[PATCH v3 2/7] powerpc/kernel: Add uevents in EEH error/resume

[Bjorn Helgaas]

On Wed, Jan 03, 2018 at 11:16:28AM -0600, Bryant G. Ly wrote:
> Devices can go offline when EEH is reported. This patch adds
> a change to the kernel object and lets udev know of error.
> When device resumes a change is also set reporting device as
> online. Therefore, EEH events are better propagated to user
> space for devices in powerpc arch.
> 
> Signed-off-by: Bryant G. Ly <bryantly at linux.vnet.ibm.com>
> Signed-off-by: Juan J. Alvarez <jjalvare at linux.vnet.ibm.com>

Acked-by: Bjorn Helgaas <bhelgaas at google.com>

Please merge this along with the rest of your series.

But also please change the subject and the changelog so it mentions
AER as well as EEH.  And the last sentence now applies to all arches,
not just powerpc.

> ---
>  arch/powerpc/kernel/eeh_driver.c   |  8 ++++++--
>  drivers/pci/pcie/aer/aerdrv_core.c |  3 +++
>  include/linux/pci.h                | 36 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 45 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
> index 3c0fa99c5533..c2945b91b628 100644
> --- a/arch/powerpc/kernel/eeh_driver.c
> +++ b/arch/powerpc/kernel/eeh_driver.c
> @@ -228,6 +228,7 @@ static void *eeh_report_error(void *data, void *userdata)
>  
>  	edev->in_error = true;
>  	eeh_pcid_put(dev);
> +	pci_uevent_ers(dev, PCI_ERS_RESULT_NONE);
>  	return NULL;
>  }
>  
> @@ -379,8 +380,11 @@ static void *eeh_report_resume(void *data, void *userdata)
>  	}
>  
>  	driver->err_handler->resume(dev);
> -
>  	eeh_pcid_put(dev);
> +	pci_uevent_ers(dev, PCI_ERS_RESULT_RECOVERED);
> +#ifdef CONFIG_PCI_IOV
> +	eeh_ops->notify_resume(eeh_dev_to_pdn(edev));
> +#endif
>  	return NULL;
>  }
>  
> @@ -414,8 +418,8 @@ static void *eeh_report_failure(void *data, void *userdata)
>  	}
>  
>  	driver->err_handler->error_detected(dev, pci_channel_io_perm_failure);
> -
>  	eeh_pcid_put(dev);
> +	pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
>  	return NULL;
>  }
>  
> diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c
> index 744805232155..8d7448063fd1 100644
> --- a/drivers/pci/pcie/aer/aerdrv_core.c
> +++ b/drivers/pci/pcie/aer/aerdrv_core.c
> @@ -278,6 +278,7 @@ static int report_error_detected(struct pci_dev *dev, void *data)
>  	} else {
>  		err_handler = dev->driver->err_handler;
>  		vote = err_handler->error_detected(dev, result_data->state);
> +		pci_uevent_ers(dev, PCI_ERS_RESULT_NONE);
>  	}
>  
>  	result_data->result = merge_result(result_data->result, vote);
> @@ -341,6 +342,7 @@ static int report_resume(struct pci_dev *dev, void *data)
>  
>  	err_handler = dev->driver->err_handler;
>  	err_handler->resume(dev);
> +	pci_uevent_ers(dev, PCI_ERS_RESULT_RECOVERED);
>  out:
>  	device_unlock(&dev->dev);
>  	return 0;
> @@ -541,6 +543,7 @@ static void do_recovery(struct pci_dev *dev, int severity)
>  	return;
>  
>  failed:
> +	pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
>  	/* TODO: Should kernel panic here? */
>  	dev_info(&dev->dev, "AER: Device recovery failed\n");
>  }
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index e3e94467687a..405630441b74 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -2277,6 +2277,42 @@ static inline bool pci_is_thunderbolt_attached(struct pci_dev *pdev)
>  	return false;
>  }
>  
> +/**
> + * pci_uevent_ers - emit a uevent during recovery path of pci device
> + * @pdev: pci device to check
> + * @err_type: type of error event
> + *
> + */
> +static inline void pci_uevent_ers(struct pci_dev *pdev,
> +				  enum  pci_ers_result err_type)
> +{
> +	int idx = 0;
> +	char *envp[3];
> +
> +	switch (err_type) {
> +	case PCI_ERS_RESULT_NONE:
> +	case PCI_ERS_RESULT_CAN_RECOVER:
> +		envp[idx++] = "ERROR_EVENT=BEGIN_RECOVERY";
> +		envp[idx++] = "DEVICE_ONLINE=0";
> +		break;
> +	case PCI_ERS_RESULT_RECOVERED:
> +		envp[idx++] = "ERROR_EVENT=SUCCESSFUL_RECOVERY";
> +		envp[idx++] = "DEVICE_ONLINE=1";
> +		break;
> +	case PCI_ERS_RESULT_DISCONNECT:
> +		envp[idx++] = "ERROR_EVENT=FAILED_RECOVERY";
> +		envp[idx++] = "DEVICE_ONLINE=0";
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	if (idx > 0) {
> +		envp[idx++] = NULL;
> +		kobject_uevent_env(&pdev->dev.kobj, KOBJ_CHANGE, envp);
> +	}
> +}
> +
>  /* provide the legacy pci_dma_* API */
>  #include <linux/pci-dma-compat.h>
>  
> -- 
> 2.14.3 (Apple Git-98)
>