[PATCH 0/6] s390: constify struct class usage

[PATCH 0/6] s390: constify struct class usage

[Ricardo B. Marliere]

This is a simple and straight forward cleanup series that aims to make the
class structures in s390 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 (6):
      s390: zcrypt: make zcrypt_class constant
      s390: vmur: make vmur_class constant
      s390: vmlogrdr: make vmlogrdr_class constant
      s390: tape: make tape_class constant
      s390: raw3270: improve raw3270_init() readability
      s390: raw3270: make class3270 constant

 drivers/s390/char/fs3270.c       |  8 ++++----
 drivers/s390/char/raw3270.c      | 32 ++++++++++++++++++++------------
 drivers/s390/char/raw3270.h      |  2 +-
 drivers/s390/char/tape_class.c   | 17 ++++++++---------
 drivers/s390/char/vmlogrdr.c     | 19 +++++++++----------
 drivers/s390/char/vmur.c         | 18 +++++++++---------
 drivers/s390/crypto/zcrypt_api.c | 33 +++++++++++++++++----------------
 7 files changed, 68 insertions(+), 61 deletions(-)
---
base-commit: 6a42aaf8e867f4876370c3d482ee0c21769dff58
change-id: 20240305-class_cleanup-s390-d57f7ccc15c9

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

[PATCH 1/6] s390: zcrypt: make zcrypt_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 zcrypt_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/s390/crypto/zcrypt_api.c | 33 +++++++++++++++++----------------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index e8742757085b..d0358bb6ccf2 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -116,7 +116,11 @@ EXPORT_SYMBOL(zcrypt_msgtype);
 
 struct zcdn_device;
 
-static struct class *zcrypt_class;
+static void zcdn_device_release(struct device *dev);
+static const struct class zcrypt_class = {
+	.name = ZCRYPT_NAME,
+	.dev_release = zcdn_device_release,
+};
 static dev_t zcrypt_devt;
 static struct cdev zcrypt_cdev;
 
@@ -139,7 +143,7 @@ static int zcdn_destroy(const char *name);
  */
 static inline struct zcdn_device *find_zcdndev_by_name(const char *name)
 {
-	struct device *dev = class_find_device_by_name(zcrypt_class, name);
+	struct device *dev = class_find_device_by_name(&zcrypt_class, name);
 
 	return dev ? to_zcdn_dev(dev) : NULL;
 }
@@ -151,7 +155,7 @@ static inline struct zcdn_device *find_zcdndev_by_name(const char *name)
  */
 static inline struct zcdn_device *find_zcdndev_by_devt(dev_t devt)
 {
-	struct device *dev = class_find_device_by_devt(zcrypt_class, devt);
+	struct device *dev = class_find_device_by_devt(&zcrypt_class, devt);
 
 	return dev ? to_zcdn_dev(dev) : NULL;
 }
@@ -405,7 +409,7 @@ static int zcdn_create(const char *name)
 		goto unlockout;
 	}
 	zcdndev->device.release = zcdn_device_release;
-	zcdndev->device.class = zcrypt_class;
+	zcdndev->device.class = &zcrypt_class;
 	zcdndev->device.devt = devt;
 	zcdndev->device.groups = zcdn_dev_attr_groups;
 	if (name[0])
@@ -2067,12 +2071,9 @@ static int __init zcdn_init(void)
 	int rc;
 
 	/* create a new class 'zcrypt' */
-	zcrypt_class = class_create(ZCRYPT_NAME);
-	if (IS_ERR(zcrypt_class)) {
-		rc = PTR_ERR(zcrypt_class);
+	rc = class_register(&zcrypt_class);
+	if (rc)
 		goto out_class_create_failed;
-	}
-	zcrypt_class->dev_release = zcdn_device_release;
 
 	/* alloc device minor range */
 	rc = alloc_chrdev_region(&zcrypt_devt,
@@ -2088,35 +2089,35 @@ static int __init zcdn_init(void)
 		goto out_cdev_add_failed;
 
