xref: /freebsd/sys/dev/mthca/mthca_reset.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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 
33 #include <linux/errno.h>
34 #include <linux/pci.h>
35 #include <linux/delay.h>
36 #include <linux/slab.h>
37 
38 #include "mthca_dev.h"
39 #include "mthca_cmd.h"
40 
41 int mthca_reset(struct mthca_dev *mdev)
42 {
43 	int i;
44 	int err = 0;
45 	u32 *hca_header    = NULL;
46 #ifdef __linux__
47 	u32 *bridge_header = NULL;
48 #endif
49 	struct pci_dev *bridge = NULL;
50 #ifdef __linux__
51 	int bridge_pcix_cap = 0;
52 #endif
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 #ifdef __linux__
77 		while ((bridge = pci_get_device(mdev->pdev->vendor,
78 						mdev->pdev->device + 2,
79 						bridge)) != NULL) {
80 			if (bridge->hdr_type    == PCI_HEADER_TYPE_BRIDGE &&
81 			    bridge->subordinate == mdev->pdev->bus) {
82 				mthca_dbg(mdev, "Found bridge: %s\n",
83 					  pci_name(bridge));
84 				break;
85 			}
86 		}
87 
88 		if (!bridge) {
89 			/*
90 			 * Didn't find a bridge for a Tavor device --
91 			 * assume we're in no-bridge mode and hope for
92 			 * the best.
93 			 */
94 			mthca_warn(mdev, "No bridge found for %s\n",
95 				  pci_name(mdev->pdev));
96 		}
97 #else
98 		mthca_warn(mdev, "Reset on PCI-X is not supported.\n");
99 		goto out;
100 
101 #endif
102 	}
103 
104 	/* For Arbel do we need to save off the full 4K PCI Express header?? */
105 	hca_header = kmalloc(256, GFP_KERNEL);
106 	if (!hca_header) {
107 		err = -ENOMEM;
108 		mthca_err(mdev, "Couldn't allocate memory to save HCA "
109 			  "PCI header, aborting.\n");
110 		goto out;
111 	}
112 
113 	for (i = 0; i < 64; ++i) {
114 		if (i == 22 || i == 23)
115 			continue;
116 		if (pci_read_config_dword(mdev->pdev, i * 4, hca_header + i)) {
117 			err = -ENODEV;
118 			mthca_err(mdev, "Couldn't save HCA "
119 				  "PCI header, aborting.\n");
120 			goto out;
121 		}
122 	}
123 
124 	hca_pcix_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_PCIX);
125 	hca_pcie_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_EXP);
126 
127 #ifdef __linux__
128 	if (bridge) {
129 		bridge_header = kmalloc(256, GFP_KERNEL);
130 		if (!bridge_header) {
131 			err = -ENOMEM;
132 			mthca_err(mdev, "Couldn't allocate memory to save HCA "
133 				  "bridge PCI header, aborting.\n");
134 			goto out;
135 		}
136 
137 		for (i = 0; i < 64; ++i) {
138 			if (i == 22 || i == 23)
139 				continue;
140 			if (pci_read_config_dword(bridge, i * 4, bridge_header + i)) {
141 				err = -ENODEV;
142 				mthca_err(mdev, "Couldn't save HCA bridge "
143 					  "PCI header, aborting.\n");
144 				goto out;
145 			}
146 		}
147 		bridge_pcix_cap = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
148 		if (!bridge_pcix_cap) {
149 				err = -ENODEV;
150 				mthca_err(mdev, "Couldn't locate HCA bridge "
151 					  "PCI-X capability, aborting.\n");
152 				goto out;
153 		}
154 	}
155 #endif
156 
157 	/* actually hit reset */
158 	{
159 		void __iomem *reset = ioremap(pci_resource_start(mdev->pdev, 0) +
160 					      MTHCA_RESET_OFFSET, 4);
161 
162 		if (!reset) {
163 			err = -ENOMEM;
164 			mthca_err(mdev, "Couldn't map HCA reset register, "
165 				  "aborting.\n");
166 			goto out;
167 		}
168 
169 		writel(MTHCA_RESET_VALUE, reset);
170 		iounmap(reset);
171 	}
172 
173 	/* Docs say to wait one second before accessing device */
174 	msleep(1000);
175 
176 	/* Now wait for PCI device to start responding again */
177 	{
178 		u32 v;
