drivers/gpu/drm/drm_irq.c - linux - Git at Google

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

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

 #include <drm/drm.h>
 #include <drm/drm_device.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_irq.h>
 #include <drm/drm_print.h>
 #include <drm/drm_vblank.h>

 #include "drm_internal.h"

 /**
  * DOC: irq helpers
  *
  * The DRM core provides very simple support helpers to enable IRQ handling on a
  * device through the drm_irq_install() and drm_irq_uninstall() functions. This
  * only supports devices with a single interrupt on the main device stored in
  * &drm_device.dev and set as the device paramter in drm_dev_alloc().
  *
  * These IRQ helpers are strictly optional. Drivers which roll their own only
  * need to set &drm_device.irq_enabled to signal the DRM core that vblank
  * interrupts are working. Since these helpers don't automatically clean up the
  * requested interrupt like e.g. devm_request_irq() they're not really
  * recommended.
  */

 /**
  * drm_irq_install - install IRQ handler
  * @dev: DRM device
  * @irq: IRQ number to install the handler for
  *
  * Initializes the IRQ related data. Installs the handler, calling the driver
  * &drm_driver.irq_preinstall and &drm_driver.irq_postinstall functions before
  * and after the installation.
  *
  * This is the simplified helper interface provided for drivers with no special
  * needs. Drivers which need to install interrupt handlers for multiple
  * interrupts must instead set &drm_device.irq_enabled to signal the DRM core
  * that vblank interrupts are available.
  *
  * @irq must match the interrupt number that would be passed to request_irq(),
  * if called directly instead of using this helper function.
  *
  * &drm_driver.irq_handler is called to handle the registered interrupt.
  *
  * Returns:
  * Zero on success or a negative error code on failure.
  */
 int drm_irq_install(struct drm_device *dev, int irq)
 {
 	int ret;
 	unsigned long sh_flags = 0;

 	if (irq == 0)
 		return -EINVAL;

 	/* Driver must have been initialized */
 	if (!dev->dev_private)
 		return -EINVAL;

 	if (dev->irq_enabled)
 		return -EBUSY;
 	dev->irq_enabled = true;

 	DRM_DEBUG("irq=%d\n", irq);

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

 	/* PCI devices require shared interrupts. */
 	if (dev->pdev)
 		sh_flags = IRQF_SHARED;

 	ret = request_irq(irq, dev->driver->irq_handler,
 			  sh_flags, dev->driver->name, dev);

 	if (ret < 0) {
 		dev->irq_enabled = false;
 		return ret;
 	}

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

 	if (ret < 0) {
 		dev->irq_enabled = false;
 		if (drm_core_check_feature(dev, DRIVER_LEGACY))
 			vga_client_register(dev->pdev, NULL, NULL, NULL);
 		free_irq(irq, dev);
 	} else {
 		dev->irq = irq;
 	}

 	return ret;
 }
 EXPORT_SYMBOL(drm_irq_install);

 /**
  * drm_irq_uninstall - uninstall the IRQ handler
  * @dev: DRM device
  *
  * Calls the driver's &drm_driver.irq_uninstall function and unregisters the IRQ
  * handler.  This should only be called by drivers which used drm_irq_install()
  * to set up their interrupt handler. Other drivers must only reset
  * &drm_device.irq_enabled to false.
  *
  * Note that for kernel modesetting drivers it is a bug if this function fails.
  * The sanity checks are only to catch buggy user modesetting drivers which call
  * the same function through an ioctl.
  *
  * Returns:
  * Zero on success or a negative error code on failure.
  */
 int drm_irq_uninstall(struct drm_device *dev)
 {
 	unsigned long irqflags;
 	bool irq_enabled;
 	int i;

 	irq_enabled = dev->irq_enabled;
 	dev->irq_enabled = false;

 	/*
 	 * Wake up any waiters so they don't hang. This is just to paper over
 	 * issues for UMS drivers which aren't in full control of their
 	 * vblank/irq handling. KMS drivers must ensure that vblanks are all
 	 * disabled when uninstalling the irq handler.
 	 */
 	if (dev->num_crtcs) {
 		spin_lock_irqsave(&dev->vbl_lock, irqflags);
 		for (i = 0; i < dev->num_crtcs; i++) {
 			struct drm_vblank_crtc *vblank = &dev->vblank[i];

 			if (!vblank->enabled)
 				continue;

