ffb_drv.c

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	atomic_set(&dev->ioctl_count, 0);
	atomic_set(&dev->vma_count, 0);
	dev->buf_use = 0;
	atomic_set(&dev->buf_alloc, 0);

	atomic_set(&dev->total_open, 0);
	atomic_set(&dev->total_close, 0);
	atomic_set(&dev->total_ioctl, 0);
	atomic_set(&dev->total_irq, 0);
	atomic_set(&dev->total_ctx, 0);
	atomic_set(&dev->total_locks, 0);
	atomic_set(&dev->total_unlocks, 0);
	atomic_set(&dev->total_contends, 0);
	atomic_set(&dev->total_sleeps, 0);

	for (i = 0; i < DRM_HASH_SIZE; i++) {
		dev->magiclist[i].head = NULL;
		dev->magiclist[i].tail = NULL;
	}

	dev->maplist	    = NULL;
	dev->map_count	    = 0;
	dev->vmalist	    = NULL;
	dev->lock.hw_lock   = NULL;
	init_waitqueue_head(&dev->lock.lock_queue);
	dev->queue_count    = 0;
	dev->queue_reserved = 0;
	dev->queue_slots    = 0;
	dev->queuelist	    = NULL;
	dev->irq	    = 0;
	dev->context_flag   = 0;
	dev->interrupt_flag = 0;
	dev->dma            = 0;
	dev->dma_flag	    = 0;
	dev->last_context   = 0;
	dev->last_switch    = 0;
	dev->last_checked   = 0;
	init_timer(&dev->timer);
	init_waitqueue_head(&dev->context_wait);

	dev->ctx_start	    = 0;
	dev->lck_start	    = 0;
	
	dev->buf_rp	  = dev->buf;
	dev->buf_wp	  = dev->buf;
	dev->buf_end	  = dev->buf + DRM_BSZ;
	dev->buf_async	  = NULL;
	init_waitqueue_head(&dev->buf_readers);
	init_waitqueue_head(&dev->buf_writers);

	return 0;
}

static int ffb_open(struct inode *inode, struct file *filp)
{
	drm_device_t *dev;
	int minor, i;
	int ret = 0;

	minor = MINOR(inode->i_rdev);
	for (i = 0; i < ffb_dev_table_size; i++) {
		ffb_dev_priv_t *ffb_priv;

		ffb_priv = (ffb_dev_priv_t *) (ffb_dev_table[i] + 1);

		if (ffb_priv->miscdev.minor == minor)
			break;
	}

	if (i >= ffb_dev_table_size)
		return -EINVAL;

	dev = ffb_dev_table[i];
	if (!dev)
		return -EINVAL;

	DRM_DEBUG("open_count = %d\n", dev->open_count);
	ret = drm_open_helper(inode, filp, dev);
	if (!ret) {
		atomic_inc(&dev->total_open);
		spin_lock(&dev->count_lock);
		if (!dev->open_count++) {
			spin_unlock(&dev->count_lock);
			return ffb_setup(dev);
		}
		spin_unlock(&dev->count_lock);
	}

	return ret;
}

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

	lock_kernel();
	dev = priv->dev;
	DRM_DEBUG("open_count = %d\n", dev->open_count);
	if (dev->lock.hw_lock != NULL
	    && _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock)
	    && dev->lock.pid == current->pid) {
		ffb_dev_priv_t *fpriv = (ffb_dev_priv_t *) (dev + 1);
		int context = _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock);
		int idx;

		/* We have to free up the rogue hw context state
		 * holding error or else we will leak it.
		 */
		idx = context - 1;
		if (fpriv->hw_state[idx] != NULL) {
			kfree(fpriv->hw_state[idx]);
			fpriv->hw_state[idx] = NULL;
		}
	}

	ret = drm_release(inode, filp);

	if (!ret) {
		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);
			ret = ffb_takedown(dev);
			unlock_kernel();
			return ret;
		}
		spin_unlock(&dev->count_lock);
	}

	unlock_kernel();
	return ret;
}

static int ffb_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;
	drm_ioctl_desc_t *ioctl;
	drm_ioctl_t	 *func;
	int		 ret;

	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 >= FFB_IOCTL_COUNT) {
		ret = -EINVAL;
	} else {
		ioctl	  = &ffb_ioctls[nr];
		func	  = ioctl->func;

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

	return ret;
}

static int ffb_lock(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;
        DECLARE_WAITQUEUE(entry, current);
        int               ret	= 0;
        drm_lock_t        lock;

	ret = copy_from_user(&lock, (drm_lock_t *)arg, sizeof(lock));
	if (ret)
		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 (pid %d) requests lock (0x%08x), flags = 0x%08x\n",
                  lock.context, current->pid, dev->lock.hw_lock->lock,
                  lock.flags);

	add_wait_queue(&dev->lock.lock_queue, &entry);
	for (;;) {
		if (!dev->lock.hw_lock) {
			/* Device has been unregistered */
			ret = -EINTR;
			break;
		}
		if (drm_lock_take(&dev->lock.hw_lock->lock,
				  lock.context)) {
			dev->lock.pid       = current->pid;
			dev->lock.lock_time = jiffies;
			atomic_inc(&dev->total_locks);
			break;  /* Got lock */
		}
                        
		/* Contention */
		atomic_inc(&dev->total_sleeps);
		current->state = TASK_INTERRUPTIBLE;
		current->policy |= SCHED_YIELD;
		schedule();
		if (signal_pending(current)) {
			ret = -ERESTARTSYS;
			break;
		}
	}
	current->state = TASK_RUNNING;
	remove_wait_queue(&dev->lock.lock_queue, &entry);

        if (!ret &&
	    (dev->last_context != lock.context))
		ffb_context_switch(dev, dev->last_context, lock.context);

