ACPICA 20050708 from Bob Moore <robert.moore@intel.com>

The use of the CPU stack in the debug version of the
subsystem has been considerably reduced.  Previously, a
debug structure was declared in every function that used
the debug macros.  This structure has been removed in
favor of declaring the individual elements as parameters
to the debug functions.  This reduces the cumulative stack
use during nested execution of ACPI function calls at the
cost of a small increase in the code size of the debug
version of the subsystem.  With assistance from Alexey
Starikovskiy and Len Brown.

Added the ACPI_GET_FUNCTION_NAME macro to enable the
compiler-dependent headers to define a macro that will
return the current function name at runtime (such as
__FUNCTION__ or _func_, etc.) The function name is used
by the debug trace output.  If ACPI_GET_FUNCTION_NAME
is not defined in the compiler-dependent header, the
function name is saved on the CPU stack (one pointer per
function.) This mechanism is used because apparently there
exists no standard ANSI-C defined macro that that returns
the function name.

Alexey Starikovskiy redesigned and reimplemented the
"Owner ID" mechanism used to track namespace objects
created/deleted by ACPI tables and control method
execution.  A bitmap is now used to allocate and free the
IDs, thus solving the wraparound problem present in the
previous implementation.  The size of the namespace node
descriptor was reduced by 2 bytes as a result.

Removed the UINT32_BIT and UINT16_BIT types that were used
for the bitfield flag definitions within the headers for
the predefined ACPI tables.  These have been replaced by
UINT8_BIT in order to increase the code portability of
the subsystem.  If the use of UINT8 remains a problem,
we may be forced to eliminate bitfields entirely because
of a lack of portability.

Alexey Starikovksiy enhanced the performance of
acpi_ut_update_object_reference.  This is a frequently used
function and this improvement increases the performance
of the entire subsystem.

Alexey Starikovskiy fixed several possible memory leaks
and the inverse - premature object deletion.

Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 62 insertions, 44 deletions

diff --git a/drivers/acpi/tables/tbxfroot.c b/drivers/acpi/tables/tbxfroot.c
index fe9c8317df4..abb4c934656 100644
--- a/drivers/acpi/tables/tbxfroot.c
+++ b/drivers/acpi/tables/tbxfroot.c
@@ -65,6 +65,51 @@ acpi_tb_scan_memory_for_rsdp (
 
 /*******************************************************************************
  *
+ * FUNCTION:    acpi_tb_validate_rsdp
+ *
+ * PARAMETERS:  Rsdp        - Pointer to unvalidated RSDP
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Validate the RSDP (ptr)
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_tb_validate_rsdp (
+	struct rsdp_descriptor          *rsdp)
+{
+	ACPI_FUNCTION_ENTRY ();
+
+
+	/*
+	 *  The signature and checksum must both be correct
+	 */
+	if (ACPI_STRNCMP ((char *) rsdp, RSDP_SIG, sizeof (RSDP_SIG)-1) != 0) {
+		/* Nope, BAD Signature */
+
+		return (AE_BAD_SIGNATURE);
+	}
+
+	/* Check the standard checksum */
+
+	if (acpi_tb_checksum (rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) {
+		return (AE_BAD_CHECKSUM);
+	}
+
+	/* Check extended checksum if table version >= 2 */
+
+	if ((rsdp->revision >= 2) &&
+		(acpi_tb_checksum (rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0)) {
+		return (AE_BAD_CHECKSUM);
+	}
+
+	return (AE_OK);
+}
+
+
+/*******************************************************************************
+ *
  * FUNCTION:    acpi_tb_find_table
  *
  * PARAMETERS:  Signature           - String with ACPI table signature
@@ -218,19 +263,11 @@ acpi_get_firmware_table (
 			acpi_gbl_RSDP = address.pointer.logical;
 		}
 
-		/* The signature and checksum must both be correct */
-
-		if (ACPI_STRNCMP ((char *) acpi_gbl_RSDP, RSDP_SIG,
-				sizeof (RSDP_SIG)-1) != 0) {
-			/* Nope, BAD Signature */
+		/* The RDSP signature and checksum must both be correct */
 
