x86: Move GNVS table to a writer function

Move this table over to use a writer function, for x86 only. Handle the
two cases

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

arch/x86/lib/acpi_table.c

@@ -479,66 +479,65 @@ static int acpi_create_ssdt(struct acpi_ctx *ctx,
 	return 0;
 }
 
-/*
- * QEMU's version of write_acpi_tables is defined in drivers/misc/qfw.c
- */
-static int write_acpi_tables_x86(struct acpi_ctx *ctx,
-				 const struct acpi_writer *entry)
+int acpi_write_gnvs(struct acpi_ctx *ctx, const struct acpi_writer *entry)
 {
-	struct acpi_fadt *fadt;
-	struct acpi_table_header *ssdt;
-	struct acpi_mcfg *mcfg;
-	struct acpi_tcpa *tcpa;
-	struct acpi_madt *madt;
-	struct acpi_csrt *csrt;
-	struct acpi_spcr *spcr;
 	ulong addr;
-	int ret;
-	int i;
 
 	if (!IS_ENABLED(CONFIG_ACPI_GNVS_EXTERNAL)) {
+		int i;
+
+		/* We need the DSDT to be done */
+		if (!ctx->dsdt)
+			return log_msg_ret("dsdt", -EAGAIN);
+
 		/* Pack GNVS into the ACPI table area */
 		for (i = 0; i < ctx->dsdt->length; i++) {
 			u32 *gnvs = (u32 *)((u32)ctx->dsdt + i);
 
 			if (*gnvs == ACPI_GNVS_ADDR) {
 				*gnvs = map_to_sysmem(ctx->current);
-				debug("Fix up global NVS in DSDT to %#08x\n",
-				      *gnvs);
+				log_debug("Fix up global NVS in DSDT to %#08x\n",
+					  *gnvs);
 				break;
 			}
 		}
 
 		/*
-		 * Fill in platform-specific global NVS variables. If this fails
-		 * we cannot return the error but this should only happen while
-		 * debugging.
+		 * Recalculate the length and update the DSDT checksum since we
+		 * patched the GNVS address. Set the checksum to zero since it
+		 * is part of the region being checksummed.
 		 */
-		addr = acpi_create_gnvs(ctx->current);
-		if (IS_ERR_VALUE(addr))
-			printf("Error: Gailed to create GNVS\n");
-		acpi_inc_align(ctx, sizeof(struct acpi_global_nvs));
+		ctx->dsdt->checksum = 0;
+		ctx->dsdt->checksum = table_compute_checksum((void *)ctx->dsdt,
+							     ctx->dsdt->length);
 	}
 
-	/*
-	 * Recalculate the length and update the DSDT checksum since we patched
-	 * the GNVS address. Set the checksum to zero since it is part of the
-	 * region being checksummed.
-	 */
-	ctx->dsdt->checksum = 0;
-	ctx->dsdt->checksum = table_compute_checksum((void *)ctx->dsdt,
-						     ctx->dsdt->length);
-
-	/*
-	 * Fill in platform-specific global NVS variables. If this fails we
-	 * cannot return the error but this should only happen while debugging.
-	 */
+	/* Fill in platform-specific global NVS variables */
 	addr = acpi_create_gnvs(ctx->current);
 	if (IS_ERR_VALUE(addr))
-		printf("Error: Failed to create GNVS\n");
+		return log_msg_ret("gnvs", (int)addr);
 
 	acpi_inc_align(ctx, sizeof(struct acpi_global_nvs));
 
+	return 0;
+}
+ACPI_WRITER(4gnvs, "GNVS", acpi_write_gnvs, 0);
+
+/*
+ * QEMU's version of write_acpi_tables is defined in drivers/misc/qfw.c
+ */
+int write_acpi_tables_x86(struct acpi_ctx *ctx,
+			  const struct acpi_writer *entry)
+{
+	struct acpi_fadt *fadt;
+	struct acpi_table_header *ssdt;
+	struct acpi_mcfg *mcfg;
+	struct acpi_tcpa *tcpa;
+	struct acpi_madt *madt;
+	struct acpi_csrt *csrt;
+	struct acpi_spcr *spcr;
+	int ret;
+
 	debug("ACPI:    * FADT\n");
 	fadt = ctx->current;
 	acpi_inc_align(ctx, sizeof(struct acpi_fadt));