drivers/gpu/drm/drm_irq.c

   1 /*
   2  * drm_irq.c IRQ and vblank support
   3  *
   4  * \author Rickard E. (Rik) Faith <faith@valinux.com>
   5  * \author Gareth Hughes <gareth@valinux.com>
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the next
  15  * paragraph) shall be included in all copies or substantial portions of the
  16  * Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  22  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  23  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  24  * OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27 /*
  28  * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
  29  *
  30  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
  31  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  32  * All Rights Reserved.
  33  *
  34  * Permission is hereby granted, free of charge, to any person obtaining a
  35  * copy of this software and associated documentation files (the "Software"),
  36  * to deal in the Software without restriction, including without limitation
  37  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  38  * and/or sell copies of the Software, and to permit persons to whom the
  39  * Software is furnished to do so, subject to the following conditions:
  40  *
  41  * The above copyright notice and this permission notice (including the next
  42  * paragraph) shall be included in all copies or substantial portions of the
  43  * Software.
  44  *
  45  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  46  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  47  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  48  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  49  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  50  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  51  * OTHER DEALINGS IN THE SOFTWARE.
  52  */
  53
  54
  55 #include <linux/export.h>
  56 #include <linux/interrupt.h>    /* For task queue support */
  57 #include <linux/pci.h>
  58 #include <linux/vgaarb.h>
  59
  60 #include <drm/drm.h>
  61 #include <drm/drm_device.h>
  62 #include <drm/drm_drv.h>
  63 #include <drm/drm_irq.h>
  64 #include <drm/drm_print.h>
  65 #include <drm/drm_vblank.h>
  66
  67 #include "drm_internal.h"
  68
  69 /**
  70  * DOC: irq helpers
  71  *
  72  * The DRM core provides very simple support helpers to enable IRQ handling on a
  73  * device through the drm_irq_install() and drm_irq_uninstall() functions. This
  74  * only supports devices with a single interrupt on the main device stored in
  75  * &drm_device.dev and set as the device paramter in drm_dev_alloc().
  76  *
  77  * These IRQ helpers are strictly optional. Drivers which roll their own only
  78  * need to set &drm_device.irq_enabled to signal the DRM core that vblank
  79  * interrupts are working. Since these helpers don't automatically clean up the
  80  * requested interrupt like e.g. devm_request_irq() they're not really
  81  * recommended.
  82  */
  83
  84 /**
  85  * drm_irq_install - install IRQ handler
  86  * @dev: DRM device
  87  * @irq: IRQ number to install the handler for
  88  *
  89  * Initializes the IRQ related data. Installs the handler, calling the driver
  90  * &drm_driver.irq_preinstall and &drm_driver.irq_postinstall functions before
  91  * and after the installation.
  92  *
  93  * This is the simplified helper interface provided for drivers with no special
  94  * needs. Drivers which need to install interrupt handlers for multiple
  95  * interrupts must instead set &drm_device.irq_enabled to signal the DRM core
  96  * that vblank interrupts are available.
  97  *
  98  * @irq must match the interrupt number that would be passed to request_irq(),
  99  * if called directly instead of using this helper function.
 100  *
 101  * &drm_driver.irq_handler is called to handle the registered interrupt.
 102  *
 103  * Returns:
 104  * Zero on success or a negative error code on failure.
 105  */
 106 int drm_irq_install(struct drm_device *dev, int irq)
 107 {
 108         int ret;
 109         unsigned long sh_flags = 0;
 110
 111         if (irq == 0)
 112                 return -EINVAL;
 113
 114         if (dev->irq_enabled)
 115                 return -EBUSY;
 116         dev->irq_enabled = true;
 117
 118         DRM_DEBUG("irq=%d\n", irq);
 119
 120         /* Before installing handler */
 121         if (dev->driver->irq_preinstall)
 122                 dev->driver->irq_preinstall(dev);
 123
 124         /* PCI devices require shared interrupts. */
 125         if (dev->pdev)
 126                 sh_flags = IRQF_SHARED;
 127
 128         ret = request_irq(irq, dev->driver->irq_handler,
 129                           sh_flags, dev->driver->name, dev);
 130
 131         if (ret < 0) {
 132                 dev->irq_enabled = false;
 133                 return ret;
 134         }
 135
 136         /* After installing handler */
 137         if (dev->driver->irq_postinstall)
 138                 ret = dev->driver->irq_postinstall(dev);
 139
 140         if (ret < 0) {
 141                 dev->irq_enabled = false;
 142                 if (drm_core_check_feature(dev, DRIVER_LEGACY))
 143                         vga_client_register(dev->pdev, NULL, NULL, NULL);
 144                 free_irq(irq, dev);
 145         } else {
 146                 dev->irq = irq;
 147         }
 148
 149         return ret;
 150 }
 151 EXPORT_SYMBOL(drm_irq_install);
 152
 153 /**
 154  * drm_irq_uninstall - uninstall the IRQ handler
 155  * @dev: DRM device
 156  *
 157  * Calls the driver's &drm_driver.irq_uninstall function and unregisters the IRQ
 158  * handler.  This should only be called by drivers which used drm_irq_install()
 159  * to set up their interrupt handler. Other drivers must only reset
 160  * &drm_device.irq_enabled to false.
