| Message ID | 0a891cec4bb164f8cf2f57c753791a7d1f5f1d81.1536935328.git.robin.murphy@arm.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v7,1/6] iommu/arm-smmu-v3: Implement flush_iotlb_all hook | expand |
Hi Robin, On Fri, Sep 14, 2018 at 03:30:20PM +0100, Robin Murphy wrote: > From: Zhen Lei <thunder.leizhen@huawei.com> > > 1. Save the related domain pointer in struct iommu_dma_cookie, make iovad > capable call domain->ops->flush_iotlb_all to flush TLB. > 2. During the iommu domain initialization phase, base on domain->non_strict > field to check whether non-strict mode is supported or not. If so, call > init_iova_flush_queue to register iovad->flush_cb callback. > 3. 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, and omit iommu_tlb_sync operation. Hmm, this is basically just a commentary on the code. Please could you write it more in terms of the problem that's being solved? > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> > [rm: convert raw boolean to domain attribute] > Signed-off-by: Robin Murphy <robin.murphy@arm.com> > --- > drivers/iommu/dma-iommu.c | 29 ++++++++++++++++++++++++++++- > include/linux/iommu.h | 1 + > 2 files changed, 29 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index 511ff9a1d6d9..092e6926dc3c 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -55,6 +55,9 @@ struct iommu_dma_cookie { > }; > struct list_head msi_page_list; > spinlock_t msi_lock; > + > + /* Only be assigned in non-strict mode, otherwise it's NULL */ > + struct iommu_domain *domain; > }; > > static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie) > @@ -257,6 +260,17 @@ 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; > + > + domain->ops->flush_iotlb_all(domain); Can we rely on this function pointer being non-NULL? I think it would be better to call iommu_flush_tlb_all(cookie->domain) instead. > +} > + > /** > * iommu_dma_init_domain - Initialise a DMA mapping domain > * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() > @@ -275,6 +289,7 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, > struct iommu_dma_cookie *cookie = domain->iova_cookie; > struct iova_domain *iovad = &cookie->iovad; > unsigned long order, base_pfn, end_pfn; > + int attr = 1; Do we actually need to initialise this? Will
On 2018-09-18 6:10 PM, Will Deacon wrote: > Hi Robin, > > On Fri, Sep 14, 2018 at 03:30:20PM +0100, Robin Murphy wrote: >> From: Zhen Lei <thunder.leizhen@huawei.com> >> >> 1. Save the related domain pointer in struct iommu_dma_cookie, make iovad >> capable call domain->ops->flush_iotlb_all to flush TLB. >> 2. During the iommu domain initialization phase, base on domain->non_strict >> field to check whether non-strict mode is supported or not. If so, call >> init_iova_flush_queue to register iovad->flush_cb callback. >> 3. 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, and omit iommu_tlb_sync operation. > > Hmm, this is basically just a commentary on the code. Please could you write > it more in terms of the problem that's being solved? Sure - I intentionally kept a light touch when it came to the documentation and commit messages in this rework (other than patch #1 where I eventually remembered the original reasoning and that it wasn't a bug). If we're more-or-less happy with the shape of the technical side I'll make sure to take a final pass through v8 to tidy up all the prose. >> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> >> [rm: convert raw boolean to domain attribute] >> Signed-off-by: Robin Murphy <robin.murphy@arm.com> >> --- >> drivers/iommu/dma-iommu.c | 29 ++++++++++++++++++++++++++++- >> include/linux/iommu.h | 1 + >> 2 files changed, 29 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c >> index 511ff9a1d6d9..092e6926dc3c 100644 >> --- a/drivers/iommu/dma-iommu.c >> +++ b/drivers/iommu/dma-iommu.c >> @@ -55,6 +55,9 @@ struct iommu_dma_cookie { >> }; >> struct list_head msi_page_list; >> spinlock_t msi_lock; >> + >> + /* Only be assigned in non-strict mode, otherwise it's NULL */ >> + struct iommu_domain *domain; >> }; >> >> static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie) >> @@ -257,6 +260,17 @@ 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; >> + >> + domain->ops->flush_iotlb_all(domain); > > Can we rely on this function pointer being non-NULL? I think it would > be better to call iommu_flush_tlb_all(cookie->domain) instead. Yeah, that's deliberate - in fact got as far as writing that change, then undid it as I realised that although the attribute conversion got rid of the explicit ops->flush_iotlb_all check, it still makes zero sense for an IOMMU driver to claim to support the flush queue attribute without also providing the relevant callback, so I do actually want this to blow up rather than silently do nothing if that assumption isn't met. >> +} >> + >> /** >> * iommu_dma_init_domain - Initialise a DMA mapping domain >> * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() >> @@ -275,6 +289,7 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, >> struct iommu_dma_cookie *cookie = domain->iova_cookie; >> struct iova_domain *iovad = &cookie->iovad; >> unsigned long order, base_pfn, end_pfn; >> + int attr = 1; > > Do we actually need to initialise this? Oops, no, that's a left-over from the turned-out-messier-that-I-thought v6 implementation. Thanks, Robin.
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 511ff9a1d6d9..092e6926dc3c 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -55,6 +55,9 @@ struct iommu_dma_cookie { }; struct list_head msi_page_list; spinlock_t msi_lock; + + /* Only be assigned in non-strict mode, otherwise it's NULL */ + struct iommu_domain *domain; }; static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie) @@ -257,6 +260,17 @@ 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; + + 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() @@ -275,6 +289,7 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, struct iommu_dma_cookie *cookie = domain->iova_cookie; struct iova_domain *iovad = &cookie->iovad; unsigned long order, base_pfn, end_pfn; + int attr = 1; if (!cookie || cookie->type != IOMMU_DMA_IOVA_COOKIE) return -EINVAL; @@ -308,6 +323,13 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, } init_iova_domain(iovad, 1UL << order, base_pfn); + + if (!iommu_domain_get_attr(domain, DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE, + &attr) && attr) { + cookie->domain = domain; + init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all, NULL); + } + if (!dev) return 0; @@ -393,6 +415,9 @@ 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 mode */ + 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)); @@ -408,7 +433,9 @@ static void __iommu_dma_unmap(struct iommu_domain *domain, dma_addr_t dma_addr, dma_addr -= iova_off; size = iova_align(iovad, size + iova_off); - WARN_ON(iommu_unmap(domain, dma_addr, size) != size); + WARN_ON(iommu_unmap_fast(domain, dma_addr, size) != size); + if (!cookie->domain) + iommu_tlb_sync(domain); iommu_dma_free_iova(cookie, dma_addr, size); } diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 87994c265bf5..decabe8e8dbe 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -124,6 +124,7 @@ enum iommu_attr { DOMAIN_ATTR_FSL_PAMU_ENABLE, DOMAIN_ATTR_FSL_PAMUV1, DOMAIN_ATTR_NESTING, /* two stages of translation */ + DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE, DOMAIN_ATTR_MAX, };