 			WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));

 			drm_vblank_disable_and_save(dev, i);
 			wake_up(&vblank->queue);
 		}
 		spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 	}

 	if (!irq_enabled)
 		return -EINVAL;

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

 	if (drm_core_check_feature(dev, DRIVER_LEGACY))
 		vga_client_register(dev->pdev, NULL, NULL, NULL);

 	if (dev->driver->irq_uninstall)
 		dev->driver->irq_uninstall(dev);

 	free_irq(dev->irq, dev);

 	return 0;
 }
 EXPORT_SYMBOL(drm_irq_uninstall);

 #if IS_ENABLED(CONFIG_DRM_LEGACY)
 int drm_legacy_irq_control(struct drm_device *dev, void *data,
 			   struct drm_file *file_priv)
 {
 	struct drm_control *ctl = data;
 	int ret = 0, irq;

 	/* if we haven't irq we fallback for compatibility reasons -
 	 * this used to be a separate function in drm_dma.h
 	 */

 	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 		return 0;
 	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
 		return 0;
 	/* UMS was only ever supported on pci devices. */
 	if (WARN_ON(!dev->pdev))
 		return -EINVAL;

 	switch (ctl->func) {
 	case DRM_INST_HANDLER:
 		irq = dev->pdev->irq;

 		if (dev->if_version < DRM_IF_VERSION(1, 2) &&
 		    ctl->irq != irq)
 			return -EINVAL;
 		mutex_lock(&dev->struct_mutex);
 		ret = drm_irq_install(dev, irq);
 		mutex_unlock(&dev->struct_mutex);

 		return ret;
 	case DRM_UNINST_HANDLER:
 		mutex_lock(&dev->struct_mutex);
 		ret = drm_irq_uninstall(dev);
 		mutex_unlock(&dev->struct_mutex);

 		return ret;
 	default:
 		return -EINVAL;
 	}
 }
 #endif
	/*
	* drm_irq.c IRQ and vblank support
	*
	* \author Rickard E. (Rik) Faith <faith@valinux.com>
	* \author Gareth Hughes <gareth@valinux.com>
	*
	* 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.
	*/

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

	#include <drm/drm.h>
	#include <drm/drm_device.h>
	#include <drm/drm_drv.h>
	#include <drm/drm_irq.h>
	#include <drm/drm_print.h>
	#include <drm/drm_vblank.h>

	#include "drm_internal.h"

	/**
	* DOC: irq helpers
	*
	* The DRM core provides very simple support helpers to enable IRQ handling on a
	* device through the drm_irq_install() and drm_irq_uninstall() functions. This
	* only supports devices with a single interrupt on the main device stored in
	* &drm_device.dev and set as the device paramter in drm_dev_alloc().
	*
	* These IRQ helpers are strictly optional. Drivers which roll their own only
	* need to set &drm_device.irq_enabled to signal the DRM core that vblank
	* interrupts are working. Since these helpers don't automatically clean up the
	* requested interrupt like e.g. devm_request_irq() they're not really
	* recommended.
	*/

	/**
	* drm_irq_install - install IRQ handler
	* @dev: DRM device
	* @irq: IRQ number to install the handler for
	*
	* Initializes the IRQ related data. Installs the handler, calling the driver
	* &drm_driver.irq_preinstall and &drm_driver.irq_postinstall functions before
	* and after the installation.
	*
	* This is the simplified helper interface provided for drivers with no special
	* needs. Drivers which need to install interrupt handlers for multiple
	* interrupts must instead set &drm_device.irq_enabled to signal the DRM core
	* that vblank interrupts are available.
	*
	* @irq must match the interrupt number that would be passed to request_irq(),
	* if called directly instead of using this helper function.
	*
	* &drm_driver.irq_handler is called to handle the registered interrupt.
	*
	* Returns:
	* Zero on success or a negative error code on failure.
	*/
	int drm_irq_install(struct drm_device *dev, int irq)
	{
	int ret;
	unsigned long sh_flags = 0;

	if (irq == 0)
	return -EINVAL;

