lib/dmabuf_sync_file: move common stuff into lib

So we can use this across different tests.

v2
  - Add docs for everything (Petri)
  - Add missing copyright and fix headers slightly (Kamil)
v3:
  - Just return true/false, for the has() family of functions, instead
    of tripping up an assert() (Kamil)

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Kamil Konieczny <kamil.konieczny@linux.intel.com>
Cc: Petri Latvala <petri.latvala@intel.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>

1 files changed, 208 insertions, 0 deletions

diff --git a/lib/dmabuf_sync_file.c b/lib/dmabuf_sync_file.c
new file mode 100644
index 000000000..7803ec67d
--- /dev/null
+++ b/lib/dmabuf_sync_file.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#include "igt.h"
+#include "igt_vgem.h"
+#include "sw_sync.h"
+
+#include "dmabuf_sync_file.h"
+
+/**
+ * SECTION: dmabuf_sync_file
+ * @short_description: DMABUF importing/exporting fencing support library
+ * @title: DMABUF Sync File
+ * @include: dmabuf_sync_file.h
+ */
+
+struct igt_dma_buf_sync_file {
+	__u32 flags;
+	__s32 fd;
+};
+
+#define IGT_DMA_BUF_IOCTL_EXPORT_SYNC_FILE _IOWR(DMA_BUF_BASE, 2, struct igt_dma_buf_sync_file)
+#define IGT_DMA_BUF_IOCTL_IMPORT_SYNC_FILE _IOW(DMA_BUF_BASE, 3, struct igt_dma_buf_sync_file)
+
+/**
+ * has_dmabuf_export_sync_file:
+ * @fd: The open drm fd
+ *
+ * Check if the kernel supports exporting a sync file from dmabuf.
+ */
+bool has_dmabuf_export_sync_file(int fd)
+{
+	struct vgem_bo bo;
+	int dmabuf, ret;
+	struct igt_dma_buf_sync_file arg;
+
+	bo.width = 1;
+	bo.height = 1;
+	bo.bpp = 32;
+	vgem_create(fd, &bo);
+
+	dmabuf = prime_handle_to_fd(fd, bo.handle);
+	gem_close(fd, bo.handle);
+
+	arg.flags = DMA_BUF_SYNC_WRITE;
+	arg.fd = -1;
+
+	ret = igt_ioctl(dmabuf, IGT_DMA_BUF_IOCTL_EXPORT_SYNC_FILE, &arg);
+	close(dmabuf);
+
+	return (ret == 0 || errno == ENOTTY);
+}
+
+/**
+ * dmabuf_export_sync_file:
+ * @dmabuf: The dmabuf fd
+ * @flags: The flags to control the behaviour
+ *
+ * Take a snapshot of the current dma-resv fences in the dmabuf, and export as a
+ * syncfile. The @flags should at least specify either DMA_BUF_SYNC_WRITE or
+ * DMA_BUF_SYNC_READ, depending on if we care about the read or write fences.
+ */
+int dmabuf_export_sync_file(int dmabuf, uint32_t flags)
+{
+	struct igt_dma_buf_sync_file arg;
+
+	arg.flags = flags;
+	arg.fd = -1;
+	do_ioctl(dmabuf, IGT_DMA_BUF_IOCTL_EXPORT_SYNC_FILE, &arg);
+
+	return arg.fd;
+}
+
+/**
+ * has_dmabuf_import_sync_file:
+ * @fd: The open drm fd
+ *
+ * Check if the kernel supports importing a sync file into a dmabuf.
+ */
+bool has_dmabuf_import_sync_file(int fd)
+{
+	struct vgem_bo bo;
+	int dmabuf, timeline, fence, ret;
+	struct igt_dma_buf_sync_file arg;
+
+	bo.width = 1;
+	bo.height = 1;
+	bo.bpp = 32;
+	vgem_create(fd, &bo);
+
+	dmabuf = prime_handle_to_fd(fd, bo.handle);
+	gem_close(fd, bo.handle);
+
+	timeline = sw_sync_timeline_create();
+	fence = sw_sync_timeline_create_fence(timeline, 1);
+	sw_sync_timeline_inc(timeline, 1);
+
+	arg.flags = DMA_BUF_SYNC_RW;
+	arg.fd = fence;
+
+	ret = igt_ioctl(dmabuf, IGT_DMA_BUF_IOCTL_IMPORT_SYNC_FILE, &arg);
