MALI: bifrost: Optimize gpu mem sysfs entry

One process corresponds to only one node,
simplifying the upper-level access.

ls -l sys/class/misc/mali0/device/kprcs/(pid)/
-r--r--r-- 1 root root 4096 2025-06-16 09:47 private_gpu_mem
-r--r--r-- 1 root root 4096 2025-06-16 09:47 total_gpu_mem

Signed-off-by: Weixin Zhou <zwx@rock-chips.com>
Change-Id: Ia198059560c84c5097bfb04f9a16c056db1edaf3

drivers/gpu/arm/bifrost/context/mali_kbase_context.c

@@ -72,6 +72,75 @@ static struct kbase_process *find_process_node(struct rb_node *node, pid_t tgid)
 	return kprcs;
 }
 
+static ssize_t kbase_kctx_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
+{
+	struct kobj_attribute *kattr = container_of(attr, struct kobj_attribute, attr);
+
+	if (kattr->show)
+		return kattr->show(kobj, kattr, buf);
+
+	return -EIO;
+}
+
+static ssize_t kbase_total_gpu_mem_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	struct kbase_context *kctx = container_of(kobj, struct kbase_context, kobj);
+
+	return scnprintf(buf, PAGE_SIZE, "%zu\n", kctx->kprcs->total_gpu_pages << PAGE_SHIFT);
+}
+
+static ssize_t kbase_private_gpu_mem_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	struct kbase_context *kctx = container_of(kobj, struct kbase_context, kobj);
+	struct kbase_process *kprcs = kctx->kprcs;
+	struct kbase_context *tmp_kctx;
+	size_t total_pages = 0;
+
+	/* Sum up used_pages from all contexts in the process */
+	list_for_each_entry(tmp_kctx, &kprcs->kctx_list, kprcs_link) {
+		total_pages += atomic_read(&tmp_kctx->used_pages);
+	}
+
+	return scnprintf(buf, PAGE_SIZE, "%zu\n", total_pages << PAGE_SHIFT);
+}
+
+static struct kobj_attribute kbase_total_gpu_mem_attr = {
+	.attr = {
+		.name = "total_gpu_mem",
+		.mode = 0444,
+	},
+	.show = kbase_total_gpu_mem_show,
+	.store = NULL,
+};
+
+static struct kobj_attribute kbase_private_gpu_mem_attr = {
+	.attr = {
+		.name = "private_gpu_mem",
+		.mode = 0444,
+	},
+	.show = kbase_private_gpu_mem_show,
+	.store = NULL,
+};
+
+static struct attribute *kbase_kctx_attrs[] = {
+	&kbase_total_gpu_mem_attr.attr,
+	&kbase_private_gpu_mem_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group kbase_kctx_attr_group = {
+	.attrs = kbase_kctx_attrs,
+};
+
+static const struct sysfs_ops kbase_kctx_sysfs_ops = {
+	.show = kbase_kctx_attr_show,
+};
+
+static const struct kobj_type kbase_kctx_ktype = {
+	.sysfs_ops = &kbase_kctx_sysfs_ops,
+	.default_groups = (const struct attribute_group *[]) { &kbase_kctx_attr_group, NULL },
+};
+
 /**
  * kbase_insert_kctx_to_process - Initialise kbase process context.
  *
@@ -100,6 +169,8 @@ static int kbase_insert_kctx_to_process(struct kbase_context *kctx)
 	 */
 	if (!kprcs) {
 		struct rb_node **new = &prcs_root->rb_node, *parent = NULL;
+		char kctx_name[64];
+		int ret = 0;
 
 		kprcs = kzalloc(sizeof(*kprcs), GFP_KERNEL);
 		if (kprcs == NULL)
@@ -109,6 +180,15 @@ static int kbase_insert_kctx_to_process(struct kbase_context *kctx)
 		kprcs->dma_buf_root = RB_ROOT;
 		kprcs->total_gpu_pages = 0;
 
+		if (unlikely(!scnprintf(kctx_name, 64, "%d", tgid)))
+			return -ENOMEM;
+
+		ret = kobject_init_and_add(&kctx->kobj, &kbase_kctx_ktype, kctx->kbdev->kprcs_kobj, kctx_name);
+		if (ret) {
+			dev_err(kctx->kbdev->dev, "Failed to create kctx kobject");
+			kobject_put(&kctx->kobj);
+		}
+
 		while (*new) {
 			struct kbase_process *prcs_node;
 
