ACPI: Interpreter update to 20021111 - Adds support for SMBus OpRegions

drivers/acpi/events/evevent.c

 /******************************************************************************
  *
  * Module Name: evevent - Fixed and General Purpose Even handling and dispatch
- *              $Revision: 95 $
+ *              $Revision: 96 $
  *
  *****************************************************************************/
 
@@ -503,9 +503,9 @@ acpi_ev_gpe_initialize (void)
 
 			ACPI_REPORT_INFO (("GPE Block%d defined as GPE%d to GPE%d\n",
 				(s32) gpe_block,
-				acpi_gbl_gpe_block_info[gpe_block].block_base_number,
-				acpi_gbl_gpe_block_info[gpe_block].block_base_number +
-					((acpi_gbl_gpe_block_info[gpe_block].register_count * 8) -1)));
+				(u32) acpi_gbl_gpe_block_info[gpe_block].block_base_number,
+				(u32) (acpi_gbl_gpe_block_info[gpe_block].block_base_number +
+					((acpi_gbl_gpe_block_info[gpe_block].register_count * 8) -1))));
 		}
 	}
 

drivers/acpi/executer/exdump.c

 /******************************************************************************
  *
  * Module Name: exdump - Interpreter debug output routines
- *              $Revision: 162 $
+ *              $Revision: 163 $
  *
  *****************************************************************************/
 
@@ -590,6 +590,7 @@ acpi_ex_dump_object_descriptor (
 
 		acpi_ex_out_integer ("Length",       obj_desc->buffer.length);
 		acpi_ex_out_pointer ("Pointer",      obj_desc->buffer.pointer);
+		ACPI_DUMP_BUFFER (obj_desc->buffer.pointer, obj_desc->buffer.length);
 		break;
 
 

drivers/acpi/executer/exfield.c

 /******************************************************************************
  *
  * Module Name: exfield - ACPI AML (p-code) execution - field manipulation
- *              $Revision: 112 $
+ *              $Revision: 113 $
  *
  *****************************************************************************/
 
@@ -27,6 +27,8 @@
 #include "acpi.h"
 #include "acdispat.h"
 #include "acinterp.h"
+#include "acevents.h"
+#include "amlcode.h"
 
 
 #define _COMPONENT          ACPI_EXECUTER
@@ -82,6 +84,45 @@ acpi_ex_read_data_from_field (
 			}
 		}
 	}
+	else if ((ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD) &&
+			 (obj_desc->field.region_obj->region.space_id == ACPI_ADR_SPACE_SMBUS)) {
+		/*
+		 * This is an SMBus read.  We must create a buffer to hold the data
+		 * and directly access the region handler.
+		 */
+		buffer_desc = acpi_ut_create_internal_object (ACPI_TYPE_BUFFER);
+		if (!buffer_desc) {
+			return_ACPI_STATUS (AE_NO_MEMORY);
+		}
+
+		/* Create the actual read buffer */
+
+		buffer_desc->buffer.pointer = ACPI_MEM_CALLOCATE (ACPI_SMBUS_BUFFER_SIZE);
+		if (!buffer_desc->buffer.pointer) {
+			acpi_ut_remove_reference (buffer_desc);
+			return_ACPI_STATUS (AE_NO_MEMORY);
+		}
+
+		/* Complete the buffer object initialization */
+
+		buffer_desc->common.flags = AOPOBJ_DATA_VALID;
+		buffer_desc->buffer.length = ACPI_SMBUS_BUFFER_SIZE;
+		buffer = buffer_desc->buffer.pointer;
+
+		/* Lock entire transaction if requested */
+
+		locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
+
+		/*
+		 * Perform the read.
+		 * Note: Smbus protocol value is passed in upper 16-bits of Function
+		 */
+		status = acpi_ex_access_region (obj_desc, 0,
+				  (acpi_integer *) buffer_desc->buffer.pointer,
+				  ACPI_READ | (obj_desc->field.attribute << 16));
+		acpi_ex_release_global_lock (locked);
+		goto exit;
+	}
 
 	/*
 	 * Allocate a buffer for the contents of the field.
@@ -138,17 +179,17 @@ acpi_ex_read_data_from_field (
 		obj_desc->common_field.start_field_bit_offset,
 		obj_desc->common_field.base_byte_offset));
 
