2 files changed, 75 insertions, 18 deletions

diff --git a/drivers/acpi/tables/tbfadt.c b/drivers/acpi/tables/tbfadt.c
index a4a41ba2484b..2c7885e7ffba 100644
--- a/drivers/acpi/tables/tbfadt.c
+++ b/drivers/acpi/tables/tbfadt.c
@@ -50,7 +50,7 @@ ACPI_MODULE_NAME("tbfadt")
 /* Local prototypes */
 static void inline
 acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
-                             u8 bit_width, u64 address);
+                             u8 byte_width, u64 address);
 
 static void acpi_tb_convert_fadt(void);
 
@@ -111,7 +111,7 @@ static struct acpi_fadt_info fadt_info_table[] = {
  * FUNCTION:    acpi_tb_init_generic_address
  *
  * PARAMETERS:  generic_address     - GAS struct to be initialized
- *              bit_width           - Width of this register
+ *              byte_width          - Width of this register
  *              Address             - Address of the register
  *
  * RETURN:      None
@@ -124,7 +124,7 @@ static struct acpi_fadt_info fadt_info_table[] = {
 
 static void inline
 acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
-                             u8 bit_width, u64 address)
+                             u8 byte_width, u64 address)
 {
 
         /*
@@ -136,7 +136,7 @@ acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
         /* All other fields are byte-wide */
 
         generic_address->space_id = ACPI_ADR_SPACE_SYSTEM_IO;
-        generic_address->bit_width = bit_width;
+        generic_address->bit_width = byte_width << 3;
         generic_address->bit_offset = 0;
         generic_address->access_width = 0;
 }
@@ -342,9 +342,20 @@ static void acpi_tb_convert_fadt(void)
          * useful to calculate them once, here.
          *
          * The PM event blocks are split into two register blocks, first is the
-         * PM Status Register block, followed immediately by the PM Enable Register
-         * block. Each is of length (pm1_event_length/2)
+         * PM Status Register block, followed immediately by the PM Enable
+         * Register block. Each is of length (xpm1x_event_block.bit_width/2).
+         *
+         * On various systems the v2 fields (and particularly the bit widths)
+         * cannot be relied upon, though. Hence resort to using the v1 length
+         * here (and warn about the inconsistency).
          */
+        if (acpi_gbl_FADT.xpm1a_event_block.bit_width
+            != acpi_gbl_FADT.pm1_event_length * 8)
+                printk(KERN_WARNING "FADT: "
+                       "X_PM1a_EVT_BLK.bit_width (%u) does not match"
+                       " PM1_EVT_LEN (%u)\n",
+                       acpi_gbl_FADT.xpm1a_event_block.bit_width,
+                       acpi_gbl_FADT.pm1_event_length);
         pm1_register_length = (u8) ACPI_DIV_2(acpi_gbl_FADT.pm1_event_length);
 
         /* The PM1A register block is required */
@@ -360,13 +371,20 @@ static void acpi_tb_convert_fadt(void)
         /* The PM1B register block is optional, ignore if not present */
 
         if (acpi_gbl_FADT.xpm1b_event_block.address) {
+                if (acpi_gbl_FADT.xpm1b_event_block.bit_width
+                    != acpi_gbl_FADT.pm1_event_length * 8)
+                        printk(KERN_WARNING "FADT: "
+                               "X_PM1b_EVT_BLK.bit_width (%u) does not match"
+                               " PM1_EVT_LEN (%u)\n",
+                               acpi_gbl_FADT.xpm1b_event_block.bit_width,
+                               acpi_gbl_FADT.pm1_event_length);
                 acpi_tb_init_generic_address(&acpi_gbl_xpm1b_enable,
                                              pm1_register_length,
                                              (acpi_gbl_FADT.xpm1b_event_block.
                                               address + pm1_register_length));
                 /* Don't forget to copy space_id of the GAS */
                 acpi_gbl_xpm1b_enable.space_id =
-                    acpi_gbl_FADT.xpm1a_event_block.space_id;
+                    acpi_gbl_FADT.xpm1b_event_block.space_id;
 
         }
 }
diff --git a/drivers/acpi/tables/tbinstal.c b/drivers/acpi/tables/tbinstal.c
index b22185f55a16..18747ce8dd2f 100644
--- a/drivers/acpi/tables/tbinstal.c
+++ b/drivers/acpi/tables/tbinstal.c
@@ -110,7 +110,6 @@ acpi_status
 acpi_tb_add_table(struct acpi_table_desc *table_desc, u32 *table_index)
 {
         u32 i;
-        u32 length;
         acpi_status status = AE_OK;
 
         ACPI_FUNCTION_TRACE(tb_add_table);
@@ -145,25 +144,64 @@ acpi_tb_add_table(struct acpi_table_desc *table_desc, u32 *table_index)
                         }
                 }
 
-                length = ACPI_MIN(table_desc->length,
-                                  acpi_gbl_root_table_list.tables[i].length);
+                /*
+                 * Check for a table match on the entire table length,
+                 * not just the header.
+                 */
+                if (table_desc->length !=
+                    acpi_gbl_root_table_list.tables[i].length) {
+                        continue;
+                }
+
                 if (ACPI_MEMCMP(table_desc->pointer,
                                 acpi_gbl_root_table_list.tables[i].pointer,
-                                length)) {
+                                acpi_gbl_root_table_list.tables[i].length)) {
                         continue;
                 }
 
-                /* Table is already registered */
-
+                /*
+                 * Note: the current mechanism does not unregister a table if it is
+                 * dynamically unloaded. The related namespace entries are deleted,
+                 * but the table remains in the root table list.
+                 *
+                 * The assumption here is that the number of different tables that
+                 * will be loaded is actually small, and there is minimal overhead
+                 * in just keeping the table in case it is needed again.
+                 *
+                 * If this assumption changes in the future (perhaps on large
+                 * machines with many table load/unload operations), tables will
+                 * need to be unregistered when they are unloaded, and slots in the
+                 * root table list should be reused when empty.
+                 */
+
+                /*
+                 * Table is already registered.
+                 * We can delete the table that was passed as a parameter.
+                 */
                 acpi_tb_delete_table(table_desc);
                 *table_index = i;
-                status = AE_ALREADY_EXISTS;
-                goto release;
+
+                if (acpi_gbl_root_table_list.tables[i].
+                    flags & ACPI_TABLE_IS_LOADED) {
+
+                        /* Table is still loaded, this is an error */
+
+                        status = AE_ALREADY_EXISTS;
+                        goto release;
+                } else {
+                        /* Table was unloaded, allow it to be reloaded */
+
+                        table_desc->pointer =
+                            acpi_gbl_root_table_list.tables[i].pointer;
+                        table_desc->address =
+                            acpi_gbl_root_table_list.tables[i].address;
+                        status = AE_OK;
+                        goto print_header;
+                }
         }
 
-        /*
-         * Add the table to the global table list
-         */
+        /* Add the table to the global root table list */
+
         status = acpi_tb_store_table(table_desc->address, table_desc->pointer,
                                      table_desc->length, table_desc->flags,
                                      table_index);
@@ -171,6 +209,7 @@ acpi_tb_add_table(struct acpi_table_desc *table_desc, u32 *table_index)
                 goto release;
         }
 
+      print_header:
         acpi_tb_print_table_header(table_desc->address, table_desc->pointer);
 
       release: