[PATCH RESEND drm-misc 0/4] drm: constify struct class usage

[PATCH RESEND drm-misc 0/4] drm: constify struct class usage

[Ricardo B. Marliere]

This is a simple and straight forward cleanup series that aims to make the
class structures in drm constant. This has been possible since 2023 [1].

[1]: https://lore.kernel.org/all/2023040248-customary-release-4aec@gregkh/

Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
---
Ricardo B. Marliere (4):
      drm/dp: make drm_dp_aux_dev_class constant
      drm/sysfs: make drm_class constant
      drm/fbdev/core: make fb_class constant
      dma-buf: heaps: make dma_heap_class constant

 drivers/dma-buf/dma-heap.c               | 26 ++++++++++---------
 drivers/gpu/drm/display/drm_dp_aux_dev.c | 22 ++++++++--------
 drivers/gpu/drm/drm_internal.h           |  2 +-
 drivers/gpu/drm/drm_privacy_screen.c     |  2 +-
 drivers/gpu/drm/drm_sysfs.c              | 44 ++++++++++++++------------------
 drivers/video/fbdev/core/fb_internal.h   |  2 +-
 drivers/video/fbdev/core/fbcon.c         |  4 +--
 drivers/video/fbdev/core/fbmem.c         | 17 ++++++------
 drivers/video/fbdev/core/fbsysfs.c       |  4 +--
 9 files changed, 60 insertions(+), 63 deletions(-)
---
base-commit: 4a0e7b3c37531aabddf6f144b83ae9b65ec809fd
change-id: 20240305-class_cleanup-drm-591ca73b31f2

Best regards,
-- 
Ricardo B. Marliere <ricardo@marliere.net>

[PATCH RESEND drm-misc 1/4] drm/dp: make drm_dp_aux_dev_class constant

[Ricardo B. Marliere]

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the drm_dp_aux_dev_class structure to be declared at build
time placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
---
 drivers/gpu/drm/display/drm_dp_aux_dev.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_dp_aux_dev.c b/drivers/gpu/drm/display/drm_dp_aux_dev.c
index 29555b9f03c8..213abde5b09f 100644
--- a/drivers/gpu/drm/display/drm_dp_aux_dev.c
+++ b/drivers/gpu/drm/display/drm_dp_aux_dev.c
@@ -54,7 +54,6 @@ struct drm_dp_aux_dev {
 #define AUX_MAX_OFFSET	(1 << 20)
 static DEFINE_IDR(aux_idr);
 static DEFINE_MUTEX(aux_idr_mutex);
-static struct class *drm_dp_aux_dev_class;
 static int drm_dev_major = -1;
 
 static struct drm_dp_aux_dev *drm_dp_aux_dev_get_by_minor(unsigned index)
@@ -125,6 +124,11 @@ static struct attribute *drm_dp_aux_attrs[] = {
 };
 ATTRIBUTE_GROUPS(drm_dp_aux);
 
+static const struct class drm_dp_aux_dev_class = {
+	.name = "drm_dp_aux_dev",
+	.dev_groups = drm_dp_aux_groups,
+};
+
 static int auxdev_open(struct inode *inode, struct file *file)
 {
 	unsigned int minor = iminor(inode);
@@ -293,7 +297,7 @@ void drm_dp_aux_unregister_devnode(struct drm_dp_aux *aux)
 
 	minor = aux_dev->index;
 	if (aux_dev->dev)
-		device_destroy(drm_dp_aux_dev_class,
+		device_destroy(&drm_dp_aux_dev_class,
 			       MKDEV(drm_dev_major, minor));
 
 	DRM_DEBUG("drm_dp_aux_dev: aux [%s] unregistering\n", aux->name);
@@ -309,7 +313,7 @@ int drm_dp_aux_register_devnode(struct drm_dp_aux *aux)
 	if (IS_ERR(aux_dev))
 		return PTR_ERR(aux_dev);
 
-	aux_dev->dev = device_create(drm_dp_aux_dev_class, aux->dev,
+	aux_dev->dev = device_create(&drm_dp_aux_dev_class, aux->dev,
 				     MKDEV(drm_dev_major, aux_dev->index), NULL,
 				     "drm_dp_aux%d", aux_dev->index);
 	if (IS_ERR(aux_dev->dev)) {
@@ -330,11 +334,9 @@ int drm_dp_aux_dev_init(void)
 {
 	int res;
 
