xref: /linux/drivers/infiniband/hw/mthca/mthca_reset.c (revision 858259cf7d1c443c836a2022b78cb281f0a9b95e)
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 #include <linux/slab.h>
41 
42 #include "mthca_dev.h"
43 #include "mthca_cmd.h"
44 
45 int mthca_reset(struct mthca_dev *mdev)
46 {
47 	int i;
48 	int err = 0;
49 	u32 *hca_header    = NULL;
50 	u32 *bridge_header = NULL;
51 	struct pci_dev *bridge = NULL;
52 
53 #define MTHCA_RESET_OFFSET 0xf0010
54 #define MTHCA_RESET_VALUE  swab32(1)
55 
56 	/*
57 	 * Reset the chip.  This is somewhat ugly because we have to
58 	 * save off the PCI header before reset and then restore it
59 	 * after the chip reboots.  We skip config space offsets 22
60 	 * and 23 since those have a special meaning.
61 	 *
62 	 * To make matters worse, for Tavor (PCI-X HCA) we have to
63 	 * find the associated bridge device and save off its PCI
64 	 * header as well.
65 	 */
66 
67 	if (!(mdev->mthca_flags & MTHCA_FLAG_PCIE)) {
68 		/* Look for the bridge -- its device ID will be 2 more
69 		   than HCA's device ID. */
70 		while ((bridge = pci_get_device(mdev->pdev->vendor,
71 						mdev->pdev->device + 2,
72 						bridge)) != NULL) {
73 			if (bridge->hdr_type    == PCI_HEADER_TYPE_BRIDGE &&
74 			    bridge->subordinate == mdev->pdev->bus) {
75 				mthca_dbg(mdev, "Found bridge: %s\n",
76 					  pci_name(bridge));
77 				break;
78 			}
79 		}
80 
81 		if (!bridge) {
82 			/*
83 			 * Didn't find a bridge for a Tavor device --
84 			 * assume we're in no-bridge mode and hope for
85 			 * the best.
86 			 */
87 			mthca_warn(mdev, "No bridge found for %s\n",
88 				  pci_name(mdev->pdev));
89 		}
90 
91 	}
92 
93 	/* For Arbel do we need to save off the full 4K PCI Express header?? */
94 	hca_header = kmalloc(256, GFP_KERNEL);
95 	if (!hca_header) {
96 		err = -ENOMEM;
97 		mthca_err(mdev, "Couldn't allocate memory to save HCA "
98 			  "PCI header, aborting.\n");
99 		goto out;
100 	}
101 
102 	for (i = 0; i < 64; ++i) {
103 		if (i == 22 || i == 23)
104 			continue;
105 		if (pci_read_config_dword(mdev->pdev, i * 4, hca_header + i)) {
106 			err = -ENODEV;
107 			mthca_err(mdev, "Couldn't save HCA "
108 				  "PCI header, aborting.\n");
109 			goto out;
110 		}
111 	}
112 
113 	if (bridge) {
114 		bridge_header = kmalloc(256, GFP_KERNEL);
115 		if (!bridge_header) {
116 			err = -ENOMEM;
117 			mthca_err(mdev, "Couldn't allocate memory to save HCA "
118 				  "bridge PCI header, aborting.\n");
119 			goto out;
120 		}
121 
122 		for (i = 0; i < 64; ++i) {
123 			if (i == 22 || i == 23)
124 				continue;
125 			if (pci_read_config_dword(bridge, i * 4, bridge_header + i)) {
126 				err = -ENODEV;
127 				mthca_err(mdev, "Couldn't save HCA bridge "
128 					  "PCI header, aborting.\n");
129 				goto out;
130 			}
131 		}
132 	}
133 
134 	/* actually hit reset */
135 	{
136 		void __iomem *reset = ioremap(pci_resource_start(mdev->pdev, 0) +
137 					      MTHCA_RESET_OFFSET, 4);
138 
139 		if (!reset) {
140 			err = -ENOMEM;
141 			mthca_err(mdev, "Couldn't map HCA reset register, "
142 				  "aborting.\n");
143 			goto out;
144 		}
145 
146 		writel(MTHCA_RESET_VALUE, reset);
147 		iounmap(reset);
148 	}
149 
150 	/* Docs say to wait one second before accessing device */
151 	msleep(1000);
152 
153 	/* Now wait for PCI device to start responding again */
154 	{
155 		u32 v;
156 		int c = 0;
157 
158 		for (c = 0; c < 100; ++c) {
159 			if (pci_read_config_dword(bridge ? bridge : mdev->pdev, 0, &v)) {
160 				err = -ENODEV;
161 				mthca_err(mdev, "Couldn't access HCA after reset, "
162 					  "aborting.\n");
163 				goto out;
164 			}
165 
166 			if (v != 0xffffffff)
167 				goto good;
168 
169 			msleep(100);
170 		}
171 
172 		err = -ENODEV;
173 		mthca_err(mdev, "PCI device did not come back after reset, "
174 			  "aborting.\n");
175 		goto out;
176 	}
177 
178 good:
179 	/* Now restore the PCI headers */
180 	if (bridge) {
181 		/*
182 		 * Bridge control register is at 0x3e, so we'll
183 		 * naturally restore it last in this loop.
184 		 */
185 		for (i = 0; i < 16; ++i) {
186 			if (i * 4 == PCI_COMMAND)
187 				continue;
188 
189 			if (pci_write_config_dword(bridge, i * 4, bridge_header[i])) {
190 				err = -ENODEV;
191 				mthca_err(mdev, "Couldn't restore HCA bridge reg %x, "
192 					  "aborting.\n", i);
193 				goto out;
194 			}
195 		}
196 
197 		if (pci_write_config_dword(bridge, PCI_COMMAND,
198 					   bridge_header[PCI_COMMAND / 4])) {
199 			err = -ENODEV;
200 			mthca_err(mdev, "Couldn't restore HCA bridge COMMAND, "
201 				  "aborting.\n");
202 			goto out;
203 		}
204 	}
205 
206 	for (i = 0; i < 16; ++i) {
207 		if (i * 4 == PCI_COMMAND)
208 			continue;
209 
210 		if (pci_write_config_dword(mdev->pdev, i * 4, hca_header[i])) {
211 			err = -ENODEV;
212 			mthca_err(mdev, "Couldn't restore HCA reg %x, "
213 				  "aborting.\n", i);
214 			goto out;
215 		}
216 	}
217 
218 	if (pci_write_config_dword(mdev->pdev, PCI_COMMAND,
219 				   hca_header[PCI_COMMAND / 4])) {
220 		err = -ENODEV;
221 		mthca_err(mdev, "Couldn't restore HCA COMMAND, "
222 			  "aborting.\n");
223 		goto out;
224 	}
225 
226 out:
227 	if (bridge)
228 		pci_dev_put(bridge);
229 	kfree(bridge_header);
230 	kfree(hca_header);
231 
232 	return err;
233 }
234