+	/* Lock entire transaction if requested */
+
 	locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
 
 	/* Read from the field */
 
 	status = acpi_ex_extract_from_field (obj_desc, buffer, length);
-
-	/*
-	 * Release global lock if we acquired it earlier
-	 */
 	acpi_ex_release_global_lock (locked);
 
+
+exit:
 	if (ACPI_FAILURE (status)) {
 		acpi_ut_remove_reference (buffer_desc);
 	}
@@ -176,7 +217,8 @@ acpi_ex_read_data_from_field (
 acpi_status
 acpi_ex_write_data_to_field (
 	acpi_operand_object     *source_desc,
-	acpi_operand_object     *obj_desc)
+	acpi_operand_object     *obj_desc,
+	acpi_operand_object     **result_desc)
 {
 	acpi_status             status;
 	u32                     length;
@@ -184,6 +226,7 @@ acpi_ex_write_data_to_field (
 	void                    *buffer;
 	void                    *new_buffer;
 	u8                      locked;
+	acpi_operand_object     *buffer_desc;
 
 
 	ACPI_FUNCTION_TRACE_PTR ("Ex_write_data_to_field", obj_desc);
@@ -207,6 +250,64 @@ acpi_ex_write_data_to_field (
 			}
 		}
 	}
+	else if ((ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD) &&
+			 (obj_desc->field.region_obj->region.space_id == ACPI_ADR_SPACE_SMBUS)) {
+		/*
+		 * This is an SMBus write.  We will bypass the entire field mechanism
+		 * and handoff the buffer directly to the handler.
+		 *
+		 * Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
+		 */
+		if (ACPI_GET_OBJECT_TYPE (source_desc) != ACPI_TYPE_BUFFER) {
+			ACPI_REPORT_ERROR (("SMBus write requires Buffer, found type %s\n",
+				acpi_ut_get_object_type_name (source_desc)));
+			return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
+		}
+
+		if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
+			ACPI_REPORT_ERROR (("SMBus write requires Buffer of length %X, found length %X\n",
+				ACPI_SMBUS_BUFFER_SIZE, source_desc->buffer.length));
+			return_ACPI_STATUS (AE_AML_BUFFER_LIMIT);
+		}
+
+		buffer_desc = acpi_ut_create_internal_object (ACPI_TYPE_BUFFER);
+		if (!buffer_desc) {
+			return_ACPI_STATUS (AE_NO_MEMORY);
+		}
+
+		/* Create the actual read buffer */
+
+		buffer_desc->buffer.pointer = ACPI_MEM_CALLOCATE (ACPI_SMBUS_BUFFER_SIZE);
+		if (!buffer_desc->buffer.pointer) {
+			acpi_ut_remove_reference (buffer_desc);
+			return_ACPI_STATUS (AE_NO_MEMORY);
+		}
+
+		/* Complete the buffer object initialization */
+
+		buffer_desc->common.flags = AOPOBJ_DATA_VALID;
+		buffer_desc->buffer.length = ACPI_SMBUS_BUFFER_SIZE;
+		buffer = buffer_desc->buffer.pointer;
+
+
+		ACPI_MEMCPY (buffer, source_desc->buffer.pointer, ACPI_SMBUS_BUFFER_SIZE);
+
+		/* Lock entire transaction if requested */
+
+		locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
+
+		/*
+		 * Perform the write (returns status and perhaps data in the same buffer)
+		 * Note: SMBus protocol type is passed in upper 16-bits of Function.
+		 */
+		status = acpi_ex_access_region (obj_desc, 0,
+				  (acpi_integer *) buffer,
+				  ACPI_WRITE | (obj_desc->field.attribute << 16));
+		acpi_ex_release_global_lock (locked);
+
+		*result_desc = buffer_desc;
+		return_ACPI_STATUS (status);
+	}
 
 	/*
 	 * Get a pointer to the data to be written
@@ -267,16 +368,13 @@ acpi_ex_write_data_to_field (
 		obj_desc->common_field.start_field_bit_offset,
 		obj_desc->common_field.base_byte_offset));
 
