On Fri, 12 Jul 2024, superm1@xxxxxxxxxx wrote:
> From: Mario Limonciello <mario.limonciello@xxxxxxx>
>
> A string is passed to all callers of pci_dev_wait() which is utilized
> to demonstrate what kind of reset happened when there was a problem.
>
> This doesn't allow making the behavior for different reset types
> conditional though. Lay some plumbing to allow making comparisons of
> reset types with integers instead. No functional changes.
>
> Suggested-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> ---
> drivers/pci/pci-driver.c | 2 +-
> drivers/pci/pci.c | 29 +++++++++++++++++++----------
> drivers/pci/pci.h | 11 ++++++++++-
> drivers/pci/pcie/dpc.c | 2 +-
> 4 files changed, 31 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index af2996d0d17ff..ff97d08741df7 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -572,7 +572,7 @@ static void pci_pm_bridge_power_up_actions(struct pci_dev *pci_dev)
> {
> int ret;
>
> - ret = pci_bridge_wait_for_secondary_bus(pci_dev, "resume");
> + ret = pci_bridge_wait_for_secondary_bus(pci_dev, PCI_DEV_WAIT_RESUME);
> if (ret) {
> /*
> * The downstream link failed to come up, so mark the
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 35fb1f17a589c..115361a08d9e3 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -181,6 +181,15 @@ static int __init pcie_port_pm_setup(char *str)
> }
> __setup("pcie_port_pm=", pcie_port_pm_setup);
>
> +const char * const pci_reset_types[] = {
Sparse is not happy about this and expects static as it is not defined
by any header (LKP seems to also have caught this).
> + "FLR",
> + "AF_FLR",
> + "PM D3HOT->D0",
> + "bus reset",
> + "resume",
> + "DPC",
Perhaps the index-based array initialization format would be beneficial
here.
--
i.
> +};
> +
> /**
> * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children
> * @bus: pointer to PCI bus structure to search
> @@ -1250,7 +1259,7 @@ void pci_resume_bus(struct pci_bus *bus)
> pci_walk_bus(bus, pci_resume_one, NULL);
> }
>
> -static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
> +static int pci_dev_wait(struct pci_dev *dev, enum pci_reset_type reset_type, int timeout)
> {
> int delay = 1;
> bool retrain = false;
> @@ -1288,7 +1297,7 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
>
> if (delay > timeout) {
> pci_warn(dev, "not ready %dms after %s; giving up\n",
> - delay - 1, reset_type);
> + delay - 1, pci_reset_types[reset_type]);
> return -ENOTTY;
> }
>
> @@ -1301,7 +1310,7 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
> }
> }
> pci_info(dev, "not ready %dms after %s; waiting\n",
> - delay - 1, reset_type);
> + delay - 1, pci_reset_types[reset_type]);
> }
>
> msleep(delay);
> @@ -1310,10 +1319,10 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
>
> if (delay > PCI_RESET_WAIT)
> pci_info(dev, "ready %dms after %s\n", delay - 1,
> - reset_type);
> + pci_reset_types[reset_type]);
> else
> pci_dbg(dev, "ready %dms after %s\n", delay - 1,
> - reset_type);
> + pci_reset_types[reset_type]);
>
> return 0;
> }
> @@ -4465,7 +4474,7 @@ int pcie_flr(struct pci_dev *dev)
> */
> msleep(100);
>
> - return pci_dev_wait(dev, "FLR", PCIE_RESET_READY_POLL_MS);
> + return pci_dev_wait(dev, PCI_DEV_WAIT_FLR, PCIE_RESET_READY_POLL_MS);
> }
> EXPORT_SYMBOL_GPL(pcie_flr);
>
> @@ -4532,7 +4541,7 @@ static int pci_af_flr(struct pci_dev *dev, bool probe)
> */
> msleep(100);
>
> - return pci_dev_wait(dev, "AF_FLR", PCIE_RESET_READY_POLL_MS);
> + return pci_dev_wait(dev, PCI_DEV_WAIT_AF_FLR, PCIE_RESET_READY_POLL_MS);
> }
>
> /**
> @@ -4577,7 +4586,7 @@ static int pci_pm_reset(struct pci_dev *dev, bool probe)
> pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr);
> pci_dev_d3_sleep(dev);
>
> - return pci_dev_wait(dev, "PM D3hot->D0", PCIE_RESET_READY_POLL_MS);
> + return pci_dev_wait(dev, PCI_DEV_WAIT_D3HOT_D0, PCIE_RESET_READY_POLL_MS);
> }
>
> /**
> @@ -4751,7 +4760,7 @@ static int pci_bus_max_d3cold_delay(const struct pci_bus *bus)
> * Return 0 on success or -ENOTTY if the first device on the secondary bus
> * failed to become accessible.
> */
> -int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
> +int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, enum pci_reset_type reset_type)
> {
> struct pci_dev *child;
> int delay;
> @@ -4885,7 +4894,7 @@ int pci_bridge_secondary_bus_reset(struct pci_dev *dev)
> {
> pcibios_reset_secondary_bus(dev);
>
> - return pci_bridge_wait_for_secondary_bus(dev, "bus reset");
> + return pci_bridge_wait_for_secondary_bus(dev, PCI_DEV_WAIT_BUS_RESET);
> }
> EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset);
>
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index fd44565c47562..88f54d22118dc 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -4,6 +4,15 @@
>
> #include <linux/pci.h>
>
> +enum pci_reset_type {
> + PCI_DEV_WAIT_FLR,
> + PCI_DEV_WAIT_AF_FLR,
> + PCI_DEV_WAIT_D3HOT_D0,
> + PCI_DEV_WAIT_BUS_RESET,
> + PCI_DEV_WAIT_RESUME,
> + PCI_DEV_WAIT_DPC,
> +};
> +
> /* Number of possible devfns: 0.0 to 1f.7 inclusive */
> #define MAX_NR_DEVFNS 256
>
> @@ -94,7 +103,7 @@ void pci_msi_init(struct pci_dev *dev);
> void pci_msix_init(struct pci_dev *dev);
> bool pci_bridge_d3_possible(struct pci_dev *dev);
> void pci_bridge_d3_update(struct pci_dev *dev);
> -int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type);
> +int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, enum pci_reset_type reset_type);
>
> static inline void pci_wakeup_event(struct pci_dev *dev)
> {
> diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
> index a668820696dc0..306efc399e503 100644
> --- a/drivers/pci/pcie/dpc.c
> +++ b/drivers/pci/pcie/dpc.c
> @@ -174,7 +174,7 @@ pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
> pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
> PCI_EXP_DPC_STATUS_TRIGGER);
>
> - if (pci_bridge_wait_for_secondary_bus(pdev, "DPC")) {
> + if (pci_bridge_wait_for_secondary_bus(pdev, PCI_DEV_WAIT_DPC)) {
> clear_bit(PCI_DPC_RECOVERED, &pdev->priv_flags);
> ret = PCI_ERS_RESULT_DISCONNECT;
> } else {
>
