[PATCH 43/52] ACPICA: Add new ACPI table load/unload external interfaces

Len Brown
2012-07-25T03:43:36Z

From: Bob Moore <robert.moore@intel.com>

Add acpi_load_table and acpi_unload_parent_table to support
host-directed dynamic table load/unload. Intended to support
hotplug addition and removal of SSDTs.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
---
drivers/acpi/acpica/tbxface.c | 42 ----------
drivers/acpi/acpica/tbxfload.c | 178 +++++++++++++++++++++++++++++++++++++++++
include/acpi/acpixf.h | 13 ++-
3 files changed, 187 insertions(+), 46 deletions(-)

diff --git a/drivers/acpi/acpica/tbxface.c b/drivers/acpi/acpica/tbxface.c
index 472a91c..9bf34f7 100644
--- a/drivers/acpi/acpica/tbxface.c
+++ b/drivers/acpi/acpica/tbxface.c
@@ -215,48 +215,6 @@ acpi_status acpi_reallocate_root_table(void)

/*******************************************************************************
*
- * FUNCTION: acpi_load_table
- *
- * PARAMETERS: table_ptr - pointer to a buffer containing the entire
- * table to be loaded
- *
- * RETURN: Status
- *
- * DESCRIPTION: This function is called to load a table from the caller's
- * buffer. The buffer must contain an entire ACPI Table including
- * a valid header. The header fields will be verified, and if it
- * is determined that the table is invalid, the call will fail.
- *
- ******************************************************************************/
-acpi_status acpi_load_table(struct acpi_table_header *table_ptr)
-{
- acpi_status status;
- u32 table_index;
- struct acpi_table_desc table_desc;
-
- if (!table_ptr)
- return AE_BAD_PARAMETER;
-
- ACPI_MEMSET(&table_desc, 0, sizeof(struct acpi_table_desc));
- table_desc.pointer = table_ptr;
- table_desc.length = table_ptr->length;
- table_desc.flags = ACPI_TABLE_ORIGIN_UNKNOWN;
-
- /*
- * Install the new table into the local data structures
- */
- status = acpi_tb_add_table(&table_desc, &table_index);
- if (ACPI_FAILURE(status)) {
- return status;
- }
- status = acpi_ns_load_table(table_index, acpi_gbl_root_node);
- return status;
-}
-
-ACPI_EXPORT_SYMBOL(acpi_load_table)
-
-/*******************************************************************************
- *
* FUNCTION: acpi_get_table_header
*
* PARAMETERS: Signature - ACPI signature of needed table
diff --git a/drivers/acpi/acpica/tbxfload.c b/drivers/acpi/acpica/tbxfload.c
index 54a01ae..f87cc63 100644
--- a/drivers/acpi/acpica/tbxfload.c
+++ b/drivers/acpi/acpica/tbxfload.c
@@ -199,6 +199,184 @@ static acpi_status acpi_tb_load_namespace(void)
return_ACPI_STATUS(status);
}

