[PATCH v7 3/6] hw/acpi/aml-build: Improve scalability of PPTT generation

[Yanan Wang]

Use g_queue APIs to reduce the nested loops and code indentation
with the processor hierarchy levels increasing. Consenquently,
it's more scalable to add new topology level to build_pptt.

No functional change intended.

Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
---
 hw/acpi/aml-build.c | 50 +++++++++++++++++++++++++++++----------------
 1 file changed, 32 insertions(+), 18 deletions(-)

diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index b3b3310df3..6aaedca2e5 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -2001,7 +2001,10 @@ static void build_processor_hierarchy_node(GArray *tbl, 
uint32_t flags,
 void build_pptt(GArray *table_data, BIOSLinker *linker, MachineState *ms,
                 const char *oem_id, const char *oem_table_id)
 {
-    int pptt_start = table_data->len;
+    GQueue *list = g_queue_new();
+    guint pptt_start = table_data->len;
+    guint parent_offset;
+    guint length, i;
     int uid = 0;
     int socket;
     AcpiTable table = { .sig = "PPTT", .rev = 2,
@@ -2010,9 +2013,8 @@ void build_pptt(GArray *table_data, BIOSLinker *linker, 
MachineState *ms,
     acpi_table_begin(&table, table_data);
 
     for (socket = 0; socket < ms->smp.sockets; socket++) {
-        uint32_t socket_offset = table_data->len - pptt_start;
-        int core;
-
+        g_queue_push_tail(list,
+            GUINT_TO_POINTER(table_data->len - pptt_start));
         build_processor_hierarchy_node(
             table_data,
             /*
@@ -2021,35 +2023,47 @@ void build_pptt(GArray *table_data, BIOSLinker *linker, 
MachineState *ms,
              */
             (1 << 0),
             0, socket, NULL, 0);
+    }
 
-        for (core = 0; core < ms->smp.cores; core++) {
-            uint32_t core_offset = table_data->len - pptt_start;
-            int thread;
+    length = g_queue_get_length(list);
+    for (i = 0; i < length; i++) {
+        int core;
 
+        parent_offset = GPOINTER_TO_UINT(g_queue_pop_head(list));
+        for (core = 0; core < ms->smp.cores; core++) {
             if (ms->smp.threads > 1) {
+                g_queue_push_tail(list,
+                    GUINT_TO_POINTER(table_data->len - pptt_start));
                 build_processor_hierarchy_node(
                     table_data,
                     (0 << 0), /* not a physical package */
-                    socket_offset, core, NULL, 0);
-
-                for (thread = 0; thread < ms->smp.threads; thread++) {
-                    build_processor_hierarchy_node(
-                        table_data,
-                        (1 << 1) | /* ACPI Processor ID valid */
-                        (1 << 2) | /* Processor is a Thread */
-                        (1 << 3),  /* Node is a Leaf */
-                        core_offset, uid++, NULL, 0);
-                }
+                    parent_offset, core, NULL, 0);
             } else {
                 build_processor_hierarchy_node(
                     table_data,
                     (1 << 1) | /* ACPI Processor ID valid */
                     (1 << 3),  /* Node is a Leaf */
-                    socket_offset, uid++, NULL, 0);
+                    parent_offset, uid++, NULL, 0);
             }
         }
     }
 
+    length = g_queue_get_length(list);
+    for (i = 0; i < length; i++) {
+        int thread;
+
+        parent_offset = GPOINTER_TO_UINT(g_queue_pop_head(list));
+        for (thread = 0; thread < ms->smp.threads; thread++) {
+            build_processor_hierarchy_node(
+                table_data,
+                (1 << 1) | /* ACPI Processor ID valid */
+                (1 << 2) | /* Processor is a Thread */
+                (1 << 3),  /* Node is a Leaf */
+                parent_offset, uid++, NULL, 0);
+        }
+    }
+
+    g_queue_free(list);
     acpi_table_end(linker, &table);
 }
 
-- 
2.27.0