From: Will Deacon <will.deacon@arm.com>
To: Robin Murphy <robin.murphy@arm.com>
Cc: joro@8bytes.org, thunder.leizhen@huawei.com,
iommu@lists.linux-foundation.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linuxarm@huawei.com,
guohanjun@huawei.com, huawei.libin@huawei.com,
john.garry@huawei.com
Subject: Re: [PATCH v7 5/6] iommu/arm-smmu-v3: Add support for non-strict mode
Date: Tue, 18 Sep 2018 18:10:17 +0100 [thread overview]
Message-ID: <20180918171016.GL16498@arm.com> (raw)
In-Reply-To: <4f9444c7224ea0e6e4cef8ddbf77bb5292a383e3.1536935328.git.robin.murphy@arm.com>
On Fri, Sep 14, 2018 at 03:30:23PM +0100, Robin Murphy wrote:
> From: Zhen Lei <thunder.leizhen@huawei.com>
>
> Dynamically choose strict or non-strict mode for page table config based
> on the iommu domain type.
It's the domain type in conjunction with the attribute that determines
whether we use lazy or strict invalidation.
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> [rm: convert to domain attribute]
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
> drivers/iommu/arm-smmu-v3.c | 30 ++++++++++++++++++++++++------
> 1 file changed, 24 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index f10c852479fc..7bbfa5f7ce8e 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -612,6 +612,7 @@ struct arm_smmu_domain {
> struct mutex init_mutex; /* Protects smmu pointer */
>
> struct io_pgtable_ops *pgtbl_ops;
> + bool non_strict;
>
> enum arm_smmu_domain_stage stage;
> union {
> @@ -1633,6 +1634,9 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain)
> if (smmu->features & ARM_SMMU_FEAT_COHERENCY)
> pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA;
>
> + if (smmu_domain->non_strict)
> + pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT;
> +
> pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
> if (!pgtbl_ops)
> return -ENOMEM;
> @@ -1934,13 +1938,17 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
> {
> struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
>
> - if (domain->type != IOMMU_DOMAIN_UNMANAGED)
> - return -EINVAL;
> -
> switch (attr) {
> case DOMAIN_ATTR_NESTING:
> + if (domain->type != IOMMU_DOMAIN_UNMANAGED)
> + return -EINVAL;
> *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
> return 0;
> + case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE:
> + if (domain->type != IOMMU_DOMAIN_DMA)
> + return -EINVAL;
> + *(int *)data = smmu_domain->non_strict;
> + return 0;
> default:
> return -ENODEV;
Hmm, there's a change in behaviour here (and also in the set function)
which is that unknown attributes now return -ENODEV for managed domains
instead of -EINVAL. I don't know if that's a problem, but I'd be inclined
to switch on the domain type and then have a nested switch for the supported
attributes.
Will
next prev parent reply other threads:[~2018-09-18 17:10 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-14 14:30 [PATCH v7 0/6] Add non-strict mode support for iommu-dma Robin Murphy
2018-09-14 14:30 ` [PATCH v7 1/6] iommu/arm-smmu-v3: Implement flush_iotlb_all hook Robin Murphy
2018-09-14 14:30 ` [PATCH v7 2/6] iommu/dma: Add support for non-strict mode Robin Murphy
2018-09-18 17:10 ` Will Deacon
2018-09-18 18:52 ` Robin Murphy
2018-09-14 14:30 ` [PATCH v7 3/6] iommu/io-pgtable-arm: " Robin Murphy
2018-09-14 14:30 ` [PATCH v7 4/6] iommu: Add bootup option "iommu.non_strict" Robin Murphy
2018-09-18 17:10 ` Will Deacon
2018-09-18 19:01 ` Robin Murphy
2018-09-14 14:30 ` [PATCH v7 5/6] iommu/arm-smmu-v3: Add support for non-strict mode Robin Murphy
2018-09-18 17:10 ` Will Deacon [this message]
2018-09-18 19:09 ` Robin Murphy
2018-09-14 14:30 ` [PATCH v7 6/6] iommu/arm-smmu: Support " Robin Murphy
2018-09-18 17:10 ` Will Deacon
2018-09-18 19:22 ` Robin Murphy
2018-09-18 17:10 ` [PATCH v7 0/6] Add non-strict mode support for iommu-dma Will Deacon
2018-09-18 18:28 ` Robin Murphy
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