diff --git a/arch/riscv/boot/dts/thead/th1520.dtsi b/arch/riscv/boot/dts/thead/th1520.dtsi
index 42724bf7e90e08..f33601dbf3d92a 100644
--- a/arch/riscv/boot/dts/thead/th1520.dtsi
+++ b/arch/riscv/boot/dts/thead/th1520.dtsi
@@ -225,6 +225,13 @@
 		#clock-cells = <0>;
 	};
 
+	gc620_cclk: clk-gc620-fake {
+		compatible = "fixed-clock";
+		clock-frequency = <264000000>;
+		clock-output-names = "gc620_cclk";
+		#clock-cells = <0>;
+	};
+
 	stmmac_axi_config: stmmac-axi-config {
 		snps,wr_osr_lmt = <15>;
 		snps,rd_osr_lmt = <15>;
@@ -493,6 +500,18 @@
 			status = "disabled";
 		};
 
+		/* Vivante GC620, 2D only */
+		g2d: gpu@ffecc80000 {
+			compatible = "vivante,gc";
+			reg = <0xff 0xecc80000 0x0 0x40000>;
+			interrupt-parent = <&plic>;
+			interrupts = <101 IRQ_TYPE_LEVEL_HIGH>;
+
+			clocks = <&gc620_cclk>;
+			clock-names = "core";
+			status = "okay";
+		};
+
 		clk: clock-controller@ffef010000 {
 			compatible = "thead,th1520-clk-ap";
 			reg = <0xff 0xef010000 0x0 0x1000>;
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
index cf0d9049bcf1e3..a8d4394c8f6375 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
@@ -559,7 +559,11 @@ static int etnaviv_hw_reset(struct etnaviv_gpu *gpu)
 		control |= VIVS_HI_CLOCK_CONTROL_ISOLATE_GPU;
 		gpu_write(gpu, VIVS_HI_CLOCK_CONTROL, control);
 
-		if (gpu->sec_mode == ETNA_SEC_KERNEL) {
+		if (etnaviv_is_model_rev(gpu, 0x620, 0x5552)) {
+			gpu_write(gpu, VIVS_DEC400EX_UNK00800, 0x10);
+		}
+
+		if (gpu->identity.minor_features7 & chipMinorFeatures7_BIT_SECURITY) {
 			gpu_write(gpu, VIVS_MMUv2_AHB_CONTROL,
 			          VIVS_MMUv2_AHB_CONTROL_RESET);
 		} else {
@@ -797,7 +801,16 @@ static void etnaviv_gpu_hw_init(struct etnaviv_gpu *gpu)
 		gpu_write(gpu, VIVS_MC_BUS_CONFIG, bus_config);
 	}
 
-	if (gpu->sec_mode == ETNA_SEC_KERNEL) {
+	/*
+	 * FIXME: Required by GC620 r5552 as a bug workaround, but might be
+	 * useful on other GPUs with G2D_DEC400EX feature too.
+	 */
+	if (etnaviv_is_model_rev(gpu, 0x620, 0x5552)) {
+		gpu_write(gpu, VIVS_DEC400EX_UNK00800, 0x2010188);
+		gpu_write(gpu, VIVS_DEC400EX_UNK00808, 0x3fc104);
+	}
+
+	if (gpu->identity.minor_features7 & chipMinorFeatures7_BIT_SECURITY) {
 		u32 val = gpu_read(gpu, VIVS_MMUv2_AHB_CONTROL);
 		val |= VIVS_MMUv2_AHB_CONTROL_NONSEC_ACCESS;
 		gpu_write(gpu, VIVS_MMUv2_AHB_CONTROL, val);
@@ -853,7 +866,7 @@ int etnaviv_gpu_init(struct etnaviv_gpu *gpu)
 	 * On cores with security features supported, we claim control over the
 	 * security states.
 	 */
-	if ((gpu->identity.minor_features7 & chipMinorFeatures7_BIT_SECURITY) &&
+	if ((gpu->identity.minor_features7 & chipMinorFeatures7_BIT_SECURITY) ||
 	    (gpu->identity.minor_features10 & chipMinorFeatures10_SECURITY_AHB))
 		gpu->sec_mode = ETNA_SEC_KERNEL;
 
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_hwdb.c b/drivers/gpu/drm/etnaviv/etnaviv_hwdb.c
index 8665f2658d51b3..6a56f1ab444498 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_hwdb.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_hwdb.c
@@ -69,6 +69,37 @@ static const struct etnaviv_chip_identity etnaviv_chip_identities[] = {
 		.minor_features10 = 0x00000000,
 		.minor_features11 = 0x00000000,
 	},
+	{
+		.model = 0x620,
+		.revision = 0x5552,
+		.product_id = 0x6200,
+		.customer_id = 0x20b,
+		.eco_id = 0,
+		.stream_count = 1,
+		.register_max = 64,
+		.thread_count = 256,
+		.shader_core_count = 1,
+		.vertex_cache_size = 8,
+		.vertex_output_buffer_size = 512,
+		.pixel_pipes = 1,
+		.instruction_count = 256,
+		.num_constants = 168,
+		.buffer_size = 0,
+		.varyings_count = 8,
+		.features = 0x001b4a40,
+		.minor_features0 = 0xa0600080,
+		.minor_features1 = 0x18050000,
+		.minor_features2 = 0x04f30000,
+		.minor_features3 = 0x00060005,
+		.minor_features4 = 0x20629000,
+		.minor_features5 = 0x0003380c,
+		.minor_features6 = 0x00000000,
+		.minor_features7 = 0x00001000,
+		.minor_features8 = 0x00000000,
+		.minor_features9 = 0x00000180,
+		.minor_features10 = 0x00004000,
+		.minor_features11 = 0x00000000,
+	},
 	{
 		.model = 0x7000,
 		.revision = 0x6202,
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_iommu.c b/drivers/gpu/drm/etnaviv/etnaviv_iommu.c
index afe5dd6a9925bf..6fdce63b9971a2 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_iommu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_iommu.c
@@ -39,7 +39,7 @@ static void etnaviv_iommuv1_free(struct etnaviv_iommu_context *context)
 	dma_free_wc(context->global->dev, PT_SIZE, v1_context->pgtable_cpu,
 		    v1_context->pgtable_dma);
 
