Snap for 8564071 from 95be3cd08d582499c402ff79db4d4093b1b8c780 to mainline-sdkext-releaseaml_sdk_331812000aml_sdk_331811100aml_sdk_331811000aml_sdk_331412000aml_sdk_331410000aml_sdk_331310010aml_sdk_331111000aml_sdk_330810050aml_sdk_330810010android13-mainline-sdkext-release

Change-Id: I129b4e72d8b841253c02fc27ce45a85631227ffe

1 files changed, 126 insertions, 0 deletions

diff --git a/src/venus/vkr_ring.h b/src/venus/vkr_ring.h
new file mode 100644
index 00000000..8dc83bb5
--- /dev/null
+++ b/src/venus/vkr_ring.h
@@ -0,0 +1,126 @@
+/*
+ * Copyright 2021 Google LLC
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef VKR_RING_H
+#define VKR_RING_H
+
+#include "vkr_common.h"
+
+/* We read from the ring buffer to a temporary buffer for
+ * virgl_context::submit_cmd.  Until that is changed, we want to put a limit
+ * on the size of the temporary buffer.  It also makes no sense to have huge
+ * rings.
+ *
+ * This must not exceed UINT32_MAX because the ring head and tail are 32-bit.
+ */
+#define VKR_RING_BUFFER_MAX_SIZE (16u * 1024 * 1024)
+
+/* The layout of a ring in a virgl_resource.  This is parsed and discarded by
+ * vkr_ring_create.
+ */
+struct vkr_ring_layout {
+   struct virgl_resource *resource;
+
+   struct vkr_region head;
+   struct vkr_region tail;
+   struct vkr_region status;
+   struct vkr_region buffer;
+   struct vkr_region extra;
+};
+
+static_assert(ATOMIC_INT_LOCK_FREE == 2 && sizeof(atomic_uint) == 4,
+              "vkr_ring_control requires lock-free 32-bit atomic_uint");
+
+/* the control region of a ring */
+struct vkr_ring_control {
+   /* Pointers to ring head, tail, and status.
+    *
+    * Clients increment the tail after commands are added.  We increment the
+    * head after commands are executed.  The status is updated when there is a
+    * status change to the ring thread.
+    */
+   volatile atomic_uint *head;
+   const volatile atomic_uint *tail;
+   volatile atomic_uint *status;
+};
+
+/* the buffer region of a ring */
+struct vkr_ring_buffer {
+   /* the base of the region in the resource */
+   int base_iov_index;
+   size_t base_iov_offset;
+
+   uint32_t size;
+   uint32_t mask;
+
+   /* The current offset in the buffer region.  It is free-running and must be
+    * masked to be between [0, size).
+    */
+   uint32_t cur;
+
+   /* The current iov and iov offset in the resource. */
+   const struct iovec *cur_iov;
+   int cur_iov_index;
+   size_t cur_iov_offset;
+};
+
+/* the extra region of a ring */
+struct vkr_ring_extra {
+   /* the base of the region in the resource */
+   int base_iov_index;
+   size_t base_iov_offset;
+
+   /* used for offset validation */
+   struct vkr_region region;
+
+   /* cache the latest offset->pointer result */
+   size_t cached_offset;
+   volatile atomic_uint *cached_data;
+};
+
+struct vkr_ring {
+   /* used by the caller */
+   vkr_object_id id;
+   struct list_head head;
+
+   /* ring regions */
+   struct virgl_resource *resource;
+   struct vkr_ring_control control;
+   struct vkr_ring_buffer buffer;
+   struct vkr_ring_extra extra;
+
+   /* ring thread */
+   struct virgl_context *context;
+   uint64_t idle_timeout;
+   void *cmd;
+
+   mtx_t mutex;
+   cnd_t cond;
+   thrd_t thread;
+   atomic_bool started;
+   atomic_bool pending_notify;
+};
+
+struct vkr_ring *
+vkr_ring_create(const struct vkr_ring_layout *layout,
+                struct virgl_context *ctx,
+                uint64_t idle_timeout);
+
+void
+vkr_ring_destroy(struct vkr_ring *ring);
+
+void
+vkr_ring_start(struct vkr_ring *ring);
+
+bool
+vkr_ring_stop(struct vkr_ring *ring);
+
+void
+vkr_ring_notify(struct vkr_ring *ring);
+
+bool
+vkr_ring_write_extra(struct vkr_ring *ring, size_t offset, uint32_t val);
+
+#endif /* VKR_RING_H */