xref: /linux/drivers/infiniband/hw/mthca/mthca_reset.c (revision 5e8d780d745c1619aba81fe7166c5a4b5cad2b84)
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 	int bridge_pcix_cap = 0;
53 	int hca_pcie_cap = 0;
54 	int hca_pcix_cap = 0;
55 
56 	u16 devctl;
57 	u16 linkctl;
58 
59 #define MTHCA_RESET_OFFSET 0xf0010
60 #define MTHCA_RESET_VALUE  swab32(1)
61 
62 	/*
63 	 * Reset the chip.  This is somewhat ugly because we have to
64 	 * save off the PCI header before reset and then restore it
65 	 * after the chip reboots.  We skip config space offsets 22
66 	 * and 23 since those have a special meaning.
67 	 *
68 	 * To make matters worse, for Tavor (PCI-X HCA) we have to
69 	 * find the associated bridge device and save off its PCI
70 	 * header as well.
71 	 */
72 
73 	if (!(mdev->mthca_flags & MTHCA_FLAG_PCIE)) {
74 		/* Look for the bridge -- its device ID will be 2 more
75 		   than HCA's device ID. */
76 		while ((bridge = pci_get_device(mdev->pdev->vendor,
77 						mdev->pdev->device + 2,
78 						bridge)) != NULL) {
79 			if (bridge->hdr_type    == PCI_HEADER_TYPE_BRIDGE &&
80 			    bridge->subordinate == mdev->pdev->bus) {
81 				mthca_dbg(mdev, "Found bridge: %s\n",
82 					  pci_name(bridge));
83 				break;
84 			}
85 		}
86 
87 		if (!bridge) {
88 			/*
89 			 * Didn't find a bridge for a Tavor device --
90 			 * assume we're in no-bridge mode and hope for
91 			 * the best.
92 			 */
93 			mthca_warn(mdev, "No bridge found for %s\n",
94 				  pci_name(mdev->pdev));
95 		}
96 
97 	}
98 
99 	/* For Arbel do we need to save off the full 4K PCI Express header?? */
100 	hca_header = kmalloc(256, GFP_KERNEL);
101 	if (!hca_header) {
102 		err = -ENOMEM;
103 		mthca_err(mdev, "Couldn't allocate memory to save HCA "
104 			  "PCI header, aborting.\n");
105 		goto out;
106 	}
107 
108 	for (i = 0; i < 64; ++i) {
109 		if (i == 22 || i == 23)
110 			continue;
111 		if (pci_read_config_dword(mdev->pdev, i * 4, hca_header + i)) {
112 			err = -ENODEV;
113 			mthca_err(mdev, "Couldn't save HCA "
114 				  "PCI header, aborting.\n");
115 			goto out;
116 		}
117 	}
118 
119 	hca_pcix_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_PCIX);
120 	hca_pcie_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_EXP);
121 
122 	if (bridge) {
123 		bridge_header = kmalloc(256, GFP_KERNEL);
124 		if (!bridge_header) {
125 			err = -ENOMEM;
126 			mthca_err(mdev, "Couldn't allocate memory to save HCA "
127 				  "bridge PCI header, aborting.\n");
128 			goto out;
129 		}
130 
131 		for (i = 0; i < 64; ++i) {
132 			if (i == 22 || i == 23)
133 				continue;
134 			if (pci_read_config_dword(bridge, i * 4, bridge_header + i)) {
135 				err = -ENODEV;
136 				mthca_err(mdev, "Couldn't save HCA bridge "
137 					  "PCI header, aborting.\n");
138 				goto out;
139 			}
140 		}
141 		bridge_pcix_cap = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
142 		if (!bridge_pcix_cap) {
143 				err = -ENODEV;
144 				mthca_err(mdev, "Couldn't locate HCA bridge "
145 					  "PCI-X capability, aborting.\n");
146 				goto out;
147 		}
148 	}
149 
150 	/* actually hit reset */
151 	{
152 		void __iomem *reset = ioremap(pci_resource_start(mdev->pdev, 0) +
153 					      MTHCA_RESET_OFFSET, 4);
154 
155 		if (!reset) {
156 			err = -ENOMEM;
157 			mthca_err(mdev, "Couldn't map HCA reset register, "
158 				  "aborting.\n");
159 			goto out;
160 		}
161 
162 		writel(MTHCA_RESET_VALUE, reset);
163 		iounmap(reset);
164 	}
165 
166 	/* Docs say to wait one second before accessing device */