179 		int c = 0;
180 
181 		for (c = 0; c < 100; ++c) {
182 			if (pci_read_config_dword(bridge ? bridge : mdev->pdev, 0, &v)) {
183 				err = -ENODEV;
184 				mthca_err(mdev, "Couldn't access HCA after reset, "
185 					  "aborting.\n");
186 				goto out;
187 			}
188 
189 			if (v != 0xffffffff)
190 				goto good;
191 
192 			msleep(100);
193 		}
194 
195 		err = -ENODEV;
196 		mthca_err(mdev, "PCI device did not come back after reset, "
197 			  "aborting.\n");
198 		goto out;
199 	}
200 
201 good:
202 #ifdef __linux__
203 	/* Now restore the PCI headers */
204 	if (bridge) {
205 		if (pci_write_config_dword(bridge, bridge_pcix_cap + 0x8,
206 				 bridge_header[(bridge_pcix_cap + 0x8) / 4])) {
207 			err = -ENODEV;
208 			mthca_err(mdev, "Couldn't restore HCA bridge Upstream "
209 				  "split transaction control, aborting.\n");
210 			goto out;
211 		}
212 		if (pci_write_config_dword(bridge, bridge_pcix_cap + 0xc,
213 				 bridge_header[(bridge_pcix_cap + 0xc) / 4])) {
214 			err = -ENODEV;
215 			mthca_err(mdev, "Couldn't restore HCA bridge Downstream "
216 				  "split transaction control, aborting.\n");
217 			goto out;
218 		}
219 		/*
220 		 * Bridge control register is at 0x3e, so we'll
221 		 * naturally restore it last in this loop.
222 		 */
223 		for (i = 0; i < 16; ++i) {
224 			if (i * 4 == PCI_COMMAND)
225 				continue;
226 
227 			if (pci_write_config_dword(bridge, i * 4, bridge_header[i])) {
228 				err = -ENODEV;
229 				mthca_err(mdev, "Couldn't restore HCA bridge reg %x, "
230 					  "aborting.\n", i);
231 				goto out;
232 			}
233 		}
234 
235 		if (pci_write_config_dword(bridge, PCI_COMMAND,
236 					   bridge_header[PCI_COMMAND / 4])) {
237 			err = -ENODEV;
238 			mthca_err(mdev, "Couldn't restore HCA bridge COMMAND, "
239 				  "aborting.\n");
240 			goto out;
241 		}
242 	}
243 #endif
244 
245 	if (hca_pcix_cap) {
246 		if (pci_write_config_dword(mdev->pdev, hca_pcix_cap,
247 				 hca_header[hca_pcix_cap / 4])) {
248 			err = -ENODEV;
249 			mthca_err(mdev, "Couldn't restore HCA PCI-X "
250 				  "command register, aborting.\n");
251 			goto out;
252 		}
253 	}
254 
255 	if (hca_pcie_cap) {
256 		devctl = hca_header[(hca_pcie_cap + PCI_EXP_DEVCTL) / 4];
257 		if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_DEVCTL,
258 					   devctl)) {
259 			err = -ENODEV;
260 			mthca_err(mdev, "Couldn't restore HCA PCI Express "
261 				  "Device Control register, aborting.\n");
262 			goto out;
263 		}
264 		linkctl = hca_header[(hca_pcie_cap + PCI_EXP_LNKCTL) / 4];
265 		if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_LNKCTL,
266 					   linkctl)) {
267 			err = -ENODEV;
268 			mthca_err(mdev, "Couldn't restore HCA PCI Express "
269 				  "Link control register, aborting.\n");
270 			goto out;
271 		}
272 	}
273 
274 	for (i = 0; i < 16; ++i) {
275 		if (i * 4 == PCI_COMMAND)
276 			continue;
277 
278 		if (pci_write_config_dword(mdev->pdev, i * 4, hca_header[i])) {
279 			err = -ENODEV;
280 			mthca_err(mdev, "Couldn't restore HCA reg %x, "
281 				  "aborting.\n", i);
282 			goto out;
283 		}
284 	}
285 
286 	if (pci_write_config_dword(mdev->pdev, PCI_COMMAND,
287 				   hca_header[PCI_COMMAND / 4])) {
288 		err = -ENODEV;
289 		mthca_err(mdev, "Couldn't restore HCA COMMAND, "
290 			  "aborting.\n");
291 		goto out;
292 	}
293 
294 out:
295 #ifdef __linux__
296 	if (bridge)
297 		pci_dev_put(bridge);
298 	kfree(bridge_header);
299 #endif
300 	kfree(hca_header);
301 
302 	return err;
303 }
304