lib/firmware_table: tables: Add CDAT table parsing support

The CDAT table is very similar to ACPI tables when it comes to sub-table
and entry structures. The helper functions can be also used to parse the
CDAT table. Add support to the helper functions to deal with an external
CDAT table, and also handle the endieness since CDAT can be processed by a
BE host. Export a function cdat_table_parse() for CXL driver to parse
a CDAT table.

In order to minimize ACPICA code changes, __force is being utilized to deal
with the case of a big endian (BE) host parsing a CDAT. All CDAT data
structure variables are being force casted to __leX as appropriate.

Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Len Brown <lenb@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/170319615131.2212653.10932785667981494238.stgit@djiang5-mobl3
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 20 insertions, 1 deletions

diff --git a/include/linux/fw_table.h b/include/linux/fw_table.h
index ca49947f0a77..95421860397a 100644
--- a/include/linux/fw_table.h
+++ b/include/linux/fw_table.h
@@ -25,16 +25,35 @@ struct acpi_subtable_proc {
 	int count;
 };
 
+union fw_table_header {
+	struct acpi_table_header acpi;
+	struct acpi_table_cdat cdat;
+};
+
 union acpi_subtable_headers {
 	struct acpi_subtable_header common;
 	struct acpi_hmat_structure hmat;
 	struct acpi_prmt_module_header prmt;
 	struct acpi_cedt_header cedt;
+	struct acpi_cdat_header cdat;
 };
 
 int acpi_parse_entries_array(char *id, unsigned long table_size,
-			     struct acpi_table_header *table_header,
+			     union fw_table_header *table_header,
 			     struct acpi_subtable_proc *proc,
 			     int proc_num, unsigned int max_entries);
 
+int cdat_table_parse(enum acpi_cdat_type type,
+		     acpi_tbl_entry_handler_arg handler_arg, void *arg,
+		     struct acpi_table_cdat *table_header);
+
+/* CXL is the only non-ACPI consumer of the FIRMWARE_TABLE library */
+#if IS_ENABLED(CONFIG_ACPI) && !IS_ENABLED(CONFIG_CXL_BUS)
+#define EXPORT_SYMBOL_FWTBL_LIB(x) EXPORT_SYMBOL_ACPI_LIB(x)
+#define __init_or_fwtbl_lib __init_or_acpilib
+#else
+#define EXPORT_SYMBOL_FWTBL_LIB(x) EXPORT_SYMBOL_NS_GPL(x, CXL)
+#define __init_or_fwtbl_lib
+#endif
+
 #endif