drm: misc cleanup

[firewire-audio.git] / drivers / char / drm / drm_irq.c

/**
 * \file drm_irq.h 
 * IRQ support
 *
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Gareth Hughes <gareth@valinux.com>
 */

/*
 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
 *
 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include "drmP.h"

#include <linux/interrupt.h>    /* For task queue support */

/**
 * Get interrupt from bus id.
 * 
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_irq_busid structure.
 * \return zero on success or a negative number on failure.
 * 
 * Finds the PCI device with the specified bus id and gets its IRQ number.
 * This IOCTL is deprecated, and will now return EINVAL for any busid not equal
 * to that of the device that this DRM instance attached to.
 */
int drm_irq_by_busid(struct inode *inode, struct file *filp,
                   unsigned int cmd, unsigned long arg)
{
        drm_file_t *priv = filp->private_data;
        drm_device_t *dev = priv->head->dev;
        drm_irq_busid_t __user *argp = (void __user *)arg;
        drm_irq_busid_t p;

        if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
                return -EINVAL;

        if (copy_from_user(&p, argp, sizeof(p)))
                return -EFAULT;

        if ((p.busnum >> 8) != dev->pci_domain ||
            (p.busnum & 0xff) != dev->pci_bus ||
            p.devnum != dev->pci_slot ||
            p.funcnum != dev->pci_func)
                return -EINVAL;

        p.irq = dev->irq;

        DRM_DEBUG("%d:%d:%d => IRQ %d\n",
                  p.busnum, p.devnum, p.funcnum, p.irq);
        if (copy_to_user(argp, &p, sizeof(p)))
                return -EFAULT;
        return 0;
}

/**
 * Install IRQ handler.
 *
 * \param dev DRM device.
 * \param irq IRQ number.
 *
 * Initializes the IRQ related data, and setups drm_device::vbl_queue. Installs the handler, calling the driver
 * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
 * before and after the installation.
 */
static int drm_irq_install( drm_device_t *dev )
{
        int ret;
        unsigned long sh_flags=0;

        if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
                return -EINVAL;

        if ( dev->irq == 0 )
                return -EINVAL;

        down( &dev->struct_sem );

        /* Driver must have been initialized */
        if ( !dev->dev_private ) {
                up( &dev->struct_sem );
                return -EINVAL;
        }

        if ( dev->irq_enabled ) {
                up( &dev->struct_sem );
                return -EBUSY;
        }
        dev->irq_enabled = 1;
        up( &dev->struct_sem );

        DRM_DEBUG( "%s: irq=%d\n", __FUNCTION__, dev->irq );

        if (drm_core_check_feature(dev, DRIVER_IRQ_VBL)) {
                init_waitqueue_head(&dev->vbl_queue);
                
                spin_lock_init( &dev->vbl_lock );
                
                INIT_LIST_HEAD( &dev->vbl_sigs.head );
                
                dev->vbl_pending = 0;
        }

                                /* Before installing handler */
        dev->driver->irq_preinstall(dev);

                                /* Install handler */
        if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
                sh_flags = SA_SHIRQ;
        
        ret = request_irq( dev->irq, dev->driver->irq_handler,
                           sh_flags, dev->devname, dev );
        if ( ret < 0 ) {
                down( &dev->struct_sem );
                dev->irq_enabled = 0;
                up( &dev->struct_sem );
                return ret;
        }

                                /* After installing handler */
        dev->driver->irq_postinstall(dev);

        return 0;
}

/**
 * Uninstall the IRQ handler.
 *
 * \param dev DRM device.
 *
 * Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
 */
int drm_irq_uninstall( drm_device_t *dev )
{
        int irq_enabled;

        if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
                return -EINVAL;

        down( &dev->struct_sem );
        irq_enabled = dev->irq_enabled;
        dev->irq_enabled = 0;
        up( &dev->struct_sem );

        if ( !irq_enabled )
                return -EINVAL;

        DRM_DEBUG( "%s: irq=%d\n", __FUNCTION__, dev->irq );

        dev->driver->irq_uninstall(dev);

        free_irq( dev->irq, dev );

        return 0;
}
EXPORT_SYMBOL(drm_irq_uninstall);

/**
 * IRQ control ioctl.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_control structure.
 * \return zero on success or a negative number on failure.
 *
 * Calls irq_install() or irq_uninstall() according to \p arg.
 */
int drm_control( struct inode *inode, struct file *filp,
                  unsigned int cmd, unsigned long arg )
{
        drm_file_t *priv = filp->private_data;
        drm_device_t *dev = priv->head->dev;
        drm_control_t ctl;
        
        /* if we haven't irq we fallback for compatibility reasons - this used to be a separate function in drm_dma.h */

        if ( copy_from_user( &ctl, (drm_control_t __user *)arg, sizeof(ctl) ) )
                return -EFAULT;

        switch ( ctl.func ) {
        case DRM_INST_HANDLER:
                if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
                        return 0;
                if (dev->if_version < DRM_IF_VERSION(1, 2) &&
                    ctl.irq != dev->irq)
                        return -EINVAL;
                return drm_irq_install( dev );
        case DRM_UNINST_HANDLER:
                if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
                        return 0;
                return drm_irq_uninstall( dev );
        default:
                return -EINVAL;
        }
}

