Re: [PATCH v16 3/9] PCI/ERR: Remove service dependency in pcie_do_recovery()

Bjorn Helgaas
2020-03-03T17:04:46Z

On Thu, Feb 27, 2020 at 04:59:45PM -0800, sathyanarayanan.kuppuswamy@linux.intel.com wrote:
> From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
>
> Currently we pass PCIe service type parameter to pcie_do_recovery()
> function which was in-turn used by reset_link() function to identify
> the underlying pci_port_service_driver and then initiate the driver
> specific reset_link call. Instead of using this roundabout way, we
> can just pass the driver specific reset_link callback function when
> calling pcie_do_recovery() function.

I love this! And I think pcie_port_find_service() is now unused. I
can add a patch to remove it.

> This change will also enable non PCIe service driver to call
> pcie_do_recovery() function. This is required for adding Error
> Disconnect Recover (EDR) support.
>
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> ---
> drivers/pci/pci.h | 2 +-
> drivers/pci/pcie/aer.c | 11 +++++------
> drivers/pci/pcie/dpc.c | 2 +-
> drivers/pci/pcie/err.c | 16 ++++++++--------
> 4 files changed, 15 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index a4c360515a69..2962200bfe35 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -548,7 +548,7 @@ static inline int pci_dev_specific_disable_acs_redir(struct pci_dev *dev)
>
> /* PCI error reporting and recovery */
> void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
> - u32 service);
> + pci_ers_result_t (*reset_cb)(struct pci_dev *pdev));
>
> bool pcie_wait_for_link(struct pci_dev *pdev, bool active);
> #ifdef CONFIG_PCIEASPM
> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> index 4a818b07a1af..1235eca0a2e6 100644
> --- a/drivers/pci/pcie/aer.c
> +++ b/drivers/pci/pcie/aer.c
> @@ -102,6 +102,7 @@ struct aer_stats {
> #define ERR_UNCOR_ID(d) (d >> 16)
>
> static int pcie_aer_disable;
> +static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
>
> void pci_no_aer(void)
> {
> @@ -1053,11 +1054,9 @@ static void handle_error_source(struct pci_dev *dev, struct aer_err_info *info)
> info->status);
> pci_aer_clear_device_status(dev);
> } else if (info->severity == AER_NONFATAL)
> - pcie_do_recovery(dev, pci_channel_io_normal,
> - PCIE_PORT_SERVICE_AER);
> + pcie_do_recovery(dev, pci_channel_io_normal, aer_root_reset);
> else if (info->severity == AER_FATAL)
> - pcie_do_recovery(dev, pci_channel_io_frozen,
> - PCIE_PORT_SERVICE_AER);
> + pcie_do_recovery(dev, pci_channel_io_frozen, aer_root_reset);
> pci_dev_put(dev);
> }
>
> @@ -1094,10 +1093,10 @@ static void aer_recover_work_func(struct work_struct *work)
> cper_print_aer(pdev, entry.severity, entry.regs);
> if (entry.severity == AER_NONFATAL)
> pcie_do_recovery(pdev, pci_channel_io_normal,
> - PCIE_PORT_SERVICE_AER);
> + aer_root_reset);
> else if (entry.severity == AER_FATAL)
> pcie_do_recovery(pdev, pci_channel_io_frozen,
> - PCIE_PORT_SERVICE_AER);
> + aer_root_reset);
> pci_dev_put(pdev);
> }
> }
> diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
> index 6b116d7fdb89..114358d62ddf 100644
> --- a/drivers/pci/pcie/dpc.c
> +++ b/drivers/pci/pcie/dpc.c
> @@ -227,7 +227,7 @@ static irqreturn_t dpc_handler(int irq, void *context)
> }
>
> /* We configure DPC so it only triggers on ERR_FATAL */
> - pcie_do_recovery(pdev, pci_channel_io_frozen, PCIE_PORT_SERVICE_DPC);
> + pcie_do_recovery(pdev, pci_channel_io_frozen, dpc_reset_link);
>
> return IRQ_HANDLED;
> }
> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
> index eefefe03857a..05f87bc9d011 100644
> --- a/drivers/pci/pcie/err.c
> +++ b/drivers/pci/pcie/err.c
> @@ -162,14 +162,13 @@ static pci_ers_result_t default_reset_link(struct pci_dev *dev)
> return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
> }
>
> -static pci_ers_result_t reset_link(struct pci_dev *dev, u32 service)
> +static pci_ers_result_t reset_link(struct pci_dev *dev,
> + pci_ers_result_t (*reset_cb)(struct pci_dev *pdev))
> {
> pci_ers_result_t status;
> - struct pcie_port_service_driver *driver = NULL;
>
> - driver = pcie_port_find_service(dev, service);
> - if (driver && driver->reset_link) {
> - status = driver->reset_link(dev);
> + if (reset_cb) {
> + status = reset_cb(dev);
> } else if (pcie_downstream_port(dev)) {
> status = default_reset_link(dev);
> } else {
> @@ -187,8 +186,9 @@ static pci_ers_result_t reset_link(struct pci_dev *dev, u32 service)
> return status;
> }
>
> -void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
> - u32 service)
> +void pcie_do_recovery(struct pci_dev *dev,
> + enum pci_channel_state state,
> + pci_ers_result_t (*reset_cb)(struct pci_dev *pdev))
> {
> pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
> struct pci_bus *bus;
> @@ -209,7 +209,7 @@ void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
> pci_walk_bus(bus, report_normal_detected, &status);
>
> if (state == pci_channel_io_frozen) {
> - status = reset_link(dev, service);
> + status = reset_link(dev, reset_cb);
> if (status != PCI_ERS_RESULT_RECOVERED)
> goto failed;
> }
> --
> 2.21.0
>