Messages in this thread Patch in this message | | | From | Yong Wu <> | Subject | [PATCH v2 2/4] iommu/mediatek: Move the tlb_sync into tlb_flush | Date | Wed, 9 Oct 2019 21:19:01 +0800 |
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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 dom->pgtlock, 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
To fix this issue, we can add dom->pgtlock in the "mtk_iommu_iotlb_sync".
In addition, when checking this issue, we find that __arm_v7s_unmap call io_pgtable_tlb_add_flush consecutively when it is supersection/largepage, this also is potential unsafe for us. There is no tlb flush queue in the MediaTek M4U HW. The HW always expect the tlb_flush/tlb_sync one by one. If v7s don't always gurarantee the sequence, Thus, In this patch I move the tlb_sync into tlb_flush(also rename the function deleting "_nosync"). and we don't care if it is leaf, rearrange the callback functions. Also, the tlb flush/sync was already finished in v7s, then iotlb_sync is unnecessary.
Fixes: 4d689b619445 ("iommu/io-pgtable-arm-v7s: Convert to IOMMU API TLB sync") Signed-off-by: Chao Hao <chao.hao@mediatek.com> Signed-off-by: Yong Wu <yong.wu@mediatek.com> --- drivers/iommu/mtk_iommu.c | 63 +++++++++++++---------------------------------- drivers/iommu/mtk_iommu.h | 1 - 2 files changed, 17 insertions(+), 47 deletions(-)
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 76b9388..24a13a6 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -173,11 +173,12 @@ static void mtk_iommu_tlb_flush_all(void *cookie) } } -static void mtk_iommu_tlb_add_flush_nosync(unsigned long iova, size_t size, - size_t granule, bool leaf, - void *cookie) +static void mtk_iommu_tlb_add_flush(unsigned long iova, size_t size, + size_t granule, void *cookie) { struct mtk_iommu_data *data = cookie; + int ret; + u32 tmp; for_each_m4u(data) { writel_relaxed(F_INVLD_EN1 | F_INVLD_EN0, @@ -188,21 +189,12 @@ static void mtk_iommu_tlb_add_flush_nosync(unsigned long iova, size_t size, data->base + REG_MMU_INVLD_END_A); writel_relaxed(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE); - data->tlb_flush_active = true; - } -} - -static void mtk_iommu_tlb_sync(void *cookie) -{ - struct mtk_iommu_data *data = cookie; - int ret; - u32 tmp; - - for_each_m4u(data) { - /* Avoid timing out if there's nothing to wait for */ - if (!data->tlb_flush_active) - return; + /* + * There is no tlb flush queue in the HW, the HW always expect + * tlb_flush and tlb_sync in pair strictly. Here tlb_sync always + * follows tlb_flush to avoid break the sequence. + */ ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE, tmp, tmp != 0, 10, 100000); if (ret) { @@ -212,36 +204,21 @@ static void mtk_iommu_tlb_sync(void *cookie) } /* Clear the CPE status */ writel_relaxed(0, data->base + REG_MMU_CPE_DONE); - data->tlb_flush_active = false; } } -static void mtk_iommu_tlb_flush_walk(unsigned long iova, size_t size, - size_t granule, void *cookie) -{ - mtk_iommu_tlb_add_flush_nosync(iova, size, granule, false, cookie); - mtk_iommu_tlb_sync(cookie); -} - -static void mtk_iommu_tlb_flush_leaf(unsigned long iova, size_t size, - size_t granule, void *cookie) +static void mtk_iommu_tlb_flush_page(struct iommu_iotlb_gather *gather, + unsigned long iova, size_t granule, + void *cookie) { - mtk_iommu_tlb_add_flush_nosync(iova, size, granule, true, cookie); - mtk_iommu_tlb_sync(cookie); -} - -static void mtk_iommu_tlb_flush_page_nosync(struct iommu_iotlb_gather *gather, - unsigned long iova, size_t granule, - void *cookie) -{ - mtk_iommu_tlb_add_flush_nosync(iova, granule, granule, true, cookie); + mtk_iommu_tlb_add_flush(iova, granule, granule, cookie); } static const struct iommu_flush_ops mtk_iommu_flush_ops = { .tlb_flush_all = mtk_iommu_tlb_flush_all, - .tlb_flush_walk = mtk_iommu_tlb_flush_walk, - .tlb_flush_leaf = mtk_iommu_tlb_flush_leaf, - .tlb_add_page = mtk_iommu_tlb_flush_page_nosync, + .tlb_flush_walk = mtk_iommu_tlb_add_flush, + .tlb_flush_leaf = mtk_iommu_tlb_add_flush, + .tlb_add_page = mtk_iommu_tlb_flush_page, }; static irqreturn_t mtk_iommu_isr(int irq, void *dev_id) @@ -450,12 +427,6 @@ static void mtk_iommu_flush_iotlb_all(struct iommu_domain *domain) mtk_iommu_tlb_flush_all(mtk_iommu_get_m4u_data()); } -static void mtk_iommu_iotlb_sync(struct iommu_domain *domain, - struct iommu_iotlb_gather *gather) -{ - mtk_iommu_tlb_sync(mtk_iommu_get_m4u_data()); -} - static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova) { @@ -558,7 +529,7 @@ static int mtk_iommu_of_xlate(struct device *dev, struct of_phandle_args *args) .map = mtk_iommu_map, .unmap = mtk_iommu_unmap, .flush_iotlb_all = mtk_iommu_flush_iotlb_all, - .iotlb_sync = mtk_iommu_iotlb_sync, + /* No iotlb_sync here since the tlb_sync always follows the tlb_flush */ .iova_to_phys = mtk_iommu_iova_to_phys, .add_device = mtk_iommu_add_device, .remove_device = mtk_iommu_remove_device, diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h index fc0f16e..24712f5 100644 --- a/drivers/iommu/mtk_iommu.h +++ b/drivers/iommu/mtk_iommu.h @@ -57,7 +57,6 @@ struct mtk_iommu_data { struct mtk_iommu_domain *m4u_dom; struct iommu_group *m4u_group; bool enable_4GB; - bool tlb_flush_active; struct iommu_device iommu; const struct mtk_iommu_plat_data *plat_data; -- 1.9.1
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