renesas/virt/virtio-spec.git - Virtio specification

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Diffstat (limited to 'content.tex')

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/** * \file drm_irq.c * 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 file_priv DRM file private. * \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 drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_irq_busid *p = data; if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) return -EINVAL; if ((p->busnum >> 8) != drm_get_pci_domain(dev) || (p->busnum & 0xff) != dev->pdev->bus->number || p->devnum != PCI_SLOT(dev->pdev->devfn) || p->funcnum != PCI_FUNC(dev->pdev->devfn)) return -EINVAL; p->irq = dev->pdev->irq; DRM_DEBUG("%d:%d:%d => IRQ %d\n", p->busnum, p->devnum, p->funcnum, p->irq); return 0; } static void vblank_disable_fn(unsigned long arg) { struct drm_device *dev = (struct drm_device *)arg; unsigned long irqflags; int i; if (!dev->vblank_disable_allowed) return; for (i = 0; i < dev->num_crtcs; i++) { spin_lock_irqsave(&dev->vbl_lock, irqflags); if (atomic_read(&dev->vblank_refcount[i]) == 0 && dev->vblank_enabled[i]) { DRM_DEBUG("disabling vblank on crtc %d\n", i); dev->last_vblank[i] = dev->driver->get_vblank_counter(dev, i); dev->driver->disable_vblank(dev, i); dev->vblank_enabled[i] = 0; } spin_unlock_irqrestore(&dev->vbl_lock, irqflags); } } void drm_vblank_cleanup(struct drm_device *dev) { /* Bail if the driver didn't call drm_vblank_init() */ if (dev->num_crtcs == 0) return; del_timer(&dev->vblank_disable_timer); vblank_disable_fn((unsigned long)dev); drm_free(dev->vbl_queue, sizeof(*dev->vbl_queue) * dev->num_crtcs, DRM_MEM_DRIVER); drm_free(dev->vbl_sigs, sizeof(*dev->vbl_sigs) * dev->num_crtcs, DRM_MEM_DRIVER); drm_free(dev->_vblank_count, sizeof(*dev->_vblank_count) * dev->num_crtcs, DRM_MEM_DRIVER); drm_free(dev->vblank_refcount, sizeof(*dev->vblank_refcount) * dev->num_crtcs, DRM_MEM_DRIVER); drm_free(dev->vblank_enabled, sizeof(*dev->vblank_enabled) * dev->num_crtcs, DRM_MEM_DRIVER); drm_free(dev->last_vblank, sizeof(*dev->last_vblank) * dev->num_crtcs, DRM_MEM_DRIVER); drm_free(dev->vblank_inmodeset, sizeof(*dev->vblank_inmodeset) * dev->num_crtcs, DRM_MEM_DRIVER); dev->num_crtcs = 0; } int drm_vblank_init(struct drm_device *dev, int num_crtcs) { int i, ret = -ENOMEM; setup_timer(&dev->vblank_disable_timer, vblank_disable_fn, (unsigned long)dev); init_timer_deferrable(&dev->vblank_disable_timer); spin_lock_init(&dev->vbl_lock); atomic_set(&dev->vbl_signal_pending, 0); dev->num_crtcs = num_crtcs; dev->vbl_queue = drm_alloc(sizeof(wait_queue_head_t) * num_crtcs, DRM_MEM_DRIVER); if (!dev->vbl_queue) goto err; dev->vbl_sigs = drm_alloc(sizeof(struct list_head) * num_crtcs, DRM_MEM_DRIVER); if (!dev->vbl_sigs) goto err; dev->_vblank_count = drm_alloc(sizeof(atomic_t) * num_crtcs, DRM_MEM_DRIVER); if (!dev->_vblank_count) goto err; dev->vblank_refcount = drm_alloc(sizeof(atomic_t) * num_crtcs, DRM_MEM_DRIVER); if (!dev->vblank_refcount) goto err; dev->vblank_enabled = drm_calloc(num_crtcs, sizeof(int), DRM_MEM_DRIVER); if (!dev->vblank_enabled) goto err; dev->last_vblank = drm_calloc(num_crtcs, sizeof(u32), DRM_MEM_DRIVER); if (!dev->last_vblank) goto err; dev->vblank_inmodeset = drm_calloc(num_crtcs, sizeof(int), DRM_MEM_DRIVER); if (!dev->vblank_inmodeset) goto err; /* Zero per-crtc vblank stuff */ for (i = 0; i < num_crtcs; i++) { init_waitqueue_head(&dev->vbl_queue[i]); INIT_LIST_HEAD(&dev->vbl_sigs[i]); atomic_set(&dev->_vblank_count[i], 0); atomic_set(&dev->vblank_refcount[i], 