[Qemu-devel] [RFC 01/47] acpi: introduce AML composer aml_append()

[Igor Mammedov <imammedo@redhat.com>]

Adds for dynamic AML creation, which will be used
for piecing ASL/AML primitives together and hiding
from user/caller details about how nested context
should be closed/packed leaving less space for
mistakes and necessity to know how AML should be
encoded, allowing user to concentrate on ASL
representation instead.

For example it will allow to create AML like this:

AcpiAml scope = acpi_scope("PCI0")
AcpiAml dev = acpi_device("PM")
    aml_append(&dev, acpi_name_decl("_ADR", acpi_int(addr)))
aml_append(&scope, dev);

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
 hw/acpi/acpi_gen_utils.c         | 39 +++++++++++++++++++++++++++++++++++++++
 include/hw/acpi/acpi_gen_utils.h | 16 ++++++++++++++++
 2 files changed, 55 insertions(+)

diff --git a/hw/acpi/acpi_gen_utils.c b/hw/acpi/acpi_gen_utils.c
index 291b938..c9050ef 100644
--- a/hw/acpi/acpi_gen_utils.c
+++ b/hw/acpi/acpi_gen_utils.c
@@ -242,3 +242,42 @@ void build_append_int(GArray *table, uint32_t value)
         build_append_value(table, value, 4);
     }
 }
+
+static void build_prepend_int(GArray *array, uint32_t value)
+{
+    GArray *data = build_alloc_array();
+
+    build_append_int(data, value);
+    g_array_prepend_vals(array, data->data, data->len);
+    build_free_array(data);
+}
+
+void aml_append(AcpiAml *parent_ctx, AcpiAml child)
+{
+    switch (child.block_flags) {
+    case EXT_PACKAGE:
+        build_extop_package(child.buf, child.op);
+        break;
+
+    case PACKAGE:
+        build_package(child.buf, child.op);
+        break;
+
+    case RES_TEMPLATE:
+        build_append_byte(child.buf, 0x79); /* EndTag */
+        /*
+         * checksum operations is treated as succeeded if checksum
+         * field is zero. [ACPI Spec 5.0, 6.4.2.9 End Tag]
+         */
+        build_append_byte(child.buf, 0);
+        /* fall through, to pack resources in buffer */
+    case BUFFER:
+        build_prepend_int(child.buf, child.buf->len);
+        build_package(child.buf, child.op);
+        break;
+    default:
+        break;
+    }
+    build_append_array(parent_ctx->buf, child.buf);
+    build_free_array(child.buf);
+}
diff --git a/include/hw/acpi/acpi_gen_utils.h b/include/hw/acpi/acpi_gen_utils.h
index 199f003..64e7ec3 100644
--- a/include/hw/acpi/acpi_gen_utils.h
+++ b/include/hw/acpi/acpi_gen_utils.h
@@ -5,6 +5,22 @@
 #include <glib.h>
 #include "qemu/compiler.h"
 
+typedef enum {
+    NON_BLOCK,
+    PACKAGE,
+    EXT_PACKAGE,
+    BUFFER,
+    RES_TEMPLATE,
+} AcpiBlockFlags;
+
+typedef struct AcpiAml {
+    GArray *buf;
+    uint8_t op;
+    AcpiBlockFlags block_flags;
+} AcpiAml;
+
+void aml_append(AcpiAml *parent_ctx, AcpiAml child);
+
 GArray *build_alloc_array(void);
 void build_free_array(GArray *array);
 void build_prepend_byte(GArray *array, uint8_t val);
-- 
1.8.3.1