diff options
| author | Bob Moore <robert.moore@intel.com> | 2008-07-04 10:48:43 +0800 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2008-10-22 23:14:35 -0400 |
| commit | e56f561736e340a4e923b0db65f65dabf5d94823 (patch) | |
| tree | a8677ad9130168fb2cdeadfd5cb4b07398db8815 /drivers/acpi | |
| parent | 237a927682a63f02adb542dbdaafe8a81566451d (diff) | |
ACPICA: Allow same ACPI table to be loaded/unloaded more than once
Without this change, a table cannot be loaded again once it has
been loaded/unloaded one time. The current mechanism does not
unregister a table upon an unload. During a load, if the same
table is found, this no longer returns an exception.
http://www.acpica.org/bugzilla/show_bug.cgi?id=722
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/tables/tbinstal.c | 49 |
1 files changed, 42 insertions, 7 deletions
diff --git a/drivers/acpi/tables/tbinstal.c b/drivers/acpi/tables/tbinstal.c index b22185f55a1..905dc38ab23 100644 --- a/drivers/acpi/tables/tbinstal.c +++ b/drivers/acpi/tables/tbinstal.c @@ -145,6 +145,8 @@ acpi_tb_add_table(struct acpi_table_desc *table_desc, u32 *table_index) } } + /* Check for a table match on the entire table length */ + length = ACPI_MIN(table_desc->length, acpi_gbl_root_table_list.tables[i].length); if (ACPI_MEMCMP(table_desc->pointer, @@ -153,17 +155,49 @@ acpi_tb_add_table(struct acpi_table_desc *table_desc, u32 *table_index) 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 +205,7 @@ 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: |