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SubjectRe: [PATCH v11 4/7] PCI/DPC: Unify and plumb error handling into DPC
On 2018-02-24 05:37, Bjorn Helgaas wrote:
> On Fri, Feb 23, 2018 at 01:54:01PM +0530, Oza Pawandeep wrote:
>> Current DPC driver does not do recovery, e.g. calling end-point's
>> driver's
>> callbacks, which sanitize the sw.
>>
>> DPC driver implements link_reset callback, and calls pcie_do_recovery.
>
> s/pcie_do_recovery/pcie_do_recovery()/
>

sure.

>> Signed-off-by: Oza Pawandeep <poza@codeaurora.org>
>>
>> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
>> index abc514e..f8575da 100644
>> --- a/drivers/pci/pci.h
>> +++ b/drivers/pci/pci.h
>> @@ -343,6 +343,8 @@ static inline resource_size_t
>> pci_resource_alignment(struct pci_dev *dev,
>> void pci_enable_acs(struct pci_dev *dev);
>>
>> /* PCI error reporting and recovery */
>> +#define DPC_FATAL 4
>
> This needs to go next to the AER_FATAL, etc., definitions because
> DPC_FATAL shares the namespace and they all need to have distinct
> values. I can't tell from this patch whether they do or not.
>

sure.

>> void pcie_do_recovery(struct pci_dev *dev, int severity);
>>
>> #ifdef CONFIG_PCIEASPM
>> diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c
>> index 38e40c6..5c01c63 100644
>> --- a/drivers/pci/pcie/pcie-dpc.c
>> +++ b/drivers/pci/pcie/pcie-dpc.c
>> @@ -13,6 +13,7 @@
>> #include <linux/pcieport_if.h>
>> #include "../pci.h"
>> #include "aer/aerdrv.h"
>> +#include "portdrv.h"
>>
>> struct dpc_dev {
>> struct pcie_device *dev;
>> @@ -45,6 +46,58 @@ struct dpc_dev {
>> "Memory Request Completion Timeout", /* Bit Position 18 */
>> };
>>
>> +static int find_dpc_dev_iter(struct device *device, void *data)
>> +{
>> + struct pcie_port_service_driver *service_driver;
>> + struct device **dev = (struct device **) data;;
>> +
>> + if (device->bus == &pcie_port_bus_type && device->driver) {
>> + service_driver = to_service_driver(device->driver);
>> + if (service_driver->service == PCIE_PORT_SERVICE_DPC) {
>> + *dev = device;
>> + return 1;
>> + }
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static struct device *pci_find_dpc_dev(struct pci_dev *pdev)
>> +{
>> + struct device *dev = NULL;
>> +
>> + device_for_each_child(&pdev->dev, &dev, find_dpc_dev_iter);
>> +
>> + return dev;
>> +}
>
> Ugh. You're not responsible for this and you don't need to do
> anything, but hanging the struct dpc_dev off the struct pcie_device
> and then having to grub around like this to locate it from the pci_dev
> is just ... clunky. OK, rant over, sorry :)
>

:) I keep it for now.

>> +static int find_dpc_service_iter(struct device *device, void *data)
>> +{
>> + struct pcie_port_service_driver *service_driver;
>> + struct pcie_port_service_driver **drv =
>> + (struct pcie_port_service_driver **) data;
>> +
>> + if (device->bus == &pcie_port_bus_type && device->driver) {
>> + service_driver = to_service_driver(device->driver);
>> + if (service_driver->service == PCIE_PORT_SERVICE_DPC) {
>> + *drv = service_driver;
>> + return 1;
>> + }
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +struct pcie_port_service_driver *pci_find_dpc_service(struct pci_dev
>> *dev)
>> +{
>> + struct pcie_port_service_driver *drv = NULL;
>> +
>> + device_for_each_child(&dev->dev, &drv, find_dpc_service_iter);
>> +
>> + return drv;
>> +}
>> +EXPORT_SYMBOL_GPL(pci_find_dpc_service);
>
> No module uses this, so it doesn't need to be exported.
>
> This is a clone of find_aer_service(). Can you add a preliminary patch
> to
> make a generic "find service" interface that accepts the service type
> (PCIE_PORT_SERVICE_AER, PCIE_PORT_SERVICE_DPC) as a parameter?
>
> This whole "find service" thing is ugly as sin. You're not responsible
> for
> cleaning it up, but maybe we can at least limit the proliferation of
> it.
>

I have taken care of making this as a generic find_Service in pcie port
driver now.