+/*******************************************************************************
+ *
+ * FUNCTION: acpi_load_table
+ *
+ * PARAMETERS: table - Pointer to a buffer containing the ACPI
+ * table to be loaded.
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Dynamically load an ACPI table from the caller's buffer. Must
+ * be a valid ACPI table with a valid ACPI table header.
+ * Note1: Mainly intended to support hotplug addition of SSDTs.
+ * Note2: Does not copy the incoming table. User is reponsible
+ * to ensure that the table is not deleted or unmapped.
+ *
+ ******************************************************************************/
+
+acpi_status acpi_load_table(struct acpi_table_header *table)
+{
+ acpi_status status;
+ struct acpi_table_desc table_desc;
+ u32 table_index;
+
+ ACPI_FUNCTION_TRACE(acpi_load_table);
+
+ /* Parameter validation */
+
+ if (!table) {
+ return_ACPI_STATUS(AE_BAD_PARAMETER);
+ }
+
+ /* Init local table descriptor */
+
+ ACPI_MEMSET(&table_desc, 0, sizeof(struct acpi_table_desc));
+ table_desc.address = ACPI_PTR_TO_PHYSADDR(table);
+ table_desc.pointer = table;
+ table_desc.length = table->length;
+ table_desc.flags = ACPI_TABLE_ORIGIN_UNKNOWN;
+
+ /* Must acquire the interpreter lock during this operation */
+
+ status = acpi_ut_acquire_mutex(ACPI_MTX_INTERPRETER);
+ if (ACPI_FAILURE(status)) {
+ return_ACPI_STATUS(status);
+ }
+
+ /* Install the table and load it into the namespace */
+
+ ACPI_INFO((AE_INFO, "Host-directed Dynamic ACPI Table Load:"));
+ status = acpi_tb_add_table(&table_desc, &table_index);
+ if (ACPI_FAILURE(status)) {
+ goto unlock_and_exit;
+ }
+
+ status = acpi_ns_load_table(table_index, acpi_gbl_root_node);
+
+ /* Invoke table handler if present */
+
+ if (acpi_gbl_table_handler) {
+ (void)acpi_gbl_table_handler(ACPI_TABLE_EVENT_LOAD, table,
+ acpi_gbl_table_handler_context);
+ }
+
+ unlock_and_exit:
+ (void)acpi_ut_release_mutex(ACPI_MTX_INTERPRETER);
+ return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_load_table)
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_unload_parent_table
+ *
+ * PARAMETERS: object - Handle to any namespace object owned by
+ * the table to be unloaded
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Via any namespace object within an SSDT or OEMx table, unloads
+ * the table and deletes all namespace objects associated with
+ * that table. Unloading of the DSDT is not allowed.
+ * Note: Mainly intended to support hotplug removal of SSDTs.
+ *
+ ******************************************************************************/
+acpi_status acpi_unload_parent_table(acpi_handle object)
+{
+ struct acpi_namespace_node *node =
+ ACPI_CAST_PTR(struct acpi_namespace_node, object);
+ acpi_status status = AE_NOT_EXIST;
+ acpi_owner_id owner_id;
+ u32 i;
+
+ ACPI_FUNCTION_TRACE(acpi_unload_parent_table);
+
+ /* Parameter validation */
+
+ if (!object) {
+ return_ACPI_STATUS(AE_BAD_PARAMETER);
+ }
+
+ /*
+ * The node owner_id is currently the same as the parent table ID.
+ * However, this could change in the future.
+ */
+ owner_id = node->owner_id;
+ if (!owner_id) {
+
+ /* owner_id==0 means DSDT is the owner. DSDT cannot be unloaded */
+
+ return_ACPI_STATUS(AE_TYPE);
+ }
+
+ /* Must acquire the interpreter lock during this operation */
+
+ status = acpi_ut_acquire_mutex(ACPI_MTX_INTERPRETER);
+ if (ACPI_FAILURE(status)) {
+ return_ACPI_STATUS(status);
+ }
+
+ /* Find the table in the global table list */
+
+ for (i = 0; i < acpi_gbl_root_table_list.current_table_count; i++) {
+ if (owner_id != acpi_gbl_root_table_list.tables[i].owner_id) {
+ continue;
+ }
+
+ /*
+ * Allow unload of SSDT and OEMx tables only. Do not allow unload
+ * of the DSDT. No other types of tables should get here, since
+ * only these types can contain AML and thus are the only types
+ * that can create namespace objects.
+ */
+ if (ACPI_COMPARE_NAME
+ (acpi_gbl_root_table_list.tables[i].signature.ascii,
+ ACPI_SIG_DSDT)) {
+ status = AE_TYPE;
+ break;
+ }
+
+ /* Ensure the table is actually loaded */
+
+ if (!acpi_tb_is_table_loaded(i)) {
+ status = AE_NOT_EXIST;
+ break;
+ }
+
+ /* Invoke table handler if present */
+
+ if (acpi_gbl_table_handler) {
+ (void)acpi_gbl_table_handler(ACPI_TABLE_EVENT_UNLOAD,
+ acpi_gbl_root_table_list.
+ tables[i].pointer,
+ acpi_gbl_table_handler_context);
+ }
+
+ /*
+ * Delete all namespace objects owned by this table. Note that
+ * these objects can appear anywhere in the namespace by virtue
+ * of the AML "Scope" operator. Thus, we need to track ownership
+ * by an ID, not simply a position within the hierarchy.
+ */
+ status = acpi_tb_delete_namespace_by_owner(i);
+ if (ACPI_FAILURE(status)) {
+ break;
+ }
+
+ status = acpi_tb_release_owner_id(i);
+ acpi_tb_set_table_loaded_flag(i, FALSE);
+ break;
+ }
+
+ (void)acpi_ut_release_mutex(ACPI_MTX_INTERPRETER);
+ return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_unload_parent_table)
+
static int __init acpi_no_auto_ssdt_setup(char *s) {

printk(KERN_NOTICE "ACPI: SSDT auto-load disabled\n");
diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
index 8f83f95..079bb90 100644
--- a/include/acpi/acpixf.h
+++ b/include/acpi/acpixf.h
@@ -154,15 +154,20 @@ void *acpi_callocate(u32 size);
void acpi_free(void *address);

/*
- * ACPI table manipulation interfaces
+ * ACPI table load/unload interfaces
*/
-acpi_status acpi_reallocate_root_table(void);
+acpi_status acpi_load_table(struct acpi_table_header *table);

-acpi_status acpi_find_root_pointer(acpi_size *rsdp_address);
+acpi_status acpi_unload_parent_table(acpi_handle object);

acpi_status acpi_load_tables(void);

-acpi_status acpi_load_table(struct acpi_table_header *table_ptr);
+/*
+ * ACPI table manipulation interfaces
+ */
+acpi_status acpi_reallocate_root_table(void);
+
+acpi_status acpi_find_root_pointer(acpi_size *rsdp_address);

acpi_status acpi_unload_table_id(acpi_owner_id id);

--
1.7.12.rc0