xref: /openbmc/linux/drivers/infiniband/hw/mthca/mthca_reset.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  *
32  * $Id: mthca_reset.c 1349 2004-12-16 21:09:43Z roland $
33  */
34 
35 #include <linux/config.h>
36 #include <linux/init.h>
37 #include <linux/errno.h>
38 #include <linux/pci.h>
39 #include <linux/delay.h>
40 
41 #include "mthca_dev.h"
42 #include "mthca_cmd.h"
43 
44 int mthca_reset(struct mthca_dev *mdev)
45 {
46 	int i;
47 	int err = 0;
48 	u32 *hca_header    = NULL;
49 	u32 *bridge_header = NULL;
50 	struct pci_dev *bridge = NULL;
51 
52 #define MTHCA_RESET_OFFSET 0xf0010
53 #define MTHCA_RESET_VALUE  swab32(1)
54 
55 	/*
56 	 * Reset the chip.  This is somewhat ugly because we have to
57 	 * save off the PCI header before reset and then restore it
58 	 * after the chip reboots.  We skip config space offsets 22
59 	 * and 23 since those have a special meaning.
60 	 *
61 	 * To make matters worse, for Tavor (PCI-X HCA) we have to
62 	 * find the associated bridge device and save off its PCI
63 	 * header as well.
64 	 */
65 
66 	if (mdev->hca_type == TAVOR) {
67 		/* Look for the bridge -- its device ID will be 2 more
68 		   than HCA's device ID. */
69 		while ((bridge = pci_get_device(mdev->pdev->vendor,
70 						mdev->pdev->device + 2,
71 						bridge)) != NULL) {
72 			if (bridge->hdr_type    == PCI_HEADER_TYPE_BRIDGE &&
73 			    bridge->subordinate == mdev->pdev->bus) {
74 				mthca_dbg(mdev, "Found bridge: %s (%s)\n",
75 					  pci_pretty_name(bridge), pci_name(bridge));
76 				break;
77 			}
78 		}
79 
80 		if (!bridge) {
81 			/*
82 			 * Didn't find a bridge for a Tavor device --
83 			 * assume we're in no-bridge mode and hope for
84 			 * the best.
85 			 */
86 			mthca_warn(mdev, "No bridge found for %s (%s)\n",
87 				  pci_pretty_name(mdev->pdev), pci_name(mdev->pdev));
88 		}
89 
90 	}
91 
92 	/* For Arbel do we need to save off the full 4K PCI Express header?? */
93 	hca_header = kmalloc(256, GFP_KERNEL);
94 	if (!hca_header) {
95 		err = -ENOMEM;
96 		mthca_err(mdev, "Couldn't allocate memory to save HCA "
97 			  "PCI header, aborting.\n");
98 		goto out;
99 	}
100 
101 	for (i = 0; i < 64; ++i) {
102 		if (i == 22 || i == 23)
103 			continue;
104 		if (pci_read_config_dword(mdev->pdev, i * 4, hca_header + i)) {
105 			err = -ENODEV;
106 			mthca_err(mdev, "Couldn't save HCA "
107 				  "PCI header, aborting.\n");
108 			goto out;
109 		}
110 	}
111 
112 	if (bridge) {
113 		bridge_header = kmalloc(256, GFP_KERNEL);
114 		if (!bridge_header) {
115 			err = -ENOMEM;
116 			mthca_err(mdev, "Couldn't allocate memory to save HCA "
117 				  "bridge PCI header, aborting.\n");
118 			goto out;
119 		}
120 
121 		for (i = 0; i < 64; ++i) {
122 			if (i == 22 || i == 23)
123 				continue;
124 			if (pci_read_config_dword(bridge, i * 4, bridge_header + i)) {
125 				err = -ENODEV;
126 				mthca_err(mdev, "Couldn't save HCA bridge "
127 					  "PCI header, aborting.\n");
128 				goto out;
129 			}
130 		}
131 	}
132 
133 	/* actually hit reset */
134 	{
135 		void __iomem *reset = ioremap(pci_resource_start(mdev->pdev, 0) +
136 					      MTHCA_RESET_OFFSET, 4);
137 
138 		if (!reset) {
139 			err = -ENOMEM;
140 			mthca_err(mdev, "Couldn't map HCA reset register, "
141 				  "aborting.\n");
142 			goto out;
143 		}
144 
145 		writel(MTHCA_RESET_VALUE, reset);
146 		iounmap(reset);
147 	}
148 
149 	/* Docs say to wait one second before accessing device */
150 	msleep(1000);
151 
152 	/* Now wait for PCI device to start responding again */
153 	{
154 		u32 v;
155 		int c = 0;
156 
157 		for (c = 0; c < 100; ++c) {
158 			if (pci_read_config_dword(bridge ? bridge : mdev->pdev, 0, &v)) {
159 				err = -ENODEV;
160 				mthca_err(mdev, "Couldn't access HCA after reset, "
161 					  "aborting.\n");
162 				goto out;
163 			}
164 
165 			if (v != 0xffffffff)
166 				goto good;
167 
168 			msleep(100);
169 		}
170 
171 		err = -ENODEV;
172 		mthca_err(mdev, "PCI device did not come back after reset, "
173 			  "aborting.\n");
174 		goto out;
175 	}
176 
177 good:
178 	/* Now restore the PCI headers */
179 	if (bridge) {
180 		/*
181 		 * Bridge control register is at 0x3e, so we'll
182 		 * naturally restore it last in this loop.
183 		 */
184 		for (i = 0; i < 16; ++i) {
185 			if (i * 4 == PCI_COMMAND)
186 				continue;
187 
188 			if (pci_write_config_dword(bridge, i * 4, bridge_header[i])) {
189 				err = -ENODEV;
190 				mthca_err(mdev, "Couldn't restore HCA bridge reg %x, "
191 					  "aborting.\n", i);
192 				goto out;
193 			}
194 		}
195 
196 		if (pci_write_config_dword(bridge, PCI_COMMAND,
197 					   bridge_header[PCI_COMMAND / 4])) {
198 			err = -ENODEV;
199 			mthca_err(mdev, "Couldn't restore HCA bridge COMMAND, "
200 				  "aborting.\n");
201 			goto out;
202 		}
203 	}
204 
205 	for (i = 0; i < 16; ++i) {
206 		if (i * 4 == PCI_COMMAND)
207 			continue;
208 
209 		if (pci_write_config_dword(mdev->pdev, i * 4, hca_header[i])) {
210 			err = -ENODEV;
211 			mthca_err(mdev, "Couldn't restore HCA reg %x, "
212 				  "aborting.\n", i);
213 			goto out;
214 		}
215 	}
216 
217 	if (pci_write_config_dword(mdev->pdev, PCI_COMMAND,
218 				   hca_header[PCI_COMMAND / 4])) {
219 		err = -ENODEV;
220 		mthca_err(mdev, "Couldn't restore HCA COMMAND, "
221 			  "aborting.\n");
222 		goto out;
223 	}
224 
225 out:
226 	if (bridge)
227 		pci_dev_put(bridge);
228 	kfree(bridge_header);
229 	kfree(hca_header);
230 
231 	return err;
232 }
233