arch/x86/acpigen: Add support for _DSM method generation

Add acpigen_write_dsm that generates ACPI AML code for _DSM
method. Caller should provide set of callbacks with callback[i]
corresponding to function index i of DSM method. Local0 and Local1
should not be used in any of the callbacks.

BUG=chrome-os-partner:57846

Change-Id: Ie18cba080424488fe00cc626ea50aa92c1dbb199
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/17090
Tested-by: build bot (Jenkins)
Reviewed-by: Alexander Couzens <lynxis@fe80.eu>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/arch/x86/include/arch/acpigen.h b/src/arch/x86/include/arch/acpigen.h
index dd83db85a1..7c15a31bdd 100644
--- a/src/arch/x86/include/arch/acpigen.h
+++ b/src/arch/x86/include/arch/acpigen.h
@@ -167,6 +167,14 @@ void acpigen_write_byte_buffer(uint8_t *arr, uint8_t size);
 void acpigen_write_return_byte_buffer(uint8_t *arr, uint8_t size);
 void acpigen_write_return_singleton_buffer(uint8_t arg);
 void acpigen_write_return_byte(uint8_t arg);
+/*
+ * Generate ACPI AML code for _DSM method.
+ * This function takes as input uuid for the device, set of callbacks and
+ * argument to pass into the callbacks. Callbacks should ensure that Local0 and
+ * Local1 are left untouched. Use of Local2-Local7 is permitted in callbacks.
+ */
+void acpigen_write_dsm(const char *uuid, void (*callbacks[])(void *),
+		       size_t count, void *arg);
 
 int get_cst_entries(acpi_cstate_t **);