167 	msleep(1000);
168 
169 	/* Now wait for PCI device to start responding again */
170 	{
171 		u32 v;
172 		int c = 0;
173 
174 		for (c = 0; c < 100; ++c) {
175 			if (pci_read_config_dword(bridge ? bridge : mdev->pdev, 0, &v)) {
176 				err = -ENODEV;
177 				mthca_err(mdev, "Couldn't access HCA after reset, "
178 					  "aborting.\n");
179 				goto out;
180 			}
181 
182 			if (v != 0xffffffff)
183 				goto good;
184 
185 			msleep(100);
186 		}
187 
188 		err = -ENODEV;
189 		mthca_err(mdev, "PCI device did not come back after reset, "
190 			  "aborting.\n");
191 		goto out;
192 	}
193 
194 good:
195 	/* Now restore the PCI headers */
196 	if (bridge) {
197 		if (pci_write_config_dword(bridge, bridge_pcix_cap + 0x8,
198 				 bridge_header[(bridge_pcix_cap + 0x8) / 4])) {
199 			err = -ENODEV;
200 			mthca_err(mdev, "Couldn't restore HCA bridge Upstream "
201 				  "split transaction control, aborting.\n");
202 			goto out;
203 		}
204 		if (pci_write_config_dword(bridge, bridge_pcix_cap + 0xc,
205 				 bridge_header[(bridge_pcix_cap + 0xc) / 4])) {
206 			err = -ENODEV;
207 			mthca_err(mdev, "Couldn't restore HCA bridge Downstream "
208 				  "split transaction control, aborting.\n");
209 			goto out;
210 		}
211 		/*
212 		 * Bridge control register is at 0x3e, so we'll
213 		 * naturally restore it last in this loop.
214 		 */
215 		for (i = 0; i < 16; ++i) {
216 			if (i * 4 == PCI_COMMAND)
217 				continue;
218 
219 			if (pci_write_config_dword(bridge, i * 4, bridge_header[i])) {
220 				err = -ENODEV;
221 				mthca_err(mdev, "Couldn't restore HCA bridge reg %x, "
222 					  "aborting.\n", i);
223 				goto out;
224 			}
225 		}
226 
227 		if (pci_write_config_dword(bridge, PCI_COMMAND,
228 					   bridge_header[PCI_COMMAND / 4])) {
229 			err = -ENODEV;
230 			mthca_err(mdev, "Couldn't restore HCA bridge COMMAND, "
231 				  "aborting.\n");
232 			goto out;
233 		}
234 	}
235 
236 	if (hca_pcix_cap) {
237 		if (pci_write_config_dword(mdev->pdev, hca_pcix_cap,
238 				 hca_header[hca_pcix_cap / 4])) {
239 			err = -ENODEV;
240 			mthca_err(mdev, "Couldn't restore HCA PCI-X "
241 				  "command register, aborting.\n");
242 			goto out;
243 		}
244 	}
245 
246 	if (hca_pcie_cap) {
247 		devctl = hca_header[(hca_pcie_cap + PCI_EXP_DEVCTL) / 4];
248 		if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_DEVCTL,
249 					   devctl)) {
250 			err = -ENODEV;
251 			mthca_err(mdev, "Couldn't restore HCA PCI Express "
252 				  "Device Control register, aborting.\n");
253 			goto out;
254 		}
255 		linkctl = hca_header[(hca_pcie_cap + PCI_EXP_LNKCTL) / 4];
256 		if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_LNKCTL,
257 					   linkctl)) {
258 			err = -ENODEV;
259 			mthca_err(mdev, "Couldn't restore HCA PCI Express "
260 				  "Link control register, aborting.\n");
261 			goto out;
262 		}
263 	}
264 
265 	for (i = 0; i < 16; ++i) {
266 		if (i * 4 == PCI_COMMAND)
267 			continue;
268 
269 		if (pci_write_config_dword(mdev->pdev, i * 4, hca_header[i])) {
270 			err = -ENODEV;
271 			mthca_err(mdev, "Couldn't restore HCA reg %x, "
272 				  "aborting.\n", i);
273 			goto out;
274 		}
275 	}
276 
277 	if (pci_write_config_dword(mdev->pdev, PCI_COMMAND,
278 				   hca_header[PCI_COMMAND / 4])) {
279 		err = -ENODEV;
280 		mthca_err(mdev, "Couldn't restore HCA COMMAND, "
281 			  "aborting.\n");
282 		goto out;
283 	}
284 
285 out:
286 	if (bridge)
287 		pci_dev_put(bridge);
288 	kfree(bridge_header);
289 	kfree(hca_header);
290 
291 	return err;
292 }
293