ACPICA: Add acpi_os_physical_table_override interface

This interface allows the host to override a table via a
physical address, instead of the logical address required by
acpi_os_table_override. This simplifies the host implementation.
Initial implementation by Thomas Renninger. ACPICA implementation
creates a single function for table overrides that attempts both
a logical and a physical override.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

3 files changed, 152 insertions, 63 deletions

diff --git a/drivers/acpi/acpica/actables.h b/drivers/acpi/acpica/actables.h
index d5bec304c823..6712965ba8ae 100644
--- a/drivers/acpi/acpica/actables.h
+++ b/drivers/acpi/acpica/actables.h
@@ -67,6 +67,11 @@ acpi_status acpi_tb_resize_root_table_list(void);
 
 acpi_status acpi_tb_verify_table(struct acpi_table_desc *table_desc);
 
+struct acpi_table_header *acpi_tb_table_override(struct acpi_table_header
+                                                 *table_header,
+                                                 struct acpi_table_desc
+                                                 *table_desc);
+
 acpi_status
 acpi_tb_add_table(struct acpi_table_desc *table_desc, u32 *table_index);
 
diff --git a/drivers/acpi/acpica/tbinstal.c b/drivers/acpi/acpica/tbinstal.c
index 1aecf7baa4e0..c03500b4cc7a 100644
--- a/drivers/acpi/acpica/tbinstal.c
+++ b/drivers/acpi/acpica/tbinstal.c
@@ -114,7 +114,6 @@ acpi_tb_add_table(struct acpi_table_desc *table_desc, u32 *table_index)
 {
         u32 i;
         acpi_status status = AE_OK;
-        struct acpi_table_header *override_table = NULL;
 
         ACPI_FUNCTION_TRACE(tb_add_table);
 
@@ -224,25 +223,10 @@ acpi_tb_add_table(struct acpi_table_desc *table_desc, u32 *table_index)
         /*
          * ACPI Table Override:
          * Allow the host to override dynamically loaded tables.
+         * NOTE: the table is fully mapped at this point, and the mapping will
+         * be deleted by tb_table_override if the table is actually overridden.
          */
-        status = acpi_os_table_override(table_desc->pointer, &override_table);
-        if (ACPI_SUCCESS(status) && override_table) {
-                ACPI_INFO((AE_INFO,
-                           "%4.4s @ 0x%p Table override, replaced with:",
-                           table_desc->pointer->signature,
-                           ACPI_CAST_PTR(void, table_desc->address)));
-
-                /* We can delete the table that was passed as a parameter */
-
-                acpi_tb_delete_table(table_desc);
-
-                /* Setup descriptor for the new table */
-
-                table_desc->address = ACPI_PTR_TO_PHYSADDR(override_table);
-                table_desc->pointer = override_table;
-                table_desc->length = override_table->length;
-                table_desc->flags = ACPI_TABLE_ORIGIN_OVERRIDE;
-        }
+        (void)acpi_tb_table_override(table_desc->pointer, table_desc);
 
         /* Add the table to the global root table list */
 
@@ -263,6 +247,95 @@ acpi_tb_add_table(struct acpi_table_desc *table_desc, u32 *table_index)
 
