xref: /openbmc/linux/drivers/pci/hotplug/shpchp_pci.c (revision 93dc544c)
1 /*
2  * Standard Hot Plug Controller Driver
3  *
4  * Copyright (C) 1995,2001 Compaq Computer Corporation
5  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
6  * Copyright (C) 2001 IBM Corp.
7  * Copyright (C) 2003-2004 Intel Corporation
8  *
9  * All rights reserved.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or (at
14  * your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
19  * NON INFRINGEMENT.  See the GNU General Public License for more
20  * details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25  *
26  * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
27  *
28  */
29 
30 #include <linux/module.h>
31 #include <linux/kernel.h>
32 #include <linux/types.h>
33 #include <linux/pci.h>
34 #include "../pci.h"
35 #include "shpchp.h"
36 
37 static void program_fw_provided_values(struct pci_dev *dev)
38 {
39 	u16 pci_cmd, pci_bctl;
40 	struct pci_dev *cdev;
41 	struct hotplug_params hpp;
42 
43 	/* Program hpp values for this device */
44 	if (!(dev->hdr_type == PCI_HEADER_TYPE_NORMAL ||
45 			(dev->hdr_type == PCI_HEADER_TYPE_BRIDGE &&
46 			(dev->class >> 8) == PCI_CLASS_BRIDGE_PCI)))
47 		return;
48 
49 	/* use default values if we can't get them from firmware */
50 	if (get_hp_params_from_firmware(dev, &hpp) ||
51 	    !hpp.t0 || (hpp.t0->revision > 1)) {
52 		printk(KERN_WARNING
53 		       "%s: Could not get hotplug parameters. Use defaults\n",
54 		       __func__);
55 		hpp.t0 = &hpp.type0_data;
56 		hpp.t0->revision = 0;
57 		hpp.t0->cache_line_size = 8;
58 		hpp.t0->latency_timer = 0x40;
59 		hpp.t0->enable_serr = 0;
60 		hpp.t0->enable_perr = 0;
61 	}
62 
63 	pci_write_config_byte(dev,
64 			      PCI_CACHE_LINE_SIZE, hpp.t0->cache_line_size);
65 	pci_write_config_byte(dev, PCI_LATENCY_TIMER, hpp.t0->latency_timer);
66 	pci_read_config_word(dev, PCI_COMMAND, &pci_cmd);
67 	if (hpp.t0->enable_serr)
68 		pci_cmd |= PCI_COMMAND_SERR;
69 	else
70 		pci_cmd &= ~PCI_COMMAND_SERR;
71 	if (hpp.t0->enable_perr)
72 		pci_cmd |= PCI_COMMAND_PARITY;
73 	else
74 		pci_cmd &= ~PCI_COMMAND_PARITY;
75 	pci_write_config_word(dev, PCI_COMMAND, pci_cmd);
76 
77 	/* Program bridge control value and child devices */
78 	if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
79 		pci_write_config_byte(dev, PCI_SEC_LATENCY_TIMER,
80 				hpp.t0->latency_timer);
81 		pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &pci_bctl);
82 		if (hpp.t0->enable_serr)
83 			pci_bctl |= PCI_BRIDGE_CTL_SERR;
84 		else
85 			pci_bctl &= ~PCI_BRIDGE_CTL_SERR;
86 		if (hpp.t0->enable_perr)
87 			pci_bctl |= PCI_BRIDGE_CTL_PARITY;
88 		else
89 			pci_bctl &= ~PCI_BRIDGE_CTL_PARITY;
90 		pci_write_config_word(dev, PCI_BRIDGE_CONTROL, pci_bctl);
91 		if (dev->subordinate) {
92 			list_for_each_entry(cdev, &dev->subordinate->devices,
93 					bus_list)
94 				program_fw_provided_values(cdev);
95 		}
96 	}
97 }
98 
99 int __ref shpchp_configure_device(struct slot *p_slot)
100 {
101 	struct pci_dev *dev;
102 	struct pci_bus *parent = p_slot->ctrl->pci_dev->subordinate;
103 	int num, fn;
104 
105 	dev = pci_get_slot(parent, PCI_DEVFN(p_slot->device, 0));
106 	if (dev) {
107 		err("Device %s already exists at %x:%x, cannot hot-add\n",
108 				pci_name(dev), p_slot->bus, p_slot->device);
109 		pci_dev_put(dev);
110 		return -EINVAL;
111 	}
112 
113 	num = pci_scan_slot(parent, PCI_DEVFN(p_slot->device, 0));
114 	if (num == 0) {
115 		err("No new device found\n");
116 		return -ENODEV;
117 	}
118 
119 	for (fn = 0; fn < 8; fn++) {
120 		dev = pci_get_slot(parent, PCI_DEVFN(p_slot->device, fn));
121 		if (!dev)
122 			continue;
123 		if ((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY) {
124 			err("Cannot hot-add display device %s\n",
125 					pci_name(dev));
126 			pci_dev_put(dev);
127 			continue;
128 		}
129 		if ((dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) ||
130 				(dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)) {
131 			/* Find an unused bus number for the new bridge */
132 			struct pci_bus *child;
133 			unsigned char busnr, start = parent->secondary;
134 			unsigned char end = parent->subordinate;
135 			for (busnr = start; busnr <= end; busnr++) {
136 				if (!pci_find_bus(pci_domain_nr(parent),
137 							busnr))
138 					break;
139 			}
140 			if (busnr >= end) {
141 				err("No free bus for hot-added bridge\n");
142 				pci_dev_put(dev);
143 				continue;
144 			}
145 			child = pci_add_new_bus(parent, dev, busnr);
146 			if (!child) {
147 				err("Cannot add new bus for %s\n",
148 						pci_name(dev));
149 				pci_dev_put(dev);
150 				continue;
151 			}
152 			child->subordinate = pci_do_scan_bus(child);
153 			pci_bus_size_bridges(child);
154 		}
155 		program_fw_provided_values(dev);
156 		pci_dev_put(dev);
157 	}
158 
159 	pci_bus_assign_resources(parent);
160 	pci_bus_add_devices(parent);
161 	pci_enable_bridges(parent);
162 	return 0;
163 }
164 
165 int shpchp_unconfigure_device(struct slot *p_slot)
166 {
167 	int rc = 0;
168 	int j;
169 	u8 bctl = 0;
170 	struct pci_bus *parent = p_slot->ctrl->pci_dev->subordinate;
171 
172 	dbg("%s: bus/dev = %x/%x\n", __func__, p_slot->bus, p_slot->device);
173 
174 	for (j=0; j<8 ; j++) {
175 		struct pci_dev* temp = pci_get_slot(parent,
176 				(p_slot->device << 3) | j);
177 		if (!temp)
178 			continue;
179 		if ((temp->class >> 16) == PCI_BASE_CLASS_DISPLAY) {
180 			err("Cannot remove display device %s\n",
181 					pci_name(temp));
182 			pci_dev_put(temp);
183 			continue;
184 		}
185 		if (temp->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
186 			pci_read_config_byte(temp, PCI_BRIDGE_CONTROL, &bctl);
187 			if (bctl & PCI_BRIDGE_CTL_VGA) {
188 				err("Cannot remove display device %s\n",
189 						pci_name(temp));
190 				pci_dev_put(temp);
191 				continue;
192 			}
193 		}
194 		pci_remove_bus_device(temp);
195 		pci_dev_put(temp);
196 	}
197 	return rc;
198 }
199 
200