+	/* Lock entire transaction if requested */
+
 	locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
 
-	/*
-	 * Write to the field
-	 */
-	status = acpi_ex_insert_into_field (obj_desc, buffer, length);
+	/* Write to the field */
 
-	/*
-	 * Release global lock if we acquired it earlier
-	 */
+	status = acpi_ex_insert_into_field (obj_desc, buffer, length);
 	acpi_ex_release_global_lock (locked);
 
 	/* Free temporary buffer if we used one */

drivers/acpi/executer/exfldio.c

 /******************************************************************************
  *
  * Module Name: exfldio - Aml Field I/O
- *              $Revision: 89 $
+ *              $Revision: 90 $
  *
  *****************************************************************************/
 
@@ -64,6 +64,8 @@ acpi_ex_setup_region (
 
 	rgn_desc = obj_desc->common_field.region_obj;
 
+	/* We must have a valid region */
+
 	if (ACPI_GET_OBJECT_TYPE (rgn_desc) != ACPI_TYPE_REGION) {
 		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Needed Region, found type %X (%s)\n",
 			ACPI_GET_OBJECT_TYPE (rgn_desc),
@@ -83,6 +85,12 @@ acpi_ex_setup_region (
 		}
 	}
 
+	if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS) {
+		/* SMBus has a non-linear address space */
+
+		return_ACPI_STATUS (AE_OK);
+	}
+
 	/*
 	 * Validate the request.  The entire request from the byte offset for a
 	 * length of one field datum (access width) must fit within the region.
@@ -127,8 +135,10 @@ acpi_ex_setup_region (
  * PARAMETERS:  *Obj_desc               - Field to be read
  *              Field_datum_byte_offset - Byte offset of this datum within the
  *                                        parent field
- *              *Value                  - Where to store value (must be 32 bits)
- *              Read_write              - Read or Write flag
+ *              *Value                  - Where to store value (must at least
+ *                                        the size of acpi_integer)
+ *              Function                - Read or Write flag plus other region-
+ *                                        dependent flags
  *
  * RETURN:      Status
  *
@@ -141,7 +151,7 @@ acpi_ex_access_region (
 	acpi_operand_object     *obj_desc,
 	u32                     field_datum_byte_offset,
 	acpi_integer            *value,
-	u32                     read_write)
+	u32                     function)
 {
 	acpi_status             status;
 	acpi_operand_object     *rgn_desc;
@@ -151,6 +161,15 @@ acpi_ex_access_region (
 	ACPI_FUNCTION_TRACE ("Ex_access_region");
 
 
+	/*
+	 * Ensure that the region operands are fully evaluated and verify
+	 * the validity of the request
+	 */
+	status = acpi_ex_setup_region (obj_desc, field_datum_byte_offset);
+	if (ACPI_FAILURE (status)) {
+		return_ACPI_STATUS (status);
+	}
+
 	/*
 	 * The physical address of this field datum is:
 	 *
@@ -163,7 +182,7 @@ acpi_ex_access_region (
 			 + obj_desc->common_field.base_byte_offset
 			 + field_datum_byte_offset;
 
-	if (read_write == ACPI_READ) {
+	if ((function & ACPI_IO_MASK) == ACPI_READ) {
 		ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD, "[READ]"));
 	}
 	else {
@@ -181,7 +200,7 @@ acpi_ex_access_region (
 
 	/* Invoke the appropriate Address_space/Op_region handler */
 
-	status = acpi_ev_address_space_dispatch (rgn_desc, read_write,
+	status = acpi_ev_address_space_dispatch (rgn_desc, function,
 			  address, ACPI_MUL_8 (obj_desc->common_field.access_byte_width), value);
 
 	if (ACPI_FAILURE (status)) {
@@ -191,7 +210,6 @@ acpi_ex_access_region (
 				acpi_ut_get_region_name (rgn_desc->region.space_id),
 				rgn_desc->region.space_id));
 		}
-
 		else if (status == AE_NOT_EXIST) {
 			ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
 				"Region %s(%X) has no handler\n",
@@ -371,11 +389,6 @@ acpi_ex_field_datum_io (
 		 * For simple Region_fields, we just directly access the owning
 		 * Operation Region.
 		 */
-		status = acpi_ex_setup_region (obj_desc, field_datum_byte_offset);
-		if (ACPI_FAILURE (status)) {
-			return_ACPI_STATUS (status);
-		}
-
 		status = acpi_ex_access_region (obj_desc, field_datum_byte_offset, value,
 				  read_write);
 		break;

drivers/acpi/executer/exoparg1.c

@@ -2,7 +2,7 @@
 /******************************************************************************
  *
  * Module Name: exoparg1 - AML execution - opcodes with 1 argument
- *              $Revision: 144 $
+ *              $Revision: 145 $
  *
  *****************************************************************************/
 