/**
 * Wait for VBLANK.
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param data user argument, pointing to a drm_wait_vblank structure.
 * \return zero on success or a negative number on failure.
 *
 * Verifies the IRQ is installed. 
 *
 * If a signal is requested checks if this task has already scheduled the same signal
 * for the same vblank sequence number - nothing to be done in
 * that case. If the number of tasks waiting for the interrupt exceeds 100 the
 * function fails. Otherwise adds a new entry to drm_device::vbl_sigs for this
 * task.
 *
 * If a signal is not requested, then calls vblank_wait().
 */
int drm_wait_vblank( DRM_IOCTL_ARGS )
{
        drm_file_t *priv = filp->private_data;
        drm_device_t *dev = priv->head->dev;
        drm_wait_vblank_t __user *argp = (void __user *)data;
        drm_wait_vblank_t vblwait;
        struct timeval now;
        int ret = 0;
        unsigned int flags;

        if (!drm_core_check_feature(dev, DRIVER_IRQ_VBL))
                return -EINVAL;

        if (!dev->irq)
                return -EINVAL;

        DRM_COPY_FROM_USER_IOCTL( vblwait, argp, sizeof(vblwait) );

        switch ( vblwait.request.type & ~_DRM_VBLANK_FLAGS_MASK ) {
        case _DRM_VBLANK_RELATIVE:
                vblwait.request.sequence += atomic_read( &dev->vbl_received );
                vblwait.request.type &= ~_DRM_VBLANK_RELATIVE;
        case _DRM_VBLANK_ABSOLUTE:
                break;
        default:
                return -EINVAL;
        }

        flags = vblwait.request.type & _DRM_VBLANK_FLAGS_MASK;
        
        if ( flags & _DRM_VBLANK_SIGNAL ) {
                unsigned long irqflags;
                drm_vbl_sig_t *vbl_sig;
                
                vblwait.reply.sequence = atomic_read( &dev->vbl_received );

                spin_lock_irqsave( &dev->vbl_lock, irqflags );

                /* Check if this task has already scheduled the same signal
                 * for the same vblank sequence number; nothing to be done in
                 * that case
                 */
                list_for_each_entry( vbl_sig, &dev->vbl_sigs.head, head ) {
                        if (vbl_sig->sequence == vblwait.request.sequence
                            && vbl_sig->info.si_signo == vblwait.request.signal
                            && vbl_sig->task == current)
                        {
                                spin_unlock_irqrestore( &dev->vbl_lock, irqflags );
                                goto done;
                        }
                }

                if ( dev->vbl_pending >= 100 ) {
                        spin_unlock_irqrestore( &dev->vbl_lock, irqflags );
                        return -EBUSY;
                }

                dev->vbl_pending++;

                spin_unlock_irqrestore( &dev->vbl_lock, irqflags );

                if ( !( vbl_sig = drm_alloc( sizeof( drm_vbl_sig_t ), DRM_MEM_DRIVER ) ) ) {
                        return -ENOMEM;
                }

                memset( (void *)vbl_sig, 0, sizeof(*vbl_sig) );

                vbl_sig->sequence = vblwait.request.sequence;
                vbl_sig->info.si_signo = vblwait.request.signal;
                vbl_sig->task = current;

                spin_lock_irqsave( &dev->vbl_lock, irqflags );

                list_add_tail( (struct list_head *) vbl_sig, &dev->vbl_sigs.head );

                spin_unlock_irqrestore( &dev->vbl_lock, irqflags );
        } else {
                if (dev->driver->vblank_wait)
                        ret = dev->driver->vblank_wait( dev, &vblwait.request.sequence );

                do_gettimeofday( &now );
                vblwait.reply.tval_sec = now.tv_sec;
                vblwait.reply.tval_usec = now.tv_usec;
        }

done:
        DRM_COPY_TO_USER_IOCTL( argp, vblwait, sizeof(vblwait) );

        return ret;
}

/**
 * Send the VBLANK signals.
 *
 * \param dev DRM device.
 *
 * Sends a signal for each task in drm_device::vbl_sigs and empties the list.
 *
 * If a signal is not requested, then calls vblank_wait().
 */
void drm_vbl_send_signals( drm_device_t *dev )
{
        struct list_head *list, *tmp;
        drm_vbl_sig_t *vbl_sig;
        unsigned int vbl_seq = atomic_read( &dev->vbl_received );
        unsigned long flags;

        spin_lock_irqsave( &dev->vbl_lock, flags );

        list_for_each_safe( list, tmp, &dev->vbl_sigs.head ) {
                vbl_sig = list_entry( list, drm_vbl_sig_t, head );
                if ( ( vbl_seq - vbl_sig->sequence ) <= (1<<23) ) {
                        vbl_sig->info.si_code = vbl_seq;
                        send_sig_info( vbl_sig->info.si_signo, &vbl_sig->info, vbl_sig->task );

                        list_del( list );

                        drm_free( vbl_sig, sizeof(*vbl_sig), DRM_MEM_DRIVER );

                        dev->vbl_pending--;
                }
        }

        spin_unlock_irqrestore( &dev->vbl_lock, flags );
}
EXPORT_SYMBOL(drm_vbl_send_signals);