kwin/src/core/drmdevice.cpp

/*
    KWin - the KDE window manager
    This file is part of the KDE project.

    SPDX-FileCopyrightText: 2024 Xaver Hugl <xaver.hugl@gmail.com>

    SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "drmdevice.h"

#include "gbmgraphicsbufferallocator.h"

#include <fcntl.h>
#include <gbm.h>
#include <sys/stat.h>
#include <xf86drm.h>

namespace KWin
{

DrmDevice::DrmDevice(const QString &path, dev_t id, FileDescriptor &&fd, gbm_device *gbmDevice)
    : m_path(path)
    , m_id(id)
    , m_fd(std::move(fd))
    , m_gbmDevice(gbmDevice)
    , m_allocator(std::make_unique<GbmGraphicsBufferAllocator>(gbmDevice))
{
    uint64_t value = 0;
    m_supportsSyncObjTimelines = drmGetCap(m_fd.get(), DRM_CAP_SYNCOBJ_TIMELINE, &value) == 0 && value != 0;
}

DrmDevice::~DrmDevice()
{
    gbm_device_destroy(m_gbmDevice);
}

QString DrmDevice::path() const
{
    return m_path;
}

dev_t DrmDevice::deviceId() const
{
    return m_id;
}

gbm_device *DrmDevice::gbmDevice() const
{
    return m_gbmDevice;
}

GraphicsBufferAllocator *DrmDevice::allocator() const
{
    return m_allocator.get();
}

int DrmDevice::fileDescriptor() const
{
    return m_fd.get();
}

bool DrmDevice::supportsSyncObjTimelines() const
{
    return m_supportsSyncObjTimelines;
}

std::unique_ptr<DrmDevice> DrmDevice::open(const QString &path)
{
    return openWithAuthentication(path, -1);
}

std::unique_ptr<DrmDevice> DrmDevice::openWithAuthentication(const QString &path, int authenticatedFd)
{
    FileDescriptor fd(::open(path.toLocal8Bit(), O_RDWR | O_CLOEXEC));
    if (!fd.isValid()) {
        return nullptr;
    }
    struct stat buf;
    if (fstat(fd.get(), &buf) == -1) {
        return nullptr;
    }
    if (authenticatedFd != -1) {
        drm_magic_t magic;
        drmGetMagic(fd.get(), &magic);
        drmAuthMagic(authenticatedFd, magic);
    }
    gbm_device *device = gbm_create_device(fd.get());
    if (!device) {
        return nullptr;
    }
    return std::unique_ptr<DrmDevice>(new DrmDevice(path, buf.st_rdev, std::move(fd), device));
}
}