-			return_ACPI_STATUS (AE_BAD_SIGNATURE);
-		}
-
-		if (acpi_tb_checksum (acpi_gbl_RSDP, ACPI_RSDP_CHECKSUM_LENGTH) != 0) {
-			/* Nope, BAD Checksum */
-
-			return_ACPI_STATUS (AE_BAD_CHECKSUM);
+		status = acpi_tb_validate_rsdp (acpi_gbl_RSDP);
+		if (ACPI_FAILURE (status)) {
+			return_ACPI_STATUS (status);
 		}
 	}
 
@@ -414,9 +451,9 @@ acpi_tb_scan_memory_for_rsdp (
 	u8                              *start_address,
 	u32                             length)
 {
+	acpi_status                     status;
 	u8                              *mem_rover;
 	u8                              *end_address;
-	u8                              checksum;
 
 
 	ACPI_FUNCTION_TRACE ("tb_scan_memory_for_rsdp");
@@ -428,45 +465,25 @@ acpi_tb_scan_memory_for_rsdp (
 
 	for (mem_rover = start_address; mem_rover < end_address;
 		 mem_rover += ACPI_RSDP_SCAN_STEP) {
-		/* The signature and checksum must both be correct */
+		/* The RSDP signature and checksum must both be correct */
 
-		if (ACPI_STRNCMP ((char *) mem_rover,
-				RSDP_SIG, sizeof (RSDP_SIG) - 1) != 0) {
-			/* No signature match, keep looking */
-
-			continue;
-		}
-
-		/* Signature matches, check the appropriate checksum */
-
-		if ((ACPI_CAST_PTR (struct rsdp_descriptor, mem_rover))->revision < 2) {
-			/* ACPI version 1.0 */
-
-			checksum = acpi_tb_checksum (mem_rover, ACPI_RSDP_CHECKSUM_LENGTH);
-		}
-		else {
-			/* Post ACPI 1.0, use extended_checksum */
-
-			checksum = acpi_tb_checksum (mem_rover, ACPI_RSDP_XCHECKSUM_LENGTH);
-		}
-
-		if (checksum == 0) {
-			/* Checksum valid, we have found a valid RSDP */
+		status = acpi_tb_validate_rsdp (ACPI_CAST_PTR (struct rsdp_descriptor, mem_rover));
+		if (ACPI_SUCCESS (status)) {
+			/* Sig and checksum valid, we have found a real RSDP */
 
 			ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
 				"RSDP located at physical address %p\n", mem_rover));
 			return_PTR (mem_rover);
 		}
 
-		ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
-			"Found an RSDP at physical address %p, but it has a bad checksum\n",
-			mem_rover));
+		/* No sig match or bad checksum, keep searching */
 	}
 
 	/* Searched entire block, no RSDP was found */
 
 	ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
-		"Searched entire block, no valid RSDP was found.\n"));
+		"Searched entire block from %p, valid RSDP was not found\n",
+		start_address));
 	return_PTR (NULL);
 }
 
@@ -554,7 +571,7 @@ acpi_tb_find_rsdp (
 			acpi_os_unmap_memory (table_ptr, ACPI_EBDA_WINDOW_SIZE);
 
 			if (mem_rover) {
-				/* Found it, return the physical address */
+				/* Return the physical address */
 
 				physical_address += ACPI_PTR_DIFF (mem_rover, table_ptr);
 
@@ -583,7 +600,7 @@ acpi_tb_find_rsdp (
 		acpi_os_unmap_memory (table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
 
 		if (mem_rover) {
-			/* Found it, return the physical address */
+			/* Return the physical address */
 
 			physical_address =
 				ACPI_HI_RSDP_WINDOW_BASE + ACPI_PTR_DIFF (mem_rover, table_ptr);
@@ -614,7 +631,7 @@ acpi_tb_find_rsdp (
 					  ACPI_PHYSADDR_TO_PTR (physical_address),
 					  ACPI_EBDA_WINDOW_SIZE);
 			if (mem_rover) {
-				/* Found it, return the physical address */
+				/* Return the physical address */
 
 				table_info->physical_address = ACPI_TO_INTEGER (mem_rover);
 				return_ACPI_STATUS (AE_OK);
@@ -634,8 +651,9 @@ acpi_tb_find_rsdp (
 		}
 	}
 
-	/* RSDP signature was not found */
+	/* A valid RSDP was not found */
 
+	ACPI_REPORT_ERROR (("No valid RSDP was found\n"));
 	return_ACPI_STATUS (AE_NOT_FOUND);
 }