[PATCH v6 4/4] hw/acpi/aml-build: Use existing CPU topology to build PPTT table

[Gavin Shan <gshan@redhat.com>]

When the PPTT table is built, the CPU topology is re-calculated, but
it's unecessary because the CPU topology has been populated in
virt_possible_cpu_arch_ids() on arm/virt machine.

This reworks build_pptt() to avoid by reusing the existing one in
ms->possible_cpus. Currently, the only user of build_pptt() is
arm/virt machine.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
 hw/acpi/aml-build.c | 105 ++++++++++++++++++--------------------------
 1 file changed, 43 insertions(+), 62 deletions(-)

diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index 4086879ebf..2bd062a52b 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -2002,86 +2002,67 @@ void build_pptt(GArray *table_data, BIOSLinker *linker, MachineState *ms,
                 const char *oem_id, const char *oem_table_id)
 {
     MachineClass *mc = MACHINE_GET_CLASS(ms);
-    GQueue *list = g_queue_new();
-    guint pptt_start = table_data->len;
-    guint parent_offset;
-    guint length, i;
-    int uid = 0;
-    int socket;
+    CPUArchIdList *cpus = ms->possible_cpus;
+    int64_t socket_id = -1, cluster_id = -1, core_id = -1;
+    uint32_t socket_offset = 0, cluster_offset = 0, core_offset = 0;
+    uint32_t pptt_start = table_data->len;
+    int n;
     AcpiTable table = { .sig = "PPTT", .rev = 2,
                         .oem_id = oem_id, .oem_table_id = oem_table_id };
 
     acpi_table_begin(&table, table_data);
 
-    for (socket = 0; socket < ms->smp.sockets; socket++) {
-        g_queue_push_tail(list,
-            GUINT_TO_POINTER(table_data->len - pptt_start));
-        build_processor_hierarchy_node(
-            table_data,
-            /*
-             * Physical package - represents the boundary
-             * of a physical package
-             */
-            (1 << 0),
-            0, socket, NULL, 0);
-    }
+    /*
+     * This works with the assumption that cpus[n].props.*_id has been
+     * sorted from top to down levels in mc->possible_cpu_arch_ids().
+     * Otherwise, the unexpected and duplicate containers will be created.
+     */
+    for (n = 0; n < cpus->len; n++) {
+        if (cpus->cpus[n].props.socket_id != socket_id) {
+            socket_id = cpus->cpus[n].props.socket_id;
+            cluster_id = -1;
+            core_id = -1;
+            socket_offset = table_data->len - pptt_start;
+            build_processor_hierarchy_node(table_data,
+                (1 << 0), /* Physical package */
+                0, socket_id, NULL, 0);
+        }
 
-    if (mc->smp_props.clusters_supported) {
-        length = g_queue_get_length(list);
-        for (i = 0; i < length; i++) {
-            int cluster;
-
-            parent_offset = GPOINTER_TO_UINT(g_queue_pop_head(list));
-            for (cluster = 0; cluster < ms->smp.clusters; cluster++) {
-                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 */
-                    parent_offset, cluster, NULL, 0);
+        if (mc->smp_props.clusters_supported) {
+            if (cpus->cpus[n].props.cluster_id != cluster_id) {
+                cluster_id = cpus->cpus[n].props.cluster_id;
+                core_id = -1;
+                cluster_offset = table_data->len - pptt_start;
+                build_processor_hierarchy_node(table_data,
+                    (0 << 0), /* Not a physical package */
+                    socket_offset, cluster_id, NULL, 0);
             }
+        } else {
+            cluster_offset = socket_offset;
         }
-    }
 
-    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,
+        if (ms->smp.threads <= 1) {
+            build_processor_hierarchy_node(table_data,
+                (1 << 1) | /* ACPI Processor ID valid */
+                (1 << 3),  /* Node is a Leaf */
+                cluster_offset, n, NULL, 0);
+        } else {
+            if (cpus->cpus[n].props.core_id != core_id) {
+                core_id = cpus->cpus[n].props.core_id;
+                core_offset = table_data->len - pptt_start;
+                build_processor_hierarchy_node(table_data,
                     (0 << 0), /* not a physical package */
-                    parent_offset, core, NULL, 0);
-            } else {
-                build_processor_hierarchy_node(
-                    table_data,
-                    (1 << 1) | /* ACPI Processor ID valid */
-                    (1 << 3),  /* Node is a Leaf */
-                    parent_offset, uid++, NULL, 0);
+                    cluster_offset, core_id, 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,
+            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);
+                core_offset, n, NULL, 0);
         }
     }
 
-    g_queue_free(list);
     acpi_table_end(linker, &table);
 }
 
-- 
2.23.0