drivers/gpu/drm/i915/i915_switcheroo.c

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  * Copyright © 2019 Intel Corporation
   4  */
   5
   6 #include <linux/vga_switcheroo.h>
   7
   8 #include "i915_driver.h"
   9 #include "i915_drv.h"
  10 #include "i915_switcheroo.h"
  11
  12 static void i915_switcheroo_set_state(struct pci_dev *pdev,
  13                                       enum vga_switcheroo_state state)
  14 {
  15         struct drm_i915_private *i915 = pdev_to_i915(pdev);
  16         pm_message_t pmm = { .event = PM_EVENT_SUSPEND };
  17
  18         if (!i915) {
  19                 dev_err(&pdev->dev, "DRM not initialized, aborting switch.\n");
  20                 return;
  21         }
  22
  23         if (state == VGA_SWITCHEROO_ON) {
  24                 drm_info(&i915->drm, "switched on\n");
  25                 i915->drm.switch_power_state = DRM_SWITCH_POWER_CHANGING;
  26                 /* i915 resume handler doesn't set to D0 */
  27                 pci_set_power_state(pdev, PCI_D0);
  28                 i915_driver_resume_switcheroo(i915);
  29                 i915->drm.switch_power_state = DRM_SWITCH_POWER_ON;
  30         } else {
  31                 drm_info(&i915->drm, "switched off\n");
  32                 i915->drm.switch_power_state = DRM_SWITCH_POWER_CHANGING;
  33                 i915_driver_suspend_switcheroo(i915, pmm);
  34                 i915->drm.switch_power_state = DRM_SWITCH_POWER_OFF;
  35         }
  36 }
  37
  38 static bool i915_switcheroo_can_switch(struct pci_dev *pdev)
  39 {
  40         struct drm_i915_private *i915 = pdev_to_i915(pdev);
  41
  42         /*
  43          * FIXME: open_count is protected by drm_global_mutex but that would lead to
  44          * locking inversion with the driver load path. And the access here is
  45          * completely racy anyway. So don't bother with locking for now.
  46          */
  47         return i915 && atomic_read(&i915->drm.open_count) == 0;
  48 }
  49
  50 static const struct vga_switcheroo_client_ops i915_switcheroo_ops = {
  51         .set_gpu_state = i915_switcheroo_set_state,
  52         .reprobe = NULL,
  53         .can_switch = i915_switcheroo_can_switch,
  54 };
  55
  56 int i915_switcheroo_register(struct drm_i915_private *i915)
  57 {
  58         struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
  59
  60         return vga_switcheroo_register_client(pdev, &i915_switcheroo_ops, false);
  61 }
  62
  63 void i915_switcheroo_unregister(struct drm_i915_private *i915)
  64 {
  65         struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
  66
  67         vga_switcheroo_unregister_client(pdev);
  68 }