 	/* need some class specific sysfs attributes */
-	rc = class_create_file(zcrypt_class, &class_attr_zcdn_create);
+	rc = class_create_file(&zcrypt_class, &class_attr_zcdn_create);
 	if (rc)
 		goto out_class_create_file_1_failed;
-	rc = class_create_file(zcrypt_class, &class_attr_zcdn_destroy);
+	rc = class_create_file(&zcrypt_class, &class_attr_zcdn_destroy);
 	if (rc)
 		goto out_class_create_file_2_failed;
 
 	return 0;
 
 out_class_create_file_2_failed:
-	class_remove_file(zcrypt_class, &class_attr_zcdn_create);
+	class_remove_file(&zcrypt_class, &class_attr_zcdn_create);
 out_class_create_file_1_failed:
 	cdev_del(&zcrypt_cdev);
 out_cdev_add_failed:
 	unregister_chrdev_region(zcrypt_devt, ZCRYPT_MAX_MINOR_NODES);
 out_alloc_chrdev_failed:
-	class_destroy(zcrypt_class);
+	class_unregister(&zcrypt_class);
 out_class_create_failed:
 	return rc;
 }
 
 static void zcdn_exit(void)
 {
-	class_remove_file(zcrypt_class, &class_attr_zcdn_create);
-	class_remove_file(zcrypt_class, &class_attr_zcdn_destroy);
+	class_remove_file(&zcrypt_class, &class_attr_zcdn_create);
+	class_remove_file(&zcrypt_class, &class_attr_zcdn_destroy);
 	zcdn_destroy_all();
 	cdev_del(&zcrypt_cdev);
 	unregister_chrdev_region(zcrypt_devt, ZCRYPT_MAX_MINOR_NODES);
-	class_destroy(zcrypt_class);
+	class_unregister(&zcrypt_class);
 }
 
 /*

-- 
2.43.0

Re: [PATCH 1/6] s390: zcrypt: make zcrypt_class constant

[Harald Freudenberger]

On 2024-03-05 12:25, Ricardo B. Marliere 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 zcrypt_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/s390/crypto/zcrypt_api.c | 33 
> +++++++++++++++++----------------
>  1 file changed, 17 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/s390/crypto/zcrypt_api.c 
> b/drivers/s390/crypto/zcrypt_api.c
> index e8742757085b..d0358bb6ccf2 100644
> --- a/drivers/s390/crypto/zcrypt_api.c
> +++ b/drivers/s390/crypto/zcrypt_api.c
> @@ -116,7 +116,11 @@ EXPORT_SYMBOL(zcrypt_msgtype);
> 
>  struct zcdn_device;
> 
> -static struct class *zcrypt_class;
> +static void zcdn_device_release(struct device *dev);
> +static const struct class zcrypt_class = {
> +	.name = ZCRYPT_NAME,
> +	.dev_release = zcdn_device_release,
> +};
>  static dev_t zcrypt_devt;
>  static struct cdev zcrypt_cdev;
> 
> @@ -139,7 +143,7 @@ static int zcdn_destroy(const char *name);
>   */
>  static inline struct zcdn_device *find_zcdndev_by_name(const char 
> *name)
>  {
> -	struct device *dev = class_find_device_by_name(zcrypt_class, name);
> +	struct device *dev = class_find_device_by_name(&zcrypt_class, name);
> 
>  	return dev ? to_zcdn_dev(dev) : NULL;
>  }
