On 2018/7/25 6:01, Robin Murphy wrote:
> On 2018-07-12 7:18 AM, Zhen Lei wrote:
>> 1. Save the related domain pointer in struct iommu_dma_cookie, make iovad
>> capable call domain->ops->flush_iotlb_all to flush TLB.
>> 2. Add a new iommu capability: IOMMU_CAP_NON_STRICT, which used to indicate
>> that the iommu domain support non-strict mode.
>> 3. During the iommu domain initialization phase, call capable() to check
>> whether it support non-strcit mode. If so, call init_iova_flush_queue
>> to register iovad->flush_cb callback.
>> 4. All unmap(contains iova-free) APIs will finally invoke __iommu_dma_unmap
>> -->iommu_dma_free_iova. If the domain is non-strict, call queue_iova to
>> put off iova freeing.
>>
>> Signed-off-by: Zhen Lei <[email protected]>
>> ---
>> drivers/iommu/dma-iommu.c | 25 +++++++++++++++++++++++++
>> include/linux/iommu.h | 7 +++++++
>> 2 files changed, 32 insertions(+)
>>
>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
>> index ddcbbdb..9f0c77a 100644
>> --- a/drivers/iommu/dma-iommu.c
>> +++ b/drivers/iommu/dma-iommu.c
>> @@ -55,6 +55,7 @@ struct iommu_dma_cookie {
>> };
>> struct list_head msi_page_list;
>> spinlock_t msi_lock;
>> + struct iommu_domain *domain_non_strict;
>> };
>> static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)
>> @@ -257,6 +258,17 @@ static int iova_reserve_iommu_regions(struct device
>> *dev,
>> return ret;
>> }
>> +static void iommu_dma_flush_iotlb_all(struct iova_domain *iovad)
>> +{
>> + struct iommu_dma_cookie *cookie;
>> + struct iommu_domain *domain;
>> +
>> + cookie = container_of(iovad, struct iommu_dma_cookie, iovad);
>> + domain = cookie->domain_non_strict;
>> +
>> + domain->ops->flush_iotlb_all(domain);
>> +}
>> +
>> /**
>> * iommu_dma_init_domain - Initialise a DMA mapping domain
>> * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()
>> @@ -272,6 +284,7 @@ static int iova_reserve_iommu_regions(struct device *dev,
>> int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
>> u64 size, struct device *dev)
>> {
>> + const struct iommu_ops *ops = domain->ops;
>> struct iommu_dma_cookie *cookie = domain->iova_cookie;
>> struct iova_domain *iovad = &cookie->iovad;
>> unsigned long order, base_pfn, end_pfn;
>> @@ -308,6 +321,15 @@ int iommu_dma_init_domain(struct iommu_domain *domain,
>> dma_addr_t base,
>> }
>> init_iova_domain(iovad, 1UL << order, base_pfn);
>> +
>> + if ((ops->capable && ops->capable(IOMMU_CAP_NON_STRICT)) &&
>> + (IOMMU_DOMAIN_STRICT_MODE(domain) == IOMMU_NON_STRICT)) {
>> + BUG_ON(!ops->flush_iotlb_all);
>> +
>> + cookie->domain_non_strict = domain;
>> + init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all, NULL);
>> + }
>> +
>> if (!dev)
>> return 0;
>> @@ -390,6 +412,9 @@ static void iommu_dma_free_iova(struct
>> iommu_dma_cookie *cookie,
>> /* The MSI case is only ever cleaning up its most recent allocation */
>> if (cookie->type == IOMMU_DMA_MSI_COOKIE)
>> cookie->msi_iova -= size;
>> + else if (cookie->domain_non_strict)
>> + queue_iova(iovad, iova_pfn(iovad, iova),
>> + size >> iova_shift(iovad), 0);
>> else
>> free_iova_fast(iovad, iova_pfn(iovad, iova),
>> size >> iova_shift(iovad));
>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>> index 19938ee..82ed979 100644
>> --- a/include/linux/iommu.h
>> +++ b/include/linux/iommu.h
>> @@ -86,6 +86,12 @@ struct iommu_domain_geometry {
>> #define IOMMU_DOMAIN_DMA (__IOMMU_DOMAIN_PAGING | \
>> __IOMMU_DOMAIN_DMA_API)
>> +#define IOMMU_STRICT 0
>> +#define IOMMU_NON_STRICT 1
>> +#define IOMMU_STRICT_MODE_MASK 1UL
>> +#define IOMMU_DOMAIN_STRICT_MODE(domain) \
>> + (domain->type != IOMMU_DOMAIN_UNMANAGED)
>> +
>> struct iommu_domain {
>> unsigned type;
>> const struct iommu_ops *ops;
>> @@ -101,6 +107,7 @@ enum iommu_cap {
>> transactions */
>> IOMMU_CAP_INTR_REMAP, /* IOMMU supports interrupt isolation */
>> IOMMU_CAP_NOEXEC, /* IOMMU_NOEXEC flag */
>> + IOMMU_CAP_NON_STRICT, /* IOMMU supports non-strict mode */
>
> This still isn't a capability of the hardware. Non-strict mode is pure
> software policy; *every IOMMU ever* supports it.
>
> If you want to have this kind of per-driver control, make it a domain
> attribute - that's not only more logical, but should also work out a lot
> cleaner overall.
OK, I will use quirk, so this capability will be removed in the next version.
>
> Robin.
>
>> };
>> /*
>>
>
> .
>
--
Thanks!
BestRegards
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