 161  *
 162  * Note that for kernel modesetting drivers it is a bug if this function fails.
 163  * The sanity checks are only to catch buggy user modesetting drivers which call
 164  * the same function through an ioctl.
 165  *
 166  * Returns:
 167  * Zero on success or a negative error code on failure.
 168  */
 169 int drm_irq_uninstall(struct drm_device *dev)
 170 {
 171         unsigned long irqflags;
 172         bool irq_enabled;
 173         int i;
 174
 175         irq_enabled = dev->irq_enabled;
 176         dev->irq_enabled = false;
 177
 178         /*
 179          * Wake up any waiters so they don't hang. This is just to paper over
 180          * issues for UMS drivers which aren't in full control of their
 181          * vblank/irq handling. KMS drivers must ensure that vblanks are all
 182          * disabled when uninstalling the irq handler.
 183          */
 184         if (drm_dev_has_vblank(dev)) {
 185                 spin_lock_irqsave(&dev->vbl_lock, irqflags);
 186                 for (i = 0; i < dev->num_crtcs; i++) {
 187                         struct drm_vblank_crtc *vblank = &dev->vblank[i];
 188
 189                         if (!vblank->enabled)
 190                                 continue;
 191
 192                         WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
 193
 194                         drm_vblank_disable_and_save(dev, i);
 195                         wake_up(&vblank->queue);
 196                 }
 197                 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 198         }
 199
 200         if (!irq_enabled)
 201                 return -EINVAL;
 202
 203         DRM_DEBUG("irq=%d\n", dev->irq);
 204
 205         if (drm_core_check_feature(dev, DRIVER_LEGACY))
 206                 vga_client_register(dev->pdev, NULL, NULL, NULL);
 207
 208         if (dev->driver->irq_uninstall)
 209                 dev->driver->irq_uninstall(dev);
 210
 211         free_irq(dev->irq, dev);
 212
 213         return 0;
 214 }
 215 EXPORT_SYMBOL(drm_irq_uninstall);
 216
 217 #if IS_ENABLED(CONFIG_DRM_LEGACY)
 218 int drm_legacy_irq_control(struct drm_device *dev, void *data,
 219                            struct drm_file *file_priv)
 220 {
 221         struct drm_control *ctl = data;
 222         int ret = 0, irq;
 223
 224         /* if we haven't irq we fallback for compatibility reasons -
 225          * this used to be a separate function in drm_dma.h
 226          */
 227
 228         if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
 229                 return 0;
 230         if (!drm_core_check_feature(dev, DRIVER_LEGACY))
 231                 return 0;
 232         /* UMS was only ever supported on pci devices. */
 233         if (WARN_ON(!dev->pdev))
 234                 return -EINVAL;
 235
 236         switch (ctl->func) {
 237         case DRM_INST_HANDLER:
 238                 irq = dev->pdev->irq;
 239
 240                 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
 241                     ctl->irq != irq)
 242                         return -EINVAL;
 243                 mutex_lock(&dev->struct_mutex);
 244                 ret = drm_irq_install(dev, irq);
 245                 mutex_unlock(&dev->struct_mutex);
 246
 247                 return ret;
 248         case DRM_UNINST_HANDLER:
 249                 mutex_lock(&dev->struct_mutex);
 250                 ret = drm_irq_uninstall(dev);
 251                 mutex_unlock(&dev->struct_mutex);
 252
 253                 return ret;
 254         default:
 255                 return -EINVAL;
 256         }
 257 }
 258 #endif