1 files changed, 274 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/tbxfroot.c b/drivers/acpi/acpica/tbxfroot.c
new file mode 100644
index 000000000000..3495dca4e86b
--- /dev/null
+++ b/drivers/acpi/acpica/tbxfroot.c
@@ -0,0 +1,274 @@
+/******************************************************************************
+ *
+ * Module Name: tbxfroot - Find the root ACPI table (RSDT)
+ *
+ *****************************************************************************/
+
+/*
+ * Copyright (C) 2000 - 2008, Intel Corp.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification.
+ * 2. Redistributions in binary form must reproduce at minimum a disclaimer
+ *    substantially similar to the "NO WARRANTY" disclaimer below
+ *    ("Disclaimer") and any redistribution must be conditioned upon
+ *    including a substantially similar Disclaimer requirement for further
+ *    binary redistribution.
+ * 3. Neither the names of the above-listed copyright holders nor the names
+ *    of any contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * NO WARRANTY
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGES.
+ */
+
+#include <acpi/acpi.h>
+#include <acpi/accommon.h>
+#include <acpi/actables.h>
+
+#define _COMPONENT          ACPI_TABLES
+ACPI_MODULE_NAME("tbxfroot")
+
+/* Local prototypes */
+static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length);
+
+static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp);
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_tb_validate_rsdp
+ *
+ * PARAMETERS:  Rsdp                - Pointer to unvalidated RSDP
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Validate the RSDP (ptr)
+ *
+ ******************************************************************************/
+
+static acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp)
+{
+        ACPI_FUNCTION_ENTRY();
+
+        /*
+         * The signature and checksum must both be correct
+         *
+         * Note: Sometimes there exists more than one RSDP in memory; the valid
+         * RSDP has a valid checksum, all others have an invalid checksum.
+         */
+        if (ACPI_STRNCMP((char *)rsdp, ACPI_SIG_RSDP, sizeof(ACPI_SIG_RSDP) - 1)
+            != 0) {
+
+                /* Nope, BAD Signature */
+
+                return (AE_BAD_SIGNATURE);
+        }
+
+        /* Check the standard checksum */
+
+        if (acpi_tb_checksum((u8 *) rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0) {
+                return (AE_BAD_CHECKSUM);
+        }
+
+        /* Check extended checksum if table version >= 2 */
+
+        if ((rsdp->revision >= 2) &&
+            (acpi_tb_checksum((u8 *) rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0)) {
+                return (AE_BAD_CHECKSUM);
+        }
+
+        return (AE_OK);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_find_root_pointer
+ *
+ * PARAMETERS:  table_address           - Where the table pointer is returned
+ *
+ * RETURN:      Status, RSDP physical address
+ *
+ * DESCRIPTION: Search lower 1_mbyte of memory for the root system descriptor
+ *              pointer structure.  If it is found, set *RSDP to point to it.
+ *
+ * NOTE1:       The RSDP must be either in the first 1_k of the Extended
+ *              BIOS Data Area or between E0000 and FFFFF (From ACPI Spec.)
+ *              Only a 32-bit physical address is necessary.
+ *
+ * NOTE2:       This function is always available, regardless of the
+ *              initialization state of the rest of ACPI.