0); } dev->vblank_disable_allowed = 0; return 0; err: drm_vblank_cleanup(dev); return ret; } EXPORT_SYMBOL(drm_vblank_init); /** * Install IRQ handler. * * \param dev DRM device. * * Initializes the IRQ related data. Installs the handler, calling the driver * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions * before and after the installation. */ int drm_irq_install(struct drm_device * dev) { int ret = 0; unsigned long sh_flags = 0; if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) return -EINVAL; if (dev->pdev->irq == 0) return -EINVAL; mutex_lock(&dev->struct_mutex); /* Driver must have been initialized */ if (!dev->dev_private) { mutex_unlock(&dev->struct_mutex); return -EINVAL; } if (dev->irq_enabled) { mutex_unlock(&dev->struct_mutex); return -EBUSY; } dev->irq_enabled = 1; mutex_unlock(&dev->struct_mutex); DRM_DEBUG("irq=%d\n", dev->pdev->irq); /* Before installing handler */ dev->driver->irq_preinstall(dev); /* Install handler */ if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED)) sh_flags = IRQF_SHARED; ret = request_irq(dev->pdev->irq, dev->driver->irq_handler, sh_flags, dev->devname, dev); if (ret < 0) { mutex_lock(&dev->struct_mutex); dev->irq_enabled = 0; mutex_unlock(&dev->struct_mutex); return ret; } /* Expose the device irq to device drivers that want to export it for * whatever reason. */ dev->irq = dev->pdev->irq; /* After installing handler */ ret = dev->driver->irq_postinstall(dev); if (ret < 0) { mutex_lock(&dev->struct_mutex); dev->irq_enabled = 0; mutex_unlock(&dev->struct_mutex); } return ret; } EXPORT_SYMBOL(drm_irq_install); /** * 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(struct drm_device * dev) { int irq_enabled; if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) return -EINVAL; mutex_lock(&dev->struct_mutex); irq_enabled = dev->irq_enabled; dev->irq_enabled = 0; mutex_unlock(&dev->struct_mutex); if (!irq_enabled) return -EINVAL; DRM_DEBUG("irq=%d\n", dev->pdev->irq); dev->driver->irq_uninstall(dev); free_irq(dev->pdev->irq, dev); dev->locked_tasklet_func = NULL; return 0; } EXPORT_SYMBOL(drm_irq_uninstall); /** * IRQ control ioctl. * * \param inode device inode. * \param file_priv DRM file private. * \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 drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_control *ctl = data; /* if we haven't irq we fallback for compatibility reasons - this used to be a separate function in drm_dma.h */ 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->pdev->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; } } /** * drm_vblank_count - retrieve "cooked" vblank counter value * @dev: DRM device * @crtc: which counter to retrieve * * Fetches the "cooked" vblank count value that represents the number of * vblank events since the system was booted, including lost events due to * modesetting activity. */ u32 drm_vblank_count(struct drm_device *dev, int crtc) { return atomic_read(&dev->_vblank_count[crtc]); } EXPORT_SYMBOL(drm_vblank_count); /** * drm_update_vblank_count - update the master vblank counter * @dev: DRM device * @crtc: counter to update * * Call back into the driver to update the appropriate vblank counter * (specified by @crtc). Deal with wraparound, if it occurred, and * update the last read value so we can deal with wraparound on the next * call if necessary. * * Only necessary when going from off->on, to account for frames we * didn't get an interrupt for. * * Note: caller must hold dev->vbl_lock since this reads & writes * device vblank fields. */ static void drm_update_vblank_count(struct drm_device *dev, int