PM / Hibernate: Introduce CONFIG_HIBERNATE_CALLBACKS
Xen save/restore is going to use hibernate device callbacks for
quiescing devices and putting them back to normal operations and it
would need to select CONFIG_HIBERNATION for this purpose. However,
that also would cause the hibernate interfaces for user space to be
enabled, which might confuse user space, because the Xen kernels
don't support hibernation. Moreover, it would be wasteful, as it
would make the Xen kernels include a substantial amount of code that
they would never use.
To address this issue introduce new power management Kconfig option
CONFIG_HIBERNATE_CALLBACKS, such that it will only select the code
that is necessary for the hibernate device callbacks to work and make
CONFIG_HIBERNATION select it. Then, Xen save/restore will be able to
select CONFIG_HIBERNATE_CALLBACKS without dragging the entire
hibernate code along with it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index d86ea8b..135df16 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -781,7 +781,7 @@
#endif /* !CONFIG_SUSPEND */
-#ifdef CONFIG_HIBERNATION
+#ifdef CONFIG_HIBERNATE_CALLBACKS
static int pci_pm_freeze(struct device *dev)
{
@@ -970,7 +970,7 @@
return error;
}
-#else /* !CONFIG_HIBERNATION */
+#else /* !CONFIG_HIBERNATE_CALLBACKS */
#define pci_pm_freeze NULL
#define pci_pm_freeze_noirq NULL
@@ -981,7 +981,7 @@
#define pci_pm_restore NULL
#define pci_pm_restore_noirq NULL
-#endif /* !CONFIG_HIBERNATION */
+#endif /* !CONFIG_HIBERNATE_CALLBACKS */
#ifdef CONFIG_PM_RUNTIME