+ *
+ ******************************************************************************/
+
+acpi_status acpi_find_root_pointer(acpi_size *table_address)
+{
+        u8 *table_ptr;
+        u8 *mem_rover;
+        u32 physical_address;
+
+        ACPI_FUNCTION_TRACE(acpi_find_root_pointer);
+
+        /* 1a) Get the location of the Extended BIOS Data Area (EBDA) */
+
+        table_ptr = acpi_os_map_memory((acpi_physical_address)
+                                       ACPI_EBDA_PTR_LOCATION,
+                                       ACPI_EBDA_PTR_LENGTH);
+        if (!table_ptr) {
+                ACPI_ERROR((AE_INFO,
+                            "Could not map memory at %8.8X for length %X",
+                            ACPI_EBDA_PTR_LOCATION, ACPI_EBDA_PTR_LENGTH));
+
+                return_ACPI_STATUS(AE_NO_MEMORY);
+        }
+
+        ACPI_MOVE_16_TO_32(&physical_address, table_ptr);
+
+        /* Convert segment part to physical address */
+
+        physical_address <<= 4;
+        acpi_os_unmap_memory(table_ptr, ACPI_EBDA_PTR_LENGTH);
+
+        /* EBDA present? */
+
+        if (physical_address > 0x400) {
+                /*
+                 * 1b) Search EBDA paragraphs (EBDA is required to be a
+                 *     minimum of 1_k length)
+                 */
+                table_ptr = acpi_os_map_memory((acpi_physical_address)
+                                               physical_address,
+                                               ACPI_EBDA_WINDOW_SIZE);
+                if (!table_ptr) {
+                        ACPI_ERROR((AE_INFO,
+                                    "Could not map memory at %8.8X for length %X",
+                                    physical_address, ACPI_EBDA_WINDOW_SIZE));
+
+                        return_ACPI_STATUS(AE_NO_MEMORY);
+                }
+
+                mem_rover =
+                    acpi_tb_scan_memory_for_rsdp(table_ptr,
+                                                 ACPI_EBDA_WINDOW_SIZE);
+                acpi_os_unmap_memory(table_ptr, ACPI_EBDA_WINDOW_SIZE);
+
+                if (mem_rover) {
+
+                        /* Return the physical address */
+
+                        physical_address +=
+                            (u32) ACPI_PTR_DIFF(mem_rover, table_ptr);
+
+                        *table_address = physical_address;
+                        return_ACPI_STATUS(AE_OK);
+                }
+        }
+
+        /*
+         * 2) Search upper memory: 16-byte boundaries in E0000h-FFFFFh
+         */
+        table_ptr = acpi_os_map_memory((acpi_physical_address)
+                                       ACPI_HI_RSDP_WINDOW_BASE,
+                                       ACPI_HI_RSDP_WINDOW_SIZE);
+
+        if (!table_ptr) {
+                ACPI_ERROR((AE_INFO,
+                            "Could not map memory at %8.8X for length %X",
+                            ACPI_HI_RSDP_WINDOW_BASE,
+                            ACPI_HI_RSDP_WINDOW_SIZE));
+
+                return_ACPI_STATUS(AE_NO_MEMORY);
+        }
+
+        mem_rover =
+            acpi_tb_scan_memory_for_rsdp(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
+        acpi_os_unmap_memory(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
+
+        if (mem_rover) {
+
+                /* Return the physical address */
+
+                physical_address = (u32)
+                    (ACPI_HI_RSDP_WINDOW_BASE +
+                     ACPI_PTR_DIFF(mem_rover, table_ptr));
+
+                *table_address = physical_address;
+                return_ACPI_STATUS(AE_OK);
+        }
+
+        /* A valid RSDP was not found */
+
+        ACPI_ERROR((AE_INFO, "A valid RSDP was not found"));
+        return_ACPI_STATUS(AE_NOT_FOUND);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_tb_scan_memory_for_rsdp
+ *
+ * PARAMETERS:  start_address       - Starting pointer for search
+ *              Length              - Maximum length to search
+ *
+ * RETURN:      Pointer to the RSDP if found, otherwise NULL.
+ *
+ * DESCRIPTION: Search a block of memory for the RSDP signature
+ *
+ ******************************************************************************/
+static u8 *acpi_tb_scan_memory_for_rsdp(u8 * start_address, u32 length)
+{
+        acpi_status status;
+        u8 *mem_rover;
+        u8 *end_address;
+
+        ACPI_FUNCTION_TRACE(tb_scan_memory_for_rsdp);
+
+        end_address = start_address + length;
+
+        /* Search from given start address for the requested length */
+
+        for (mem_rover = start_address; mem_rover < end_address;
+             mem_rover += ACPI_RSDP_SCAN_STEP) {
+
+                /* The RSDP signature and checksum must both be correct */
+
+                status =
+                    acpi_tb_validate_rsdp(ACPI_CAST_PTR
+                                          (struct acpi_table_rsdp, 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);
+                }
+
+                /* No sig match or bad checksum, keep searching */
+        }
+
+        /* Searched entire block, no RSDP was found */
+
+        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                          "Searched entire block from %p, valid RSDP was not found\n",
+                          start_address));
+        return_PTR(NULL);
+}