ACPICA: ACPI 4.0: Interpreter support for IPMI.

Adds support for IPMI which is similar to SMBus and uses a bi-directional data buffer.
ACPICA BZ 773.

http://acpica.org/bugzilla/show_bug.cgi?id=773

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

3 files changed, 61 insertions, 31 deletions

diff --git a/drivers/acpi/acpica/acconfig.h b/drivers/acpi/acpica/acconfig.h
index 9123d5a11627..8e679ef5b231 100644
--- a/drivers/acpi/acpica/acconfig.h
+++ b/drivers/acpi/acpica/acconfig.h
@@ -199,9 +199,10 @@
 #define ACPI_RSDP_CHECKSUM_LENGTH       20
 #define ACPI_RSDP_XCHECKSUM_LENGTH      36
 
-/* SMBus bidirectional buffer size */
+/* SMBus and IPMI bidirectional buffer size */
 
 #define ACPI_SMBUS_BUFFER_SIZE          34
+#define ACPI_IPMI_BUFFER_SIZE           66
 
 /* _sx_d and _sx_w control methods */
 
diff --git a/drivers/acpi/acpica/exfield.c b/drivers/acpi/acpica/exfield.c
index 546dcdd86785..0b33d6c887b9 100644
--- a/drivers/acpi/acpica/exfield.c
+++ b/drivers/acpi/acpica/exfield.c
@@ -72,6 +72,7 @@ acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
         union acpi_operand_object *buffer_desc;
         acpi_size length;
         void *buffer;
+        u32 function;
 
         ACPI_FUNCTION_TRACE_PTR(ex_read_data_from_field, obj_desc);
 
@@ -97,13 +98,27 @@ acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
                 }
         } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
                    (obj_desc->field.region_obj->region.space_id ==
-                    ACPI_ADR_SPACE_SMBUS)) {
+                    ACPI_ADR_SPACE_SMBUS
+                    || obj_desc->field.region_obj->region.space_id ==
+                    ACPI_ADR_SPACE_IPMI)) {
                 /*
-                 * This is an SMBus read.  We must create a buffer to hold the data
-                 * and directly access the region handler.
+                 * This is an SMBus or IPMI read. We must create a buffer to hold
+                 * the data and then directly access the region handler.
+                 *
+                 * Note: Smbus protocol value is passed in upper 16-bits of Function
                  */
-                buffer_desc =
-                    acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
+                if (obj_desc->field.region_obj->region.space_id ==
+                    ACPI_ADR_SPACE_SMBUS) {
+                        length = ACPI_SMBUS_BUFFER_SIZE;
+                        function =
+                            ACPI_READ | (obj_desc->field.attribute << 16);
+                } else {        /* IPMI */
+
+                        length = ACPI_IPMI_BUFFER_SIZE;
+                        function = ACPI_READ;
+                }
+
+                buffer_desc = acpi_ut_create_buffer_object(length);
                 if (!buffer_desc) {
                         return_ACPI_STATUS(AE_NO_MEMORY);
                 }
@@ -112,16 +127,13 @@ acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
 
                 acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 
-                /*
-                 * Perform the read.
-                 * Note: Smbus protocol value is passed in upper 16-bits of Function
-                 */
+                /* Call the region handler for the read */
+
                 status = acpi_ex_access_region(obj_desc, 0,
                                                ACPI_CAST_PTR(acpi_integer,
                                                              buffer_desc->
                                                              buffer.pointer),
-                                               ACPI_READ | (obj_desc->field.
-                                                            attribute << 16));
+                                               function);
                 acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
                 goto exit;
         }
@@ -212,6 +224,7 @@ acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
         u32 length;
         void *buffer;
         union acpi_operand_object *buffer_desc;
+        u32 function;
 
         ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
 
@@ -234,39 +247,56 @@ acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
                 }
         } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
                    (obj_desc->field.region_obj->region.space_id ==
-                    ACPI_ADR_SPACE_SMBUS)) {
+                    ACPI_ADR_SPACE_SMBUS
+                    || obj_desc->field.region_obj->region.space_id ==
+                    ACPI_ADR_SPACE_IPMI)) {
                 /*
-                 * This is an SMBus write.  We will bypass the entire field mechanism
-                 * and handoff the buffer directly to the handler.
+                 * This is an SMBus or IPMI write. We will bypass the entire field
+                 * mechanism and handoff the buffer directly to the handler. For
+                 * these address spaces, the buffer is bi-directional; on a write,
+                 * return data is returned in the same buffer.
+                 *
+                 * Source must be a buffer of sufficient size:
+                 * ACPI_SMBUS_BUFFER_SIZE or ACPI_IPMI_BUFFER_SIZE.
                  *
-                 * Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
+                 * Note: SMBus protocol type is passed in upper 16-bits of Function
                  */
                 if (source_desc->common.type != ACPI_TYPE_BUFFER) {
                         ACPI_ERROR((AE_INFO,
-                                    "SMBus write requires Buffer, found type %s",
+                                    "SMBus or IPMI write requires Buffer, found type %s",
                                     acpi_ut_get_object_type_name(source_desc)));
 
                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
                 }
 
-                if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
+                if (obj_desc->field.region_obj->region.space_id ==
+                    ACPI_ADR_SPACE_SMBUS) {
+                        length = ACPI_SMBUS_BUFFER_SIZE;
+                        function =
+                            ACPI_WRITE | (obj_desc->field.attribute << 16);
+                } else {        /* IPMI */
+
+                        length = ACPI_IPMI_BUFFER_SIZE;
+                        function = ACPI_WRITE;
+                }
+
+                if (source_desc->buffer.length < length) {
                         ACPI_ERROR((AE_INFO,
-                                    "SMBus write requires Buffer of length %X, found length %X",
-                                    ACPI_SMBUS_BUFFER_SIZE,
-                                    source_desc->buffer.length));
+                                    "SMBus or IPMI write requires Buffer of length %X, found length %X",
+                                    length, source_desc->buffer.length));
 
                         return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
                 }
 
-                buffer_desc =
-                    acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
+                /* Create the bi-directional buffer */
+
+                buffer_desc = acpi_ut_create_buffer_object(length);
                 if (!buffer_desc) {
                         return_ACPI_STATUS(AE_NO_MEMORY);
                 }
 
                 buffer = buffer_desc->buffer.pointer;
-                ACPI_MEMCPY(buffer, source_desc->buffer.pointer,
-                            ACPI_SMBUS_BUFFER_SIZE);
+                ACPI_MEMCPY(buffer, source_desc->buffer.pointer, length);
 
                 /* Lock entire transaction if requested */
 
@@ -275,12 +305,10 @@ acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
                 /*
                  * Perform the write (returns status and perhaps data in the
                  * same buffer)
-                 * Note: SMBus protocol type is passed in upper 16-bits of Function.
                  */
                 status = acpi_ex_access_region(obj_desc, 0,
                                                (acpi_integer *) buffer,
-                                               ACPI_WRITE | (obj_desc->field.
-                                                             attribute << 16));
+                                               function);
                 acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 
                 *result_desc = buffer_desc;
diff --git a/drivers/acpi/acpica/exfldio.c b/drivers/acpi/acpica/exfldio.c
index 6687be167f5f..d7b3b418fb45 100644
--- a/drivers/acpi/acpica/exfldio.c
+++ b/drivers/acpi/acpica/exfldio.c
@@ -120,12 +120,13 @@ acpi_ex_setup_region(union acpi_operand_object *obj_desc,
         }
 
         /*
-         * Exit now for SMBus address space, it has a non-linear address space
+         * Exit now for SMBus or IPMI address space, it has a non-linear address space
          * and the request cannot be directly validated
          */
-        if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS) {
+        if (rgn_desc->region.space_id == ACPI_ADR_SPACE_SMBUS ||
+            rgn_desc->region.space_id == ACPI_ADR_SPACE_IPMI) {
 
-                /* SMBus has a non-linear address space */
+                /* SMBus or IPMI has a non-linear address space */
 
                 return_ACPI_STATUS(AE_OK);
         }