1 files changed, 143 insertions, 0 deletions
diff --git a/kms++/src/dumbframebuffer.cpp b/kms++/src/dumbframebuffer.cpp
new file mode 100644
index 0000000..421dac4
--- /dev/null
+++ b/kms++/src/dumbframebuffer.cpp
@@ -0,0 +1,143 @@
+
+#include <cstring>
+#include <cerrno>
+#include <stdexcept>
+#include <sys/mman.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <drm_fourcc.h>
+#include <drm.h>
+#include <drm_mode.h>
+
+#include <kms++/kms++.h>
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+using namespace std;
+
+namespace kms
+{
+DumbFramebuffer::DumbFramebuffer(Card& card, uint32_t width, uint32_t height, const string& fourcc)
+	: DumbFramebuffer(card, width, height, fourcc_str_to_pixel_format(fourcc))
+{
+}
+
+DumbFramebuffer::DumbFramebuffer(Card& card, uint32_t width, uint32_t height, PixelFormat format)
+	: Framebuffer(card, width, height), m_format(format)
+{
+	int r;
+
+	const PixelFormatInfo& format_info = get_pixel_format_info(m_format);
+
+	m_num_planes = format_info.num_planes;
+
+	for (int i = 0; i < format_info.num_planes; ++i) {
+		FramebufferPlane& plane = m_planes.at(i);
+
+		auto [w, h, bpp] = format_info.dumb_size(width, height, i);
+
+		/* create dumb buffer */
+		struct drm_mode_create_dumb creq = drm_mode_create_dumb();
+		creq.width = w;
+		creq.height = h;
+		creq.bpp = bpp;
+		r = drmIoctl(card.fd(), DRM_IOCTL_MODE_CREATE_DUMB, &creq);
+		if (r)
+			throw invalid_argument(string("DRM_IOCTL_MODE_CREATE_DUMB failed: ") + strerror(errno));
+
+		plane.handle = creq.handle;
+		plane.stride = creq.pitch;
+		plane.size = creq.height * creq.pitch;
+		plane.offset = 0;
+		plane.map = 0;
+		plane.prime_fd = -1;
+	}
+
+	/* create framebuffer object for the dumb-buffer */
+	uint32_t bo_handles[4] = {
+		m_planes[0].handle,
+		m_planes[1].handle,
+		m_planes[2].handle,
+		m_planes[3].handle,
+	};
+	uint32_t pitches[4] = {
+		m_planes[0].stride,
+		m_planes[1].stride,
+		m_planes[2].stride,
+		m_planes[3].stride,
+	};
+	uint32_t offsets[4] = {
+		m_planes[0].offset,
+		m_planes[1].offset,
+		m_planes[2].offset,
+		m_planes[3].offset,
+	};
+	uint32_t id;
+	r = drmModeAddFB2(card.fd(), width, height, pixel_format_to_fourcc(format),
+			  bo_handles, pitches, offsets, &id, 0);
+	if (r)
+		throw invalid_argument(string("drmModeAddFB2 failed: ") + strerror(errno));
+
+	set_id(id);
+}
+
+DumbFramebuffer::~DumbFramebuffer()
+{
+	/* delete framebuffer */
+	drmModeRmFB(card().fd(), id());
+
+	for (uint i = 0; i < m_num_planes; ++i) {
+		FramebufferPlane& plane = m_planes.at(i);
+
+		/* unmap buffer */
+		if (plane.map)
+			munmap(plane.map, plane.size);
+
+		/* delete dumb buffer */
+		struct drm_mode_destroy_dumb dreq = drm_mode_destroy_dumb();
+		dreq.handle = plane.handle;
+		drmIoctl(card().fd(), DRM_IOCTL_MODE_DESTROY_DUMB, &dreq);
+		if (plane.prime_fd >= 0)
+			::close(plane.prime_fd);
+	}
+}
+
+uint8_t* DumbFramebuffer::map(unsigned plane)
+{
+	FramebufferPlane& p = m_planes.at(plane);
+
+	if (p.map)
+		return p.map;
+
+	/* prepare buffer for memory mapping */
+	struct drm_mode_map_dumb mreq = drm_mode_map_dumb();
+	mreq.handle = p.handle;
+	int r = drmIoctl(card().fd(), DRM_IOCTL_MODE_MAP_DUMB, &mreq);
+	if (r)
+		throw invalid_argument(string("DRM_IOCTL_MODE_MAP_DUMB failed: ") + strerror(errno));
+
+	/* perform actual memory mapping */
+	p.map = static_cast<uint8_t*>(mmap(0, p.size, PROT_READ | PROT_WRITE, MAP_SHARED,
+			       card().fd(), mreq.offset));
+	if (p.map == MAP_FAILED)
+		throw invalid_argument(string("mmap failed: ") + strerror(errno));
+
+	return p.map;
+}
+
+int DumbFramebuffer::prime_fd(unsigned int plane)
+{
+	if (m_planes.at(plane).prime_fd >= 0)
+		return m_planes.at(plane).prime_fd;
+
+	int r = drmPrimeHandleToFD(card().fd(), m_planes.at(plane).handle,
+				   DRM_CLOEXEC | O_RDWR, &m_planes.at(plane).prime_fd);
+	if (r)
+		throw std::runtime_error("drmPrimeHandleToFD failed");
+
+	return m_planes.at(plane).prime_fd;
+}
+
+} // namespace kms