xref: /openbmc/linux/arch/x86/pci/broadcom_bus.c (revision 7f6964c5)
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 
18 static 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, 0x44);
28 	lbus = read_pci_config_byte(bus, slot, func, 0x45);
29 	info = alloc_pci_root_info(fbus, lbus, 0, 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, 0x01f0, 0x01f7, IORESOURCE_IO, 0);
39 		update_res(info, 0x03f6, 0x03f6, IORESOURCE_IO, 0);
40 		update_res(info, 0x0170, 0x0177, IORESOURCE_IO, 0);
41 		update_res(info, 0x0376, 0x0376, IORESOURCE_IO, 0);
42 		update_res(info, 0xffa0, 0xffaf, IORESOURCE_IO, 0);
43 	}
44 
45 	/* read the non-prefetchable memory window */
46 	word1 = read_pci_config_16(bus, slot, func, 0xc0);
47 	word2 = read_pci_config_16(bus, slot, func, 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, res.start, res.end, res.flags, 0);
53 	}
54 
55 	/* read the prefetchable memory window */
56 	word1 = read_pci_config_16(bus, slot, func, 0xc4);
57 	word2 = read_pci_config_16(bus, slot, func, 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, res.start, res.end, res.flags, 0);
63 	}
64 
65 	/* read the IO port window */
66 	word1 = read_pci_config_16(bus, slot, func, 0xd0);
67 	word2 = read_pci_config_16(bus, slot, func, 0xd2);
68 	if (word1 != word2) {
69 		res.start = word1;
70 		res.end   = word2;
71 		res.flags = IORESOURCE_IO;
72 		update_res(info, res.start, res.end, res.flags, 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 
85 static 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, 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, 0);
107 		cnb20le_res(bus, slot, 1);
108 	}
109 	return 0;
110 }
111 
112 postcore_initcall(broadcom_postcore_init);
113