acpi: introduce AML composer aml_append()

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:

init_aml_allocator();
...
Aml *scope = aml_scope("PCI0")
Aml *dev = aml_device("PM")
    aml_append(dev, aml_name_decl("_ADR", aml_int(addr)))
aml_append(scope, dev);
...
free_aml_allocator();

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
index 199f003265..1e1b03bc4e 100644
--- a/include/hw/acpi/aml-build.h
+++ b/include/hw/acpi/aml-build.h
@@ -5,6 +5,61 @@
 #include <glib.h>
 #include "qemu/compiler.h"
 
+typedef enum {
+    AML_NO_OPCODE = 0,/* has only data */
+    AML_OPCODE,       /* has opcode optionally followed by data */
+    AML_PACKAGE,      /* has opcode and uses PkgLength for its length */
+    AML_EXT_PACKAGE,  /* ame as AML_PACKAGE but also has 'ExOpPrefix' */
+    AML_BUFFER,       /* data encoded as 'DefBuffer' */
+    AML_RES_TEMPLATE, /* encoded as ResourceTemplate macro */
+} AmlBlockFlags;
+
+struct Aml {
+    GArray *buf;
+
+    /*< private >*/
+    uint8_t op;
+    AmlBlockFlags block_flags;
+};
+typedef struct Aml Aml;
+
+/**
+ * init_aml_allocator:
+ *
+ * Called for initializing API allocator which allow to use
+ * AML API.
+ * Returns: toplevel container which accumulates all other
+ * AML elements for a table.
+ */
+Aml *init_aml_allocator(void);
+
+/**
+ * free_aml_allocator:
+ *
+ * Releases all elements used by AML API, frees associated memory
+ * and invalidates AML allocator. After this call @init_aml_allocator
+ * should be called again if AML API is to be used again.
+ */
+void free_aml_allocator(void);
+
+/**
+ * aml_append:
+ * @parent_ctx: context to which @child element is added
+ * @child: element that is copied into @parent_ctx context
+ *
+ * Joins Aml elements together and helps to construct AML tables
+ * Examle of usage:
+ *   Aml *table = aml_def_block("SSDT", ...);
+ *   Aml *sb = aml_scope("\_SB");
+ *   Aml *dev = aml_device("PCI0");
+ *
+ *   aml_append(dev, aml_name_decl("HID", aml_eisaid("PNP0A03")));
+ *   aml_append(sb, dev);
+ *   aml_append(table, sb);
+ */
+void aml_append(Aml *parent_ctx, Aml *child);
+
+/* other helpers */
 GArray *build_alloc_array(void);
 void build_free_array(GArray *array);
 void build_prepend_byte(GArray *array, uint8_t val);