 /*******************************************************************************
  *
+ * FUNCTION:    acpi_tb_table_override
+ *
+ * PARAMETERS:  table_header        - Header for the original table
+ *              table_desc          - Table descriptor initialized for the
+ *                                    original table. May or may not be mapped.
+ *
+ * RETURN:      Pointer to the entire new table. NULL if table not overridden.
+ *              If overridden, installs the new table within the input table
+ *              descriptor.
+ *
+ * DESCRIPTION: Attempt table override by calling the OSL override functions.
+ *              Note: If the table is overridden, then the entire new table
+ *              is mapped and returned by this function.
+ *
+ ******************************************************************************/
+
+struct acpi_table_header *acpi_tb_table_override(struct acpi_table_header
+                                                 *table_header,
+                                                 struct acpi_table_desc
+                                                 *table_desc)
+{
+        acpi_status status;
+        struct acpi_table_header *new_table = NULL;
+        acpi_physical_address new_address = 0;
+        u32 new_table_length = 0;
+        u8 new_flags;
+        char *override_type;
+
+        /* (1) Attempt logical override (returns a logical address) */
+
+        status = acpi_os_table_override(table_header, &new_table);
+        if (ACPI_SUCCESS(status) && new_table) {
+                new_address = ACPI_PTR_TO_PHYSADDR(new_table);
+                new_table_length = new_table->length;
+                new_flags = ACPI_TABLE_ORIGIN_OVERRIDE;
+                override_type = "Logical";
+                goto finish_override;
+        }
+
+        /* (2) Attempt physical override (returns a physical address) */
+
+        status = acpi_os_physical_table_override(table_header,
+                                                 &new_address,
+                                                 &new_table_length);
+        if (ACPI_SUCCESS(status) && new_address && new_table_length) {
+
+                /* Map the entire new table */
+
+                new_table = acpi_os_map_memory(new_address, new_table_length);
+                if (!new_table) {
+                        ACPI_EXCEPTION((AE_INFO, AE_NO_MEMORY,
+                                        "%4.4s %p Attempted physical table override failed",
+                                        table_header->signature,
+                                        ACPI_CAST_PTR(void,
+                                                      table_desc->address)));
+                        return (NULL);
+                }
+
+                override_type = "Physical";
+                new_flags = ACPI_TABLE_ORIGIN_MAPPED;
+                goto finish_override;
+        }
+
+        return (NULL);          /* There was no override */
+
+      finish_override:
+
+        ACPI_INFO((AE_INFO,
+                   "%4.4s %p %s table override, new table: %p",
+                   table_header->signature,
+                   ACPI_CAST_PTR(void, table_desc->address),
+                   override_type, new_table));
+
+        /* We can now unmap/delete the original table (if fully mapped) */
+
+        acpi_tb_delete_table(table_desc);
+
+        /* Setup descriptor for the new table */
+
+        table_desc->address = new_address;
+        table_desc->pointer = new_table;
+        table_desc->length = new_table_length;
+        table_desc->flags = new_flags;
+
+        return (new_table);
+}
+
+/*******************************************************************************
+ *
  * FUNCTION:    acpi_tb_resize_root_table_list
  *
  * PARAMETERS:  None
@@ -396,7 +469,11 @@ void acpi_tb_delete_table(struct acpi_table_desc *table_desc)
         case ACPI_TABLE_ORIGIN_ALLOCATED:
                 ACPI_FREE(table_desc->pointer);
                 break;
-        default:;
+
+                /* Not mapped or allocated, there is nothing we can do */
+
+        default:
+                return;
         }
 
         table_desc->pointer = NULL;
diff --git a/drivers/acpi/acpica/tbutils.c b/drivers/acpi/acpica/tbutils.c
index 1347c084fc2b..0a706cac37de 100644
--- a/drivers/acpi/acpica/tbutils.c
+++ b/drivers/acpi/acpica/tbutils.c
@@ -446,7 +446,7 @@ struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index)
  * RETURN:      None
  *
  * DESCRIPTION: Install an ACPI table into the global data structure. The
- *              table override mechanism is implemented here to allow the host
+ *              table override mechanism is called to allow the host
  *              OS to replace any table before it is installed in the root
  *              table array.
  *
@@ -456,11 +456,9 @@ void
 acpi_tb_install_table(acpi_physical_address address,
                       char *signature, u32 table_index)
 {
-        u8 flags;
-        acpi_status status;
-        struct acpi_table_header *table_to_install;
-        struct acpi_table_header *mapped_table;
-        struct acpi_table_header *override_table = NULL;
+        struct acpi_table_header *table;
+        struct acpi_table_header *final_table;
+        struct acpi_table_desc *table_desc;
 
         if (!address) {
                 ACPI_ERROR((AE_INFO,
@@ -471,69 +469,78 @@ acpi_tb_install_table(acpi_physical_address address,
 
         /* Map just the table header */
 
-        mapped_table =
-            acpi_os_map_memory(address, sizeof(struct acpi_table_header));
-        if (!mapped_table) {
+        table = acpi_os_map_memory(address, sizeof(struct acpi_table_header));
+        if (!table) {
+                ACPI_ERROR((AE_INFO,
+                            "Could not map memory for table [%s] at %p",
+                            signature, ACPI_CAST_PTR(void, address)));
                 return;
         }
 
