From: Yong Wu <yong.wu@mediatek.com>
Date: Wed, 8 Dec 2021 14:07:44 +0200
Subject: iommu/mediatek: Always tlb_flush_all when each PM resume
Git-commit: 4f23f6d45821701c68b99c2847a075472b53198c
Patch-mainline: v5.18-rc1
References: bsc#1205701
Prepare for 2 HWs that sharing pgtable in different power-domains.
When there are 2 M4U HWs, it may has problem in the flush_range in which
we get the pm_status via the m4u dev, BUT that function don't reflect the
real power-domain status of the HW since there may be other HW also use
that power-domain.
DAM allocation is often done while the allocating device is runtime
suspended. In such a case the iommu will also be suspended and partial
flushing of the tlb will not be executed.
Therefore, we add a tlb_flush_all in the pm_runtime_resume to make
sure the tlb is always clean.
In other case, the iommu's power should be active via device
link with smi.
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
[move the call to mtk_iommu_tlb_flush_all to the bottom of resume cb, improve doc/log]
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20211208120744.2415-6-dafna.hirschfeld@collabora.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/mtk_iommu.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 7cbfe3bfaaab..eb43e7edb9dc 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -975,6 +975,13 @@ static int __maybe_unused mtk_iommu_runtime_resume(struct device *dev)
writel_relaxed(reg->ivrp_paddr, base + REG_MMU_IVRP_PADDR);
writel_relaxed(reg->vld_pa_rng, base + REG_MMU_VLD_PA_RNG);
writel(m4u_dom->cfg.arm_v7s_cfg.ttbr & MMU_PT_ADDR_MASK, base + REG_MMU_PT_BASE_ADDR);
+
+ /*
+ * Users may allocate dma buffer before they call pm_runtime_get,
+ * in which case it will lack the necessary tlb flush.
+ * Thus, make sure to update the tlb after each PM resume.
+ */
+ mtk_iommu_tlb_flush_all(data);
return 0;
}