drm/vc4: hdmi: Switch to DRM-managed kfree to build regsets

The current code to build the registers set later exposed in debugfs for
the HDMI controller relies on traditional allocations, that are later
free'd as part of the driver unbind hook.

Since krealloc doesn't have a DRM-managed equivalent, let's add an action
to free the buffer later on.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-45-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -2675,7 +2675,15 @@ static int vc4_hdmi_cec_init(struct vc4_hdmi *vc4_hdmi)
 }
 #endif
 
-static int vc4_hdmi_build_regset(struct vc4_hdmi *vc4_hdmi,
+static void vc4_hdmi_free_regset(struct drm_device *drm, void *ptr)
+{
+	struct debugfs_reg32 *regs = ptr;
+
+	kfree(regs);
+}
+
+static int vc4_hdmi_build_regset(struct drm_device *drm,
+				 struct vc4_hdmi *vc4_hdmi,
 				 struct debugfs_regset32 *regset,
 				 enum vc4_hdmi_regs reg)
 {
@@ -2683,6 +2691,7 @@ static int vc4_hdmi_build_regset(struct vc4_hdmi *vc4_hdmi,
 	struct debugfs_reg32 *regs, *new_regs;
 	unsigned int count = 0;
 	unsigned int i;
+	int ret;
 
 	regs = kcalloc(variant->num_registers, sizeof(*regs),
 		       GFP_KERNEL);
@@ -2708,10 +2717,15 @@ static int vc4_hdmi_build_regset(struct vc4_hdmi *vc4_hdmi,
 	regset->regs = new_regs;
 	regset->nregs = count;
 
+	ret = drmm_add_action_or_reset(drm, vc4_hdmi_free_regset, new_regs);
+	if (ret)
+		return ret;
+
 	return 0;
 }
 
-static int vc4_hdmi_init_resources(struct vc4_hdmi *vc4_hdmi)
+static int vc4_hdmi_init_resources(struct drm_device *drm,
+				   struct vc4_hdmi *vc4_hdmi)
 {
 	struct platform_device *pdev = vc4_hdmi->pdev;
 	struct device *dev = &pdev->dev;
@@ -2725,11 +2739,11 @@ static int vc4_hdmi_init_resources(struct vc4_hdmi *vc4_hdmi)
 	if (IS_ERR(vc4_hdmi->hd_regs))
 		return PTR_ERR(vc4_hdmi->hd_regs);
 
-	ret = vc4_hdmi_build_regset(vc4_hdmi, &vc4_hdmi->hd_regset, VC4_HD);
+	ret = vc4_hdmi_build_regset(drm, vc4_hdmi, &vc4_hdmi->hd_regset, VC4_HD);
 	if (ret)
 		return ret;
 
-	ret = vc4_hdmi_build_regset(vc4_hdmi, &vc4_hdmi->hdmi_regset, VC4_HDMI);
+	ret = vc4_hdmi_build_regset(drm, vc4_hdmi, &vc4_hdmi->hdmi_regset, VC4_HDMI);
 	if (ret)
 		return ret;
 
@@ -2752,7 +2766,8 @@ static int vc4_hdmi_init_resources(struct vc4_hdmi *vc4_hdmi)
 	return 0;
 }
 
-static int vc5_hdmi_init_resources(struct vc4_hdmi *vc4_hdmi)
+static int vc5_hdmi_init_resources(struct drm_device *drm,
+				   struct vc4_hdmi *vc4_hdmi)
 {
 	struct platform_device *pdev = vc4_hdmi->pdev;
 	struct device *dev = &pdev->dev;
@@ -2854,35 +2869,35 @@ static int vc5_hdmi_init_resources(struct vc4_hdmi *vc4_hdmi)
 		return PTR_ERR(vc4_hdmi->reset);
 	}
 
