1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Read address ranges from a Broadcom CNB20LE Host Bridge
4 *
5 * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu>
6 */
7
8#include <linux/acpi.h>
9#include <linux/delay.h>
10#include <linux/dmi.h>
11#include <linux/pci.h>
12#include <linux/init.h>
13#include <asm/pci_x86.h>
14#include <asm/pci-direct.h>
15
16#include "bus_numa.h"
17
18static void __init cnb20le_res(u8 bus, u8 slot, u8 func)
19{
20 struct pci_root_info *info;
21 struct pci_root_res *root_res;
22 struct resource res;
23 u16 word1, word2;
24 u8 fbus, lbus;
25
26 /* read the PCI bus numbers */
27 fbus = read_pci_config_byte(bus, slot, func, offset: 0x44);
28 lbus = read_pci_config_byte(bus, slot, func, offset: 0x45);
29 info = alloc_pci_root_info(bus_min: fbus, bus_max: lbus, node: 0, link: 0);
30
31 /*
32 * Add the legacy IDE ports on bus 0
33 *
34 * These do not exist anywhere in the bridge registers, AFAICT. I do
35 * not have the datasheet, so this is the best I can do.
36 */
37 if (fbus == 0) {
38 update_res(info, start: 0x01f0, end: 0x01f7, IORESOURCE_IO, merge: 0);
39 update_res(info, start: 0x03f6, end: 0x03f6, IORESOURCE_IO, merge: 0);
40 update_res(info, start: 0x0170, end: 0x0177, IORESOURCE_IO, merge: 0);
41 update_res(info, start: 0x0376, end: 0x0376, IORESOURCE_IO, merge: 0);
42 update_res(info, start: 0xffa0, end: 0xffaf, IORESOURCE_IO, merge: 0);
43 }
44
45 /* read the non-prefetchable memory window */
46 word1 = read_pci_config_16(bus, slot, func, offset: 0xc0);
47 word2 = read_pci_config_16(bus, slot, func, offset: 0xc2);
48 if (word1 != word2) {
49 res.start = ((resource_size_t) word1 << 16) | 0x0000;
50 res.end = ((resource_size_t) word2 << 16) | 0xffff;
51 res.flags = IORESOURCE_MEM;
52 update_res(info, start: res.start, end: res.end, flags: res.flags, merge: 0);
53 }
54
55 /* read the prefetchable memory window */
56 word1 = read_pci_config_16(bus, slot, func, offset: 0xc4);
57 word2 = read_pci_config_16(bus, slot, func, offset: 0xc6);
58 if (word1 != word2) {
59 res.start = ((resource_size_t) word1 << 16) | 0x0000;
60 res.end = ((resource_size_t) word2 << 16) | 0xffff;
61 res.flags = IORESOURCE_MEM | IORESOURCE_PREFETCH;
62 update_res(info, start: res.start, end: res.end, flags: res.flags, merge: 0);
63 }
64
65 /* read the IO port window */
66 word1 = read_pci_config_16(bus, slot, func, offset: 0xd0);
67 word2 = read_pci_config_16(bus, slot, func, offset: 0xd2);
68 if (word1 != word2) {
69 res.start = word1;
70 res.end = word2;
71 res.flags = IORESOURCE_IO;
72 update_res(info, start: res.start, end: res.end, flags: res.flags, merge: 0);
73 }
74
75 /* print information about this host bridge */
76 res.start = fbus;
77 res.end = lbus;
78 res.flags = IORESOURCE_BUS;
79 printk(KERN_INFO "CNB20LE PCI Host Bridge (domain 0000 %pR)\n", &res);
80
81 list_for_each_entry(root_res, &info->resources, list)
82 printk(KERN_INFO "host bridge window %pR\n", &root_res->res);
83}
84
85static int __init broadcom_postcore_init(void)
86{
87 u8 bus = 0, slot = 0;
88 u32 id;
89 u16 vendor, device;
90
91#ifdef CONFIG_ACPI
92 /*
93 * We should get host bridge information from ACPI unless the BIOS
94 * doesn't support it.
95 */
96 if (!acpi_disabled && acpi_os_get_root_pointer())
97 return 0;
98#endif
99
100 id = read_pci_config(bus, slot, func: 0, PCI_VENDOR_ID);
101 vendor = id & 0xffff;
102 device = (id >> 16) & 0xffff;
103
104 if (vendor == PCI_VENDOR_ID_SERVERWORKS &&
105 device == PCI_DEVICE_ID_SERVERWORKS_LE) {
106 cnb20le_res(bus, slot, func: 0);
107 cnb20le_res(bus, slot, func: 1);
108 }
109 return 0;
110}
111
112postcore_initcall(broadcom_postcore_init);
113

source code of linux/arch/x86/pci/broadcom_bus.c