crypto: inside-secure - Remove #ifdef checks

When both PCI and OF are disabled, no drivers are registered, and
we get some unused-function warnings:

drivers/crypto/inside-secure/safexcel.c:1221:13: error: unused function 'safexcel_unregister_algorithms' [-Werror,-Wunused-function]
static void safexcel_unregister_algorithms(struct safexcel_crypto_priv *priv)
drivers/crypto/inside-secure/safexcel.c:1307:12: error: unused function 'safexcel_probe_generic' [-Werror,-Wunused-function]
static int safexcel_probe_generic(void *pdev,
drivers/crypto/inside-secure/safexcel.c:1531:13: error: unused function 'safexcel_hw_reset_rings' [-Werror,-Wunused-function]
static void safexcel_hw_reset_rings(struct safexcel_crypto_priv *priv)

It's better to make the compiler see what is going on and remove
such ifdef checks completely. In case of PCI, this is trivial since
pci_register_driver() is defined to an empty function that makes the
compiler subsequently drop all unused code silently.

The global pcireg_rc/ofreg_rc variables are not actually needed here
since the driver registration does not fail in ways that would make
it helpful.

For CONFIG_OF, an IS_ENABLED() check is still required, since platform
drivers can exist both with and without it.

A little change to linux/pci.h is needed to ensure that
pcim_enable_device() is visible to the driver. Moving the declaration
outside of ifdef would be sufficient here, but for consistency with the
rest of the file, adding an inline helper is probably best.

Fixes: 212ef6f2 ("crypto: inside-secure - Fix unused variable warning when CONFIG_PCI=n")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>	# pci.h
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/inside-secure/safexcel.c

@@ -1671,7 +1671,6 @@ static void safexcel_hw_reset_rings(struct safexcel_crypto_priv *priv)
 	}
 }
 
-#if IS_ENABLED(CONFIG_OF)
 /* for Device Tree platform driver */
 
 static int safexcel_probe(struct platform_device *pdev)
@@ -1790,9 +1789,7 @@ static struct platform_driver  crypto_safexcel = {
 		.of_match_table = safexcel_of_match_table,
 	},
 };
-#endif
 
-#if IS_ENABLED(CONFIG_PCI)
 /* PCIE devices - i.e. Inside Secure development boards */
 
 static int safexcel_pci_probe(struct pci_dev *pdev,
@@ -1913,54 +1910,32 @@ static struct pci_driver safexcel_pci_driver = {
 	.probe         = safexcel_pci_probe,
 	.remove        = safexcel_pci_remove,
 };
-#endif
-
-/* Unfortunately, we have to resort to global variables here */
-#if IS_ENABLED(CONFIG_PCI)
-int pcireg_rc = -EINVAL; /* Default safe value */
-#endif
-#if IS_ENABLED(CONFIG_OF)
-int ofreg_rc = -EINVAL; /* Default safe value */
-#endif
 
 static int __init safexcel_init(void)
 {
-#if IS_ENABLED(CONFIG_PCI)
+	int ret;
+
 	/* Register PCI driver */
-	pcireg_rc = pci_register_driver(&safexcel_pci_driver);
-#endif
+	ret = pci_register_driver(&safexcel_pci_driver);
 
-#if IS_ENABLED(CONFIG_OF)
 	/* Register platform driver */
-	ofreg_rc = platform_driver_register(&crypto_safexcel);
- #if IS_ENABLED(CONFIG_PCI)
-	/* Return success if either PCI or OF registered OK */
-	return pcireg_rc ? ofreg_rc : 0;
- #else
-	return ofreg_rc;
- #endif
-#else
- #if IS_ENABLED(CONFIG_PCI)
-	return pcireg_rc;
- #else
-	return -EINVAL;
- #endif
-#endif
+	if (IS_ENABLED(CONFIG_OF) && !ret) {
+		ret = platform_driver_register(&crypto_safexcel);
+		if (ret)
+			pci_unregister_driver(&safexcel_pci_driver);
+	}
+
+	return ret;
 }
 
 static void __exit safexcel_exit(void)
 {
-#if IS_ENABLED(CONFIG_OF)
 	/* Unregister platform driver */
-	if (!ofreg_rc)
+	if (IS_ENABLED(CONFIG_OF))
 		platform_driver_unregister(&crypto_safexcel);
-#endif
 
-#if IS_ENABLED(CONFIG_PCI)
 	/* Unregister PCI driver if successfully registered before */
-	if (!pcireg_rc)
 	pci_unregister_driver(&safexcel_pci_driver);
-#endif
 }
 
 module_init(safexcel_init);

include/linux/pci.h

@@ -1686,6 +1686,7 @@ static inline struct pci_dev *pci_get_class(unsigned int class,
 static inline void pci_set_master(struct pci_dev *dev) { }
 static inline int pci_enable_device(struct pci_dev *dev) { return -EIO; }
 static inline void pci_disable_device(struct pci_dev *dev) { }
+static inline int pcim_enable_device(struct pci_dev *pdev) { return -EIO; }
 static inline int pci_assign_resource(struct pci_dev *dev, int i)
 { return -EBUSY; }
 static inline int __pci_register_driver(struct pci_driver *drv,