-	drm_dp_aux_dev_class = class_create("drm_dp_aux_dev");
-	if (IS_ERR(drm_dp_aux_dev_class)) {
-		return PTR_ERR(drm_dp_aux_dev_class);
-	}
-	drm_dp_aux_dev_class->dev_groups = drm_dp_aux_groups;
+	res = class_register(&drm_dp_aux_dev_class);
+	if (res)
+		return res;
 
 	res = register_chrdev(0, "aux", &auxdev_fops);
 	if (res < 0)
@@ -343,12 +345,12 @@ int drm_dp_aux_dev_init(void)
 
 	return 0;
 out:
-	class_destroy(drm_dp_aux_dev_class);
+	class_unregister(&drm_dp_aux_dev_class);
 	return res;
 }
 
 void drm_dp_aux_dev_exit(void)
 {
 	unregister_chrdev(drm_dev_major, "aux");
-	class_destroy(drm_dp_aux_dev_class);
+	class_unregister(&drm_dp_aux_dev_class);
 }

-- 
2.43.0

[PATCH RESEND drm-misc 2/4] drm/sysfs: make drm_class constant

[Ricardo B. Marliere]

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the drm_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
---
 drivers/gpu/drm/drm_internal.h       |  2 +-
 drivers/gpu/drm/drm_privacy_screen.c |  2 +-
 drivers/gpu/drm/drm_sysfs.c          | 44 ++++++++++++++++--------------------
 3 files changed, 21 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
index 8e4faf0a28e6..a881cd442a9b 100644
--- a/drivers/gpu/drm/drm_internal.h
+++ b/drivers/gpu/drm/drm_internal.h
@@ -142,7 +142,7 @@ bool drm_master_internal_acquire(struct drm_device *dev);
 void drm_master_internal_release(struct drm_device *dev);
 
 /* drm_sysfs.c */
-extern struct class *drm_class;
+extern const struct class drm_class;
 
 int drm_sysfs_init(void);
 void drm_sysfs_destroy(void);
diff --git a/drivers/gpu/drm/drm_privacy_screen.c b/drivers/gpu/drm/drm_privacy_screen.c
index 6cc39e30781f..2fbd24ba5818 100644
--- a/drivers/gpu/drm/drm_privacy_screen.c
+++ b/drivers/gpu/drm/drm_privacy_screen.c
@@ -401,7 +401,7 @@ struct drm_privacy_screen *drm_privacy_screen_register(
 	mutex_init(&priv->lock);
 	BLOCKING_INIT_NOTIFIER_HEAD(&priv->notifier_head);
 
-	priv->dev.class = drm_class;
+	priv->dev.class = &drm_class;
 	priv->dev.type = &drm_privacy_screen_type;
 	priv->dev.parent = parent;
 	priv->dev.release = drm_privacy_screen_device_release;
diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
index a953f69a34b6..90145f9256a2 100644
--- a/drivers/gpu/drm/drm_sysfs.c
+++ b/drivers/gpu/drm/drm_sysfs.c
@@ -58,7 +58,15 @@ static struct device_type drm_sysfs_device_connector = {
 	.name = "drm_connector",
 };
 
-struct class *drm_class;
+static char *drm_devnode(const struct device *dev, umode_t *mode)
+{
+	return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
+}
+
+const struct class drm_class = {
+	.name = "drm",
+	.devnode = drm_devnode,
+};
 
 #ifdef CONFIG_ACPI
 static bool drm_connector_acpi_bus_match(struct device *dev)
@@ -93,11 +101,6 @@ static void drm_sysfs_acpi_register(void) { }
 static void drm_sysfs_acpi_unregister(void) { }
 #endif
 
-static char *drm_devnode(const struct device *dev, umode_t *mode)
-{
-	return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
-}
-
 static int typec_connector_bind(struct device *dev,
 				struct device *typec_connector, void *data)
 {
@@ -142,19 +145,16 @@ int drm_sysfs_init(void)
 {
 	int err;
 
-	drm_class = class_create("drm");
-	if (IS_ERR(drm_class))
-		return PTR_ERR(drm_class);
+	err = class_register(&drm_class);
+	if (err)
+		return err;
 
-	err = class_create_file(drm_class, &class_attr_version.attr);
+	err = class_create_file(&drm_class, &class_attr_version.attr);
 	if (err) {
-		class_destroy(drm_class);
-		drm_class = NULL;
+		class_unregister(&drm_class);
 		return err;
 	}
 
