LXR linux/drivers/pci/controller/pci-host-generic.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Simple, generic PCI host controller driver targeting firmware-initialised
   4 * systems and virtual machines (e.g. the PCI emulation provided by kvmtool).
   5 *
   6 * Copyright (C) 2014 ARM Limited
   7 *
   8 * Author: Will Deacon <will.deacon@arm.com>
   9 */
  10
  11#include <linux/kernel.h>
  12#include <linux/init.h>
  13#include <linux/of_address.h>
  14#include <linux/of_pci.h>
  15#include <linux/pci-ecam.h>
  16#include <linux/platform_device.h>
  17
  18static struct pci_ecam_ops gen_pci_cfg_cam_bus_ops = {
  19        .bus_shift      = 16,
  20        .pci_ops        = {
  21                .map_bus        = pci_ecam_map_bus,
  22                .read           = pci_generic_config_read,
  23                .write          = pci_generic_config_write,
  24        }
  25};
  26
  27static bool pci_dw_valid_device(struct pci_bus *bus, unsigned int devfn)
  28{
  29        struct pci_config_window *cfg = bus->sysdata;
  30
  31        /*
  32         * The Synopsys DesignWare PCIe controller in ECAM mode will not filter
  33         * type 0 config TLPs sent to devices 1 and up on its downstream port,
  34         * resulting in devices appearing multiple times on bus 0 unless we
  35         * filter out those accesses here.
  36         */
  37        if (bus->number == cfg->busr.start && PCI_SLOT(devfn) > 0)
  38                return false;
  39
  40        return true;
  41}
  42
  43static void __iomem *pci_dw_ecam_map_bus(struct pci_bus *bus,
  44                                         unsigned int devfn, int where)
  45{
  46        if (!pci_dw_valid_device(bus, devfn))
  47                return NULL;
  48
  49        return pci_ecam_map_bus(bus, devfn, where);
  50}
  51
  52static struct pci_ecam_ops pci_dw_ecam_bus_ops = {
  53        .bus_shift      = 20,
  54        .pci_ops        = {
  55                .map_bus        = pci_dw_ecam_map_bus,
  56                .read           = pci_generic_config_read,
  57                .write          = pci_generic_config_write,
  58        }
  59};
  60
  61static const struct of_device_id gen_pci_of_match[] = {
  62        { .compatible = "pci-host-cam-generic",
  63          .data = &gen_pci_cfg_cam_bus_ops },
  64
  65        { .compatible = "pci-host-ecam-generic",
  66          .data = &pci_generic_ecam_ops },
  67
  68        { .compatible = "marvell,armada8k-pcie-ecam",
  69          .data = &pci_dw_ecam_bus_ops },
  70
  71        { .compatible = "socionext,synquacer-pcie-ecam",
  72          .data = &pci_dw_ecam_bus_ops },
  73
  74        { .compatible = "snps,dw-pcie-ecam",
  75          .data = &pci_dw_ecam_bus_ops },
  76
  77        { },
  78};
  79
  80static int gen_pci_probe(struct platform_device *pdev)
  81{
  82        const struct of_device_id *of_id;
  83        struct pci_ecam_ops *ops;
  84
  85        of_id = of_match_node(gen_pci_of_match, pdev->dev.of_node);
  86        ops = (struct pci_ecam_ops *)of_id->data;
  87
  88        return pci_host_common_probe(pdev, ops);
  89}
  90
  91static struct platform_driver gen_pci_driver = {
  92        .driver = {
  93                .name = "pci-host-generic",
  94                .of_match_table = gen_pci_of_match,
  95                .suppress_bind_attrs = true,
  96        },
  97        .probe = gen_pci_probe,
  98        .remove = pci_host_common_remove,
  99};
 100builtin_platform_driver(gen_pci_driver);
 101