-	context->global->v1.shared_context = NULL;
+	context->global->shared_context = NULL;
 
 	kfree(v1_context);
 }
@@ -136,8 +136,8 @@ etnaviv_iommuv1_context_alloc(struct etnaviv_iommu_global *global)
 	 * a stop the world operation, so we only support a single shared
 	 * context with this version.
 	 */
-	if (global->v1.shared_context) {
-		context = global->v1.shared_context;
+	if (global->shared_context) {
+		context = global->shared_context;
 		etnaviv_iommu_context_get(context);
 		mutex_unlock(&global->lock);
 		return context;
@@ -163,7 +163,7 @@ etnaviv_iommuv1_context_alloc(struct etnaviv_iommu_global *global)
 	mutex_init(&context->lock);
 	INIT_LIST_HEAD(&context->mappings);
 	drm_mm_init(&context->mm, GPU_MEM_START, PT_ENTRIES * SZ_4K);
-	context->global->v1.shared_context = context;
+	context->global->shared_context = context;
 
 	mutex_unlock(&global->lock);
 
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c b/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c
index d664ae29ae2096..960ba3d659dc50 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c
@@ -272,20 +272,24 @@ etnaviv_iommuv2_context_alloc(struct etnaviv_iommu_global *global)
 	struct etnaviv_iommuv2_context *v2_context;
 	struct etnaviv_iommu_context *context;
 
+	mutex_lock(&global->lock);
+	if (global->shared_context) {
+		context = global->shared_context;
+		etnaviv_iommu_context_get(context);
+		mutex_unlock(&global->lock);
+		return context;
+	}
+
 	v2_context = vzalloc(sizeof(*v2_context));
 	if (!v2_context)
-		return NULL;
+		goto out_mutex_unlock;
 
-	mutex_lock(&global->lock);
 	v2_context->id = find_first_zero_bit(global->v2.pta_alloc,
 					     ETNAVIV_PTA_ENTRIES);
-	if (v2_context->id < ETNAVIV_PTA_ENTRIES) {
+	if (v2_context->id < ETNAVIV_PTA_ENTRIES)
 		set_bit(v2_context->id, global->v2.pta_alloc);
-	} else {
-		mutex_unlock(&global->lock);
+	else
 		goto out_free;
-	}
-	mutex_unlock(&global->lock);
 
 	v2_context->mtlb_cpu = dma_alloc_wc(global->dev, SZ_4K,
 					    &v2_context->mtlb_dma, GFP_KERNEL);
@@ -303,12 +307,17 @@ etnaviv_iommuv2_context_alloc(struct etnaviv_iommu_global *global)
 	mutex_init(&context->lock);
 	INIT_LIST_HEAD(&context->mappings);
 	drm_mm_init(&context->mm, SZ_4K, (u64)SZ_1G * 4 - SZ_4K);
+	if (global->v2.broken_pta)
+		global->shared_context = context;
 
+	mutex_unlock(&global->lock);
 	return context;
 
 out_free_id:
 	clear_bit(v2_context->id, global->v2.pta_alloc);
 out_free:
 	vfree(v2_context);
+out_mutex_unlock:
+	mutex_unlock(&global->lock);
 	return NULL;
 }
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
index df5192083b2019..a0f9c950504e0b 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_mmu.c
@@ -504,6 +504,7 @@ int etnaviv_iommu_global_init(struct etnaviv_gpu *gpu)
 	memset32(global->bad_page_cpu, 0xdead55aa, SZ_4K / sizeof(u32));
 
 	if (version == ETNAVIV_IOMMU_V2) {
+		global->v2.broken_pta = gpu->identity.model == chipModel_GC620;
 		global->v2.pta_cpu = dma_alloc_wc(dev, ETNAVIV_PTA_SIZE,
 					       &global->v2.pta_dma, GFP_KERNEL);
 		if (!global->v2.pta_cpu)
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_mmu.h b/drivers/gpu/drm/etnaviv/etnaviv_mmu.h
index 7f8ac017854748..5627d2a0d02377 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_mmu.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_mmu.h
@@ -49,21 +49,15 @@ struct etnaviv_iommu_global {
 
 	u32 memory_base;
 
-	/*
-	 * This union holds members needed by either MMUv1 or MMUv2, which
-	 * can not exist at the same time.
-	 */
-	union {
-		struct {
-			struct etnaviv_iommu_context *shared_context;
-		} v1;
-		struct {
-			/* P(age) T(able) A(rray) */
-			u64 *pta_cpu;
-			dma_addr_t pta_dma;
-			DECLARE_BITMAP(pta_alloc, ETNAVIV_PTA_ENTRIES);
-		} v2;
-	};
+	struct etnaviv_iommu_context *shared_context;
+	struct {
+		/* P(age) T(able) A(rray) */
+		u64 *pta_cpu;
+		dma_addr_t pta_dma;
+		DECLARE_BITMAP(pta_alloc, ETNAVIV_PTA_ENTRIES);
+		/* Whether runtime switching page table ID will fail */
+		bool broken_pta;
+	} v2;
 };
 
 struct etnaviv_iommu_context {