> @@ -151,7 +155,7 @@ static inline struct zcdn_device
> *find_zcdndev_by_name(const char *name)
>   */
>  static inline struct zcdn_device *find_zcdndev_by_devt(dev_t devt)
>  {
> -	struct device *dev = class_find_device_by_devt(zcrypt_class, devt);
> +	struct device *dev = class_find_device_by_devt(&zcrypt_class, devt);
> 
>  	return dev ? to_zcdn_dev(dev) : NULL;
>  }
> @@ -405,7 +409,7 @@ static int zcdn_create(const char *name)
>  		goto unlockout;
>  	}
>  	zcdndev->device.release = zcdn_device_release;
> -	zcdndev->device.class = zcrypt_class;
> +	zcdndev->device.class = &zcrypt_class;
>  	zcdndev->device.devt = devt;
>  	zcdndev->device.groups = zcdn_dev_attr_groups;
>  	if (name[0])
> @@ -2067,12 +2071,9 @@ static int __init zcdn_init(void)
>  	int rc;
> 
>  	/* create a new class 'zcrypt' */
> -	zcrypt_class = class_create(ZCRYPT_NAME);
> -	if (IS_ERR(zcrypt_class)) {
> -		rc = PTR_ERR(zcrypt_class);
> +	rc = class_register(&zcrypt_class);
> +	if (rc)
>  		goto out_class_create_failed;
> -	}
> -	zcrypt_class->dev_release = zcdn_device_release;
> 
>  	/* alloc device minor range */
>  	rc = alloc_chrdev_region(&zcrypt_devt,
> @@ -2088,35 +2089,35 @@ static int __init zcdn_init(void)
>  		goto out_cdev_add_failed;
> 
>  	/* need some class specific sysfs attributes */
> -	rc = class_create_file(zcrypt_class, &class_attr_zcdn_create);
> +	rc = class_create_file(&zcrypt_class, &class_attr_zcdn_create);
>  	if (rc)
>  		goto out_class_create_file_1_failed;
> -	rc = class_create_file(zcrypt_class, &class_attr_zcdn_destroy);
> +	rc = class_create_file(&zcrypt_class, &class_attr_zcdn_destroy);
>  	if (rc)
>  		goto out_class_create_file_2_failed;
> 
>  	return 0;
> 
>  out_class_create_file_2_failed:
> -	class_remove_file(zcrypt_class, &class_attr_zcdn_create);
> +	class_remove_file(&zcrypt_class, &class_attr_zcdn_create);
>  out_class_create_file_1_failed:
>  	cdev_del(&zcrypt_cdev);
>  out_cdev_add_failed:
>  	unregister_chrdev_region(zcrypt_devt, ZCRYPT_MAX_MINOR_NODES);
>  out_alloc_chrdev_failed:
> -	class_destroy(zcrypt_class);
> +	class_unregister(&zcrypt_class);
>  out_class_create_failed:
>  	return rc;
>  }
> 
>  static void zcdn_exit(void)
>  {
> -	class_remove_file(zcrypt_class, &class_attr_zcdn_create);
> -	class_remove_file(zcrypt_class, &class_attr_zcdn_destroy);
> +	class_remove_file(&zcrypt_class, &class_attr_zcdn_create);
> +	class_remove_file(&zcrypt_class, &class_attr_zcdn_destroy);
>  	zcdn_destroy_all();
>  	cdev_del(&zcrypt_cdev);
>  	unregister_chrdev_region(zcrypt_devt, ZCRYPT_MAX_MINOR_NODES);
> -	class_destroy(zcrypt_class);
> +	class_unregister(&zcrypt_class);
>  }
> 
>  /*

