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, 3 insertions, 8 deletions

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 739a4a6b3b9b..327291586f84 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -66,8 +66,6 @@ struct acpi_os_dpc {
 /* stuff for debugger support */
 int acpi_in_debugger;
 EXPORT_SYMBOL(acpi_in_debugger);
-
-extern char line_buf[80];
 #endif				/*ENABLE_DEBUGGER */
 
 static int (*__acpi_os_prepare_sleep)(u8 sleep_state, u32 pm1a_ctrl,
@@ -1345,15 +1343,13 @@ acpi_status acpi_os_signal_semaphore(acpi_handle handle, u32 units)
 	return AE_OK;
 }
 
-#ifdef ACPI_FUTURE_USAGE
-u32 acpi_os_get_line(char *buffer)
+acpi_status acpi_os_get_line(char *buffer, u32 buffer_length, u32 *bytes_read)
 {
-
 #ifdef ENABLE_DEBUGGER
 	if (acpi_in_debugger) {
 		u32 chars;
 
-		kdb_read(buffer, sizeof(line_buf));
+		kdb_read(buffer, buffer_length);
 
 		/* remove the CR kdb includes */
 		chars = strlen(buffer) - 1;
@@ -1361,9 +1357,8 @@ u32 acpi_os_get_line(char *buffer)
 	}
 #endif
 
-	return 0;
+	return AE_OK;
 }
-#endif				/*  ACPI_FUTURE_USAGE  */
 
 acpi_status acpi_os_signal(u32 function, void *info)
 {