[PATCH v3 13/26] ACPICA: Namespace: Add support to allow overriding objects.

Lv Zheng
2015-07-01T06:44:52Z

ACPICA commit 6084e34e44565c6293f446c0202b5e59b055e351

This patch adds an "NamespaceOverride" flag in struct acpi_walk_state, and allows
namespace objects to be overridden when this flag is set. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/6084e34e
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
---
drivers/acpi/acpica/acnamesp.h | 1 +
drivers/acpi/acpica/acstruct.h | 1 +
drivers/acpi/acpica/dswload.c | 17 +++++++++++++----
drivers/acpi/acpica/nsaccess.c | 10 +++++++++-
drivers/acpi/acpica/nssearch.c | 22 ++++++++++++++++++++--
5 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/acpica/acnamesp.h b/drivers/acpi/acpica/acnamesp.h
index 952fbe0..0dd0882 100644
--- a/drivers/acpi/acpica/acnamesp.h
+++ b/drivers/acpi/acpica/acnamesp.h
@@ -66,6 +66,7 @@
#define ACPI_NS_PREFIX_IS_SCOPE 0x10
#define ACPI_NS_EXTERNAL 0x20
#define ACPI_NS_TEMPORARY 0x40
+#define ACPI_NS_OVERRIDE_IF_FOUND 0x80

/* Flags for acpi_ns_walk_namespace */

diff --git a/drivers/acpi/acpica/acstruct.h b/drivers/acpi/acpica/acstruct.h
index 87c7860..44997ca 100644
--- a/drivers/acpi/acpica/acstruct.h
+++ b/drivers/acpi/acpica/acstruct.h
@@ -82,6 +82,7 @@ struct acpi_walk_state {
u8 return_used;
u8 scope_depth;
u8 pass_number; /* Parse pass during table load */
+ u8 namespace_override; /* Override existing objects */
u8 result_size; /* Total elements for the result stack */
u8 result_count; /* Current number of occupied elements of result stack */
u32 aml_offset;
diff --git a/drivers/acpi/acpica/dswload.c b/drivers/acpi/acpica/dswload.c
index 843942f..845ff44 100644
--- a/drivers/acpi/acpica/dswload.c
+++ b/drivers/acpi/acpica/dswload.c
@@ -315,10 +315,19 @@ acpi_ds_load1_begin_op(struct acpi_walk_state * walk_state,
flags = ACPI_NS_NO_UPSEARCH;
if ((walk_state->opcode != AML_SCOPE_OP) &&
(!(walk_state->parse_flags & ACPI_PARSE_DEFERRED_OP))) {
- flags |= ACPI_NS_ERROR_IF_FOUND;
- ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
- "[%s] Cannot already exist\n",
- acpi_ut_get_type_name(object_type)));
+ if (walk_state->namespace_override) {
+ flags |= ACPI_NS_OVERRIDE_IF_FOUND;
+ ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
+ "[%s] Override allowed\n",
+ acpi_ut_get_type_name
+ (object_type)));
+ } else {
+ flags |= ACPI_NS_ERROR_IF_FOUND;
+ ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
+ "[%s] Cannot already exist\n",
+ acpi_ut_get_type_name
+ (object_type)));
+ }
} else {
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"[%s] Both Find or Create allowed\n",
diff --git a/drivers/acpi/acpica/nsaccess.c b/drivers/acpi/acpica/nsaccess.c
index 24fa19a..19ad0b5 100644
--- a/drivers/acpi/acpica/nsaccess.c
+++ b/drivers/acpi/acpica/nsaccess.c
@@ -304,7 +304,9 @@ acpi_ns_lookup(union acpi_generic_state *scope_info,
return_ACPI_STATUS(AE_BAD_PARAMETER);
}

- local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_SEARCH_PARENT);
+ local_flags = flags &
+ ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_OVERRIDE_IF_FOUND |
+ ACPI_NS_SEARCH_PARENT);
*return_node = ACPI_ENTRY_NOT_FOUND;
acpi_gbl_ns_lookup_count++;

@@ -547,6 +549,12 @@ acpi_ns_lookup(union acpi_generic_state *scope_info,
if (flags & ACPI_NS_ERROR_IF_FOUND) {
local_flags |= ACPI_NS_ERROR_IF_FOUND;
}
+
+ /* Set override flag according to caller */
+
+ if (flags & ACPI_NS_OVERRIDE_IF_FOUND) {
+ local_flags |= ACPI_NS_OVERRIDE_IF_FOUND;
+ }
}

/* Extract one ACPI name from the front of the pathname */
diff --git a/drivers/acpi/acpica/nssearch.c b/drivers/acpi/acpica/nssearch.c
index 4a9d4a6..47fbe5b 100644
--- a/drivers/acpi/acpica/nssearch.c
+++ b/drivers/acpi/acpica/nssearch.c
@@ -325,8 +325,26 @@ acpi_ns_search_and_enter(u32 target_name,
* If we found it AND the request specifies that a find is an error,
* return the error
*/
- if ((status == AE_OK) && (flags & ACPI_NS_ERROR_IF_FOUND)) {
- status = AE_ALREADY_EXISTS;
+ if (status == AE_OK) {
+
+ /* The node was found in the namespace */
+
+ /*
+ * If the namespace override feature is enabled for this node,
+ * delete any existing node. This can only happen during the
+ * boot stage, thus it is safe to remove the node here.
+ */
+ if (flags & ACPI_NS_OVERRIDE_IF_FOUND) {
+ acpi_ns_delete_children(*return_node);
+ acpi_ns_remove_node(*return_node);
+ *return_node = ACPI_ENTRY_NOT_FOUND;
+ }
+
+ /* Return an error if we don't expect to find the object */
+
+ else if (flags & ACPI_NS_ERROR_IF_FOUND) {
+ status = AE_ALREADY_EXISTS;
+ }
}
#ifdef ACPI_ASL_COMPILER
if (*return_node && (*return_node)->type == ACPI_TYPE_ANY) {
--
1.7.10