-	drm_class->devnode = drm_devnode;
-
 	drm_sysfs_acpi_register();
 	return 0;
 }
@@ -166,12 +166,9 @@ int drm_sysfs_init(void)
  */
 void drm_sysfs_destroy(void)
 {
-	if (IS_ERR_OR_NULL(drm_class))
-		return;
 	drm_sysfs_acpi_unregister();
-	class_remove_file(drm_class, &class_attr_version.attr);
-	class_destroy(drm_class);
-	drm_class = NULL;
+	class_remove_file(&drm_class, &class_attr_version.attr);
+	class_unregister(&drm_class);
 }
 
 static void drm_sysfs_release(struct device *dev)
@@ -372,7 +369,7 @@ int drm_sysfs_connector_add(struct drm_connector *connector)
 		return -ENOMEM;
 
 	device_initialize(kdev);
-	kdev->class = drm_class;
+	kdev->class = &drm_class;
 	kdev->type = &drm_sysfs_device_connector;
 	kdev->parent = dev->primary->kdev;
 	kdev->groups = connector_dev_groups;
@@ -550,7 +547,7 @@ struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
 			minor_str = "card%d";
 
 		kdev->devt = MKDEV(DRM_MAJOR, minor->index);
-		kdev->class = drm_class;
+		kdev->class = &drm_class;
 		kdev->type = &drm_sysfs_device_minor;
 	}
 
@@ -579,10 +576,7 @@ struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
  */
 int drm_class_device_register(struct device *dev)
 {
-	if (!drm_class || IS_ERR(drm_class))
-		return -ENOENT;
-
-	dev->class = drm_class;
+	dev->class = &drm_class;
 	return device_register(dev);
 }
 EXPORT_SYMBOL_GPL(drm_class_device_register);

-- 
2.43.0

[PATCH RESEND drm-misc 3/4] drm/fbdev/core: make fb_class constant

[Ricardo B. Marliere]

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the fb_class structure to be declared at build time placing
it into read-only memory, instead of having to be dynamically allocated at
boot time.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
---
 drivers/video/fbdev/core/fb_internal.h |  2 +-
 drivers/video/fbdev/core/fbcon.c       |  4 ++--
 drivers/video/fbdev/core/fbmem.c       | 17 ++++++++---------
 drivers/video/fbdev/core/fbsysfs.c     |  4 ++--
 4 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/video/fbdev/core/fb_internal.h b/drivers/video/fbdev/core/fb_internal.h
index 613832d335fe..f1c0f1386675 100644
--- a/drivers/video/fbdev/core/fb_internal.h
+++ b/drivers/video/fbdev/core/fb_internal.h
@@ -38,7 +38,7 @@ static inline int fb_show_logo(struct fb_info *info, int rotate)
 #endif /* CONFIG_LOGO */
 
 /* fbmem.c */
-extern struct class *fb_class;
+extern const struct class fb_class;
 extern struct mutex registration_lock;
 extern struct fb_info *registered_fb[FB_MAX];
 extern int num_registered_fb;
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 1183e7a871f8..4d87a6ebdbdf 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -3380,7 +3380,7 @@ void __init fb_console_init(void)
 	int i;
 
 	console_lock();
-	fbcon_device = device_create(fb_class, NULL, MKDEV(0, 0), NULL,
+	fbcon_device = device_create(&fb_class, NULL, MKDEV(0, 0), NULL,
 				     "fbcon");
 
 	if (IS_ERR(fbcon_device)) {
@@ -3425,7 +3425,7 @@ void __exit fb_console_exit(void)
 
 	console_lock();
 	fbcon_deinit_device();
-	device_destroy(fb_class, MKDEV(0, 0));
+	device_destroy(&fb_class, MKDEV(0, 0));
 
 	do_unregister_con_driver(&fb_con);
 	console_unlock();
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 48287366e0d4..d868194499fb 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -26,7 +26,9 @@
 
 #define FBPIXMAPSIZE	(1024 * 8)
 
-struct class *fb_class;
+const struct class fb_class = {
+	.name = "graphics",
+};
 
 DEFINE_MUTEX(registration_lock);
 struct fb_info *registered_fb[FB_MAX] __read_mostly;
@@ -571,11 +573,10 @@ static int __init fbmem_init(void)
 {
 	int ret;
 
