24.01.2019 21:29, navneet kumar пишет: > On 1/17/19 7:25 AM, Dmitry Osipenko wrote: >> 16.01.2019 23:50, Navneet Kumar пишет: >>> Use PTB_ASID instead of SMMU_CONFIG to flush smmu. >>> PTB_ASID can be accessed from non-secure mode, SMMU_CONFIG cannot be. >>> Using SMMU_CONFIG could pose a problem when kernel doesn't have secure >>> mode access enabled from boot. >>> >>> Signed-off-by: Navneet Kumar <navne...@nvidia.com> >>> --- >>> drivers/iommu/tegra-smmu.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c >>> index ee4d8a8..fa175d9 100644 >>> --- a/drivers/iommu/tegra-smmu.c >>> +++ b/drivers/iommu/tegra-smmu.c >>> @@ -235,7 +235,7 @@ static inline void smmu_flush_tlb_group(struct >>> tegra_smmu *smmu, >>> >>> static inline void smmu_flush(struct tegra_smmu *smmu) >>> { >>> - smmu_readl(smmu, SMMU_CONFIG); >>> + smmu_readl(smmu, SMMU_PTB_ASID); >>> } >>> >>> static int tegra_smmu_alloc_asid(struct tegra_smmu *smmu, unsigned int >>> *idp) >>> >> >> Driver writes to SMMU_CONFIG during of the probing. Looks like it's better >> to drop this patch for now and make it part of a complete solution that will >> add proper support for a stricter insecure-mode platforms. >> > Thanks for the comment Dmitry. On secure platforms, writing to SMMU_CONFIG > will be a no-op and > will pose no harm. Having this patch is important because it fixes the > flushing behavior on > such platforms, which is critical. > > I propose to keep this patch as is, however, i can add more explanation to > the commit message, > stating the case of probe and how it will not have any ill effects. Pls > ACK/NACK, and i shall post > a V2. >
Nothing breaks with this change at least for T30. Please extend the commit message and add a clarifying comment to the code, thanks. With the clarifying message being addressed: Reviewed-by: Dmitry Osipenko <dig...@gmail.com> Tested-by: Dmitry Osipenko <dig...@gmail.com> _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu