linux-kernel - [PATCH v2 4/5] drivers/xen: make sys-hypervisor.c explicitly non-modular

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Date:	Sun, 21 Feb 2016 19:06:07 -0500
From:	Paul Gortmaker <paul.gortmaker@...driver.com>
To:	<linux-kernel@...r.kernel.org>
CC:	Paul Gortmaker <paul.gortmaker@...driver.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	Boris Ostrovsky <boris.ostrovsky@...cle.com>,
	David Vrabel <david.vrabel@...rix.com>,
	Stefano Stabellini <stefano.stabellini@...citrix.com>,
	<xen-devel@...ts.xenproject.org>
Subject: [PATCH v2 4/5] drivers/xen: make sys-hypervisor.c explicitly non-modular

The Kconfig currently controlling compilation of this code is:

config XEN_SYS_HYPERVISOR
       bool "Create xen entries under /sys/hypervisor"

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.  However
one could argue that fs_initcall() might make more sense here.

This change means that the one line function xen_properties_destroy()
has only one user left, and since that is inside an #ifdef, we just
manually inline it there vs. adding more ifdeffery around the function
to avoid compile warnings about "defined but not used".

In order to be consistent we also manually inline the other _destroy
functions that are also just one line sysfs functions calls with only
one call site remaing, even though they wouldn't need #ifdeffery.

Cc: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@...cle.com>
Cc: David Vrabel <david.vrabel@...rix.com>
Cc: Stefano Stabellini <stefano.stabellini@...citrix.com>
Cc: xen-devel@...ts.xenproject.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@...driver.com>
---
 drivers/xen/sys-hypervisor.c | 59 ++++++--------------------------------------
 1 file changed, 8 insertions(+), 51 deletions(-)

diff --git a/drivers/xen/sys-hypervisor.c b/drivers/xen/sys-hypervisor.c
index b5a7342e0ba5..6881b3ceb675 100644
--- a/drivers/xen/sys-hypervisor.c
+++ b/drivers/xen/sys-hypervisor.c
@@ -9,7 +9,7 @@
 
 #include <linux/slab.h>
 #include <linux/kernel.h>
-#include <linux/module.h>
+#include <linux/init.h>
 #include <linux/kobject.h>
 #include <linux/err.h>
 
@@ -50,11 +50,6 @@ static int __init xen_sysfs_type_init(void)
 	return sysfs_create_file(hypervisor_kobj, &type_attr.attr);
 }
 
-static void xen_sysfs_type_destroy(void)
-{
-	sysfs_remove_file(hypervisor_kobj, &type_attr.attr);
-}
-
 /* xen version attributes */
 static ssize_t major_show(struct hyp_sysfs_attr *attr, char *buffer)
 {
@@ -111,11 +106,6 @@ static int __init xen_sysfs_version_init(void)
 	return sysfs_create_group(hypervisor_kobj, &version_group);
 }
 
-static void xen_sysfs_version_destroy(void)
-{
-	sysfs_remove_group(hypervisor_kobj, &version_group);
-}
-
 /* UUID */
 
 static ssize_t uuid_show_fallback(struct hyp_sysfs_attr *attr, char *buffer)
@@ -157,11 +147,6 @@ static int __init xen_sysfs_uuid_init(void)
 	return sysfs_create_file(hypervisor_kobj, &uuid_attr.attr);
 }
 
-static void xen_sysfs_uuid_destroy(void)
-{
-	sysfs_remove_file(hypervisor_kobj, &uuid_attr.attr);
-}
-
 /* xen compilation attributes */
 
 static ssize_t compiler_show(struct hyp_sysfs_attr *attr, char *buffer)
@@ -235,11 +220,6 @@ static int __init xen_compilation_init(void)
 	return sysfs_create_group(hypervisor_kobj, &xen_compilation_group);
 }
 
-static void xen_compilation_destroy(void)
-{
-	sysfs_remove_group(hypervisor_kobj, &xen_compilation_group);
-}
-
 /* xen properties info */
 
 static ssize_t capabilities_show(struct hyp_sysfs_attr *attr, char *buffer)
@@ -366,11 +346,6 @@ static int __init xen_properties_init(void)
 	return sysfs_create_group(hypervisor_kobj, &xen_properties_group);
 }
 
-static void xen_properties_destroy(void)
-{
-	sysfs_remove_group(hypervisor_kobj, &xen_properties_group);
-}
-
 #ifdef CONFIG_XEN_HAVE_VPMU
 struct pmu_mode {
 	const char *name;
@@ -484,11 +459,6 @@ static int __init xen_pmu_init(void)
 {
 	return sysfs_create_group(hypervisor_kobj, &xen_pmu_group);
 }
-
-static void xen_pmu_destroy(void)
-{
-	sysfs_remove_group(hypervisor_kobj, &xen_pmu_group);
-}
 #endif
 
 static int __init hyper_sysfs_init(void)
@@ -517,7 +487,8 @@ static int __init hyper_sysfs_init(void)
 	if (xen_initial_domain()) {
 		ret = xen_pmu_init();
 		if (ret) {
-			xen_properties_destroy();
+			sysfs_remove_group(hypervisor_kobj,
+					   &xen_properties_group);
 			goto prop_out;
 		}
 	}
@@ -525,31 +496,17 @@ static int __init hyper_sysfs_init(void)
 	goto out;
 
 prop_out:
-	xen_sysfs_uuid_destroy();
+	sysfs_remove_file(hypervisor_kobj, &uuid_attr.attr);
 uuid_out:
-	xen_compilation_destroy();
+	sysfs_remove_group(hypervisor_kobj, &xen_compilation_group);
 comp_out:
-	xen_sysfs_version_destroy();
+	sysfs_remove_group(hypervisor_kobj, &version_group);
 version_out:
-	xen_sysfs_type_destroy();
+	sysfs_remove_file(hypervisor_kobj, &type_attr.attr);
 out:
 	return ret;
 }
-
-static void __exit hyper_sysfs_exit(void)
-{
-#ifdef CONFIG_XEN_HAVE_VPMU
-	xen_pmu_destroy();
-#endif
-	xen_properties_destroy();
-	xen_compilation_destroy();
-	xen_sysfs_uuid_destroy();
-	xen_sysfs_version_destroy();
-	xen_sysfs_type_destroy();
-
-}
-module_init(hyper_sysfs_init);
-module_exit(hyper_sysfs_exit);
+device_initcall(hyper_sysfs_init);
 
 static ssize_t hyp_sysfs_show(struct kobject *kobj,
 			      struct attribute *attr,
-- 
2.6.1