+	close(dmabuf);
+	close(fence);
+	return (ret == 0 || errno == ENOTTY);
+}
+
+/**
+ * dmabuf_import_sync_file:
+ * @dmabuf: The dmabuf fd
+ * @flags: The flags to control the behaviour
+ * @sync_fd: The sync file (i.e our fence) to import
+ *
+ * Import the sync file @sync_fd, into the dmabuf. The @flags should at least
+ * specify DMA_BUF_SYNC_WRITE or DMA_BUF_SYNC_READ, depending on if we are
+ * importing the @sync_fd as a read or write fence.
+ */
+void dmabuf_import_sync_file(int dmabuf, uint32_t flags, int sync_fd)
+{
+	struct igt_dma_buf_sync_file arg;
+
+	arg.flags = flags;
+	arg.fd = sync_fd;
+	do_ioctl(dmabuf, IGT_DMA_BUF_IOCTL_IMPORT_SYNC_FILE, &arg);
+}
+
+/**
+ * dmabuf_import_timeline_fence:
+ * @dmabuf: The dmabuf fd
+ * @flags: The flags to control the behaviour
+ * @timeline: The sync file timeline where the new fence is created
+ * @seqno: The sequence number to use for the fence
+ *
+ * Create a new fence as part of @timeline, and import as a sync file into the
+ * dmabuf.  The @flags should at least specify DMA_BUF_SYNC_WRITE or
+ * DMA_BUF_SYNC_READ, depending on if we are importing the new fence as a read
+ * or write fence.
+ */
+void dmabuf_import_timeline_fence(int dmabuf, uint32_t flags,
+				  int timeline, uint32_t seqno)
+{
+	int fence;
+
+	fence = sw_sync_timeline_create_fence(timeline, seqno);
+	dmabuf_import_sync_file(dmabuf, flags, fence);
+	close(fence);
+}
+
+/**
+ * dmabuf_busy:
+ * @dmabuf: The dmabuf fd
+ * @flags: The flags to control the behaviour
+ *
+ * Check if the fences in the dmabuf are still busy. The @flags should at least
+ * specify DMA_BUF_SYNC_WRITE or DMA_BUF_SYNC_READ, depending on if we are
+ * checking if the read or read fences have all signalled. Or DMA_BUF_SYNC_RW if
+ * we care about both.
+ */
+bool dmabuf_busy(int dmabuf, uint32_t flags)
+{
+	struct pollfd pfd = { .fd = dmabuf };
+
+	/* If DMA_BUF_SYNC_WRITE is set, we don't want to set POLLIN or
+	 * else poll() may return a non-zero value if there are only read
+	 * fences because POLLIN is ready even if POLLOUT isn't.
+	 */
+	if (flags & DMA_BUF_SYNC_WRITE)
+		pfd.events |= POLLOUT;
+	else if (flags & DMA_BUF_SYNC_READ)
+		pfd.events |= POLLIN;
+
+	return poll(&pfd, 1, 0) == 0;
+}
+
+/**
+ * sync_file_busy:
+ * @sync_file: The sync file to check
+ *
+ * Check if the @sync_file is still busy or not.
+ */
+bool sync_file_busy(int sync_file)
+{
+	struct pollfd pfd = { .fd = sync_file, .events = POLLIN };
+	return poll(&pfd, 1, 0) == 0;
+}
+
+/**
+ * dmabuf_sync_file_busy:
+ * @dmabuf: The dmabuf fd
+ * @flags: The flags to control the behaviour
+ *
+ * Export the current fences in @dmabuf as a sync file and check if still busy.
+ * The @flags should at least contain DMA_BUF_SYNC_WRITE or DMA_BUF_SYNC_READ,
+ * to specify which fences are to be exported from the @dmabuf and checked if
+ * busy. Or DMA_BUF_SYNC_RW if we care about both.
+ */
+bool dmabuf_sync_file_busy(int dmabuf, uint32_t flags)
+{
+	int sync_file;
+	bool busy;
+
+	sync_file = dmabuf_export_sync_file(dmabuf, flags);
+	busy = sync_file_busy(sync_file);
+	close(sync_file);
+
+	return busy;
+}