        DRM_DEBUG("%d %s\n", lock.context, ret ? "interrupted" : "has lock");

        return ret;
}

int ffb_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;
	unsigned int old, new, prev, ctx;
	int ret;

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

	/* We no longer really hold it, but if we are the next
	 * agent to request it then we should just be able to
	 * take it immediately and not eat the ioctl.
	 */
	dev->lock.pid = 0;
	{
		__volatile__ unsigned int *plock = &dev->lock.hw_lock->lock;

		do {
			old  = *plock;
			new  = ctx;
			prev = cmpxchg(plock, old, new);
		} while (prev != old);
	}

	wake_up_interruptible(&dev->lock.lock_queue);
	
	return 0;
}

static void align_fb_mapping(struct vm_area_struct *vma)
{
	unsigned long j, alignment;

	j = vma->vm_end - vma->vm_start;
	for (alignment = (4 * 1024 * 1024); alignment > PAGE_SIZE; alignment >>= 3)
		if (j >= alignment)
			break;
	if (alignment > PAGE_SIZE) {
		j = alignment;
		alignment = j - (vma->vm_start & (j - 1));
		if (alignment != j) {
			struct vm_area_struct *vmm = find_vma(current->mm,vma->vm_start);

			if (!vmm || vmm->vm_start >= vma->vm_end + alignment) {
				vma->vm_start += alignment;
				vma->vm_end += alignment;
			}
		}
	}
}

/* The problem here is, due to virtual cache aliasing,
 * we must make sure the shared memory area lands in the
 * same dcache line for both the kernel and all drm clients.
 */
static void align_shm_mapping(struct vm_area_struct *vma, unsigned long kvirt)
{
	kvirt &= PAGE_SIZE;
	if ((vma->vm_start & PAGE_SIZE) != kvirt) {
		struct vm_area_struct *vmm = find_vma(current->mm, vma->vm_start);

		if (!vmm || vmm->vm_start >= vma->vm_end + PAGE_SIZE) {
			vma->vm_start += PAGE_SIZE;
			vma->vm_end += PAGE_SIZE;
		}
	}
}

extern struct vm_operations_struct drm_vm_ops;
extern struct vm_operations_struct drm_vm_shm_ops;
extern struct vm_operations_struct drm_vm_shm_lock_ops;

static int ffb_mmap(struct file *filp, struct vm_area_struct *vma)
{
	drm_file_t	*priv	= filp->private_data;
	drm_device_t	*dev	= priv->dev;
	drm_map_t	*map	= NULL;
	ffb_dev_priv_t	*ffb_priv;
	int		i, minor;
	
	DRM_DEBUG("start = 0x%lx, end = 0x%lx, offset = 0x%lx\n",
		  vma->vm_start, vma->vm_end, VM_OFFSET(vma));

	minor = MINOR(filp->f_dentry->d_inode->i_rdev);
	ffb_priv = NULL;
	for (i = 0; i < ffb_dev_table_size; i++) {
		ffb_priv = (ffb_dev_priv_t *) (ffb_dev_table[i] + 1);
		if (ffb_priv->miscdev.minor == minor)
			break;
	}
	if (i >= ffb_dev_table_size)
		return -EINVAL;

	/* We don't support/need dma mappings, so... */
	if (!VM_OFFSET(vma))
		return -EINVAL;

	for (i = 0; i < dev->map_count; i++) {
		unsigned long off;

		map = dev->maplist[i];

		/* Ok, a little hack to make 32-bit apps work. */
		off = (map->offset & 0xffffffff);
		if (off == VM_OFFSET(vma))
			break;
	}

	if (i >= dev->map_count)
		return -EINVAL;

	if (!map ||
	    ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
		return -EPERM;

	if (map->size != (vma->vm_end - vma->vm_start))
		return -EINVAL;

	/* Set read-only attribute before mappings are created
	 * so it works for fb/reg maps too.
	 */
	if (map->flags & _DRM_READ_ONLY)
		vma->vm_page_prot = __pgprot(pte_val(pte_wrprotect(
			__pte(pgprot_val(vma->vm_page_prot)))));

	switch (map->type) {
	case _DRM_FRAME_BUFFER:
		align_fb_mapping(vma);
		/* FALLTHROUGH */

	case _DRM_REGISTERS:
		/* In order to handle 32-bit drm apps/xserver we
		 * play a trick.  The mappings only really specify
		 * the 32-bit offset from the cards 64-bit base
		 * address, and we just add in the base here.
		 */
		vma->vm_flags |= VM_IO;
		if (io_remap_page_range(vma->vm_start,
					ffb_priv->card_phys_base + VM_OFFSET(vma),
					vma->vm_end - vma->vm_start,
					vma->vm_page_prot, 0))
			return -EAGAIN;

		vma->vm_ops = &drm_vm_ops;
		break;
	case _DRM_SHM:
		align_shm_mapping(vma, (unsigned long)dev->lock.hw_lock);
		if (map->flags & _DRM_CONTAINS_LOCK)
			vma->vm_ops = &drm_vm_shm_lock_ops;
		else {
			vma->vm_ops = &drm_vm_shm_ops;
			vma->vm_private_data = (void *) map;
		}

		/* Don't let this area swap.  Change when
		 * DRM_KERNEL advisory is supported.
		 */
		vma->vm_flags |= VM_LOCKED;
		break;
	default:
		return -EINVAL;	/* This should never happen. */
	};

	vma->vm_flags |= VM_LOCKED | VM_SHM; /* Don't swap */

	vma->vm_file = filp; /* Needed for drm_vm_open() */
	drm_vm_open(vma);
	return 0;
}

module_init(ffb_init);
module_exit(ffb_cleanup);