-	fb_class = class_create("graphics");
-	if (IS_ERR(fb_class)) {
-		ret = PTR_ERR(fb_class);
+	ret = class_register(&fb_class);
+	if (ret) {
 		pr_err("Unable to create fb class; errno = %d\n", ret);
-		goto err_fb_class;
+		return ret;
 	}
 
 	ret = fb_init_procfs();
@@ -593,9 +594,7 @@ static int __init fbmem_init(void)
 err_fb_cleanup_procfs:
 	fb_cleanup_procfs();
 err_class_destroy:
-	class_destroy(fb_class);
-err_fb_class:
-	fb_class = NULL;
+	class_unregister(&fb_class);
 	return ret;
 }
 
@@ -605,7 +604,7 @@ static void __exit fbmem_exit(void)
 	fb_console_exit();
 	fb_unregister_chrdev();
 	fb_cleanup_procfs();
-	class_destroy(fb_class);
+	class_unregister(&fb_class);
 }
 
 module_init(fbmem_init);
diff --git a/drivers/video/fbdev/core/fbsysfs.c b/drivers/video/fbdev/core/fbsysfs.c
index 1b3c9958ef5c..aac013dfe06a 100644
--- a/drivers/video/fbdev/core/fbsysfs.c
+++ b/drivers/video/fbdev/core/fbsysfs.c
@@ -476,7 +476,7 @@ int fb_device_create(struct fb_info *fb_info)
 	dev_t devt = MKDEV(FB_MAJOR, node);
 	int ret;
 
-	fb_info->dev = device_create(fb_class, fb_info->device, devt, NULL, "fb%d", node);
+	fb_info->dev = device_create(&fb_class, fb_info->device, devt, NULL, "fb%d", node);
 	if (IS_ERR(fb_info->dev)) {
 		/* Not fatal */
 		ret = PTR_ERR(fb_info->dev);
@@ -497,6 +497,6 @@ void fb_device_destroy(struct fb_info *fb_info)
 		return;
 
 	fb_cleanup_device(fb_info);
-	device_destroy(fb_class, devt);
+	device_destroy(&fb_class, devt);
 	fb_info->dev = NULL;
 }

-- 
2.43.0

[PATCH RESEND drm-misc 4/4] dma-buf: heaps: make dma_heap_class constant

[Ricardo B. Marliere]

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the dma_heap_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
---
 drivers/dma-buf/dma-heap.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
index 84ae708fafe7..bcca6a2bbce8 100644
--- a/drivers/dma-buf/dma-heap.c
+++ b/drivers/dma-buf/dma-heap.c
@@ -43,10 +43,18 @@ struct dma_heap {
 	struct cdev heap_cdev;
 };
 
+static char *dma_heap_devnode(const struct device *dev, umode_t *mode)
+{
+	return kasprintf(GFP_KERNEL, "dma_heap/%s", dev_name(dev));
+}
+
 static LIST_HEAD(heap_list);
 static DEFINE_MUTEX(heap_list_lock);
 static dev_t dma_heap_devt;
-static struct class *dma_heap_class;
+static struct class dma_heap_class = {
+	.name = DEVNAME,
+	.devnode = dma_heap_devnode,
+};
 static DEFINE_XARRAY_ALLOC(dma_heap_minors);
 
 static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len,
@@ -261,7 +269,7 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
 		goto err1;
 	}
 
-	dev_ret = device_create(dma_heap_class,
+	dev_ret = device_create(&dma_heap_class,
 				NULL,
 				heap->heap_devt,
 				NULL,
@@ -291,7 +299,7 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
 	return heap;
 
 err3:
-	device_destroy(dma_heap_class, heap->heap_devt);
+	device_destroy(&dma_heap_class, heap->heap_devt);
 err2:
 	cdev_del(&heap->heap_cdev);
 err1:
@@ -301,11 +309,6 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
 	return err_ret;
 }
 
-static char *dma_heap_devnode(const struct device *dev, umode_t *mode)
-{
-	return kasprintf(GFP_KERNEL, "dma_heap/%s", dev_name(dev));
-}
-
 static int dma_heap_init(void)
 {
 	int ret;
@@ -314,12 +317,11 @@ static int dma_heap_init(void)
 	if (ret)
 		return ret;
 
-	dma_heap_class = class_create(DEVNAME);
-	if (IS_ERR(dma_heap_class)) {
+	ret = class_register(&dma_heap_class);
+	if (ret) {
 		unregister_chrdev_region(dma_heap_devt, NUM_HEAP_MINORS);
-		return PTR_ERR(dma_heap_class);
+		return ret;
 	}
-	dma_heap_class->devnode = dma_heap_devnode;
 
 	return 0;
 }

-- 
2.43.0

Re: [PATCH RESEND drm-misc 4/4] dma-buf: heaps: make dma_heap_class constant

[T.J. Mercier]

