return ret;
}
+static int vfio_pci_runtime_pm_entry(struct vfio_pci_core_device *vdev)
+{
+ /*
+ * The vdev power related flags are protected with 'memory_lock'
+ * semaphore.
+ */
+ vfio_pci_zap_and_down_write_memory_lock(vdev);
+ if (vdev->pm_runtime_engaged) {
+ up_write(&vdev->memory_lock);
+ return -EINVAL;
+ }
+
+ vdev->pm_runtime_engaged = true;
+ pm_runtime_put_noidle(&vdev->pdev->dev);
+ up_write(&vdev->memory_lock);
+
+ return 0;
+}
+
+static int vfio_pci_core_pm_entry(struct vfio_device *device, u32 flags,
+ void __user *arg, size_t argsz)
+{
+ struct vfio_pci_core_device *vdev =
+ container_of(device, struct vfio_pci_core_device, vdev);
+ int ret;
+
+ ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_SET, 0);
+ if (ret != 1)
+ return ret;
+
+ /*
+ * Inside vfio_pci_runtime_pm_entry(), only the runtime PM usage count
+ * will be decremented. The pm_runtime_put() will be invoked again
+ * while returning from the ioctl and then the device can go into
+ * runtime suspended state.
+ */
+ return vfio_pci_runtime_pm_entry(vdev);
+}
+
+static void __vfio_pci_runtime_pm_exit(struct vfio_pci_core_device *vdev)
+{
+ if (vdev->pm_runtime_engaged) {
+ vdev->pm_runtime_engaged = false;
+ pm_runtime_get_noresume(&vdev->pdev->dev);
+ }
+}
+
+static void vfio_pci_runtime_pm_exit(struct vfio_pci_core_device *vdev)
+{
+ /*
+ * The vdev power related flags are protected with 'memory_lock'
+ * semaphore.
+ */
+ down_write(&vdev->memory_lock);
+ __vfio_pci_runtime_pm_exit(vdev);
+ up_write(&vdev->memory_lock);
+}
+
+static int vfio_pci_core_pm_exit(struct vfio_device *device, u32 flags,
+ void __user *arg, size_t argsz)
+{
+ struct vfio_pci_core_device *vdev =
+ container_of(device, struct vfio_pci_core_device, vdev);
+ int ret;
+
+ ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_SET, 0);
+ if (ret != 1)
+ return ret;
+
+ /*
+ * The device is always in the active state here due to pm wrappers
+ * around ioctls.
+ */
+ vfio_pci_runtime_pm_exit(vdev);
+ return 0;
+}
+
#ifdef CONFIG_PM
static int vfio_pci_core_runtime_suspend(struct device *dev)
{
struct vfio_pci_core_device *vdev = dev_get_drvdata(dev);
+ down_write(&vdev->memory_lock);
+ /*
+ * The user can move the device into D3hot state before invoking
+ * power management IOCTL. Move the device into D0 state here and then
+ * the pci-driver core runtime PM suspend function will move the device
+ * into the low power state. Also, for the devices which have
+ * NoSoftRst-, it will help in restoring the original state
+ * (saved locally in 'vdev->pm_save').
+ */
+ vfio_pci_set_power_state(vdev, PCI_D0);
+ up_write(&vdev->memory_lock);
+
/*
* If INTx is enabled, then mask INTx before going into the runtime
* suspended state and unmask the same in the runtime resume.
/*
* This function can be invoked while the power state is non-D0.
+ * This non-D0 power state can be with or without runtime PM.
+ * vfio_pci_runtime_pm_exit() will internally increment the usage
+ * count corresponding to pm_runtime_put() called during low power
+ * feature entry and then pm_runtime_resume() will wake up the device,
+ * if the device has already gone into the suspended state. Otherwise,
+ * the vfio_pci_set_power_state() will change the device power state
+ * to D0.
+ */
+ vfio_pci_runtime_pm_exit(vdev);
+ pm_runtime_resume(&pdev->dev);
+
+ /*
* This function calls __pci_reset_function_locked() which internally
* can use pci_pm_reset() for the function reset. pci_pm_reset() will
* fail if the power state is non-D0. Also, for the devices which
void __user *arg, size_t argsz)
{
switch (flags & VFIO_DEVICE_FEATURE_MASK) {
+ case VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY:
+ return vfio_pci_core_pm_entry(device, flags, arg, argsz);
+ case VFIO_DEVICE_FEATURE_LOW_POWER_EXIT:
+ return vfio_pci_core_pm_exit(device, flags, arg, argsz);
case VFIO_DEVICE_FEATURE_PCI_VF_TOKEN:
return vfio_pci_core_feature_token(device, flags, arg, argsz);
default:
size_t count, loff_t *ppos, bool iswrite)
{
unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
+ int ret;
if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
return -EINVAL;
+ ret = pm_runtime_resume_and_get(&vdev->pdev->dev);
+ if (ret) {
+ pci_info_ratelimited(vdev->pdev, "runtime resume failed %d\n",
+ ret);
+ return -EIO;
+ }
+
switch (index) {
case VFIO_PCI_CONFIG_REGION_INDEX:
- return vfio_pci_config_rw(vdev, buf, count, ppos, iswrite);
+ ret = vfio_pci_config_rw(vdev, buf, count, ppos, iswrite);
+ break;
case VFIO_PCI_ROM_REGION_INDEX:
if (iswrite)
- return -EINVAL;
- return vfio_pci_bar_rw(vdev, buf, count, ppos, false);
+ ret = -EINVAL;
+ else
+ ret = vfio_pci_bar_rw(vdev, buf, count, ppos, false);
+ break;
case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
- return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
+ ret = vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
+ break;
case VFIO_PCI_VGA_REGION_INDEX:
- return vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite);
+ ret = vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite);
+ break;
+
default:
index -= VFIO_PCI_NUM_REGIONS;
- return vdev->region[index].ops->rw(vdev, buf,
+ ret = vdev->region[index].ops->rw(vdev, buf,
count, ppos, iswrite);
+ break;
}
- return -EINVAL;
+ pm_runtime_put(&vdev->pdev->dev);
+ return ret;
}
ssize_t vfio_pci_core_read(struct vfio_device *core_vdev, char __user *buf,
mutex_lock(&vdev->vma_lock);
down_read(&vdev->memory_lock);
- if (!__vfio_pci_memory_enabled(vdev)) {
+ /*
+ * Memory region cannot be accessed if the low power feature is engaged
+ * or memory access is disabled.
+ */
+ if (vdev->pm_runtime_engaged || !__vfio_pci_memory_enabled(vdev)) {
ret = VM_FAULT_SIGBUS;
goto up_out;
}
goto err_unlock;
}
+ /*
+ * Some of the devices in the dev_set can be in the runtime suspended
+ * state. Increment the usage count for all the devices in the dev_set
+ * before reset and decrement the same after reset.
+ */
+ ret = vfio_pci_dev_set_pm_runtime_get(dev_set);
+ if (ret)
+ goto err_unlock;
+
list_for_each_entry(cur_vma, &dev_set->device_list, vdev.dev_set_list) {
/*
* Test whether all the affected devices are contained by the
else
mutex_unlock(&cur->vma_lock);
}
+
+ list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list)
+ pm_runtime_put(&cur->pdev->dev);
err_unlock:
mutex_unlock(&dev_set->lock);
return ret;