firmware: coreboot: Generate aliases for coreboot modules

Generate aliases for coreboot modules to allow automatic module probing.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20240212-coreboot-mod-defconfig-v4-2-d14172676f6d@collabora.com
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

Author: nfraprado

include/linux/mod_devicetable.h

@@ -960,4 +960,14 @@ struct vchiq_device_id {
 	char name[32];
 };
 
+/**
+ * struct coreboot_device_id - Identifies a coreboot table entry
+ * @tag: tag ID
+ * @driver_data: driver specific data
+ */
+struct coreboot_device_id {
+	__u32 tag;
+	kernel_ulong_t driver_data;
+};
+
 #endif /* LINUX_MOD_DEVICETABLE_H */

scripts/mod/devicetable-offsets.c

@@ -274,5 +274,8 @@ int main(void)
 	DEVID(vchiq_device_id);
 	DEVID_FIELD(vchiq_device_id, name);
 
+	DEVID(coreboot_device_id);
+	DEVID_FIELD(coreboot_device_id, tag);
+
 	return 0;
 }

scripts/mod/file2alias.c

@@ -1494,6 +1494,15 @@ static int do_vchiq_entry(const char *filename, void *symval, char *alias)
 	return 1;
 }
 
+/* Looks like: coreboot:tN */
+static int do_coreboot_entry(const char *filename, void *symval, char *alias)
+{
+	DEF_FIELD(symval, coreboot_device_id, tag);
+	sprintf(alias, "coreboot:t%08X", tag);
+
+	return 1;
+}
+
 /* Does namelen bytes of name exactly match the symbol? */
 static bool sym_is(const char *name, unsigned namelen, const char *symbol)
 {
@@ -1575,6 +1584,7 @@ static const struct devtable devtable[] = {
 	{"ishtp", SIZE_ishtp_device_id, do_ishtp_entry},
 	{"cdx", SIZE_cdx_device_id, do_cdx_entry},
 	{"vchiq", SIZE_vchiq_device_id, do_vchiq_entry},
+	{"coreboot", SIZE_coreboot_device_id, do_coreboot_entry},
 };
 
 /* Create MODULE_ALIAS() statements.