iommu/mediatek: Fix VLD_PA_RNG register backup when suspend

The register VLD_PA_RNG(0x118) was forgot to backup while adding 4GB
mode support for mt2712. this patch add it.

Fixes: 30e2fccf95 ("iommu/mediatek: Enlarge the validate PA range
for 4GB mode")
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: Evan Green <evgreen@chromium.org>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/mtk_iommu.c

@@ -742,6 +742,7 @@ static int __maybe_unused mtk_iommu_suspend(struct device *dev)
 	reg->int_control0 = readl_relaxed(base + REG_MMU_INT_CONTROL0);
 	reg->int_main_control = readl_relaxed(base + REG_MMU_INT_MAIN_CONTROL);
 	reg->ivrp_paddr = readl_relaxed(base + REG_MMU_IVRP_PADDR);
+	reg->vld_pa_rng = readl_relaxed(base + REG_MMU_VLD_PA_RNG);
 	clk_disable_unprepare(data->bclk);
 	return 0;
 }
@@ -766,6 +767,7 @@ static int __maybe_unused mtk_iommu_resume(struct device *dev)
 	writel_relaxed(reg->int_control0, base + REG_MMU_INT_CONTROL0);
 	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);
 	if (m4u_dom)
 		writel(m4u_dom->cfg.arm_v7s_cfg.ttbr[0] & MMU_PT_ADDR_MASK,
 		       base + REG_MMU_PT_BASE_ADDR);

drivers/iommu/mtk_iommu.h

@@ -24,6 +24,7 @@ struct mtk_iommu_suspend_reg {
 	u32				int_control0;
 	u32				int_main_control;
 	u32				ivrp_paddr;
+	u32				vld_pa_rng;
 };
 
 enum mtk_iommu_plat {