x86: acpi: Support generation of the DBG2 table

Add an implementation of the DBG2 (Debug Port Table 2) ACPI table.
Adjust one of the header includes to be in the correct order, before
adding more.

Note that the DBG2 table is generic but the PCI UART is x86-specific at
present since it assumes an ns16550 UART. It can be generalised later
if necessary.

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

1 files changed, 64 insertions, 0 deletions

diff --git a/lib/acpi/acpi_table.c b/lib/acpi/acpi_table.c
index acc55e7fad..908d890389 100644
--- a/lib/acpi/acpi_table.c
+++ b/lib/acpi/acpi_table.c
@@ -264,3 +264,67 @@ void acpi_setup_base_tables(struct acpi_ctx *ctx, void *start)
 	 */
 	acpi_align64(ctx);
 }
+
+void acpi_create_dbg2(struct acpi_dbg2_header *dbg2,
+		      int port_type, int port_subtype,
+		      struct acpi_gen_regaddr *address, u32 address_size,
+		      const char *device_path)
+{
+	uintptr_t current;
+	struct acpi_dbg2_device *device;
+	u32 *dbg2_addr_size;
+	struct acpi_table_header *header;
+	size_t path_len;
+	const char *path;
+	char *namespace;
+
+	/* Fill out header fields. */
+	current = (uintptr_t)dbg2;
+	memset(dbg2, '\0', sizeof(struct acpi_dbg2_header));
+	header = &dbg2->header;
+
+	header->revision = acpi_get_table_revision(ACPITAB_DBG2);
+	acpi_fill_header(header, "DBG2");
+	header->aslc_revision = ASL_REVISION;
+
+	/* One debug device defined */
+	dbg2->devices_offset = sizeof(struct acpi_dbg2_header);
+	dbg2->devices_count = 1;
+	current += sizeof(struct acpi_dbg2_header);
+
+	/* Device comes after the header */
+	device = (struct acpi_dbg2_device *)current;
+	memset(device, 0, sizeof(struct acpi_dbg2_device));
+	current += sizeof(struct acpi_dbg2_device);
+
+	device->revision = 0;
+	device->address_count = 1;
+	device->port_type = port_type;
+	device->port_subtype = port_subtype;
+
+	/* Base Address comes after device structure */
+	memcpy((void *)current, address, sizeof(struct acpi_gen_regaddr));
+	device->base_address_offset = current - (uintptr_t)device;
+	current += sizeof(struct acpi_gen_regaddr);
+
+	/* Address Size comes after address structure */
+	dbg2_addr_size = (uint32_t *)current;
+	device->address_size_offset = current - (uintptr_t)device;
+	*dbg2_addr_size = address_size;
+	current += sizeof(uint32_t);
+
+	/* Namespace string comes last, use '.' if not provided */
+	path = device_path ? : ".";
+	/* Namespace string length includes NULL terminator */
+	path_len = strlen(path) + 1;
+	namespace = (char *)current;
+	device->namespace_string_length = path_len;
+	device->namespace_string_offset = current - (uintptr_t)device;
+	strncpy(namespace, path, path_len);
+	current += path_len;
+
+	/* Update structure lengths and checksum */
+	device->length = current - (uintptr_t)device;
+	header->length = current - (uintptr_t)dbg2;
+	header->checksum = table_compute_checksum(dbg2, header->length);
+}