[PATCH] PCI: endpoint: make pci_epc_class constant

[PATCH] PCI: endpoint: make pci_epc_class constant

[Greg Kroah-Hartman]

Now that the driver core allows for struct class to be in read-only
memory, we should make all 'class' structures declared at build time
placing them into read-only memory, instead of having to be dynamically
allocated at runtime.

Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: "Krzysztof Wilczyński" <kw@linux.com>
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: Kishon Vijay Abraham I <kishon@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/pci/endpoint/pci-epc-core.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 47d27ec7439d..ed038dd77f83 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -14,7 +14,9 @@
 #include <linux/pci-epf.h>
 #include <linux/pci-ep-cfs.h>
 
-static struct class *pci_epc_class;
+static const struct class pci_epc_class = {
+	.name = "pci_epc",
+};
 
 static void devm_pci_epc_release(struct device *dev, void *res)
 {
@@ -60,7 +62,7 @@ struct pci_epc *pci_epc_get(const char *epc_name)
 	struct device *dev;
 	struct class_dev_iter iter;
 
-	class_dev_iter_init(&iter, pci_epc_class, NULL, NULL);
+	class_dev_iter_init(&iter, &pci_epc_class, NULL, NULL);
 	while ((dev = class_dev_iter_next(&iter))) {
 		if (strcmp(epc_name, dev_name(dev)))
 			continue;
@@ -867,7 +869,7 @@ __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
 	INIT_LIST_HEAD(&epc->pci_epf);
 
 	device_initialize(&epc->dev);
-	epc->dev.class = pci_epc_class;
+	epc->dev.class = &pci_epc_class;
 	epc->dev.parent = dev;
 	epc->dev.release = pci_epc_release;
 	epc->ops = ops;
@@ -927,20 +929,13 @@ EXPORT_SYMBOL_GPL(__devm_pci_epc_create);
 
 static int __init pci_epc_init(void)
 {
-	pci_epc_class = class_create("pci_epc");
-	if (IS_ERR(pci_epc_class)) {
-		pr_err("failed to create pci epc class --> %ld\n",
-		       PTR_ERR(pci_epc_class));
-		return PTR_ERR(pci_epc_class);
-	}
-
-	return 0;
+	return class_register(&pci_epc_class);
 }
 module_init(pci_epc_init);
 
 static void __exit pci_epc_exit(void)
 {
-	class_destroy(pci_epc_class);
+	class_unregister(&pci_epc_class);
 }
 module_exit(pci_epc_exit);
 
-- 
2.45.2

Re: [PATCH] PCI: endpoint: make pci_epc_class constant

[Bjorn Helgaas]

On Mon, Jun 10, 2024 at 10:20:12AM +0200, Greg Kroah-Hartman wrote:
> Now that the driver core allows for struct class to be in read-only
> memory, we should make all 'class' structures declared at build time
> placing them into read-only memory, instead of having to be dynamically
> allocated at runtime.
> 
> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
> Cc: "Krzysztof Wilczyński" <kw@linux.com>
> Cc: Manivannan Sadhasivam <mani@kernel.org>
> Cc: Kishon Vijay Abraham I <kishon@kernel.org>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: linux-pci@vger.kernel.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Applied to pci/endpoint for v6.11, thanks!

> ---
>  drivers/pci/endpoint/pci-epc-core.c | 19 +++++++------------
>  1 file changed, 7 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> index 47d27ec7439d..ed038dd77f83 100644
> --- a/drivers/pci/endpoint/pci-epc-core.c
> +++ b/drivers/pci/endpoint/pci-epc-core.c
> @@ -14,7 +14,9 @@
>  #include <linux/pci-epf.h>
>  #include <linux/pci-ep-cfs.h>
>  
> -static struct class *pci_epc_class;
> +static const struct class pci_epc_class = {
> +	.name = "pci_epc",
> +};
>  
>  static void devm_pci_epc_release(struct device *dev, void *res)
>  {
> @@ -60,7 +62,7 @@ struct pci_epc *pci_epc_get(const char *epc_name)
>  	struct device *dev;
>  	struct class_dev_iter iter;
>  
> -	class_dev_iter_init(&iter, pci_epc_class, NULL, NULL);
> +	class_dev_iter_init(&iter, &pci_epc_class, NULL, NULL);
>  	while ((dev = class_dev_iter_next(&iter))) {
>  		if (strcmp(epc_name, dev_name(dev)))
>  			continue;
> @@ -867,7 +869,7 @@ __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
>  	INIT_LIST_HEAD(&epc->pci_epf);
>  
>  	device_initialize(&epc->dev);
> -	epc->dev.class = pci_epc_class;
> +	epc->dev.class = &pci_epc_class;
>  	epc->dev.parent = dev;
>  	epc->dev.release = pci_epc_release;
>  	epc->ops = ops;
> @@ -927,20 +929,13 @@ EXPORT_SYMBOL_GPL(__devm_pci_epc_create);
>  
>  static int __init pci_epc_init(void)
>  {
> -	pci_epc_class = class_create("pci_epc");
> -	if (IS_ERR(pci_epc_class)) {
> -		pr_err("failed to create pci epc class --> %ld\n",
> -		       PTR_ERR(pci_epc_class));
> -		return PTR_ERR(pci_epc_class);
> -	}
> -
> -	return 0;
> +	return class_register(&pci_epc_class);
>  }
>  module_init(pci_epc_init);
>  
>  static void __exit pci_epc_exit(void)
>  {
> -	class_destroy(pci_epc_class);
> +	class_unregister(&pci_epc_class);
>  }
>  module_exit(pci_epc_exit);
>  
> -- 
> 2.45.2
>