drivers/pci/host/pci-host-generic.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Simple, generic PCI host controller driver targetting 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
  18 static 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
  27 static 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
  43 static 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
  52 static 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
  61 static 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
  80 static 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
  91 static 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 };
  99 builtin_platform_driver(gen_pci_driver);