Thanks Ricardo, nice work.
The only thing I would do is to rename the label 
"out_class_create_failed"
with "out_class_register_failed".

Who will pick this patch? As this is part of a bundle of fixes, Richardo
do you have a way to push this into the kernel? Otherwise as the 
AP/zcrypt
maintainer I would pick only this patch and forward it to the s390 
subsystem.

Acked-by: Harald Freudenberger <freude@linux.ibm.com>

Re: [PATCH 1/6] s390: zcrypt: make zcrypt_class constant

[Ricardo B. Marliere]

On  8 Mar 15:19, Harald Freudenberger wrote:
> On 2024-03-05 12:25, Ricardo B. Marliere 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 zcrypt_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/s390/crypto/zcrypt_api.c | 33 +++++++++++++++++----------------
> >  1 file changed, 17 insertions(+), 16 deletions(-)
> > 
> > diff --git a/drivers/s390/crypto/zcrypt_api.c
> > b/drivers/s390/crypto/zcrypt_api.c
> > index e8742757085b..d0358bb6ccf2 100644
> > --- a/drivers/s390/crypto/zcrypt_api.c
> > +++ b/drivers/s390/crypto/zcrypt_api.c
> > @@ -116,7 +116,11 @@ EXPORT_SYMBOL(zcrypt_msgtype);
> > 
> >  struct zcdn_device;
> > 
> > -static struct class *zcrypt_class;
> > +static void zcdn_device_release(struct device *dev);
> > +static const struct class zcrypt_class = {
> > +	.name = ZCRYPT_NAME,
> > +	.dev_release = zcdn_device_release,
> > +};
> >  static dev_t zcrypt_devt;
> >  static struct cdev zcrypt_cdev;
> > 
> > @@ -139,7 +143,7 @@ static int zcdn_destroy(const char *name);
> >   */
> >  static inline struct zcdn_device *find_zcdndev_by_name(const char
> > *name)
> >  {
> > -	struct device *dev = class_find_device_by_name(zcrypt_class, name);
> > +	struct device *dev = class_find_device_by_name(&zcrypt_class, name);
> > 
> >  	return dev ? to_zcdn_dev(dev) : NULL;
> >  }
> > @@ -151,7 +155,7 @@ static inline struct zcdn_device
> > *find_zcdndev_by_name(const char *name)
> >   */
> >  static inline struct zcdn_device *find_zcdndev_by_devt(dev_t devt)
> >  {
> > -	struct device *dev = class_find_device_by_devt(zcrypt_class, devt);
> > +	struct device *dev = class_find_device_by_devt(&zcrypt_class, devt);
> > 
> >  	return dev ? to_zcdn_dev(dev) : NULL;
> >  }
> > @@ -405,7 +409,7 @@ static int zcdn_create(const char *name)
> >  		goto unlockout;
> >  	}
> >  	zcdndev->device.release = zcdn_device_release;
> > -	zcdndev->device.class = zcrypt_class;
> > +	zcdndev->device.class = &zcrypt_class;
> >  	zcdndev->device.devt = devt;
> >  	zcdndev->device.groups = zcdn_dev_attr_groups;
> >  	if (name[0])
> > @@ -2067,12 +2071,9 @@ static int __init zcdn_init(void)
> >  	int rc;
> > 
> >  	/* create a new class 'zcrypt' */
> > -	zcrypt_class = class_create(ZCRYPT_NAME);
> > -	if (IS_ERR(zcrypt_class)) {
> > -		rc = PTR_ERR(zcrypt_class);
> > +	rc = class_register(&zcrypt_class);
> > +	if (rc)
> >  		goto out_class_create_failed;
> > -	}
> > -	zcrypt_class->dev_release = zcdn_device_release;
> > 
> >  	/* alloc device minor range */
> >  	rc = alloc_chrdev_region(&zcrypt_devt,
> > @@ -2088,35 +2089,35 @@ static int __init zcdn_init(void)
> >  		goto out_cdev_add_failed;
> > 
> >  	/* need some class specific sysfs attributes */
> > -	rc = class_create_file(zcrypt_class, &class_attr_zcdn_create);
> > +	rc = class_create_file(&zcrypt_class, &class_attr_zcdn_create);
> >  	if (rc)
> >  		goto out_class_create_file_1_failed;
> > -	rc = class_create_file(zcrypt_class, &class_attr_zcdn_destroy);
> > +	rc = class_create_file(&zcrypt_class, &class_attr_zcdn_destroy);
> >  	if (rc)
> >  		goto out_class_create_file_2_failed;
> > 
> >  	return 0;
> > 
> >  out_class_create_file_2_failed:
> > -	class_remove_file(zcrypt_class, &class_attr_zcdn_create);
> > +	class_remove_file(&zcrypt_class, &class_attr_zcdn_create);
> >  out_class_create_file_1_failed:
> >  	cdev_del(&zcrypt_cdev);
> >  out_cdev_add_failed:
> >  	unregister_chrdev_region(zcrypt_devt, ZCRYPT_MAX_MINOR_NODES);
> >  out_alloc_chrdev_failed:
> > -	class_destroy(zcrypt_class);
> > +	class_unregister(&zcrypt_class);
> >  out_class_create_failed:
> >  	return rc;
> >  }
> > 
> >  static void zcdn_exit(void)
> >  {
> > -	class_remove_file(zcrypt_class, &class_attr_zcdn_create);
> > -	class_remove_file(zcrypt_class, &class_attr_zcdn_destroy);
> > +	class_remove_file(&zcrypt_class, &class_attr_zcdn_create);
> > +	class_remove_file(&zcrypt_class, &class_attr_zcdn_destroy);
> >  	zcdn_destroy_all();
> >  	cdev_del(&zcrypt_cdev);
> >  	unregister_chrdev_region(zcrypt_devt, ZCRYPT_MAX_MINOR_NODES);
> > -	class_destroy(zcrypt_class);
> > +	class_unregister(&zcrypt_class);
> >  }
> > 
> >  /*
> 
> Thanks Ricardo, nice work.
> The only thing I would do is to rename the label "out_class_create_failed"
> with "out_class_register_failed".

Ah, indeed. Thanks for catching that. I will wait for more feedback on
the other patches and send a v2 if required.

> 
> Who will pick this patch? As this is part of a bundle of fixes, Richardo
> do you have a way to push this into the kernel? Otherwise as the AP/zcrypt
> maintainer I would pick only this patch and forward it to the s390
> subsystem.

