diff options
Diffstat (limited to 'drivers/pci/controller/dwc/pcie-al.c')
| -rw-r--r-- | drivers/pci/controller/dwc/pcie-al.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/drivers/pci/controller/dwc/pcie-al.c b/drivers/pci/controller/dwc/pcie-al.c new file mode 100644 index 000000000000..3ab58f0584a8 --- /dev/null +++ b/drivers/pci/controller/dwc/pcie-al.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCIe host controller driver for Amazon's Annapurna Labs IP (used in chips + * such as Graviton and Alpine) + * + * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. + * + * Author: Jonathan Chocron <jonnyc@amazon.com> + */ + +#include <linux/pci.h> +#include <linux/pci-ecam.h> +#include <linux/pci-acpi.h> +#include "../../pci.h" + +#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) + +struct al_pcie_acpi { + void __iomem *dbi_base; +}; + +static void __iomem *al_pcie_map_bus(struct pci_bus *bus, unsigned int devfn, + int where) +{ + struct pci_config_window *cfg = bus->sysdata; + struct al_pcie_acpi *pcie = cfg->priv; + void __iomem *dbi_base = pcie->dbi_base; + + if (bus->number == cfg->busr.start) { + /* + * The DW PCIe core doesn't filter out transactions to other + * devices/functions on the root bus num, so we do this here. + */ + if (PCI_SLOT(devfn) > 0) + return NULL; + else + return dbi_base + where; + } + + return pci_ecam_map_bus(bus, devfn, where); +} + +static int al_pcie_init(struct pci_config_window *cfg) +{ + struct device *dev = cfg->parent; + struct acpi_device *adev = to_acpi_device(dev); + struct acpi_pci_root *root = acpi_driver_data(adev); + struct al_pcie_acpi *al_pcie; + struct resource *res; + int ret; + + al_pcie = devm_kzalloc(dev, sizeof(*al_pcie), GFP_KERNEL); + if (!al_pcie) + return -ENOMEM; + + res = devm_kzalloc(dev, sizeof(*res), GFP_KERNEL); + if (!res) + return -ENOMEM; + + ret = acpi_get_rc_resources(dev, "AMZN0001", root->segment, res); + if (ret) { + dev_err(dev, "can't get rc dbi base address for SEG %d\n", + root->segment); + return ret; + } + + dev_dbg(dev, "Root port dbi res: %pR\n", res); + + al_pcie->dbi_base = devm_pci_remap_cfg_resource(dev, res); + if (IS_ERR(al_pcie->dbi_base)) { + long err = PTR_ERR(al_pcie->dbi_base); + + dev_err(dev, "couldn't remap dbi base %pR (err:%ld)\n", + res, err); + return err; + } + + cfg->priv = al_pcie; + + return 0; +} + +struct pci_ecam_ops al_pcie_ops = { + .bus_shift = 20, + .init = al_pcie_init, + .pci_ops = { + .map_bus = al_pcie_map_bus, + .read = pci_generic_config_read, + .write = pci_generic_config_write, + } +}; + +#endif /* defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) */ |