gamma_drv.c

讲述linux的初始化过程

					 sizeof(*dev->queuelist[0]),
					 DRM_MEM_QUEUES);
				dev->queuelist[i] = NULL;
			}
		}
		drm_free(dev->queuelist,
			 dev->queue_slots * sizeof(*dev->queuelist),
			 DRM_MEM_QUEUES);
		dev->queuelist	 = NULL;
	}

	drm_dma_takedown(dev);

	dev->queue_count     = 0;
	if (dev->lock.hw_lock) {
		dev->lock.hw_lock    = NULL; /* SHM removed */
		dev->lock.pid	     = 0;
		wake_up_interruptible(&dev->lock.lock_queue);
	}
	up(&dev->struct_sem);

	return 0;
}

int gamma_found(void)
{
	return devices;
}

int gamma_find_devices(void)
{
	struct pci_dev *d = NULL, *one = NULL, *two = NULL;

	d = pci_find_device(PCI_VENDOR_ID_3DLABS,PCI_DEVICE_ID_3DLABS_GAMMA,d);
	if (!d) return 0;

	one = pci_find_device(PCI_VENDOR_ID_3DLABS,PCI_DEVICE_ID_3DLABS_MX,d);
	if (!one) return 0;

	/* Make sure it's on the same card, if not - no MX's found */
	if (PCI_SLOT(d->devfn) != PCI_SLOT(one->devfn)) return 0;

	two = pci_find_device(PCI_VENDOR_ID_3DLABS,PCI_DEVICE_ID_3DLABS_MX,one);
	if (!two) return 1;

	/* Make sure it's on the same card, if not - only 1 MX found */
	if (PCI_SLOT(d->devfn) != PCI_SLOT(two->devfn)) return 1;

	/* Two MX's found - we don't currently support more than 2 */
	return 2;
}

/* gamma_init is called via init_module at module load time, or via
 * linux/init/main.c (this is not currently supported). */

static int __init gamma_init(void)
{
	int		      retcode;
	drm_device_t	      *dev = &gamma_device;

	DRM_DEBUG("\n");

	memset((void *)dev, 0, sizeof(*dev));
	dev->count_lock	  = SPIN_LOCK_UNLOCKED;
	sema_init(&dev->struct_sem, 1);

#ifdef MODULE
	drm_parse_options(gamma);
#endif
	devices = gamma_find_devices();
	if (devices == 0) return -1;

	if ((retcode = misc_register(&gamma_misc))) {
		DRM_ERROR("Cannot register \"%s\"\n", GAMMA_NAME);
		return retcode;
	}
	dev->device = MKDEV(MISC_MAJOR, gamma_misc.minor);
	dev->name   = GAMMA_NAME;

	drm_mem_init();
	drm_proc_init(dev);

	DRM_INFO("Initialized %s %d.%d.%d %s on minor %d with %d MX devices\n",
		 GAMMA_NAME,
		 GAMMA_MAJOR,
		 GAMMA_MINOR,
		 GAMMA_PATCHLEVEL,
		 GAMMA_DATE,
		 gamma_misc.minor,
		 devices);

	return 0;
}

/* gamma_cleanup is called via cleanup_module at module unload time. */

static void __exit gamma_cleanup(void)
{
	drm_device_t	      *dev = &gamma_device;

	DRM_DEBUG("\n");

	drm_proc_cleanup();
	if (misc_deregister(&gamma_misc)) {
		DRM_ERROR("Cannot unload module\n");
	} else {
		DRM_INFO("Module unloaded\n");
	}
	gamma_takedown(dev);
}

module_init(gamma_init);
module_exit(gamma_cleanup);


int gamma_version(struct inode *inode, struct file *filp, unsigned int cmd,
		  unsigned long arg)
{
	drm_version_t version;
	int	      len;

	if (copy_from_user(&version,
			   (drm_version_t *)arg,
			   sizeof(version)))
		return -EFAULT;

#define DRM_COPY(name,value)				     \
	len = strlen(value);				     \
	if (len > name##_len) len = name##_len;		     \
	name##_len = strlen(value);			     \
	if (len && name) {				     \
		if (copy_to_user(name, value, len))	     \
			return -EFAULT;			     \
	}

	version.version_major	   = GAMMA_MAJOR;
	version.version_minor	   = GAMMA_MINOR;
	version.version_patchlevel = GAMMA_PATCHLEVEL;

	DRM_COPY(version.name, GAMMA_NAME);
	DRM_COPY(version.date, GAMMA_DATE);
	DRM_COPY(version.desc, GAMMA_DESC);

	if (copy_to_user((drm_version_t *)arg,
			 &version,
			 sizeof(version)))
		return -EFAULT;
	return 0;
}

int gamma_open(struct inode *inode, struct file *filp)
{
	drm_device_t  *dev    = &gamma_device;
	int	      retcode = 0;