         /* If a particular signature is expected (DSDT/FACS), it must match */
 
-        if (signature && !ACPI_COMPARE_NAME(mapped_table->signature, signature)) {
+        if (signature && !ACPI_COMPARE_NAME(table->signature, signature)) {
                 ACPI_ERROR((AE_INFO,
                             "Invalid signature 0x%X for ACPI table, expected [%s]",
-                            *ACPI_CAST_PTR(u32, mapped_table->signature),
-                            signature));
+                            *ACPI_CAST_PTR(u32, table->signature), signature));
                 goto unmap_and_exit;
         }
 
         /*
+         * Initialize the table entry. Set the pointer to NULL, since the
+         * table is not fully mapped at this time.
+         */
+        table_desc = &acpi_gbl_root_table_list.tables[table_index];
+
+        table_desc->address = address;
+        table_desc->pointer = NULL;
+        table_desc->length = table->length;
+        table_desc->flags = ACPI_TABLE_ORIGIN_MAPPED;
+        ACPI_MOVE_32_TO_32(table_desc->signature.ascii, table->signature);
+
+        /*
          * ACPI Table Override:
          *
          * Before we install the table, let the host OS override it with a new
          * one if desired. Any table within the RSDT/XSDT can be replaced,
          * including the DSDT which is pointed to by the FADT.
+         *
+         * NOTE: If the table is overridden, then final_table will contain a
+         * mapped pointer to the full new table. If the table is not overridden,
+         * or if there has been a physical override, then the table will be
+         * fully mapped later (in verify table). In any case, we must
+         * unmap the header that was mapped above.
          */
-        status = acpi_os_table_override(mapped_table, &override_table);
-        if (ACPI_SUCCESS(status) && override_table) {
-                ACPI_INFO((AE_INFO,
-                           "%4.4s @ 0x%p Table override, replaced with:",
-                           mapped_table->signature, ACPI_CAST_PTR(void,
-                                                                  address)));
-
-                acpi_gbl_root_table_list.tables[table_index].pointer =
-                    override_table;
-                address = ACPI_PTR_TO_PHYSADDR(override_table);
-
-                table_to_install = override_table;
-                flags = ACPI_TABLE_ORIGIN_OVERRIDE;
-        } else {
-                table_to_install = mapped_table;
-                flags = ACPI_TABLE_ORIGIN_MAPPED;
+        final_table = acpi_tb_table_override(table, table_desc);
+        if (!final_table) {
+                final_table = table;    /* There was no override */
         }
 
-        /* Initialize the table entry */
+        acpi_tb_print_table_header(table_desc->address, final_table);
 
-        acpi_gbl_root_table_list.tables[table_index].address = address;
-        acpi_gbl_root_table_list.tables[table_index].length =
-            table_to_install->length;
-        acpi_gbl_root_table_list.tables[table_index].flags = flags;
-
-        ACPI_MOVE_32_TO_32(&
-                           (acpi_gbl_root_table_list.tables[table_index].
-                            signature), table_to_install->signature);
-
-        acpi_tb_print_table_header(address, table_to_install);
+        /* Set the global integer width (based upon revision of the DSDT) */
 
         if (table_index == ACPI_TABLE_INDEX_DSDT) {
+                acpi_ut_set_integer_width(final_table->revision);
+        }
 
-                /* Global integer width is based upon revision of the DSDT */
-
-                acpi_ut_set_integer_width(table_to_install->revision);
+        /*
+         * If we have a physical override during this early loading of the ACPI
+         * tables, unmap the table for now. It will be mapped again later when
+         * it is actually used. This supports very early loading of ACPI tables,
+         * before virtual memory is fully initialized and running within the
+         * host OS. Note: A logical override has the ACPI_TABLE_ORIGIN_OVERRIDE
+         * flag set and will not be deleted below.
+         */
+        if (final_table != table) {
+                acpi_tb_delete_table(table_desc);
         }
 
       unmap_and_exit:
-        acpi_os_unmap_memory(mapped_table, sizeof(struct acpi_table_header));
+
+        /* Always unmap the table header that we mapped above */
+
+        acpi_os_unmap_memory(table, sizeof(struct acpi_table_header));
 }
 
 /*******************************************************************************