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/module.h>
  14 #include <linux/pci-ecam.h>
  15 #include <linux/platform_device.h>
  16
  17 static const struct pci_ecam_ops gen_pci_cfg_cam_bus_ops = {
  18         .bus_shift      = 16,
  19         .pci_ops        = {
  20                 .map_bus        = pci_ecam_map_bus,
  21                 .read           = pci_generic_config_read,
  22                 .write          = pci_generic_config_write,
  23         }
  24 };
  25
  26 static bool pci_dw_valid_device(struct pci_bus *bus, unsigned int devfn)
  27 {
  28         struct pci_config_window *cfg = bus->sysdata;
  29
  30         /*
  31          * The Synopsys DesignWare PCIe controller in ECAM mode will not filter
  32          * type 0 config TLPs sent to devices 1 and up on its downstream port,
  33          * resulting in devices appearing multiple times on bus 0 unless we
  34          * filter out those accesses here.
  35          */
  36         if (bus->number == cfg->busr.start && PCI_SLOT(devfn) > 0)
  37                 return false;
  38
  39         return true;
  40 }
  41
  42 static void __iomem *pci_dw_ecam_map_bus(struct pci_bus *bus,
  43                                          unsigned int devfn, int where)
  44 {
  45         if (!pci_dw_valid_device(bus, devfn))
  46                 return NULL;
  47
  48         return pci_ecam_map_bus(bus, devfn, where);
  49 }
  50
  51 static const struct pci_ecam_ops pci_dw_ecam_bus_ops = {
  52         .pci_ops        = {
  53                 .map_bus        = pci_dw_ecam_map_bus,
  54                 .read           = pci_generic_config_read,
  55                 .write          = pci_generic_config_write,
  56         }
  57 };
  58
  59 static const struct of_device_id gen_pci_of_match[] = {
  60         { .compatible = "pci-host-cam-generic",
  61           .data = &gen_pci_cfg_cam_bus_ops },
  62
  63         { .compatible = "pci-host-ecam-generic",
  64           .data = &pci_generic_ecam_ops },
  65
  66         { .compatible = "marvell,armada8k-pcie-ecam",
  67           .data = &pci_dw_ecam_bus_ops },
  68
  69         { .compatible = "socionext,synquacer-pcie-ecam",
  70           .data = &pci_dw_ecam_bus_ops },
  71
  72         { .compatible = "snps,dw-pcie-ecam",
  73           .data = &pci_dw_ecam_bus_ops },
  74
  75         { },
  76 };
  77 MODULE_DEVICE_TABLE(of, gen_pci_of_match);
  78
  79 static struct platform_driver gen_pci_driver = {
  80         .driver = {
  81                 .name = "pci-host-generic",
  82                 .of_match_table = gen_pci_of_match,
  83         },
  84         .probe = pci_host_common_probe,
  85         .remove = pci_host_common_remove,
  86 };
  87 module_platform_driver(gen_pci_driver);
  88
  89 MODULE_LICENSE("GPL v2");