@@ -260,6 +340,7 @@ static void kbase_remove_kctx_from_process(struct kbase_context *kctx)
 	 * we can remove it from the process rb_tree.
 	 */
 	if (list_empty(&kprcs->kctx_list)) {
+		kobject_put(&kctx->kobj);
 		rb_erase(&kprcs->kprcs_node, &kctx->kbdev->process_root);
 		/* Add checks, so that the terminating process Should not
 		 * hold any gpu_memory.

drivers/gpu/arm/bifrost/mali_kbase_core_linux.c

@@ -360,8 +360,6 @@ static void kbase_file_delete(struct kbase_file *const kfile)
 #endif
 		kbase_context_debugfs_term(kctx);
 
-		kobject_put(&kctx->kobj);
-
 		kbase_destroy_context(kctx);
 
 		dev_dbg(kbdev->dev, "deleted base context\n");
@@ -626,74 +624,14 @@ static const struct file_operations kbase_force_same_va_fops = {
 };
 #endif /* CONFIG_DEBUG_FS */
 
-static ssize_t kbase_kctx_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
-{
-	struct kobj_attribute *kattr = container_of(attr, struct kobj_attribute, attr);
-
-	if (kattr->show)
-		return kattr->show(kobj, kattr, buf);
-
-	return -EIO;
-}
-
-static ssize_t kbase_total_gpu_mem_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
-{
-	struct kbase_context *kctx = container_of(kobj, struct kbase_context, kobj);
-
-	return scnprintf(buf, PAGE_SIZE, "%zu\n", kctx->kprcs->total_gpu_pages << PAGE_SHIFT);
-}
-
-static ssize_t kbase_private_gpu_mem_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
-{
-	struct kbase_context *kctx = container_of(kobj, struct kbase_context, kobj);
-
-	return scnprintf(buf, PAGE_SIZE, "%d\n", atomic_read(&kctx->used_pages) << PAGE_SHIFT);
-}
-
-static struct kobj_attribute kbase_total_gpu_mem_attr = {
-	.attr = {
-		.name = "total_gpu_mem",
-		.mode = 0444,
-	},
-	.show = kbase_total_gpu_mem_show,
-	.store = NULL,
-};
-
-static struct kobj_attribute kbase_private_gpu_mem_attr = {
-	.attr = {
-		.name = "private_gpu_mem",
-		.mode = 0444,
-	},
-	.show = kbase_private_gpu_mem_show,
-	.store = NULL,
-};
-
-static struct attribute *kbase_kctx_attrs[] = {
-	&kbase_total_gpu_mem_attr.attr,
-	&kbase_private_gpu_mem_attr.attr,
-	NULL,
-};
-
-static const struct attribute_group kbase_kctx_attr_group = {
-	.attrs = kbase_kctx_attrs,
-};
-
-static const struct sysfs_ops kbase_kctx_sysfs_ops = {
-	.show = kbase_kctx_attr_show,
-};
-
-static const struct kobj_type kbase_kctx_ktype = {
-	.sysfs_ops = &kbase_kctx_sysfs_ops,
-	.default_groups = (const struct attribute_group *[]) { &kbase_kctx_attr_group, NULL },
-};
-
 static int kbase_file_create_kctx(struct kbase_file *const kfile,
 				  base_context_create_flags const flags)
 {
 	struct kbase_device *kbdev = NULL;
 	struct kbase_context *kctx = NULL;
+#if IS_ENABLED(CONFIG_DEBUG_FS)
 	char kctx_name[64];
-	int ret = 0;
+#endif
 
 	if (WARN_ON(!kfile))
 		return -EINVAL;
@@ -738,12 +676,6 @@ static int kbase_file_create_kctx(struct kbase_file *const kfile,
 	}
 #endif /* CONFIG_DEBUG_FS */
 
-	ret = kobject_init_and_add(&kctx->kobj, &kbase_kctx_ktype, kbdev->kprcs_kobj, kctx_name);
-	if (ret) {
-		dev_err(kbdev->dev, "Failed to create kctx kobject");
-		kobject_put(&kctx->kobj);
-	}
-
 	dev_dbg(kbdev->dev, "created base context\n");
 
 	kfile->kctx = kctx;