On Tue, Mar 5, 2024 at 3:34 AM Ricardo B. Marliere <ricardo@marliere.net> wrote:
>
> Since commit 43a7206b0963 ("driver core: class: make class_register() take
> a const *"), the driver core allows for struct class to be in read-only
> memory, so move the dma_heap_class structure to be declared at build time
> placing it into read-only memory, instead of having to be dynamically
> allocated at boot time.
>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
> ---
>  drivers/dma-buf/dma-heap.c | 26 ++++++++++++++------------
>  1 file changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
> index 84ae708fafe7..bcca6a2bbce8 100644
> --- a/drivers/dma-buf/dma-heap.c
> +++ b/drivers/dma-buf/dma-heap.c
> @@ -43,10 +43,18 @@ struct dma_heap {
>         struct cdev heap_cdev;
>  };
>
> +static char *dma_heap_devnode(const struct device *dev, umode_t *mode)
> +{
> +       return kasprintf(GFP_KERNEL, "dma_heap/%s", dev_name(dev));
> +}
> +
>  static LIST_HEAD(heap_list);
>  static DEFINE_MUTEX(heap_list_lock);
>  static dev_t dma_heap_devt;
> -static struct class *dma_heap_class;
> +static struct class dma_heap_class = {
> +       .name = DEVNAME,
> +       .devnode = dma_heap_devnode,
> +};
>  static DEFINE_XARRAY_ALLOC(dma_heap_minors);
>
>  static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len,
> @@ -261,7 +269,7 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
>                 goto err1;
>         }
>
> -       dev_ret = device_create(dma_heap_class,
> +       dev_ret = device_create(&dma_heap_class,
>                                 NULL,
>                                 heap->heap_devt,
>                                 NULL,
> @@ -291,7 +299,7 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
>         return heap;
>
>  err3:
> -       device_destroy(dma_heap_class, heap->heap_devt);
> +       device_destroy(&dma_heap_class, heap->heap_devt);
>  err2:
>         cdev_del(&heap->heap_cdev);
>  err1:
> @@ -301,11 +309,6 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
>         return err_ret;
>  }
>
> -static char *dma_heap_devnode(const struct device *dev, umode_t *mode)
> -{
> -       return kasprintf(GFP_KERNEL, "dma_heap/%s", dev_name(dev));
> -}
> -
>  static int dma_heap_init(void)
>  {
>         int ret;
> @@ -314,12 +317,11 @@ static int dma_heap_init(void)
>         if (ret)
>                 return ret;
>
> -       dma_heap_class = class_create(DEVNAME);
> -       if (IS_ERR(dma_heap_class)) {
> +       ret = class_register(&dma_heap_class);
> +       if (ret) {
>                 unregister_chrdev_region(dma_heap_devt, NUM_HEAP_MINORS);
> -               return PTR_ERR(dma_heap_class);
> +               return ret;
>         }
> -       dma_heap_class->devnode = dma_heap_devnode;
>
>         return 0;
>  }
>
> --
> 2.43.0

Reviewed-by: T.J. Mercier <tjmercier@google.com>

Is this really a resend? I don't see anything on lore and I can't
recall seeing this patch in my inbox before.

Re: [PATCH RESEND drm-misc 4/4] dma-buf: heaps: make dma_heap_class constant

[Ricardo B. Marliere]

On  5 Mar 09:07, T.J. Mercier wrote:
> 
> Reviewed-by: T.J. Mercier <tjmercier@google.com>
> 
> Is this really a resend? I don't see anything on lore and I can't
> recall seeing this patch in my inbox before.

Hi T.J. thanks for reviewing!

I'm sorry about that, I sent the series only to Greg before but I
thought it had Cc'ed the lists as well. Then I realized it was sent
publicly only once. Double mistake :(

Best regards,
-	Ricardo.

