ACPI: Enable build of AML interpreter debugger

This patch enables ACPICA debugger files using a configurable
CONFIG_ACPI_DEBUGGER configuration item. Those debugger related code that
was originally masked as ACPI_FUTURE_USAGE now gets unmasked.

Necessary OSL stubs are also added in this patch:
1. acpi_os_readable(): This should be arch specific in Linux, while this
    patch doesn't introduce real implementation and a complex mechanism to
    allow architecture specific acpi_os_readable() to be implemented to
    validate the address. It may be done by future commits.
2. acpi_os_get_line(): This is used to obtain debugger command input. This
    patch only introduces a simple KDB concept example in it and the
    example should be co-working with the code implemented in
    acpi_os_printf(). Since this KDB example won't be compiled unless
    ENABLE_DEBUGGER is defined and it seems Linux has already stopped to
    use ENABLE_DEBUGGER, thus do not expect it can work properly.

This patch also cleans up all other ACPI_FUTURE_USAGE surroundings
accordingly.
1. Since linkage error can be automatically detected, declaration in the
   headers needn't be surrounded by ACPI_FUTURE_USAGE.
   So only the following separate exported fuction bodies are masked by
   this macro (other exported fucntions may have already been masked at
   entire module level via drivers/acpi/acpica/Makefile):
     acpi_install_exception_handler()
     acpi_subsystem_status()
     acpi_get_system_info()
     acpi_get_statistics()
     acpi_install_initialization_handler()
2. Since strip can automatically zap the no-user functions, functions that
   are not marked with ACPI_EXPORT_SYMBOL() needn't get surrounded by
   ACPI_FUTURE_USAGE.
   So the following function which is not used by Linux kernel now won't
   get surrounded by this macro:
     acpi_ps_get_name()

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 0 insertions, 2 deletions

diff --git a/drivers/acpi/acpica/psutils.c b/drivers/acpi/acpica/psutils.c
index 183cc1efbc51..71d2877cd2ce 100644
--- a/drivers/acpi/acpica/psutils.c
+++ b/drivers/acpi/acpica/psutils.c
@@ -205,7 +205,6 @@ u8 acpi_ps_is_leading_char(u32 c)
 /*
  * Get op's name (4-byte name segment) or 0 if unnamed
  */
-#ifdef ACPI_FUTURE_USAGE
 u32 acpi_ps_get_name(union acpi_parse_object * op)
 {
 
@@ -219,7 +218,6 @@ u32 acpi_ps_get_name(union acpi_parse_object * op)
 
 	return (op->named.name);
 }
-#endif				/*  ACPI_FUTURE_USAGE  */
 
 /*
  * Set op's name