[BACKPORTED] drm/v3d: Allocate all resources before enabling the clock

Move all resource allocation operations before actually enabling the
clock, as those operations don't require the GPU to be powered on.

This is a preparation for runtime PM support. The next commit will
move all code related to powering on and initiating the GPU into the
runtime PM resume callback and all resource allocation will happen
before resume().

Reviewed-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Maíra Canal <mcanal@igalia.com>

Author: mairacanal

drivers/gpu/drm/v3d/v3d_drv.c

@@ -364,14 +364,50 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
 			return ret;
 	}
 
+	if (v3d->ver < V3D_GEN_41) {
+		ret = map_regs(v3d, &v3d->gca_regs, "gca");
+		if (ret)
+			return ret;
+	}
+
+	v3d->reset = devm_reset_control_get_optional_exclusive(dev, NULL);
+	if (IS_ERR(v3d->reset))
+		return dev_err_probe(dev, PTR_ERR(v3d->reset),
+				     "Failed to get reset control\n");
+
+	if (!v3d->reset) {
+		ret = map_regs(v3d, &v3d->bridge_regs, "bridge");
+		if (ret) {
+			dev_err(dev, "Failed to get bridge registers\n");
+			return ret;
+		}
+	}
+
 	v3d->clk = devm_clk_get_optional(dev, NULL);
 	if (IS_ERR(v3d->clk))
 		return dev_err_probe(dev, PTR_ERR(v3d->clk), "Failed to get V3D clock\n");
 
+	ret = v3d_irq_init(v3d);
+	if (ret)
+		return ret;
+
+	v3d_perfmon_init(v3d);
+
+	v3d->mmu_scratch = dma_alloc_wc(dev, 4096, &v3d->mmu_scratch_paddr,
+					GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
+	if (!v3d->mmu_scratch) {
+		dev_err(dev, "Failed to allocate MMU scratch page\n");
+		return -ENOMEM;
+	}
+
+	ret = v3d_gem_init(drm);
+	if (ret)
+		goto dma_free;
+
 	ret = clk_prepare_enable(v3d->clk);
 	if (ret) {
 		dev_err(&pdev->dev, "Couldn't enable the V3D clock\n");
-		return ret;
+		goto gem_destroy;
 	}
 
 	v3d_idle_sms(v3d);
@@ -398,44 +434,9 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
 	ident3 = V3D_READ(V3D_HUB_IDENT3);
 	v3d->rev = V3D_GET_FIELD(ident3, V3D_HUB_IDENT3_IPREV);
 
-	v3d_perfmon_init(v3d);
-
-	v3d->reset = devm_reset_control_get_optional_exclusive(dev, NULL);
-	if (IS_ERR(v3d->reset)) {
-		ret = dev_err_probe(dev, PTR_ERR(v3d->reset),
-				    "Failed to get reset control\n");
-		goto clk_disable;
-	}
-
-	if (!v3d->reset) {
-		ret = map_regs(v3d, &v3d->bridge_regs, "bridge");
-		if (ret) {
-			dev_err(dev, "Failed to get bridge registers\n");
-			goto clk_disable;
-		}
-	}
-
-	if (v3d->ver < V3D_GEN_41) {
-		ret = map_regs(v3d, &v3d->gca_regs, "gca");
-		if (ret)
-			goto clk_disable;
-	}
-
-	v3d->mmu_scratch = dma_alloc_wc(dev, 4096, &v3d->mmu_scratch_paddr,
-					GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO);
-	if (!v3d->mmu_scratch) {
-		dev_err(dev, "Failed to allocate MMU scratch page\n");
-		ret = -ENOMEM;
-		goto clk_disable;
-	}
-
-	ret = v3d_gem_init(drm);
-	if (ret)
-		goto dma_free;
-
-	ret = v3d_irq_init(v3d);
-	if (ret)
-		goto gem_destroy;
+	v3d_init_hw_state(v3d);
+	v3d_mmu_set_page_table(v3d);
+	v3d_irq_enable(v3d);
 
 	ret = drm_dev_register(drm, 0);
 	if (ret)
@@ -451,12 +452,13 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
 	drm_dev_unregister(drm);
 irq_disable:
 	v3d_irq_disable(v3d);
+clk_disable:
+	v3d_power_off_sms(v3d);
+	clk_disable_unprepare(v3d->clk);
 gem_destroy:
 	v3d_gem_destroy(drm);
 dma_free:
 	dma_free_wc(dev, 4096, v3d->mmu_scratch, v3d->mmu_scratch_paddr);
-clk_disable:
-	clk_disable_unprepare(v3d->clk);
 	return ret;
 }
 