>> static int dpc_wait_rp_inactive(struct dpc_dev *dpc)
>> {
>> unsigned long timeout = jiffies + HZ;
>> @@ -82,12 +135,25 @@ static void dpc_wait_link_inactive(struct dpc_dev
>> *dpc)
>> dev_warn(dev, "Link state not disabled for DPC event\n");
>> }
>>
>> -static void dpc_work(struct work_struct *work)
>> +/**
>> + * dpc_reset_link - reset link DPC routine
>
> s/ / / (remove extra space)
sure.
>
>> + * @dev: pointer to Root Port's pci_dev data structure
>> + *
>> + * Invoked by Port Bus driver when performing link reset at Root
>> Port.
>> + */
>> +static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
>> {
>> - struct dpc_dev *dpc = container_of(work, struct dpc_dev, work);
>> - struct pci_dev *dev, *temp, *pdev = dpc->dev->port;
>> struct pci_bus *parent = pdev->subordinate;
>> - u16 cap = dpc->cap_pos, ctl;
>> + struct pci_dev *dev, *temp;
>> + struct dpc_dev *dpc;
>> + struct pcie_device *pciedev;
>> + struct device *devdpc;
>> + u16 cap, ctl;
>> +
>> + devdpc = pci_find_dpc_dev(pdev);
>> + pciedev = to_pcie_device(devdpc);
>> + dpc = get_service_data(pciedev);
>> + cap = dpc->cap_pos;
>>
>> pci_lock_rescan_remove();
>> list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
>> @@ -104,21 +170,31 @@ static void dpc_work(struct work_struct *work)
>>
>> dpc_wait_link_inactive(dpc);
>> if (dpc->rp_extensions && dpc_wait_rp_inactive(dpc))
>> - return;
>> + return PCI_ERS_RESULT_DISCONNECT;
>> if (dpc->rp_extensions && dpc->rp_pio_status) {
>> pci_write_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS,
>> dpc->rp_pio_status);
>> dpc->rp_pio_status = 0;
>> }
>>
>> - pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
>> + pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS,
>> PCI_EXP_DPC_STATUS_TRIGGER | PCI_EXP_DPC_STATUS_INTERRUPT);
>>
>> pci_read_config_word(pdev, cap + PCI_EXP_DPC_CTL, &ctl);
>> pci_write_config_word(pdev, cap + PCI_EXP_DPC_CTL,
>> - ctl | PCI_EXP_DPC_CTL_INT_EN);
>> + ctl | PCI_EXP_DPC_CTL_INT_EN);
>
> Align "ctl" with "pdev".

