| Message ID | 1571196792-12382-4-git-send-email-yong.wu@mediatek.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | a7a04ea34e1c483d10d3e72250ff5503b1076fe3 |
| Headers | show |
| Series | Improve tlb range flush | expand |
On Wed, Oct 16, 2019 at 11:33:08AM +0800, Yong Wu wrote: > Use the iommu_gather mechanism to achieve the tlb range flush. > Gather the iova range in the "tlb_add_page", then flush the merged iova > range in iotlb_sync. > > Suggested-by: Tomasz Figa <tfiga@chromium.org> > Signed-off-by: Yong Wu <yong.wu@mediatek.com> > --- > drivers/iommu/mtk_iommu.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > index c2f6c78..81ac95f 100644 > --- a/drivers/iommu/mtk_iommu.c > +++ b/drivers/iommu/mtk_iommu.c > @@ -245,11 +245,9 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather, > void *cookie) > { > struct mtk_iommu_data *data = cookie; > - unsigned long flags; > + struct iommu_domain *domain = &data->m4u_dom->domain; > > - spin_lock_irqsave(&data->tlb_lock, flags); > - mtk_iommu_tlb_add_flush_nosync(iova, granule, granule, true, cookie); > - spin_unlock_irqrestore(&data->tlb_lock, flags); > + iommu_iotlb_gather_add_page(domain, gather, iova, granule); You need to be careful here, because iommu_iotlb_gather_add_page() can call iommu_tlb_sync() in some situations and you don't hold the lock. > static const struct iommu_flush_ops mtk_iommu_flush_ops = { > @@ -469,9 +467,15 @@ static void mtk_iommu_iotlb_sync(struct iommu_domain *domain, > struct iommu_iotlb_gather *gather) > { > struct mtk_iommu_data *data = mtk_iommu_get_m4u_data(); > + size_t length = gather->end - gather->start; > unsigned long flags; > > + if (gather->start == ULONG_MAX) > + return; > + > spin_lock_irqsave(&data->tlb_lock, flags); > + mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize, > + false, data); > mtk_iommu_tlb_sync(data); > spin_unlock_irqrestore(&data->tlb_lock, flags); Modulo my comment above, this fixes my previous comment. Given that mainline is already broken, I guess the runtime bisectability isn't a problem. Will
On Wed, 2019-10-23 at 17:55 +0100, Will Deacon wrote: > On Wed, Oct 16, 2019 at 11:33:08AM +0800, Yong Wu wrote: > > Use the iommu_gather mechanism to achieve the tlb range flush. > > Gather the iova range in the "tlb_add_page", then flush the merged iova > > range in iotlb_sync. > > > > Suggested-by: Tomasz Figa <tfiga@chromium.org> > > Signed-off-by: Yong Wu <yong.wu@mediatek.com> > > --- > > drivers/iommu/mtk_iommu.c | 12 ++++++++---- > > 1 file changed, 8 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > > index c2f6c78..81ac95f 100644 > > --- a/drivers/iommu/mtk_iommu.c > > +++ b/drivers/iommu/mtk_iommu.c > > @@ -245,11 +245,9 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather, > > void *cookie) > > { > > struct mtk_iommu_data *data = cookie; > > - unsigned long flags; > > + struct iommu_domain *domain = &data->m4u_dom->domain; > > > > - spin_lock_irqsave(&data->tlb_lock, flags); > > - mtk_iommu_tlb_add_flush_nosync(iova, granule, granule, true, cookie); > > - spin_unlock_irqrestore(&data->tlb_lock, flags); > > + iommu_iotlb_gather_add_page(domain, gather, iova, granule); > > You need to be careful here, because iommu_iotlb_gather_add_page() can > call iommu_tlb_sync() in some situations and you don't hold the lock. The mtk_iommu_iotlb_sync below already has the lock in it, so I delete the lock here. > > > static const struct iommu_flush_ops mtk_iommu_flush_ops = { > > @@ -469,9 +467,15 @@ static void mtk_iommu_iotlb_sync(struct iommu_domain *domain, > > struct iommu_iotlb_gather *gather) > > { > > struct mtk_iommu_data *data = mtk_iommu_get_m4u_data(); > > + size_t length = gather->end - gather->start; > > unsigned long flags; > > > > + if (gather->start == ULONG_MAX) > > + return; > > + > > spin_lock_irqsave(&data->tlb_lock, flags); > > + mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize, > > + false, data); > > mtk_iommu_tlb_sync(data); > > spin_unlock_irqrestore(&data->tlb_lock, flags); > > Modulo my comment above, this fixes my previous comment. Given that mainline > is already broken, I guess the runtime bisectability isn't a problem. As the reply in [2/7]. the mainline is not broken after [2/7], it only go to the previous status before commit(4d689b619445). After using the iommu_gather, the iova will be the merged range in this iotlb_sync, it is just fit to do the tlb-flush/tlb-sync. then it fixes our potential issue(No tlb-sync for the previous tlb-flush range). > > Will
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index c2f6c78..81ac95f 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -245,11 +245,9 @@ static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather, void *cookie) { struct mtk_iommu_data *data = cookie; - unsigned long flags; + struct iommu_domain *domain = &data->m4u_dom->domain; - spin_lock_irqsave(&data->tlb_lock, flags); - mtk_iommu_tlb_add_flush_nosync(iova, granule, granule, true, cookie); - spin_unlock_irqrestore(&data->tlb_lock, flags); + iommu_iotlb_gather_add_page(domain, gather, iova, granule); } static const struct iommu_flush_ops mtk_iommu_flush_ops = { @@ -469,9 +467,15 @@ static void mtk_iommu_iotlb_sync(struct iommu_domain *domain, struct iommu_iotlb_gather *gather) { struct mtk_iommu_data *data = mtk_iommu_get_m4u_data(); + size_t length = gather->end - gather->start; unsigned long flags; + if (gather->start == ULONG_MAX) + return; + spin_lock_irqsave(&data->tlb_lock, flags); + mtk_iommu_tlb_add_flush_nosync(gather->start, length, gather->pgsize, + false, data); mtk_iommu_tlb_sync(data); spin_unlock_irqrestore(&data->tlb_lock, flags); }
Use the iommu_gather mechanism to achieve the tlb range flush. Gather the iova range in the "tlb_add_page", then flush the merged iova range in iotlb_sync. Suggested-by: Tomasz Figa <tfiga@chromium.org> Signed-off-by: Yong Wu <yong.wu@mediatek.com> --- drivers/iommu/mtk_iommu.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)