@@ -389,14 +389,16 @@ acpi_ex_opcode_1A_1T_1R (
 			return_ACPI_STATUS (status);
 		}
 
-		/*
-		 * Normally, we would remove a reference on the Operand[0] parameter;
-		 * But since it is being used as the internal return object
-		 * (meaning we would normally increment it), the two cancel out,
-		 * and we simply don't do anything.
-		 */
-		walk_state->result_obj = operand[0];
-		walk_state->operands[0] = NULL; /* Prevent deletion */
+		if (!walk_state->result_obj) {
+			/*
+			 * Normally, we would remove a reference on the Operand[0] parameter;
+			 * But since it is being used as the internal return object
+			 * (meaning we would normally increment it), the two cancel out,
+			 * and we simply don't do anything.
+			 */
+			walk_state->result_obj = operand[0];
+			walk_state->operands[0] = NULL; /* Prevent deletion */
+		}
 		return_ACPI_STATUS (status);
 
 
@@ -461,7 +463,9 @@ acpi_ex_opcode_1A_1T_1R (
 
 cleanup:
 
-	walk_state->result_obj = return_desc;
+	if (!walk_state->result_obj) {
+		walk_state->result_obj = return_desc;
+	}
 
 	/* Delete return object on error */
 

drivers/acpi/executer/exoparg2.c

 /******************************************************************************
  *
  * Module Name: exoparg2 - AML execution - opcodes with 2 arguments
- *              $Revision: 113 $
+ *              $Revision: 114 $
  *
  *****************************************************************************/
 
@@ -490,7 +490,9 @@ acpi_ex_opcode_2A_1T_1R (
 			goto cleanup;
 		}
 
-		walk_state->result_obj = return_desc;
+		if (!walk_state->result_obj) {
+			walk_state->result_obj = return_desc;
+		}
 	}
 
 

drivers/acpi/executer/exoparg3.c

@@ -2,7 +2,7 @@
 /******************************************************************************
  *
  * Module Name: exoparg3 - AML execution - opcodes with 3 arguments
- *              $Revision: 14 $
+ *              $Revision: 15 $
  *
  *****************************************************************************/
 
@@ -226,7 +226,9 @@ acpi_ex_opcode_3A_1T_1R (
 
 	/* Set the return object and exit */
 
-	walk_state->result_obj = return_desc;
+	if (!walk_state->result_obj) {
+		walk_state->result_obj = return_desc;
+	}
 	return_ACPI_STATUS (status);
 }
 

drivers/acpi/executer/exprep.c

@@ -2,7 +2,7 @@
 /******************************************************************************
  *
  * Module Name: exprep - ACPI AML (p-code) execution - field prep utilities
- *              $Revision: 120 $
+ *              $Revision: 121 $
  *
  *****************************************************************************/
 
@@ -107,28 +107,24 @@ acpi_ex_decode_field_access (
 		break;
 
 	case AML_FIELD_ACCESS_BYTE:
+	case AML_FIELD_ACCESS_BUFFER:   /* ACPI 2.0 (SMBus Buffer) */
 		byte_alignment = 1;
-		bit_length = 8;
+		bit_length    = 8;
 		break;
 
 	case AML_FIELD_ACCESS_WORD:
 		byte_alignment = 2;
-		bit_length = 16;
+		bit_length    = 16;
 		break;
 
 	case AML_FIELD_ACCESS_DWORD:
 		byte_alignment = 4;
-		bit_length = 32;
+		bit_length    = 32;
 		break;
 