I have no ways of pushing this, sorry. The series is based on
s390/linux.git/for-next, so perhaps the s390 maintainers can pick this
one along with the others with your Acked-by: provided? :) 

Thank you,
-	Ricardo.


> 
> Acked-by: Harald Freudenberger <freude@linux.ibm.com>
> 

Re: [PATCH 1/6] s390: zcrypt: make zcrypt_class constant

[Heiko Carstens]

On Fri, Mar 08, 2024 at 11:38:14AM -0300, Ricardo B. Marliere wrote:
> > Thanks Ricardo, nice work.
> > The only thing I would do is to rename the label "out_class_create_failed"
> > with "out_class_register_failed".
> 
> Ah, indeed. Thanks for catching that. I will wait for more feedback on
> the other patches and send a v2 if required.
> 
> > 
> > Who will pick this patch? As this is part of a bundle of fixes, Richardo
> > do you have a way to push this into the kernel? Otherwise as the AP/zcrypt
> > maintainer I would pick only this patch and forward it to the s390
> > subsystem.
> 
> I have no ways of pushing this, sorry. The series is based on
> s390/linux.git/for-next, so perhaps the s390 maintainers can pick this
> one along with the others with your Acked-by: provided? :) 

I will pick up the whole series, but need some more time.

There is no need to send a v2 for this patch - I'll change the label as
requested by Harald.

Re: [PATCH 1/6] s390: zcrypt: make zcrypt_class constant

[Ricardo B. Marliere]

Hi Heiko!

On  8 Mar 15:44, Heiko Carstens wrote:
> On Fri, Mar 08, 2024 at 11:38:14AM -0300, Ricardo B. Marliere wrote:
> > > Thanks Ricardo, nice work.
> > > The only thing I would do is to rename the label "out_class_create_failed"
> > > with "out_class_register_failed".
> > 
> > Ah, indeed. Thanks for catching that. I will wait for more feedback on
> > the other patches and send a v2 if required.
> > 
> > > 
> > > Who will pick this patch? As this is part of a bundle of fixes, Richardo
> > > do you have a way to push this into the kernel? Otherwise as the AP/zcrypt
> > > maintainer I would pick only this patch and forward it to the s390
> > > subsystem.
> > 
> > I have no ways of pushing this, sorry. The series is based on
> > s390/linux.git/for-next, so perhaps the s390 maintainers can pick this
> > one along with the others with your Acked-by: provided? :) 
> 
> I will pick up the whole series, but need some more time.
> 
> There is no need to send a v2 for this patch - I'll change the label as
> requested by Harald.

Thank you for this.
-	Ricardo

[PATCH 2/6] s390: vmur: make vmur_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 vmur_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/s390/char/vmur.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/s390/char/vmur.c b/drivers/s390/char/vmur.c
index 1d17a83569ce..47bfb50f8eb1 100644
--- a/drivers/s390/char/vmur.c
+++ b/drivers/s390/char/vmur.c
@@ -48,7 +48,9 @@ MODULE_DESCRIPTION("s390 z/VM virtual unit record device driver");
 MODULE_LICENSE("GPL");
 
 static dev_t ur_first_dev_maj_min;
-static struct class *vmur_class;
+static const struct class vmur_class = {
+	.name = "vmur",
+};
 static struct debug_info *vmur_dbf;
 
 /* We put the device's record length (for writes) in the driver_info field */
@@ -912,7 +914,7 @@ static int ur_set_online(struct ccw_device *cdev)
 		goto fail_free_cdev;
 	}
 
-	urd->device = device_create(vmur_class, &cdev->dev,
+	urd->device = device_create(&vmur_class, &cdev->dev,
 				    urd->char_device->dev, NULL, "%s", node_id);
 	if (IS_ERR(urd->device)) {
 		rc = PTR_ERR(urd->device);
@@ -958,7 +960,7 @@ static int ur_set_offline_force(struct ccw_device *cdev, int force)
 		/* Work not run yet - need to release reference here */
 		urdev_put(urd);
 	}
-	device_destroy(vmur_class, urd->char_device->dev);
+	device_destroy(&vmur_class, urd->char_device->dev);
 	cdev_del(urd->char_device);
 	urd->char_device = NULL;
 	rc = 0;
@@ -1022,11 +1024,9 @@ static int __init ur_init(void)
 
 	debug_set_level(vmur_dbf, 6);
 
