From f3fe20bdde5b7d19b5fe94c83445ce477eade432 Mon Sep 17 00:00:00 2001
From: Wim Taymans <wtaymans@redhat.com>
Date: Tue, 2 Apr 2024 11:42:09 +0200
Subject: [PATCH] buffer: add GenericFd memory type

Add a Generic fd type. These could be eventfd or timerfd, the meaning
can depend on extra metadata.
---
 spa/include/spa/buffer/buffer.h              | 14 +++++++++++---
 spa/include/spa/buffer/type-info.h           |  1 +
 src/modules/module-client-node/client-node.c |  1 +
 test/test-spa-buffer.c                       |  3 ++-
 4 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/spa/include/spa/buffer/buffer.h b/spa/include/spa/buffer/buffer.h
index 8c02e9e08..e29be088a 100644
--- a/spa/include/spa/buffer/buffer.h
+++ b/spa/include/spa/buffer/buffer.h
@@ -27,9 +27,17 @@ enum spa_data_type {
 	SPA_DATA_Invalid,
 	SPA_DATA_MemPtr,		/**< pointer to memory, the data field in
 					  *  struct spa_data is set. */
-	SPA_DATA_MemFd,			/**< generic fd, mmap to get to memory */
-	SPA_DATA_DmaBuf,		/**< fd to dmabuf memory */
-	SPA_DATA_MemId,			/**< memory is identified with an id */
+	SPA_DATA_MemFd,			/**< memfd, mmap to get to memory. */
+	SPA_DATA_DmaBuf,		/**< fd to dmabuf memory. This might not be readily
+					  *  mappable (unless the MAPPABLE flag is set) and should
+					  *  normally be handled with DMABUF apis. */
+	SPA_DATA_MemId,			/**< memory is identified with an id. The actual memory
+					  *  can be obtained in some other way and can be identified
+					  *  with this id. */
+	SPA_DATA_GenericFd,		/**< generic fd, type and usage might be in metadata. If
+					  *  there is a size and MAPPABLE flag, this can be mmapped
+					  *  to obtain a memory region. The semantics of memfd might
+					  *  not be available (SEALING, ...) */
 
 	_SPA_DATA_LAST,			/**< not part of ABI */
 };
diff --git a/spa/include/spa/buffer/type-info.h b/spa/include/spa/buffer/type-info.h
index 83dce2b80..bb4103f3f 100644
--- a/spa/include/spa/buffer/type-info.h
+++ b/spa/include/spa/buffer/type-info.h
@@ -35,6 +35,7 @@ static const struct spa_type_info spa_type_data_type[] = {
 	{ SPA_DATA_MemFd, SPA_TYPE_Int, SPA_TYPE_INFO_DATA_FD_BASE "MemFd", NULL },
 	{ SPA_DATA_DmaBuf, SPA_TYPE_Int, SPA_TYPE_INFO_DATA_FD_BASE "DmaBuf", NULL },
 	{ SPA_DATA_MemId, SPA_TYPE_Int, SPA_TYPE_INFO_DATA_BASE "MemId", NULL },
+	{ SPA_DATA_GenericFd, SPA_TYPE_Int, SPA_TYPE_INFO_DATA_BASE "GenericFd", NULL },
 	{ 0, 0, NULL, NULL },
 };
 
diff --git a/src/modules/module-client-node/client-node.c b/src/modules/module-client-node/client-node.c
index 45ab83627..a3b70810b 100644
--- a/src/modules/module-client-node/client-node.c
+++ b/src/modules/module-client-node/client-node.c
@@ -855,6 +855,7 @@ do_port_use_buffers(struct impl *impl,
 			switch (d->type) {
 			case SPA_DATA_DmaBuf:
 			case SPA_DATA_MemFd:
+			case SPA_DATA_GenericFd:
 			{
 				uint32_t flags = PW_MEMBLOCK_FLAG_DONT_CLOSE;
 
diff --git a/test/test-spa-buffer.c b/test/test-spa-buffer.c
index d0c0e0bb9..eb4076951 100644
--- a/test/test-spa-buffer.c
+++ b/test/test-spa-buffer.c
@@ -17,7 +17,8 @@ PWTEST(buffer_abi_types)
 	pwtest_int_eq(SPA_DATA_MemFd, 2);
 	pwtest_int_eq(SPA_DATA_DmaBuf, 3);
 	pwtest_int_eq(SPA_DATA_MemId, 4);
-	pwtest_int_eq(_SPA_DATA_LAST, 5);
+	pwtest_int_eq(SPA_DATA_GenericFd, 5);
+	pwtest_int_eq(_SPA_DATA_LAST, 6);
 
 	/* meta */
 	pwtest_int_eq(SPA_META_Invalid, 0);