[PATCH v4 3/7] iommu/mediatek: Use gather to achieve the tlb range flush

From: Yong Wu
Date: Tue Oct 15 2019 - 23:34:01 EST


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@xxxxxxxxxxxx>
Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
---
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);
}

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);
}
--
1.9.1