[PATCH v6 2/2] iommu/mediatek: Allow page table PA up to 35bit

[yf.wang]

From: Yunfei Wang <yf.wang@xxxxxxxxxxxx>

The level 1 and level 2 pgtable are both allocated in ZONE_DMA32, and
may have two possible problem:
1.The level 2 pgtable is allocated in ZONE_DMA32 with atomic flag, and
it may fail if ZONE_DMA32 memory is used out.
2.Single memory feature will make ZONE_DMA32 empty, and cause level
1 and level 2 pgtable PA more than 32bit.

So add the quirk IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT support for single
normal zone, so that level 1 and level 2 pgtable can support at most
35bit PA.

Signed-off-by: Ning Li <ning.li@xxxxxxxxxxxx>
Signed-off-by: Yunfei Wang <yf.wang@xxxxxxxxxxxx>
---
 drivers/iommu/mtk_iommu.c | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 6fd75a60abd6..1b9a876ef271 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -33,6 +33,7 @@
 
 #define REG_MMU_PT_BASE_ADDR			0x000
 #define MMU_PT_ADDR_MASK			GENMASK(31, 7)
+#define MMU_PT_ADDR_2_0_MASK			GENMASK(2, 0)
 
 #define REG_MMU_INVALIDATE			0x020
 #define F_ALL_INVLD				0x2
@@ -118,6 +119,7 @@
 #define WR_THROT_EN			BIT(6)
 #define HAS_LEGACY_IVRP_PADDR		BIT(7)
 #define IOVA_34_EN			BIT(8)
+#define PGTABLE_PA_35_EN		BIT(9)
 
 #define MTK_IOMMU_HAS_FLAG(pdata, _x) \
 		((((pdata)->flags) & (_x)) == (_x))
@@ -401,6 +403,9 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom,
 		.iommu_dev = data->dev,
 	};
 
+	if (MTK_IOMMU_HAS_FLAG(data->plat_data, PGTABLE_PA_35_EN))
+		dom->cfg.quirks |= IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT;
+
 	if (MTK_IOMMU_HAS_FLAG(data->plat_data, HAS_4GB_MODE))
 		dom->cfg.oas = data->enable_4GB ? 33 : 32;
 	else
@@ -450,6 +455,7 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain,
 	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
 	struct device *m4udev = data->dev;
 	int ret, domid;
+	u32 regval;
 
 	domid = mtk_iommu_get_domain_id(dev, data->plat_data);
 	if (domid < 0)
@@ -472,8 +478,14 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain,
 			return ret;
 		}
 		data->m4u_dom = dom;
-		writel(dom->cfg.arm_v7s_cfg.ttbr & MMU_PT_ADDR_MASK,
-		       data->base + REG_MMU_PT_BASE_ADDR);
+
+		/* Bits[6:3] are invalid for mediatek platform */
+		if (MTK_IOMMU_HAS_FLAG(data->plat_data, PGTABLE_PA_35_EN))
+			regval = (dom->cfg.arm_v7s_cfg.ttbr & MMU_PT_ADDR_MASK) |
+				 (dom->cfg.arm_v7s_cfg.ttbr & MMU_PT_ADDR_2_0_MASK);
+		else
+			regval = dom->cfg.arm_v7s_cfg.ttbr & MMU_PT_ADDR_MASK;
+		writel(regval, data->base + REG_MMU_PT_BASE_ADDR);
 
 		pm_runtime_put(m4udev);
 	}
@@ -987,6 +999,7 @@ static int __maybe_unused mtk_iommu_runtime_resume(struct device *dev)
 	struct mtk_iommu_suspend_reg *reg = &data->reg;
 	struct mtk_iommu_domain *m4u_dom = data->m4u_dom;
 	void __iomem *base = data->base;
+	u32 regval;
 	int ret;
 
 	ret = clk_prepare_enable(data->bclk);
@@ -1010,7 +1023,14 @@ static int __maybe_unused mtk_iommu_runtime_resume(struct device *dev)
 	writel_relaxed(reg->int_main_control, base + REG_MMU_INT_MAIN_CONTROL);
 	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);
+
+	/* Bits[6:3] are invalid for mediatek platform */
+	if (MTK_IOMMU_HAS_FLAG(data->plat_data, PGTABLE_PA_35_EN))
+		regval = (m4u_dom->cfg.arm_v7s_cfg.ttbr & MMU_PT_ADDR_MASK) |
+			 (m4u_dom->cfg.arm_v7s_cfg.ttbr & MMU_PT_ADDR_2_0_MASK);
+	else
+		regval = m4u_dom->cfg.arm_v7s_cfg.ttbr & MMU_PT_ADDR_MASK;
+	writel(regval, base + REG_MMU_PT_BASE_ADDR);
 
 	/*
 	 * Users may allocate dma buffer before they call pm_runtime_get,
@@ -1038,7 +1058,8 @@ static const struct mtk_iommu_plat_data mt2712_data = {
 
 static const struct mtk_iommu_plat_data mt6779_data = {
 	.m4u_plat      = M4U_MT6779,
-	.flags         = HAS_SUB_COMM | OUT_ORDER_WR_EN | WR_THROT_EN,
+	.flags         = HAS_SUB_COMM | OUT_ORDER_WR_EN | WR_THROT_EN |
+			 PGTABLE_PA_35_EN,
 	.inv_sel_reg   = REG_MMU_INV_SEL_GEN2,
 	.iova_region   = single_domain,
 	.iova_region_nr = ARRAY_SIZE(single_domain),
-- 
2.18.0