ---
> drivers/iommu/arm-smmu.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index bc89b4d..08a9020 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -1483,6 +1483,8 @@ static bool arm_smmu_capable(enum iommu_cap cap)
> return true;
> case IOMMU_CAP_NOEXEC:
> return true;
> + case IOMMU_CAP_BYPASS:
> + return true;

Except when it isn't, of course.

Beware that what we'd like to do in the long term is flip the polarity
of disable_bypass, because there isn't generally a good reason for
Non-Secure DMA to be happening behind Linux's back.

Robin.

> default:
> return false;
> }
>

\
 
 \ /
  Last update: 2017-07-19 13:00    [W:0.196 / U:0.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site