x86: Move FACS table to a writer function

Move this table over to use a writer function, moving the code from the
x86 implementation.

Add a pointer to the DSDT in struct acpi_ctx so we can reference it later.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/x86/lib/acpi_table.c

@@ -38,21 +38,6 @@ extern const unsigned char AmlCode[];
 /* ACPI RSDP address to be used in boot parameters */
 static ulong acpi_rsdp_addr;
 
-static void acpi_create_facs(struct acpi_facs *facs)
-{
-	memset((void *)facs, 0, sizeof(struct acpi_facs));
-
-	memcpy(facs->signature, "FACS", 4);
-	facs->length = sizeof(struct acpi_facs);
-	facs->hardware_signature = 0;
-	facs->firmware_waking_vector = 0;
-	facs->global_lock = 0;
-	facs->flags = 0;
-	facs->x_firmware_waking_vector_l = 0;
-	facs->x_firmware_waking_vector_h = 0;
-	facs->version = 1;
-}
-
 static int acpi_create_madt_lapic(struct acpi_madt_lapic *lapic,
 				  u8 cpu, u8 apic)
 {
@@ -507,7 +492,6 @@ static int write_acpi_tables_x86(struct acpi_ctx *ctx,
 				 const struct acpi_writer *entry)
 {
 	const int thl = sizeof(struct acpi_table_header);
-	struct acpi_facs *facs;
 	struct acpi_table_header *dsdt;
 	struct acpi_fadt *fadt;
 	struct acpi_table_header *ssdt;
@@ -521,12 +505,6 @@ static int write_acpi_tables_x86(struct acpi_ctx *ctx,
 	int ret;
 	int i;
 
-	debug("ACPI:    * FACS\n");
-	facs = ctx->current;
-	acpi_inc_align(ctx, sizeof(struct acpi_facs));
-
-	acpi_create_facs(facs);
-
 	debug("ACPI:    * DSDT\n");
 	dsdt = ctx->current;
 
@@ -599,7 +577,7 @@ static int write_acpi_tables_x86(struct acpi_ctx *ctx,
 	debug("ACPI:    * FADT\n");
 	fadt = ctx->current;
 	acpi_inc_align(ctx, sizeof(struct acpi_fadt));
-	acpi_create_fadt(fadt, facs, dsdt);
+	acpi_create_fadt(fadt, ctx->facs, dsdt);
 	acpi_add_table(ctx, fadt);
 
 	debug("ACPI:     * SSDT\n");
@@ -666,7 +644,7 @@ static int write_acpi_tables_x86(struct acpi_ctx *ctx,
 
 	return 0;
 }
-ACPI_WRITER(x86, NULL, write_acpi_tables_x86, 0);
+ACPI_WRITER(2x86, NULL, write_acpi_tables_x86, 0);
 
 ulong acpi_get_rsdp_addr(void)
 {

include/dm/acpi.h

@@ -52,6 +52,7 @@ enum acpi_dump_option {
  *	adding a new table. The RSDP holds pointers to the RSDT and XSDT.
  * @rsdt: Pointer to the Root System Description Table
  * @xsdt: Pointer to the Extended System Description Table
+ * @facs: Pointer to the Firmware ACPI Control Structure
  * @nhlt: Intel Non-High-Definition-Audio Link Table (NHLT) pointer, used to
  *	build up information that audio codecs need to provide in the NHLT ACPI
  *	table
@@ -65,6 +66,7 @@ struct acpi_ctx {
 	struct acpi_rsdp *rsdp;
 	struct acpi_rsdt *rsdt;
 	struct acpi_xsdt *xsdt;
+	struct acpi_facs *facs;
 	struct nhlt *nhlt;
 	char *len_stack[ACPIGEN_LENSTACK_SIZE];
 	int ltop;

lib/acpi/Makefile

@@ -10,4 +10,5 @@ obj-y += acpi_writer.o
 # With QEMU the ACPI tables come from there, not from U-Boot
 ifndef CONFIG_QEMU
 obj-y += base.o
+obj-y += facs.o
 endif

lib/acpi/facs.c

@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Write an ACPI Firmware ACPI Control Structure (FACS) table
+ *
+ * Copyright 2021 Google LLC
+ */
+
+#include <common.h>
+#include <acpi/acpi_table.h>
+#include <dm/acpi.h>
+
+int acpi_write_facs(struct acpi_ctx *ctx, const struct acpi_writer *entry)
+{
+	struct acpi_facs *facs = ctx->current;
+
+	memset((void *)facs, '\0', sizeof(struct acpi_facs));
+
+	memcpy(facs->signature, "FACS", 4);
+	facs->length = sizeof(struct acpi_facs);
+	facs->hardware_signature = 0;
+	facs->firmware_waking_vector = 0;
+	facs->global_lock = 0;
+	facs->flags = 0;
+	facs->x_firmware_waking_vector_l = 0;
+	facs->x_firmware_waking_vector_h = 0;
+	facs->version = 1;
+
+	ctx->facs = facs;
+	acpi_inc(ctx, sizeof(struct acpi_facs));
+
+	return 0;
+}
+ACPI_WRITER(1facs, "FACS", acpi_write_facs, 0);