-	case AML_FIELD_ACCESS_QWORD:  /* ACPI 2.0 */
+	case AML_FIELD_ACCESS_QWORD:    /* ACPI 2.0 */
 		byte_alignment = 8;
-		bit_length = 64;
-		break;
-
-	case AML_FIELD_ACCESS_BUFFER:  /* ACPI 2.0 */
-		byte_alignment = 8;
-		bit_length = 8;
+		bit_length    = 64;
 		break;
 
 	default:

drivers/acpi/executer/exstore.c

@@ -2,7 +2,7 @@
 /******************************************************************************
  *
  * Module Name: exstore - AML Interpreter object store support
- *              $Revision: 173 $
+ *              $Revision: 174 $
  *
  *****************************************************************************/
 
@@ -81,7 +81,7 @@ acpi_ex_store (
 	if (ACPI_GET_DESCRIPTOR_TYPE (dest_desc) == ACPI_DESC_TYPE_NAMED) {
 		/*
 		 * Dest is a namespace node,
-		 * Storing an object into a Name "container"
+		 * Storing an object into a Named node.
 		 */
 		status = acpi_ex_store_object_to_node (source_desc,
 				 (acpi_namespace_node *) dest_desc, walk_state);
@@ -435,7 +435,7 @@ acpi_ex_store_object_to_node (
 		/*
 		 * For fields, copy the source data to the target field.
 		 */
-		status = acpi_ex_write_data_to_field (source_desc, target_desc);
+		status = acpi_ex_write_data_to_field (source_desc, target_desc, &walk_state->result_obj);
 		break;
 
 

drivers/acpi/include/acconfig.h

 /******************************************************************************
  *
  * Name: acconfig.h - Global configuration constants
- *       $Revision: 115 $
+ *       $Revision: 117 $
  *
  *****************************************************************************/
 
@@ -54,7 +54,7 @@
 
 /* Version string */
 
-#define ACPI_CA_VERSION                 0x20021101
+#define ACPI_CA_VERSION                 0x20021111
 
 /* Version of ACPI supported */
 
@@ -166,6 +166,10 @@
 #define ACPI_RSDP_CHECKSUM_LENGTH       20
 #define ACPI_RSDP_XCHECKSUM_LENGTH      36
 
+/* SMBus bidirectional buffer size */
+
+#define ACPI_SMBUS_BUFFER_SIZE          34
+
 
 /******************************************************************************
  *

drivers/acpi/include/acdisasm.h

 /******************************************************************************
  *
  * Name: acdisasm.h - AML disassembler
- *       $Revision: 4 $
+ *       $Revision: 5 $
  *
  *****************************************************************************/
 
@@ -239,6 +239,9 @@ void
 acpi_dm_bit_list (
 	u16                     mask);
 
+void
+acpi_dm_decode_attribute (
+	u8                      attribute);
 
 /*
  * dmresrcl

drivers/acpi/include/acinterp.h

 /******************************************************************************
  *
  * Name: acinterp.h - Interpreter subcomponent prototypes and defines
- *       $Revision: 141 $
+ *       $Revision: 142 $
  *
  *****************************************************************************/
 
@@ -164,7 +164,8 @@ acpi_ex_read_data_from_field (
 acpi_status
 acpi_ex_write_data_to_field (
 	acpi_operand_object     *source_desc,
-	acpi_operand_object     *obj_desc);
+	acpi_operand_object     *obj_desc,
+	acpi_operand_object     **result_desc);
 
 /*
  * exmisc - ACPI AML (p-code) execution - specific opcodes

drivers/acpi/include/actypes.h

 /******************************************************************************
  *
  * Name: actypes.h - Common data types for the entire ACPI subsystem
- *       $Revision: 240 $
+ *       $Revision: 241 $
  *
  *****************************************************************************/
 
@@ -499,6 +499,7 @@ typedef u32                             acpi_object_type;
  */
 #define ACPI_READ                       0
 #define ACPI_WRITE                      1
+#define ACPI_IO_MASK                    1
 
 
 /*

drivers/acpi/include/amlcode.h

@@ -3,7 +3,7 @@
  * Name: amlcode.h - Definitions for AML, as included in "definition blocks"
  *                   Declarations and definitions contained herein are derived
  *                   directly from the ACPI specification.
- *       $Revision: 70 $
+ *       $Revision: 71 $
  *
  *****************************************************************************/
 