crtc) { u32 cur_vblank, diff; /* * Interrupts were disabled prior to this call, so deal with counter * wrap if needed. * NOTE! It's possible we lost a full dev->max_vblank_count events * here if the register is small or we had vblank interrupts off for * a long time. */ cur_vblank = dev->driver->get_vblank_counter(dev, crtc); diff = cur_vblank - dev->last_vblank[crtc]; if (cur_vblank < dev->last_vblank[crtc]) { diff += dev->max_vblank_count; DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n", crtc, dev->last_vblank[crtc], cur_vblank, diff); } DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n", crtc, diff); atomic_add(diff, &dev->_vblank_count[crtc]); } /** * drm_vblank_get - get a reference count on vblank events * @dev: DRM device * @crtc: which CRTC to own * * Acquire a reference count on vblank events to avoid having them disabled * while in use. * * RETURNS * Zero on success, nonzero on failure. */ int drm_vblank_get(struct drm_device *dev, int crtc) { unsigned long irqflags; int ret = 0; spin_lock_irqsave(&dev->vbl_lock, irqflags); /* Going from 0->1 means we have to enable interrupts again */ if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1 && !dev->vblank_enabled[crtc]) { ret = dev->driver->enable_vblank(dev, crtc); if (ret) atomic_dec(&dev->vblank_refcount[crtc]); else { dev->vblank_enabled[crtc] = 1; drm_update_vblank_count(dev, crtc); } } spin_unlock_irqrestore(&dev->vbl_lock, irqflags); return ret; } EXPORT_SYMBOL(drm_vblank_get); /** * drm_vblank_put - give up ownership of vblank events * @dev: DRM device * @crtc: which counter to give up * * Release ownership of a given vblank counter, turning off interrupts * if possible. */ void drm_vblank_put(struct drm_device *dev, int crtc) { /* Last user schedules interrupt disable */ if (atomic_dec_and_test(&dev->vblank_refcount[crtc])) mod_timer(&dev->vblank_disable_timer, jiffies + 5*DRM_HZ); } EXPORT_SYMBOL(drm_vblank_put); /** * drm_modeset_ctl - handle vblank event counter changes across mode switch * @DRM_IOCTL_ARGS: standard ioctl arguments * * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET * ioctls around modesetting so that any lost vblank events are accounted for. * * Generally the counter will reset across mode sets. If interrupts are * enabled around this call, we don't have to do anything since the counter * will have already been incremented. */ int drm_modeset_ctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_modeset_ctl *modeset = data; unsigned long irqflags; int crtc, ret = 0; /* If drm_vblank_init() hasn't been called yet, just no-op */ if (!dev->num_crtcs) goto out; crtc = modeset->crtc; if (crtc >= dev->num_crtcs) { ret = -EINVAL; goto out; } /* * To avoid all the problems that might happen if interrupts * were enabled/disabled around or between these calls, we just * have the kernel take a reference on the CRTC (just once though * to avoid corrupting the count if multiple, mismatch calls occur), * so that interrupts remain enabled in the interim. */ switch (modeset->cmd) { case _DRM_PRE_MODESET: if (!dev->vblank_inmodeset[crtc]) { dev->vblank_inmodeset[crtc] = 1; drm_vblank_get(dev, crtc); } break; case _DRM_POST_MODESET: if (dev->vblank_inmodeset[crtc]) { spin_lock_irqsave(&dev->vbl_lock, irqflags); dev->vblank_disable_allowed = 1; dev->vblank_inmodeset[crtc] = 0; spin_unlock_irqrestore(&dev->vbl_lock, irqflags); drm_vblank_put(dev, crtc); } break; default: ret = -EINVAL; break; } out: return ret; } /** * Wait for VBLANK. * * \param inode device inode. * \param file_priv DRM file private. * \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(struct