	DRM_DEBUG("open_count = %d\n", dev->open_count);
	if (!(retcode = drm_open_helper(inode, filp, dev))) {
#if LINUX_VERSION_CODE < 0x020333
		MOD_INC_USE_COUNT; /* Needed before Linux 2.3.51 */
#endif
		atomic_inc(&dev->total_open);
		spin_lock(&dev->count_lock);
		if (!dev->open_count++) {
			spin_unlock(&dev->count_lock);
			return gamma_setup(dev);
		}
		spin_unlock(&dev->count_lock);
	}
	return retcode;
}

int gamma_release(struct inode *inode, struct file *filp)
{
	drm_file_t    *priv   = filp->private_data;
	drm_device_t  *dev;
	int	      retcode = 0;

	lock_kernel();
	dev = priv->dev;

	DRM_DEBUG("open_count = %d\n", dev->open_count);
	if (!(retcode = drm_release(inode, filp))) {
#if LINUX_VERSION_CODE < 0x020333
		MOD_DEC_USE_COUNT; /* Needed before Linux 2.3.51 */
#endif
		atomic_inc(&dev->total_close);
		spin_lock(&dev->count_lock);
		if (!--dev->open_count) {
			if (atomic_read(&dev->ioctl_count) || dev->blocked) {
				DRM_ERROR("Device busy: %d %d\n",
					  atomic_read(&dev->ioctl_count),
					  dev->blocked);
				spin_unlock(&dev->count_lock);
				unlock_kernel();
				return -EBUSY;
			}
			spin_unlock(&dev->count_lock);
			unlock_kernel();
			return gamma_takedown(dev);
		}
		spin_unlock(&dev->count_lock);
	}
	unlock_kernel();
	return retcode;
}

/* drm_ioctl is called whenever a process performs an ioctl on /dev/drm. */

int gamma_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
		unsigned long arg)
{
	int		 nr	 = DRM_IOCTL_NR(cmd);
	drm_file_t	 *priv	 = filp->private_data;
	drm_device_t	 *dev	 = priv->dev;
	int		 retcode = 0;
	drm_ioctl_desc_t *ioctl;
	drm_ioctl_t	 *func;

	atomic_inc(&dev->ioctl_count);
	atomic_inc(&dev->total_ioctl);
	++priv->ioctl_count;

	DRM_DEBUG("pid = %d, cmd = 0x%02x, nr = 0x%02x, dev 0x%x, auth = %d\n",
		  current->pid, cmd, nr, dev->device, priv->authenticated);

	if (nr >= GAMMA_IOCTL_COUNT) {
		retcode = -EINVAL;
	} else {
		ioctl	  = &gamma_ioctls[nr];
		func	  = ioctl->func;

		if (!func) {
			DRM_DEBUG("no function\n");
			retcode = -EINVAL;
		} else if ((ioctl->root_only && !capable(CAP_SYS_ADMIN))
			    || (ioctl->auth_needed && !priv->authenticated)) {
			retcode = -EACCES;
		} else {
			retcode = (func)(inode, filp, cmd, arg);
		}
	}

	atomic_dec(&dev->ioctl_count);
	return retcode;
}


int gamma_unlock(struct inode *inode, struct file *filp, unsigned int cmd,
		 unsigned long arg)
{
	drm_file_t	  *priv	  = filp->private_data;
	drm_device_t	  *dev	  = priv->dev;
	drm_lock_t	  lock;

	if (copy_from_user(&lock, (drm_lock_t *)arg, sizeof(lock)))
		return -EFAULT;

	if (lock.context == DRM_KERNEL_CONTEXT) {
		DRM_ERROR("Process %d using kernel context %d\n",
			  current->pid, lock.context);
		return -EINVAL;
	}

	DRM_DEBUG("%d frees lock (%d holds)\n",
		  lock.context,
		  _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock));
	atomic_inc(&dev->total_unlocks);
	if (_DRM_LOCK_IS_CONT(dev->lock.hw_lock->lock))
		atomic_inc(&dev->total_contends);
	drm_lock_transfer(dev, &dev->lock.hw_lock->lock, DRM_KERNEL_CONTEXT);
	gamma_dma_schedule(dev, 1);
	if (!dev->context_flag) {
		if (drm_lock_free(dev, &dev->lock.hw_lock->lock,
				  DRM_KERNEL_CONTEXT)) {
			DRM_ERROR("\n");
		}
	}
#if DRM_DMA_HISTOGRAM
	atomic_inc(&dev->histo.lhld[drm_histogram_slot(get_cycles()
						       - dev->lck_start)]);
#endif

	unblock_all_signals();
	return 0;
}