@@ -462,7 +462,8 @@ typedef enum
 	AML_FIELD_ATTRIB_SMB_BYTE       = 0x06,
 	AML_FIELD_ATTRIB_SMB_WORD       = 0x08,
 	AML_FIELD_ATTRIB_SMB_BLOCK      = 0x0A,
-	AML_FIELD_ATTRIB_SMB_CALL       = 0x0E
+	AML_FIELD_ATTRIB_SMB_WORD_CALL  = 0x0C,
+	AML_FIELD_ATTRIB_SMB_BLOCK_CALL = 0x0D
 
 } AML_ACCESS_ATTRIBUTE;
 

drivers/acpi/namespace/nsdump.c

 /******************************************************************************
  *
  * Module Name: nsdump - table dumping routines for debug
- *              $Revision: 145 $
+ *              $Revision: 146 $
  *
  *****************************************************************************/
 
@@ -180,7 +180,7 @@ acpi_ns_dump_one_object (
 
 	/* Indent the object according to the level */
 
-	acpi_os_printf ("%2d%*s", level - 1, level * 2, " ");
+	acpi_os_printf ("%2d%*s", (u32) level - 1, (int) level * 2, " ");
 
 	/* Check the node type and name */
 

drivers/acpi/namespace/nsutils.c

@@ -2,7 +2,7 @@
  *
  * Module Name: nsutils - Utilities for accessing ACPI namespace, accessing
  *                        parents and siblings and Scope manipulation
- *              $Revision: 115 $
+ *              $Revision: 116 $
  *
  *****************************************************************************/
 
@@ -45,7 +45,7 @@
  *
  * RETURN:      None
  *
- * DESCRIPTION: Print warning message
+ * DESCRIPTION: Print warning message with full pathname
  *
  ******************************************************************************/
 
@@ -61,12 +61,16 @@ acpi_ns_report_error (
 	char                    *name;
 
 
+	/* Convert path to external format */
+
 	status = acpi_ns_externalize_name (ACPI_UINT32_MAX, internal_name, NULL, &name);
 
 	acpi_os_printf ("%8s-%04d: *** Error: Looking up ",
 		module_name, line_number);
 
-	if (name) {
+	/* Print target name */
+
+	if (ACPI_SUCCESS (status)) {
 		acpi_os_printf ("[%s]", name);
 	}
 	else {

drivers/acpi/tables/tbxfroot.c

 /******************************************************************************
  *
  * Module Name: tbxfroot - Find the root ACPI table (RSDT)
- *              $Revision: 64 $
+ *              $Revision: 65 $
  *
  *****************************************************************************/
 
@@ -302,7 +302,8 @@ acpi_find_root_pointer (
 
 	status = acpi_tb_find_rsdp (&table_info, flags);
 	if (ACPI_FAILURE (status)) {
-		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "RSDP structure not found\n"));
+		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "RSDP structure not found, %s Flags=%X\n",
+			acpi_format_exception (status), flags));
 		return_ACPI_STATUS (AE_NO_ACPI_TABLES);
 	}
 
@@ -406,6 +407,8 @@ acpi_tb_find_rsdp (
 		status = acpi_os_map_memory ((u64) LO_RSDP_WINDOW_BASE, LO_RSDP_WINDOW_SIZE,
 				  (void **) &table_ptr);
 		if (ACPI_FAILURE (status)) {
+			ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not map memory at %X for length %X\n",
+				LO_RSDP_WINDOW_BASE, LO_RSDP_WINDOW_SIZE));
 			return_ACPI_STATUS (status);
 		}
 
@@ -428,6 +431,8 @@ acpi_tb_find_rsdp (
 		status = acpi_os_map_memory ((u64) HI_RSDP_WINDOW_BASE, HI_RSDP_WINDOW_SIZE,
 				  (void **) &table_ptr);
 		if (ACPI_FAILURE (status)) {
+			ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not map memory at %X for length %X\n",
+				HI_RSDP_WINDOW_BASE, HI_RSDP_WINDOW_SIZE));
 			return_ACPI_STATUS (status);
 		}