-	vmur_class = class_create("vmur");
-	if (IS_ERR(vmur_class)) {
-		rc = PTR_ERR(vmur_class);
+	rc = class_register(&vmur_class);
+	if (rc)
 		goto fail_free_dbf;
-	}
 
 	rc = ccw_driver_register(&ur_driver);
 	if (rc)
@@ -1046,7 +1046,7 @@ static int __init ur_init(void)
 fail_unregister_driver:
 	ccw_driver_unregister(&ur_driver);
 fail_class_destroy:
-	class_destroy(vmur_class);
+	class_unregister(&vmur_class);
 fail_free_dbf:
 	debug_unregister(vmur_dbf);
 	return rc;
@@ -1056,7 +1056,7 @@ static void __exit ur_exit(void)
 {
 	unregister_chrdev_region(ur_first_dev_maj_min, NUM_MINORS);
 	ccw_driver_unregister(&ur_driver);
-	class_destroy(vmur_class);
+	class_unregister(&vmur_class);
 	debug_unregister(vmur_dbf);
 	pr_info("%s unloaded.\n", ur_banner);
 }

-- 
2.43.0

[PATCH 3/6] s390: vmlogrdr: make vmlogrdr_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 vmlogrdr_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/s390/char/vmlogrdr.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/s390/char/vmlogrdr.c b/drivers/s390/char/vmlogrdr.c
index 6946ba9a9de2..063d8f3565c9 100644
--- a/drivers/s390/char/vmlogrdr.c
+++ b/drivers/s390/char/vmlogrdr.c
@@ -679,7 +679,9 @@ static const struct attribute_group *vmlogrdr_attr_groups[] = {
 	NULL,
 };
 
-static struct class *vmlogrdr_class;
+static const struct class vmlogrdr_class = {
+	.name = "vmlogrdr_class",
+};
 static struct device_driver vmlogrdr_driver = {
 	.name = "vmlogrdr",
 	.bus  = &iucv_bus,
@@ -699,12 +701,10 @@ static int vmlogrdr_register_driver(void)
 	if (ret)
 		goto out_iucv;
 
-	vmlogrdr_class = class_create("vmlogrdr");
-	if (IS_ERR(vmlogrdr_class)) {
-		ret = PTR_ERR(vmlogrdr_class);
-		vmlogrdr_class = NULL;
+	ret = class_register(&vmlogrdr_class);
+	if (ret)
 		goto out_driver;
-	}
+
 	return 0;
 
 out_driver:
@@ -718,8 +718,7 @@ static int vmlogrdr_register_driver(void)
 
 static void vmlogrdr_unregister_driver(void)
 {
-	class_destroy(vmlogrdr_class);
-	vmlogrdr_class = NULL;
+	class_unregister(&vmlogrdr_class);
 	driver_unregister(&vmlogrdr_driver);
 	iucv_unregister(&vmlogrdr_iucv_handler, 1);
 }
@@ -754,7 +753,7 @@ static int vmlogrdr_register_device(struct vmlogrdr_priv_t *priv)
 		return ret;
 	}
 
-	priv->class_device = device_create(vmlogrdr_class, dev,
+	priv->class_device = device_create(&vmlogrdr_class, dev,
 					   MKDEV(vmlogrdr_major,
 						 priv->minor_num),
 					   priv, "%s", dev_name(dev));
@@ -771,7 +770,7 @@ static int vmlogrdr_register_device(struct vmlogrdr_priv_t *priv)
 
 static int vmlogrdr_unregister_device(struct vmlogrdr_priv_t *priv)
 {
-	device_destroy(vmlogrdr_class, MKDEV(vmlogrdr_major, priv->minor_num));
+	device_destroy(&vmlogrdr_class, MKDEV(vmlogrdr_major, priv->minor_num));
 	if (priv->device != NULL) {
 		device_unregister(priv->device);
 		priv->device=NULL;

-- 
2.43.0

[PATCH 4/6] s390: tape: make tape_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 tape_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/s390/char/tape_class.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/s390/char/tape_class.c b/drivers/s390/char/tape_class.c
index 277a0f903d11..eae362bbfbb5 100644
--- a/drivers/s390/char/tape_class.c
+++ b/drivers/s390/char/tape_class.c
@@ -22,7 +22,9 @@ MODULE_DESCRIPTION(
 );
 MODULE_LICENSE("GPL");
 