drm_device *dev, void *data, struct drm_file *file_priv) { union drm_wait_vblank *vblwait = data; int ret = 0; unsigned int flags, seq, crtc; if ((!dev->pdev->irq) || (!dev->irq_enabled)) return -EINVAL; if (vblwait->request.type & ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK)) { DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n", vblwait->request.type, (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK)); return -EINVAL; } flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK; crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0; if (crtc >= dev->num_crtcs) return -EINVAL; ret = drm_vblank_get(dev, crtc); if (ret) return ret; seq = drm_vblank_count(dev, crtc); switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) { case _DRM_VBLANK_RELATIVE: vblwait->request.sequence += seq; vblwait->request.type &= ~_DRM_VBLANK_RELATIVE; case _DRM_VBLANK_ABSOLUTE: break; default: ret = -EINVAL; goto done; } if ((flags & _DRM_VBLANK_NEXTONMISS) && (seq - vblwait->request.sequence) <= (1<<23)) { vblwait->request.sequence = seq + 1; } if (flags & _DRM_VBLANK_SIGNAL) { unsigned long irqflags; struct list_head *vbl_sigs = &dev->vbl_sigs[crtc]; struct drm_vbl_sig *vbl_sig; 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, vbl_sigs, 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); vblwait->reply.sequence = seq; goto done; } } if (atomic_read(&dev->vbl_signal_pending) >= 100) { spin_unlock_irqrestore(&dev->vbl_lock, irqflags); ret = -EBUSY; goto done; } spin_unlock_irqrestore(&dev->vbl_lock, irqflags); vbl_sig = drm_calloc(1, sizeof(struct drm_vbl_sig), DRM_MEM_DRIVER); if (!vbl_sig) { ret = -ENOMEM; goto done; } ret = drm_vblank_get(dev, crtc); if (ret) { drm_free(vbl_sig, sizeof(struct drm_vbl_sig), DRM_MEM_DRIVER); return ret; } atomic_inc(&dev->vbl_signal_pending); 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(&vbl_sig->head, vbl_sigs); spin_unlock_irqrestore(&dev->vbl_lock, irqflags); vblwait->reply.sequence = seq; } else { DRM_WAIT_ON(ret, dev->vbl_queue[crtc], 3 * DRM_HZ, ((drm_vblank_count(dev, crtc) - vblwait->request.sequence) <= (1 << 23))); if (ret != -EINTR) { struct timeval now; do_gettimeofday(&now); vblwait->reply.tval_sec = now.tv_sec; vblwait->reply.tval_usec = now.tv_usec; vblwait->reply.sequence = drm_vblank_count(dev, crtc); } } done: drm_vblank_put(dev, crtc); return ret; } /** * Send the VBLANK signals. * * \param dev DRM device. * \param crtc CRTC where the vblank event occurred * * 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(). */ static void drm_vbl_send_signals(struct drm_device * dev, int crtc) { struct drm_vbl_sig *vbl_sig, *tmp; struct list_head *vbl_sigs; unsigned int vbl_seq; unsigned long flags; spin_lock_irqsave(&dev->vbl_lock, flags); vbl_sigs = &dev->vbl_sigs[crtc]; vbl_seq = drm_vblank_count(dev, crtc); list_for_each_entry_safe(vbl_sig, tmp, vbl_sigs, 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(&vbl_sig->head); drm_free(vbl_sig, sizeof(*vbl_sig), DRM_MEM_DRIVER); atomic_dec(&dev->vbl_signal_pending); drm_vblank_put(dev, crtc); } } spin_unlock_irqrestore(&dev->vbl_lock, flags); } /** * drm_handle_vblank - handle a vblank event * @dev: DRM device * @crtc: where this event occurred * * Drivers should call this routine in their vblank interrupt handlers to * update the vblank counter and send any signals that may be pending. */ void drm_handle_vblank(struct drm_device *dev, int crtc) { atomic_inc(&dev->_vblank_count[crtc]); DRM_WAKEUP(&dev->vbl_queue[crtc]);


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