	/* Driver must have been initialized */
	if (!dev->dev_private)
	return -EINVAL;

	if (dev->irq_enabled)
	return -EBUSY;
	dev->irq_enabled = true;

	DRM_DEBUG("irq=%d\n", irq);

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

	/* PCI devices require shared interrupts. */
	if (dev->pdev)
	sh_flags = IRQF_SHARED;

	ret = request_irq(irq, dev->driver->irq_handler,
	sh_flags, dev->driver->name, dev);

	if (ret < 0) {
	dev->irq_enabled = false;
	return ret;
	}

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

	if (ret < 0) {
	dev->irq_enabled = false;
	if (drm_core_check_feature(dev, DRIVER_LEGACY))
	vga_client_register(dev->pdev, NULL, NULL, NULL);
	free_irq(irq, dev);
	} else {
	dev->irq = irq;
	}

	return ret;
	}
	EXPORT_SYMBOL(drm_irq_install);

	/**
	* drm_irq_uninstall - uninstall the IRQ handler
	* @dev: DRM device
	*
	* Calls the driver's &drm_driver.irq_uninstall function and unregisters the IRQ
	* handler. This should only be called by drivers which used drm_irq_install()
	* to set up their interrupt handler. Other drivers must only reset
	* &drm_device.irq_enabled to false.
	*
	* Note that for kernel modesetting drivers it is a bug if this function fails.
	* The sanity checks are only to catch buggy user modesetting drivers which call
	* the same function through an ioctl.
	*
	* Returns:
	* Zero on success or a negative error code on failure.
	*/
	int drm_irq_uninstall(struct drm_device *dev)
	{
	unsigned long irqflags;
	bool irq_enabled;
	int i;

	irq_enabled = dev->irq_enabled;
	dev->irq_enabled = false;

	/*
	* Wake up any waiters so they don't hang. This is just to paper over
	* issues for UMS drivers which aren't in full control of their
	* vblank/irq handling. KMS drivers must ensure that vblanks are all
	* disabled when uninstalling the irq handler.
	*/
	if (dev->num_crtcs) {
	spin_lock_irqsave(&dev->vbl_lock, irqflags);
	for (i = 0; i < dev->num_crtcs; i++) {
	struct drm_vblank_crtc *vblank = &dev->vblank[i];

	if (!vblank->enabled)
	continue;

	WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));

	drm_vblank_disable_and_save(dev, i);
	wake_up(&vblank->queue);
	}
	spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
	}

	if (!irq_enabled)
	return -EINVAL;

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

	if (drm_core_check_feature(dev, DRIVER_LEGACY))
	vga_client_register(dev->pdev, NULL, NULL, NULL);

	if (dev->driver->irq_uninstall)
	dev->driver->irq_uninstall(dev);

	free_irq(dev->irq, dev);

	return 0;
	}
	EXPORT_SYMBOL(drm_irq_uninstall);

	#if IS_ENABLED(CONFIG_DRM_LEGACY)
	int drm_legacy_irq_control(struct drm_device dev, void data,
	struct drm_file *file_priv)
	{
	struct drm_control *ctl = data;
	int ret = 0, irq;

	/* if we haven't irq we fallback for compatibility reasons -
	* this used to be a separate function in drm_dma.h
	*/

	if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
	return 0;
	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
	return 0;
	/* UMS was only ever supported on pci devices. */
	if (WARN_ON(!dev->pdev))
	return -EINVAL;

	switch (ctl->func) {
	case DRM_INST_HANDLER:
	irq = dev->pdev->irq;

	if (dev->if_version < DRM_IF_VERSION(1, 2) &&
	ctl->irq != irq)
	return -EINVAL;
	mutex_lock(&dev->struct_mutex);
	ret = drm_irq_install(dev, irq);
	mutex_unlock(&dev->struct_mutex);

	return ret;
	case DRM_UNINST_HANDLER:
	mutex_lock(&dev->struct_mutex);
	ret = drm_irq_uninstall(dev);
	mutex_unlock(&dev->struct_mutex);

	return ret;
	default:
	return -EINVAL;
	}
	}
	#endif