From: Wei Liu <[email protected]> Some PCI controllers provide a function reset mechanism that is not advertised in PCI configuration space. Allow them to expose it through an optional pci_ops callback.
Add the controller reset method to the standard reset_method interface. Prefer FLR and AF FLR by default, and use the controller operation before PM and bus reset fallbacks. Signed-off-by: Wei Liu <[email protected]> --- drivers/pci/pci.c | 22 ++++++++++++++++++++++ include/linux/pci.h | 3 ++- 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 77b17b13ee61..4e55da202cad 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4962,6 +4962,27 @@ static int pci_reset_bus_function(struct pci_dev *dev, bool probe) return rc; } +static int pci_controller_reset(struct pci_dev *dev, bool probe) +{ + int rc; + + if (!dev->bus->ops->reset) + return -ENOTTY; + + if (probe) + return dev->bus->ops->reset(dev, probe); + + rc = pci_dev_reset_iommu_prepare(dev); + if (rc) { + pci_err(dev, "failed to stop IOMMU for a PCI reset: %d\n", rc); + return rc; + } + + rc = dev->bus->ops->reset(dev, probe); + pci_dev_reset_iommu_done(dev); + return rc; +} + static int cxl_reset_bus_function(struct pci_dev *dev, bool probe) { struct pci_dev *bridge; @@ -5094,6 +5115,7 @@ const struct pci_reset_fn_method pci_reset_fn_methods[] = { { pci_dev_acpi_reset, .name = "acpi" }, { pcie_reset_flr, .name = "flr" }, { pci_af_flr, .name = "af_flr" }, + { pci_controller_reset, .name = "controller" }, { pci_pm_reset, .name = "pm" }, { pci_reset_bus_function, .name = "bus" }, { cxl_reset_bus_function, .name = "cxl_bus" }, diff --git a/include/linux/pci.h b/include/linux/pci.h index 64b308b6e61c..d7759ee70670 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -52,7 +52,7 @@ PCI_STATUS_PARITY) /* Number of reset methods used in pci_reset_fn_methods array in pci.c */ -#define PCI_NUM_RESET_METHODS 8 +#define PCI_NUM_RESET_METHODS 9 #define PCI_RESET_PROBE true #define PCI_RESET_DO_RESET false @@ -875,6 +875,7 @@ struct pci_ops { void __iomem *(*map_bus)(struct pci_bus *bus, unsigned int devfn, int where); int (*read)(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val); int (*write)(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val); + int (*reset)(struct pci_dev *dev, bool probe); }; /* -- 2.53.0
