1 files changed, 129 insertions, 0 deletions
diff --git a/kms++/src/dmabufframebuffer.cpp b/kms++/src/dmabufframebuffer.cpp
new file mode 100644
index 0000000..00ab94e
--- /dev/null
+++ b/kms++/src/dmabufframebuffer.cpp
@@ -0,0 +1,129 @@
+
+#include <cstring>
+#include <cerrno>
+
+#include <stdexcept>
+#include <sys/mman.h>
+#include <sys/ioctl.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+#include <linux/dma-buf.h>
+
+#include <kms++/kms++.h>
+
+using namespace std;
+
+namespace kms
+{
+
+DmabufFramebuffer::DmabufFramebuffer(Card& card, uint32_t width, uint32_t height, PixelFormat format,
+				     vector<int> fds, vector<uint32_t> pitches, vector<uint32_t> offsets)
+	: Framebuffer(card, width, height)
+{
+	int r;
+
+	m_format = format;
+
+	const PixelFormatInfo& format_info = get_pixel_format_info(format);
+
+	m_num_planes = format_info.num_planes;
+
+	for (int i = 0; i < format_info.num_planes; ++i) {
+		FramebufferPlane& plane = m_planes[i];
+
+		plane.prime_fd = fds[i];
+
+		r = drmPrimeFDToHandle(card.fd(), fds[i], &plane.handle);
+		if (r)
+			throw invalid_argument(string("drmPrimeFDToHandle: ") + strerror(errno));
+
+		plane.stride = pitches[i];
+		plane.offset = offsets[i];
+		plane.size = plane.stride * height;
+		plane.map = 0;
+	}
+
+	uint32_t id;
+	uint32_t bo_handles[4] = { m_planes[0].handle, m_planes[1].handle, m_planes[2].handle, m_planes[3].handle };
+	r = drmModeAddFB2(card.fd(), width, height, (uint32_t)format,
+			  bo_handles, pitches.data(), offsets.data(), &id, 0);
+	if (r)
+		throw invalid_argument(string("drmModeAddFB2 failed: ") + strerror(errno));
+
+	set_id(id);
+}
+
+DmabufFramebuffer::~DmabufFramebuffer()
+{
+	drmModeRmFB(card().fd(), id());
+}
+
+uint8_t* DmabufFramebuffer::map(unsigned plane)
+{
+	FramebufferPlane& p = m_planes[plane];
+
+	if (p.map)
+		return p.map;
+
+	p.map = (uint8_t *)mmap(0, p.size, PROT_READ | PROT_WRITE, MAP_SHARED,
+				p.prime_fd, 0);
+	if (p.map == MAP_FAILED)
+		throw invalid_argument(string("mmap failed: ") + strerror(errno));
+
+	return p.map;
+}
+
+int DmabufFramebuffer::prime_fd(unsigned plane)
+{
+	FramebufferPlane& p = m_planes[plane];
+
+	return p.prime_fd;
+}
+
+void DmabufFramebuffer::begin_cpu_access(CpuAccess access)
+{
+	if (m_sync_flags != 0)
+		throw runtime_error("begin_cpu sync already started");
+
+	switch (access) {
+	case CpuAccess::Read:
+		m_sync_flags = DMA_BUF_SYNC_READ;
+		break;
+	case CpuAccess::Write:
+		m_sync_flags = DMA_BUF_SYNC_WRITE;
+		break;
+	case CpuAccess::ReadWrite:
+		m_sync_flags = DMA_BUF_SYNC_RW;
+		break;
+	}
+
+	dma_buf_sync dbs {
+		.flags = DMA_BUF_SYNC_START | m_sync_flags
+	};
+
+	for (uint32_t p = 0; p < m_num_planes; ++p) {
+		int r = ioctl(prime_fd(p), DMA_BUF_IOCTL_SYNC, &dbs);
+		if (r)
+			throw runtime_error("DMA_BUF_IOCTL_SYNC failed");
+	}
+}
+
+void DmabufFramebuffer::end_cpu_access()
+{
+	if (m_sync_flags == 0)
+		throw runtime_error("begin_cpu sync not started");
+
+	dma_buf_sync dbs {
+		.flags = DMA_BUF_SYNC_END | m_sync_flags
+	};
+
+	for (uint32_t p = 0; p < m_num_planes; ++p) {
+		int r = ioctl(prime_fd(p), DMA_BUF_IOCTL_SYNC, &dbs);
+		if (r)
+			throw runtime_error("DMA_BUF_IOCTL_SYNC failed");
+	}
+
+	m_sync_flags = 0;
+}
+
+}