panvk: Add cs_single_link_list

The linked list will be used to store occlusion queries to signal after a
renderpass.

Reviewed-by: Lars-Ivar Hesselberg Simonsen <lars-ivar.simonsen@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35687>

src/panfrost/.clang-format

@@ -44,6 +44,7 @@ ForEachMacros: [
   'cs_exception_handler_def',
   'cs_if',
   'cs_match',
+  'cs_single_link_list_for_each_from',
   'cs_update_compute_ctx',
   'cs_update_frag_ctx',
   'cs_update_progress_seqno',

src/panfrost/genxml/cs_builder.h

@@ -1439,6 +1439,15 @@ cs_patch_maybe(struct cs_builder *b, struct cs_maybe *maybe)
    }
 }
 
+struct cs_single_link_list_node {
+   uint64_t next;
+};
+
+struct cs_single_link_list {
+   uint64_t head;
+   uint64_t tail;
+};
+
 /* Pseudoinstructions follow */
 
 static inline void
@@ -2585,6 +2594,55 @@ cs_trace_run_compute_indirect(struct cs_builder *b,
    cs_flush_stores(b);
 }
 
+#define cs_single_link_list_for_each_from(b, current, node_type, base_name)    \
+   cs_while(b, MALI_CS_CONDITION_NEQUAL, current)                              \
+      for (bool done = false; !done;                                           \
+           cs_load64_to(b, current, current,                                   \
+                        offsetof(node_type, base_name.next)),                  \
+                done = true)
+
+/**
+ * Append an item to a cs_single_link_list.
+ *
+ * @param b The current cs_builder.
+ * @param list_base CS register with the base address for the list pointer.
+ * @param list_offset Offset added to list_base.
+ * @param new_node_gpu GPU address of the node to insert.
+ * @param base_offset Offset of cs_single_link_list_node in the new node.
+ * @param head_tail Temporary register pair used in the function.
+ */
+static inline void
+cs_single_link_list_add_tail(struct cs_builder *b, struct cs_index list_base,
+                             int list_offset, struct cs_index new_node_gpu,
+                             int base_offset, struct cs_index head_tail)
+{
+   assert(head_tail.size == 4);
+   assert(head_tail.reg % 2 == 0);
+
+   STATIC_ASSERT(offsetof(struct cs_single_link_list, tail) ==
+                 offsetof(struct cs_single_link_list, head) + sizeof(uint64_t));
+   struct cs_index head = cs_reg64(b, head_tail.reg);
+   struct cs_index tail = cs_reg64(b, head_tail.reg + 2);
+
+   /* Offset of the next pointer inside the node pointed to by new_node_gpu. */
+   const int offset_next =
+      base_offset + offsetof(struct cs_single_link_list_node, next);
+
+   STATIC_ASSERT(offsetof(struct cs_single_link_list, head) == 0);
+   cs_load_to(b, head_tail, list_base, BITFIELD_MASK(4), list_offset);
+
+   /* If the list is empty (head == NULL), set the head, otherwise append to the
+    * last node. */
+   cs_if(b, MALI_CS_CONDITION_EQUAL, head)
+      cs_add64(b, head, new_node_gpu, 0);
+   cs_else(b)
+      cs_store64(b, new_node_gpu, tail, offset_next);
+
+   cs_add64(b, tail, new_node_gpu, 0);
+   cs_store(b, head_tail, list_base, BITFIELD_MASK(4), list_offset);
+   cs_flush_stores(b);
+}
+
 #ifdef __cplusplus
 }
 #endif