-	ret = vc4_hdmi_build_regset(vc4_hdmi, &vc4_hdmi->hdmi_regset, VC4_HDMI);
+	ret = vc4_hdmi_build_regset(drm, vc4_hdmi, &vc4_hdmi->hdmi_regset, VC4_HDMI);
 	if (ret)
 		return ret;
 
-	ret = vc4_hdmi_build_regset(vc4_hdmi, &vc4_hdmi->hd_regset, VC4_HD);
+	ret = vc4_hdmi_build_regset(drm, vc4_hdmi, &vc4_hdmi->hd_regset, VC4_HD);
 	if (ret)
 		return ret;
 
-	ret = vc4_hdmi_build_regset(vc4_hdmi, &vc4_hdmi->cec_regset, VC5_CEC);
+	ret = vc4_hdmi_build_regset(drm, vc4_hdmi, &vc4_hdmi->cec_regset, VC5_CEC);
 	if (ret)
 		return ret;
 
-	ret = vc4_hdmi_build_regset(vc4_hdmi, &vc4_hdmi->csc_regset, VC5_CSC);
+	ret = vc4_hdmi_build_regset(drm, vc4_hdmi, &vc4_hdmi->csc_regset, VC5_CSC);
 	if (ret)
 		return ret;
 
-	ret = vc4_hdmi_build_regset(vc4_hdmi, &vc4_hdmi->dvp_regset, VC5_DVP);
+	ret = vc4_hdmi_build_regset(drm, vc4_hdmi, &vc4_hdmi->dvp_regset, VC5_DVP);
 	if (ret)
 		return ret;
 
-	ret = vc4_hdmi_build_regset(vc4_hdmi, &vc4_hdmi->phy_regset, VC5_PHY);
+	ret = vc4_hdmi_build_regset(drm, vc4_hdmi, &vc4_hdmi->phy_regset, VC5_PHY);
 	if (ret)
 		return ret;
 
-	ret = vc4_hdmi_build_regset(vc4_hdmi, &vc4_hdmi->ram_regset, VC5_RAM);
+	ret = vc4_hdmi_build_regset(drm, vc4_hdmi, &vc4_hdmi->ram_regset, VC5_RAM);
 	if (ret)
 		return ret;
 
-	ret = vc4_hdmi_build_regset(vc4_hdmi, &vc4_hdmi->rm_regset, VC5_RM);
+	ret = vc4_hdmi_build_regset(drm, vc4_hdmi, &vc4_hdmi->rm_regset, VC5_RM);
 	if (ret)
 		return ret;
 
@@ -2977,7 +2992,7 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
 	if (variant->max_pixel_clock > HDMI_14_MAX_TMDS_CLK)
 		vc4_hdmi->scdc_enabled = true;
 
-	ret = variant->init_resources(vc4_hdmi);
+	ret = variant->init_resources(drm, vc4_hdmi);
 	if (ret)
 		return ret;
 
@@ -3104,9 +3119,6 @@ static void vc4_hdmi_unbind(struct device *dev, struct device *master,
 	BUILD_BUG_ON(offsetof(struct vc4_hdmi, audio) != 0);
 	vc4_hdmi = dev_get_drvdata(dev);
 
-	kfree(vc4_hdmi->hdmi_regset.regs);
-	kfree(vc4_hdmi->hd_regset.regs);
-
 	vc4_hdmi_hotplug_exit(vc4_hdmi);
 
 	pm_runtime_disable(dev);

drivers/gpu/drm/vc4/vc4_hdmi.h

@@ -58,7 +58,8 @@ struct vc4_hdmi_variant {
 	/* Callback to get the resources (memory region, interrupts,
 	 * clocks, etc) for that variant.
 	 */
-	int (*init_resources)(struct vc4_hdmi *vc4_hdmi);
+	int (*init_resources)(struct drm_device *drm,
+			      struct vc4_hdmi *vc4_hdmi);
 
 	/* Callback to reset the HDMI block */
 	void (*reset)(struct vc4_hdmi *vc4_hdmi);