From: Yong Wu yong.wu@mediatek.com
commit da3cc91b8db403728cde03c8a95cba268d8cbf1b upstream.
The commit 4d689b619445 ("iommu/io-pgtable-arm-v7s: Convert to IOMMU API TLB sync") help move the tlb_sync of unmap from v7s into the iommu framework. It helps add a new function "mtk_iommu_iotlb_sync", But it lacked the lock, then it will cause the variable "tlb_flush_active" may be changed unexpectedly, we could see this warning log randomly:
mtk-iommu 10205000.iommu: Partial TLB flush timed out, falling back to full flush
The HW requires tlb_flush/tlb_sync in pairs strictly, this patch adds a new tlb_lock for tlb operations to fix this issue.
Fixes: 4d689b619445 ("iommu/io-pgtable-arm-v7s: Convert to IOMMU API TLB sync") Signed-off-by: Yong Wu yong.wu@mediatek.com Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/iommu/mtk_iommu.c | 23 ++++++++++++++++++++++- drivers/iommu/mtk_iommu.h | 1 + 2 files changed, 23 insertions(+), 1 deletion(-)
--- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -219,22 +219,37 @@ static void mtk_iommu_tlb_sync(void *coo static void mtk_iommu_tlb_flush_walk(unsigned long iova, size_t size, size_t granule, void *cookie) { + struct mtk_iommu_data *data = cookie; + unsigned long flags; + + spin_lock_irqsave(&data->tlb_lock, flags); mtk_iommu_tlb_add_flush_nosync(iova, size, granule, false, cookie); mtk_iommu_tlb_sync(cookie); + spin_unlock_irqrestore(&data->tlb_lock, flags); }
static void mtk_iommu_tlb_flush_leaf(unsigned long iova, size_t size, size_t granule, void *cookie) { + struct mtk_iommu_data *data = cookie; + unsigned long flags; + + spin_lock_irqsave(&data->tlb_lock, flags); mtk_iommu_tlb_add_flush_nosync(iova, size, granule, true, cookie); mtk_iommu_tlb_sync(cookie); + spin_unlock_irqrestore(&data->tlb_lock, flags); }
static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather, unsigned long iova, size_t granule, void *cookie) { + struct mtk_iommu_data *data = cookie; + unsigned long flags; + + 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); }
static const struct iommu_flush_ops mtk_iommu_flush_ops = { @@ -453,7 +468,12 @@ static void mtk_iommu_flush_iotlb_all(st static void mtk_iommu_iotlb_sync(struct iommu_domain *domain, struct iommu_iotlb_gather *gather) { - mtk_iommu_tlb_sync(mtk_iommu_get_m4u_data()); + struct mtk_iommu_data *data = mtk_iommu_get_m4u_data(); + unsigned long flags; + + spin_lock_irqsave(&data->tlb_lock, flags); + mtk_iommu_tlb_sync(data); + spin_unlock_irqrestore(&data->tlb_lock, flags); }
static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain, @@ -733,6 +753,7 @@ static int mtk_iommu_probe(struct platfo if (ret) return ret;
+ spin_lock_init(&data->tlb_lock); list_add_tail(&data->list, &m4ulist);
if (!iommu_present(&platform_bus_type)) --- a/drivers/iommu/mtk_iommu.h +++ b/drivers/iommu/mtk_iommu.h @@ -58,6 +58,7 @@ struct mtk_iommu_data { struct iommu_group *m4u_group; bool enable_4GB; bool tlb_flush_active; + spinlock_t tlb_lock; /* lock for tlb range flush */
struct iommu_device iommu; const struct mtk_iommu_plat_data *plat_data;