[IA64] Only build arch/ia64/kernel/acpi.o when CONFIG_ACPI

The following commit broke the ia64 sim_defconfig build:
	3b2b84c0b81108a9a869a88bf2beeb5a95d81dd1
	ACPI: processor: driver doesn't need to evaluate _PDC

This is because it added:
	+#include <acpi/processor.h>

To arch/ia64/kernel/acpi.c. Unfortunately, the ia64_simdefconfig does
not turn on CONFIG_ACPI, and we get build errors.

The fix described in $subject seems to be the most sensible way to
untangle the mess.

The other issue is that acpi_get_sysname() is required for all configs,
most of which define CONFIG_ACPI, but are not CONFIG_IA64_GENERIC. Turn
it into an inline to cover the "non generic" ia64 configs; to prevent
a duplicate definition build error, we need to wrap the definition in
acpi.o inside an #ifdef.

Finally, move the pm_idle and pm_power_off exports into process.c (which
is always built), similar to other architectures, and allow the sim
defconfig to link.

Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 9bcec99..454a6a4 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -60,6 +60,10 @@ unsigned long idle_halt;
 EXPORT_SYMBOL(idle_halt);
 unsigned long idle_nomwait;
 EXPORT_SYMBOL(idle_nomwait);
+void (*pm_idle) (void);
+EXPORT_SYMBOL(pm_idle);
+void (*pm_power_off) (void);
+EXPORT_SYMBOL(pm_power_off);
 
 void
 ia64_do_show_stack (struct unw_frame_info *info, void *arg)