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 	.bus_shift	= 20,
53 	.pci_ops	= {
54 		.map_bus	= pci_dw_ecam_map_bus,
55 		.read		= pci_generic_config_read,
56 		.write		= pci_generic_config_write,
57 	}
58 };
59 
60 static const struct of_device_id gen_pci_of_match[] = {
61 	{ .compatible = "pci-host-cam-generic",
62 	  .data = &gen_pci_cfg_cam_bus_ops },
63 
64 	{ .compatible = "pci-host-ecam-generic",
65 	  .data = &pci_generic_ecam_ops },
66 
67 	{ .compatible = "marvell,armada8k-pcie-ecam",
68 	  .data = &pci_dw_ecam_bus_ops },
69 
70 	{ .compatible = "socionext,synquacer-pcie-ecam",
71 	  .data = &pci_dw_ecam_bus_ops },
72 
73 	{ .compatible = "snps,dw-pcie-ecam",
74 	  .data = &pci_dw_ecam_bus_ops },
75 
76 	{ },
77 };
78 MODULE_DEVICE_TABLE(of, gen_pci_of_match);
79 
80 static struct platform_driver gen_pci_driver = {
81 	.driver = {
82 		.name = "pci-host-generic",
83 		.of_match_table = gen_pci_of_match,
84 	},
85 	.probe = pci_host_common_probe,
86 	.remove = pci_host_common_remove,
87 };
88 module_platform_driver(gen_pci_driver);
89 
90 MODULE_LICENSE("GPL v2");
91