sure.
>
>> + return PCI_ERS_RESULT_RECOVERED;
>> }
>>
>> +static void dpc_work(struct work_struct *work)
>> +{
>> + struct dpc_dev *dpc = container_of(work, struct dpc_dev, work);
>> + struct pci_dev *pdev = dpc->dev->port;
>> +
>> + /* From DPC point of view error is always FATAL. */
>> + pcie_do_recovery(pdev, DPC_FATAL);
>> +}
>> static void dpc_process_rp_pio_error(struct dpc_dev *dpc)
>> {
>> struct device *dev = &dpc->dev->device;
>> @@ -297,6 +373,7 @@ static void dpc_remove(struct pcie_device *dev)
>> .service = PCIE_PORT_SERVICE_DPC,
>> .probe = dpc_probe,
>> .remove = dpc_remove,
>> + .reset_link = dpc_reset_link,
>> };
>>
>> static int __init dpc_service_init(void)
>> diff --git a/drivers/pci/pcie/pcie-err.c b/drivers/pci/pcie/pcie-err.c
>> index f830975..1ea4b9a 100644
>> --- a/drivers/pci/pcie/pcie-err.c
>> +++ b/drivers/pci/pcie/pcie-err.c
>> @@ -19,6 +19,7 @@
>> #include <linux/aer.h>
>> #include <linux/pcieport_if.h>
>> #include "portdrv.h"
>> +#include "./../pci.h"
>>
>> static DEFINE_MUTEX(pci_err_recovery_lock);
>>
>> @@ -181,7 +182,7 @@ static pci_ers_result_t default_reset_link(struct
>> pci_dev *dev)
>> return PCI_ERS_RESULT_RECOVERED;
>> }
>>
>> -static pci_ers_result_t reset_link(struct pci_dev *dev)
>> +static pci_ers_result_t reset_link(struct pci_dev *dev, int severity)
>> {
>> struct pci_dev *udev;
>> pci_ers_result_t status;
>> @@ -195,9 +196,17 @@ static pci_ers_result_t reset_link(struct pci_dev
>> *dev)
>> udev = dev->bus->self;
>> }
>>
>> +
>> + /* Use the service driver of the component firstly */
>> +#if IS_ENABLED(CONFIG_PCIE_DPC)
>
> #ifdef CONFIG_PCIE_DPC
>
>> + if (severity == DPC_FATAL)
>> + driver = pci_find_dpc_service(udev);
>> +#endif
>> #if IS_ENABLED(CONFIG_PCIEAER)
>> - /* Use the aer driver of the component firstly */
>> - driver = pci_find_aer_service(udev);
>> + if (severity == AER_FATAL ||
>> + severity == AER_NONFATAL ||
>> + severity == AER_CORRECTABLE)
>
> This change (to check for AER_FATAL, etc) looks like it belongs in a
> different patch. This patch doesn't change any places that set the
> severity.

I have made generic service and probably now it does not look like this.

>
>> + driver = pci_find_aer_service(udev);
>> #endif
>>
>> if (driver && driver->reset_link) {
>> @@ -287,7 +296,8 @@ void pcie_do_recovery(struct pci_dev *dev, int
>> severity)
>>
>> mutex_lock(&pci_err_recovery_lock);
>>
>> - if (severity == AER_FATAL)
>> + if (severity == AER_FATAL ||
>> + severity == DPC_FATAL)
>> state = pci_channel_io_frozen;
>> else
>> state = pci_channel_io_normal;
>> @@ -297,10 +307,14 @@ void pcie_do_recovery(struct pci_dev *dev, int
>> severity)
>> "error_detected",
>> report_error_detected);
>>
>> - if (severity == AER_FATAL) {
>> - result = reset_link(dev);
>> + if (severity == AER_FATAL ||
>> + severity == DPC_FATAL) {
>> + result = reset_link(dev, severity);
>> if (result != PCI_ERS_RESULT_RECOVERED)
>> goto failed;
>> + else if (severity == DPC_FATAL)
>> + goto resume;
>> +
>> }
>>
>> if (status == PCI_ERS_RESULT_CAN_RECOVER)
>> @@ -324,6 +338,7 @@ void pcie_do_recovery(struct pci_dev *dev, int
>> severity)
>> if (status != PCI_ERS_RESULT_RECOVERED)
>> goto failed;
>>
>> +resume:
>> broadcast_error_message(dev,
>> state,
>> "resume",
>> diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h
>> index 4f1992d..b013e24 100644
>> --- a/drivers/pci/pcie/portdrv.h
>> +++ b/drivers/pci/pcie/portdrv.h
>> @@ -80,4 +80,5 @@ static inline void pcie_port_platform_notify(struct
>> pci_dev *port, int *mask){}
>> #endif /* !CONFIG_ACPI */
>>
>> struct pcie_port_service_driver *pci_find_aer_service(struct pci_dev
>> *dev);
>> +struct pcie_port_service_driver *pci_find_dpc_service(struct pci_dev
>> *dev);
>> #endif /* _PORTDRV_H_ */
>> --
>> Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
>> Technologies, Inc.,
>> a Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a
>> Linux Foundation Collaborative Project.
>>

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