-static struct class *tape_class;
+static const struct class tape_class = {
+	.name = "tape390",
+};
 
 /*
  * Register a tape device and return a pointer to the cdev structure.
@@ -74,7 +76,7 @@ struct tape_class_device *register_tape_dev(
 	if (rc)
 		goto fail_with_cdev;
 
-	tcd->class_device = device_create(tape_class, device,
+	tcd->class_device = device_create(&tape_class, device,
 					  tcd->char_device->dev, NULL,
 					  "%s", tcd->device_name);
 	rc = PTR_ERR_OR_ZERO(tcd->class_device);
@@ -91,7 +93,7 @@ struct tape_class_device *register_tape_dev(
 	return tcd;
 
 fail_with_class_device:
-	device_destroy(tape_class, tcd->char_device->dev);
+	device_destroy(&tape_class, tcd->char_device->dev);
 
 fail_with_cdev:
 	cdev_del(tcd->char_device);
@@ -107,7 +109,7 @@ void unregister_tape_dev(struct device *device, struct tape_class_device *tcd)
 {
 	if (tcd != NULL && !IS_ERR(tcd)) {
 		sysfs_remove_link(&device->kobj, tcd->mode_name);
-		device_destroy(tape_class, tcd->char_device->dev);
+		device_destroy(&tape_class, tcd->char_device->dev);
 		cdev_del(tcd->char_device);
 		kfree(tcd);
 	}
@@ -117,15 +119,12 @@ EXPORT_SYMBOL(unregister_tape_dev);
 
 static int __init tape_init(void)
 {
-	tape_class = class_create("tape390");
-
-	return 0;
+	return class_register(&tape_class);
 }
 
 static void __exit tape_exit(void)
 {
-	class_destroy(tape_class);
-	tape_class = NULL;
+	class_unregister(&tape_class);
 }
 
 postcore_initcall(tape_init);

-- 
2.43.0

[PATCH 5/6] s390: raw3270: improve raw3270_init() readability

[Ricardo B. Marliere]

Instead of checking if rc is 0, check whether it is non-zero and return
early if so. The call to class_create() can fail, so add a check to it and
move it out of the mutex region.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
---
 drivers/s390/char/raw3270.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/s390/char/raw3270.c b/drivers/s390/char/raw3270.c
index 7115c0f85650..acc4cb37a9d8 100644
--- a/drivers/s390/char/raw3270.c
+++ b/drivers/s390/char/raw3270.c
@@ -1316,17 +1316,22 @@ static int raw3270_init(void)
 		return 0;
 	raw3270_registered = 1;
 	rc = ccw_driver_register(&raw3270_ccw_driver);
-	if (rc == 0) {
-		/* Create attributes for early (= console) device. */
-		mutex_lock(&raw3270_mutex);
-		class3270 = class_create("3270");
-		list_for_each_entry(rp, &raw3270_devices, list) {
-			get_device(&rp->cdev->dev);
-			raw3270_create_attributes(rp);
-		}
-		mutex_unlock(&raw3270_mutex);
+	if (rc)
+		return rc;
+
+	class3270 = class_create("3270");
+	if (IS_ERR(class3270))
+		return PTR_ERR(class3270);
+
+	/* Create attributes for early (= console) device. */
+	mutex_lock(&raw3270_mutex);
+	list_for_each_entry(rp, &raw3270_devices, list) {
+		get_device(&rp->cdev->dev);
+		raw3270_create_attributes(rp);
 	}
-	return rc;
+	mutex_unlock(&raw3270_mutex);
+
+	return 0;
 }
 
 static void raw3270_exit(void)

-- 
2.43.0

[PATCH 6/6] s390: raw3270: make class3270 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 class3270 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/s390/char/fs3270.c  |  8 ++++----
 drivers/s390/char/raw3270.c | 13 ++++++++-----
 drivers/s390/char/raw3270.h |  2 +-
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/s390/char/fs3270.c b/drivers/s390/char/fs3270.c
index 4f26b0a55620..f83ec248e68e 100644
--- a/drivers/s390/char/fs3270.c
+++ b/drivers/s390/char/fs3270.c
@@ -521,13 +521,13 @@ static const struct file_operations fs3270_fops = {
 static void fs3270_create_cb(int minor)
 {
 	__register_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub", &fs3270_fops);
-	device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, minor),
+	device_create(&class3270, NULL, MKDEV(IBM_FS3270_MAJOR, minor),
 		      NULL, "3270/tub%d", minor);
 }
 
 static void fs3270_destroy_cb(int minor)
 {
-	device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, minor));
+	device_destroy(&class3270, MKDEV(IBM_FS3270_MAJOR, minor));
 	__unregister_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub");
 }
 
