pci/controller/pci-host-generic.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Simple, generic PCI host controller driver targeting firmware-initialised
0004  * systems and virtual machines (e.g. the PCI emulation provided by kvmtool).
0005  *
0006  * Copyright (C) 2014 ARM Limited
0007  *
0008  * Author: Will Deacon <will.deacon@arm.com>
0009  */
0010
0011 #include <linux/kernel.h>
0012 #include <linux/init.h>
0013 #include <linux/module.h>
0014 #include <linux/pci-ecam.h>
0015 #include <linux/platform_device.h>
0016
0017 static const struct pci_ecam_ops gen_pci_cfg_cam_bus_ops = {
0018     .bus_shift  = 16,
0019     .pci_ops    = {
0020         .map_bus    = pci_ecam_map_bus,
0021         .read       = pci_generic_config_read,
0022         .write      = pci_generic_config_write,
0023     }
0024 };
0025
0026 static bool pci_dw_valid_device(struct pci_bus *bus, unsigned int devfn)
0027 {
0028     struct pci_config_window *cfg = bus->sysdata;
0029
0030     /*
0031      * The Synopsys DesignWare PCIe controller in ECAM mode will not filter
0032      * type 0 config TLPs sent to devices 1 and up on its downstream port,
0033      * resulting in devices appearing multiple times on bus 0 unless we
0034      * filter out those accesses here.
0035      */
0036     if (bus->number == cfg->busr.start && PCI_SLOT(devfn) > 0)
0037         return false;
0038
0039     return true;
0040 }
0041
0042 static void __iomem *pci_dw_ecam_map_bus(struct pci_bus *bus,
0043                      unsigned int devfn, int where)
0044 {
0045     if (!pci_dw_valid_device(bus, devfn))
0046         return NULL;
0047
0048     return pci_ecam_map_bus(bus, devfn, where);
0049 }
0050
0051 static const struct pci_ecam_ops pci_dw_ecam_bus_ops = {
0052     .pci_ops    = {
0053         .map_bus    = pci_dw_ecam_map_bus,
0054         .read       = pci_generic_config_read,
0055         .write      = pci_generic_config_write,
0056     }
0057 };
0058
0059 static const struct of_device_id gen_pci_of_match[] = {
0060     { .compatible = "pci-host-cam-generic",
0061       .data = &gen_pci_cfg_cam_bus_ops },
0062
0063     { .compatible = "pci-host-ecam-generic",
0064       .data = &pci_generic_ecam_ops },
0065
0066     { .compatible = "marvell,armada8k-pcie-ecam",
0067       .data = &pci_dw_ecam_bus_ops },
0068
0069     { .compatible = "socionext,synquacer-pcie-ecam",
0070       .data = &pci_dw_ecam_bus_ops },
0071
0072     { .compatible = "snps,dw-pcie-ecam",
0073       .data = &pci_dw_ecam_bus_ops },
0074
0075     { },
0076 };
0077 MODULE_DEVICE_TABLE(of, gen_pci_of_match);
0078
0079 static struct platform_driver gen_pci_driver = {
0080     .driver = {
0081         .name = "pci-host-generic",
0082         .of_match_table = gen_pci_of_match,
0083     },
0084     .probe = pci_host_common_probe,
0085     .remove = pci_host_common_remove,
0086 };
0087 module_platform_driver(gen_pci_driver);
0088
0089 MODULE_LICENSE("GPL v2");