@@ -470,14 +472,13 @@ static void v3d_platform_drm_remove(struct platform_device *pdev)
 
 	drm_dev_unregister(drm);
 
-	v3d_gem_destroy(drm);
-
-	dma_free_wc(v3d->drm.dev, 4096, v3d->mmu_scratch,
-		    v3d->mmu_scratch_paddr);
-
 	v3d_power_off_sms(v3d);
 
 	clk_disable_unprepare(v3d->clk);
+
+	v3d_gem_destroy(drm);
+
+	dma_free_wc(dev, 4096, v3d->mmu_scratch, v3d->mmu_scratch_paddr);
 }
 
 static struct platform_driver v3d_platform_driver = {

drivers/gpu/drm/v3d/v3d_drv.h

@@ -570,6 +570,7 @@ extern const struct dma_fence_ops v3d_fence_ops;
 struct dma_fence *v3d_fence_create(struct v3d_dev *v3d, enum v3d_queue q);
 
 /* v3d_gem.c */
+void v3d_init_hw_state(struct v3d_dev *v3d);
 int v3d_gem_init(struct drm_device *dev);
 void v3d_gem_destroy(struct drm_device *dev);
 void v3d_reset_sms(struct v3d_dev *v3d);

drivers/gpu/drm/v3d/v3d_gem.c

@@ -36,13 +36,6 @@ v3d_init_core(struct v3d_dev *v3d, int core)
 	V3D_CORE_WRITE(core, V3D_CTL_L2TFLEND, ~0);
 }
 
-/* Sets invariant state for the HW. */
-static void
-v3d_init_hw_state(struct v3d_dev *v3d)
-{
-	v3d_init_core(v3d, 0);
-}
-
 static void
 v3d_idle_axi(struct v3d_dev *v3d, int core)
 {
@@ -259,6 +252,13 @@ v3d_invalidate_caches(struct v3d_dev *v3d)
 	v3d_invalidate_slices(v3d, 0);
 }
 
+/* Sets invariant state for the HW. */
+void
+v3d_init_hw_state(struct v3d_dev *v3d)
+{
+	v3d_init_core(v3d, 0);
+}
+
 int
 v3d_gem_init(struct drm_device *dev)
 {
@@ -307,9 +307,6 @@ v3d_gem_init(struct drm_device *dev)
 		return -ENOMEM;
 	}
 
-	v3d_init_hw_state(v3d);
-	v3d_mmu_set_page_table(v3d);
-
 	v3d_gemfs_init(v3d);
 
 	ret = v3d_sched_init(v3d);

drivers/gpu/drm/v3d/v3d_irq.c

@@ -251,17 +251,10 @@ v3d_hub_irq(int irq, void *arg)
 int
 v3d_irq_init(struct v3d_dev *v3d)
 {
-	int irq, ret, core;
+	int irq, ret;
 
 	INIT_WORK(&v3d->overflow_mem_work, v3d_overflow_mem_work);
 
-	/* Clear any pending interrupts someone might have left around
-	 * for us.
-	 */
-	for (core = 0; core < v3d->cores; core++)
-		V3D_CORE_WRITE(core, V3D_CTL_INT_CLR, V3D_CORE_IRQS(v3d->ver));
-	V3D_WRITE(V3D_HUB_INT_CLR, V3D_HUB_IRQS(v3d->ver));
-
 	irq = platform_get_irq_optional(v3d_to_pdev(v3d), 1);
 	if (irq == -EPROBE_DEFER)
 		return irq;
@@ -299,7 +292,6 @@ v3d_irq_init(struct v3d_dev *v3d)
 			goto fail;
 	}
 
-	v3d_irq_enable(v3d);
 	return 0;
 
 fail:
@@ -313,6 +305,11 @@ v3d_irq_enable(struct v3d_dev *v3d)
 {
 	int core;
 
+	/* Clear any pending interrupts someone might have left around for us. */
+	for (core = 0; core < v3d->cores; core++)
+		V3D_CORE_WRITE(core, V3D_CTL_INT_CLR, V3D_CORE_IRQS(v3d->ver));
+	V3D_WRITE(V3D_HUB_INT_CLR, V3D_HUB_IRQS(v3d->ver));
+
 	/* Enable our set of interrupts, masking out any others. */
 	for (core = 0; core < v3d->cores; core++) {
 		V3D_CORE_WRITE(core, V3D_CTL_INT_MSK_SET, ~V3D_CORE_IRQS(v3d->ver));