[PATCH v4 28/35] acpi: arm: virt: build_iort: use acpi_table_begin()/acpi_table_end() instead of build_header()

[Igor Mammedov <imammedo@redhat.com>]

it replaces error-prone pointer arithmetic for build_header() API,
with 2 calls to start and finish table creation,
which hides offsets magic from API user.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
---
v4:
  * drop not related change
      (Eric Auger <eric.auger@redhat.com>)
v3:
  * fix conflicts due to
      42e0f050e3a51 'hw/arm/virt-acpi-build: Add IORT support to bypass SMMUv3'
  *  * s/acpi_init_table|acpi_table_composed/acpi_table_begin|acpi_table_end/

CC: drjones@redhat.com
CC: peter.maydell@linaro.org
CC: shannon.zhaosl@gmail.com
CC: qemu-arm@nongnu.org
CC: eauger@redhat.com
---
 include/hw/acpi/acpi-defs.h | 14 ------------
 hw/arm/virt-acpi-build.c    | 44 +++++++++++++++----------------------
 2 files changed, 18 insertions(+), 40 deletions(-)

diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
index bcada37601..195f90caf6 100644
--- a/include/hw/acpi/acpi-defs.h
+++ b/include/hw/acpi/acpi-defs.h
@@ -188,20 +188,6 @@ struct AcpiGenericTimerTable {
 } QEMU_PACKED;
 typedef struct AcpiGenericTimerTable AcpiGenericTimerTable;
 
-/*
- * Input Output Remapping Table (IORT)
- * Conforms to "IO Remapping Table System Software on ARM Platforms",
- * Document number: ARM DEN 0049B, October 2015
- */
-
-struct AcpiIortTable {
-    ACPI_TABLE_HEADER_DEF     /* ACPI common table header */
-    uint32_t node_count;
-    uint32_t node_offset;
-    uint32_t reserved;
-} QEMU_PACKED;
-typedef struct AcpiIortTable AcpiIortTable;
-
 /*
  * IORT node types
  */
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 4b9687439d..42ea460313 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -273,20 +273,26 @@ static int iort_idmap_compare(gconstpointer a, gconstpointer b)
     return idmap_a->input_base - idmap_b->input_base;
 }
 
+/*
+ * Input Output Remapping Table (IORT)
+ * Conforms to "IO Remapping Table System Software on ARM Platforms",
+ * Document number: ARM DEN 0049B, October 2015
+ */
 static void
 build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
 {
-    int i, nb_nodes, rc_mapping_count, iort_start = table_data->len;
+    int i, nb_nodes, rc_mapping_count;
     AcpiIortIdMapping *idmap;
     AcpiIortItsGroup *its;
-    AcpiIortTable *iort;
     AcpiIortSmmu3 *smmu;
-    size_t node_size, iort_node_offset, iort_length, smmu_offset = 0;
     AcpiIortRC *rc;
+    const uint32_t iort_node_offset = 48;
+    size_t node_size, smmu_offset = 0;
     GArray *smmu_idmaps = g_array_new(false, true, sizeof(AcpiIortIdMapping));
     GArray *its_idmaps = g_array_new(false, true, sizeof(AcpiIortIdMapping));
 
-    iort = acpi_data_push(table_data, sizeof(*iort));
+    AcpiTable table = { .sig = "IORT", .rev = 0, .oem_id = vms->oem_id,
+                        .oem_table_id = vms->oem_table_id };
 
     if (vms->iommu == VIRT_IOMMU_SMMUV3) {
         AcpiIortIdMapping next_range = {0};
@@ -325,18 +331,16 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
         rc_mapping_count = 1;
     }
 
-    iort_length = sizeof(*iort);
-    iort->node_count = cpu_to_le32(nb_nodes);
-    /*
-     * Use a copy in case table_data->data moves during acpi_data_push
-     * operations.
-     */
-    iort_node_offset = sizeof(*iort);
-    iort->node_offset = cpu_to_le32(iort_node_offset);
+    /* Table 2 The IORT */
+    acpi_table_begin(&table, table_data);
+    /* Number of IORT Nodes */
+    build_append_int_noprefix(table_data, nb_nodes, 4);
+    /* Offset to Array of IORT Nodes */
+    build_append_int_noprefix(table_data, iort_node_offset, 4);
+    build_append_int_noprefix(table_data, 0, 4); /* Reserved */
 
     /* ITS group node */
     node_size =  sizeof(*its) + sizeof(uint32_t);
-    iort_length += node_size;
     its = acpi_data_push(table_data, node_size);
 
     its->type = ACPI_IORT_NODE_ITS_GROUP;
@@ -350,7 +354,6 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
         /* SMMUv3 node */
         smmu_offset = iort_node_offset + node_size;
         node_size = sizeof(*smmu) + sizeof(*idmap);
-        iort_length += node_size;
         smmu = acpi_data_push(table_data, node_size);
 
         smmu->type = ACPI_IORT_NODE_SMMU_V3;
@@ -375,7 +378,6 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
 
     /* Root Complex Node */
     node_size = sizeof(*rc) + sizeof(*idmap) * rc_mapping_count;
-    iort_length += node_size;
     rc = acpi_data_push(table_data, node_size);
 
     rc->type = ACPI_IORT_NODE_PCI_ROOT_COMPLEX;
@@ -424,19 +426,9 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
         idmap->output_reference = cpu_to_le32(iort_node_offset);
     }
 
+    acpi_table_end(linker, &table);
     g_array_free(smmu_idmaps, true);
     g_array_free(its_idmaps, true);
-
-    /*
-     * Update the pointer address in case table_data->data moves during above
-     * acpi_data_push operations.
-     */
-    iort = (AcpiIortTable *)(table_data->data + iort_start);
-    iort->length = cpu_to_le32(iort_length);
-
-    build_header(linker, table_data, (void *)(table_data->data + iort_start),
-                 "IORT", table_data->len - iort_start, 0, vms->oem_id,
-                 vms->oem_table_id);
 }
 
 static void
-- 
2.27.0