@@ -546,7 +546,7 @@ static int __init fs3270_init(void)
 	rc = __register_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270", &fs3270_fops);
 	if (rc)
 		return rc;
-	device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, 0),
+	device_create(&class3270, NULL, MKDEV(IBM_FS3270_MAJOR, 0),
 		      NULL, "3270/tub");
 	raw3270_register_notifier(&fs3270_notifier);
 	return 0;
@@ -555,7 +555,7 @@ static int __init fs3270_init(void)
 static void __exit fs3270_exit(void)
 {
 	raw3270_unregister_notifier(&fs3270_notifier);
-	device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, 0));
+	device_destroy(&class3270, MKDEV(IBM_FS3270_MAJOR, 0));
 	__unregister_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270");
 }
 
diff --git a/drivers/s390/char/raw3270.c b/drivers/s390/char/raw3270.c
index acc4cb37a9d8..8e9868581e0a 100644
--- a/drivers/s390/char/raw3270.c
+++ b/drivers/s390/char/raw3270.c
@@ -29,7 +29,9 @@
 #include <linux/device.h>
 #include <linux/mutex.h>
 
-struct class *class3270;
+const struct class class3270 = {
+	.name = "3270",
+};
 EXPORT_SYMBOL(class3270);
 
 /* The main 3270 data structure. */
@@ -1315,13 +1317,14 @@ static int raw3270_init(void)
 	if (raw3270_registered)
 		return 0;
 	raw3270_registered = 1;
+
 	rc = ccw_driver_register(&raw3270_ccw_driver);
 	if (rc)
 		return rc;
 
-	class3270 = class_create("3270");
-	if (IS_ERR(class3270))
-		return PTR_ERR(class3270);
+	rc = class_register(&class3270);
+	if (rc)
+		return rc;
 
 	/* Create attributes for early (= console) device. */
 	mutex_lock(&raw3270_mutex);
@@ -1337,7 +1340,7 @@ static int raw3270_init(void)
 static void raw3270_exit(void)
 {
 	ccw_driver_unregister(&raw3270_ccw_driver);
-	class_destroy(class3270);
+	class_unregister(&class3270);
 }
 
 MODULE_LICENSE("GPL");
diff --git a/drivers/s390/char/raw3270.h b/drivers/s390/char/raw3270.h
index b1beecc7a0a9..5040c7e0e051 100644
--- a/drivers/s390/char/raw3270.h
+++ b/drivers/s390/char/raw3270.h
@@ -14,7 +14,7 @@
 
 struct raw3270;
 struct raw3270_view;
-extern struct class *class3270;
+extern const struct class class3270;
 
 /* 3270 CCW request */
 struct raw3270_request {

-- 
2.43.0

Re: [PATCH 0/6] s390: constify struct class usage

[Heiko Carstens]

On Tue, Mar 05, 2024 at 08:25:18AM -0300, Ricardo B. Marliere wrote:
> This is a simple and straight forward cleanup series that aims to make the
> class structures in s390 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 (6):
>       s390: zcrypt: make zcrypt_class constant
>       s390: vmur: make vmur_class constant
>       s390: vmlogrdr: make vmlogrdr_class constant
>       s390: tape: make tape_class constant
>       s390: raw3270: improve raw3270_init() readability
>       s390: raw3270: make class3270 constant
> 
>  drivers/s390/char/fs3270.c       |  8 ++++----
>  drivers/s390/char/raw3270.c      | 32 ++++++++++++++++++++------------
>  drivers/s390/char/raw3270.h      |  2 +-
>  drivers/s390/char/tape_class.c   | 17 ++++++++---------
>  drivers/s390/char/vmlogrdr.c     | 19 +++++++++----------
>  drivers/s390/char/vmur.c         | 18 +++++++++---------
>  drivers/s390/crypto/zcrypt_api.c | 33 +++++++++++++++++----------------
>  7 files changed, 68 insertions(+), 61 deletions(-)

Series applied, thanks!