Re: [PATCH RESEND drm-misc 4/4] dma-buf: heaps: make dma_heap_class constant

[T.J. Mercier]

On Tue, Mar 5, 2024 at 10:02 AM Ricardo B. Marliere
<ricardo@marliere.net> wrote:
>
> On  5 Mar 09:07, T.J. Mercier wrote:
> >
> > Reviewed-by: T.J. Mercier <tjmercier@google.com>
> >
> > Is this really a resend? I don't see anything on lore and I can't
> > recall seeing this patch in my inbox before.
>
> Hi T.J. thanks for reviewing!
>
> I'm sorry about that, I sent the series only to Greg before but I
> thought it had Cc'ed the lists as well. Then I realized it was sent
> publicly only once. Double mistake :(
>
> Best regards,
> -       Ricardo.

Cheers, glad I don't have to try to rework my email filters. :)

Re: [PATCH RESEND drm-misc 4/4] dma-buf: heaps: make dma_heap_class constant

[Sumit Semwal]

Hello Ricardo,

On Tue, 5 Mar 2024 at 22:37, T.J. Mercier <tjmercier@google.com> wrote:
>
> On Tue, Mar 5, 2024 at 3:34 AM Ricardo B. Marliere <ricardo@marliere.net> wrote:
> >
> > Since commit 43a7206b0963 ("driver core: class: make class_register() take
> > a const *"), the driver core allows for struct class to be in read-only
> > memory, so move the dma_heap_class structure to be declared at build time
> > placing it into read-only memory, instead of having to be dynamically
> > allocated at boot time.
> >
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
> > ---
> >  drivers/dma-buf/dma-heap.c | 26 ++++++++++++++------------
> >  1 file changed, 14 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
> > index 84ae708fafe7..bcca6a2bbce8 100644
> > --- a/drivers/dma-buf/dma-heap.c
> > +++ b/drivers/dma-buf/dma-heap.c
> > @@ -43,10 +43,18 @@ struct dma_heap {
> >         struct cdev heap_cdev;
> >  };
> >
> > +static char *dma_heap_devnode(const struct device *dev, umode_t *mode)
> > +{
> > +       return kasprintf(GFP_KERNEL, "dma_heap/%s", dev_name(dev));
> > +}
> > +
> >  static LIST_HEAD(heap_list);
> >  static DEFINE_MUTEX(heap_list_lock);
> >  static dev_t dma_heap_devt;
> > -static struct class *dma_heap_class;
> > +static struct class dma_heap_class = {
> > +       .name = DEVNAME,
> > +       .devnode = dma_heap_devnode,
> > +};
> >  static DEFINE_XARRAY_ALLOC(dma_heap_minors);
> >
> >  static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len,
> > @@ -261,7 +269,7 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
> >                 goto err1;
> >         }
> >
> > -       dev_ret = device_create(dma_heap_class,
> > +       dev_ret = device_create(&dma_heap_class,
> >                                 NULL,
> >                                 heap->heap_devt,
> >                                 NULL,
> > @@ -291,7 +299,7 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
> >         return heap;
> >
> >  err3:
> > -       device_destroy(dma_heap_class, heap->heap_devt);
> > +       device_destroy(&dma_heap_class, heap->heap_devt);
> >  err2:
> >         cdev_del(&heap->heap_cdev);
> >  err1:
> > @@ -301,11 +309,6 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
> >         return err_ret;
> >  }
> >
> > -static char *dma_heap_devnode(const struct device *dev, umode_t *mode)
> > -{
> > -       return kasprintf(GFP_KERNEL, "dma_heap/%s", dev_name(dev));
> > -}
> > -
> >  static int dma_heap_init(void)
> >  {
> >         int ret;
> > @@ -314,12 +317,11 @@ static int dma_heap_init(void)
> >         if (ret)
> >                 return ret;
> >
> > -       dma_heap_class = class_create(DEVNAME);
> > -       if (IS_ERR(dma_heap_class)) {
> > +       ret = class_register(&dma_heap_class);
> > +       if (ret) {
> >                 unregister_chrdev_region(dma_heap_devt, NUM_HEAP_MINORS);
> > -               return PTR_ERR(dma_heap_class);
> > +               return ret;
> >         }
> > -       dma_heap_class->devnode = dma_heap_devnode;
> >
> >         return 0;
> >  }
> >
> > --
> > 2.43.0
>
> Reviewed-by: T.J. Mercier <tjmercier@google.com>


FWIW, please free to add my
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>

>
>
> Is this really a resend? I don't see anything on lore and I can't
> recall seeing this patch in my inbox before.


Best,
Sumit.

-- 
Thanks and regards,

Sumit Semwal (he / him)
Tech Lead - LCG, Vertical Technologies
Linaro.org │ Open source software for ARM SoCs