xref: /freebsd/sys/dev/mthca/mthca_reset.c (revision d15f2551b25f79ddcbe289faa95e655100b952da)
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 		goto out;
109 	}
110 
111 	for (i = 0; i < 64; ++i) {
112 		if (i == 22 || i == 23)
113 			continue;
114 		if (pci_read_config_dword(mdev->pdev, i * 4, hca_header + i)) {
115 			err = -ENODEV;
116 			mthca_err(mdev, "Couldn't save HCA "
117 				  "PCI header, aborting.\n");
118 			goto out;
119 		}
120 	}
121 
122 	hca_pcix_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_PCIX);
123 	hca_pcie_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_EXP);
124 
125 #ifdef __linux__
126 	if (bridge) {
127 		bridge_header = kmalloc(256, GFP_KERNEL);
128 		if (!bridge_header) {
129 			err = -ENOMEM;
130 			goto out;
131 		}
132 
133 		for (i = 0; i < 64; ++i) {
134 			if (i == 22 || i == 23)
135 				continue;
136 			if (pci_read_config_dword(bridge, i * 4, bridge_header + i)) {
137 				err = -ENODEV;
138 				mthca_err(mdev, "Couldn't save HCA bridge "
139 					  "PCI header, aborting.\n");
140 				goto out;
141 			}
142 		}
143 		bridge_pcix_cap = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
144 		if (!bridge_pcix_cap) {
145 				err = -ENODEV;
146 				mthca_err(mdev, "Couldn't locate HCA bridge "
147 					  "PCI-X capability, aborting.\n");
148 				goto out;
149 		}
150 	}
151 #endif
152 
153 	/* actually hit reset */
154 	{
155 		void __iomem *reset = ioremap(pci_resource_start(mdev->pdev, 0) +
156 					      MTHCA_RESET_OFFSET, 4);
157 
158 		if (!reset) {
159 			err = -ENOMEM;
160 			mthca_err(mdev, "Couldn't map HCA reset register, "
161 				  "aborting.\n");
162 			goto out;
163 		}
164 
165 		writel(MTHCA_RESET_VALUE, reset);
166 		iounmap(reset);
167 	}
168 
169 	/* Docs say to wait one second before accessing device */
170 	msleep(1000);
171 
172 	/* Now wait for PCI device to start responding again */
173 	{
174 		u32 v;
175 		int c = 0;
176 
177 		for (c = 0; c < 100; ++c) {
178 			if (pci_read_config_dword(bridge ? bridge : mdev->pdev, 0, &v)) {
179 				err = -ENODEV;
180 				mthca_err(mdev, "Couldn't access HCA after reset, "
181 					  "aborting.\n");
182 				goto out;
183 			}
184 
185 			if (v != 0xffffffff)
186 				goto good;
187 
188 			msleep(100);
189 		}
190 
191 		err = -ENODEV;
192 		mthca_err(mdev, "PCI device did not come back after reset, "
193 			  "aborting.\n");
194 		goto out;
195 	}
196 
197 good:
198 #ifdef __linux__
199 	/* Now restore the PCI headers */
200 	if (bridge) {
201 		if (pci_write_config_dword(bridge, bridge_pcix_cap + 0x8,
202 				 bridge_header[(bridge_pcix_cap + 0x8) / 4])) {
203 			err = -ENODEV;
204 			mthca_err(mdev, "Couldn't restore HCA bridge Upstream "
205 				  "split transaction control, aborting.\n");
206 			goto out;
207 		}
208 		if (pci_write_config_dword(bridge, bridge_pcix_cap + 0xc,
209 				 bridge_header[(bridge_pcix_cap + 0xc) / 4])) {
210 			err = -ENODEV;
211 			mthca_err(mdev, "Couldn't restore HCA bridge Downstream "
212 				  "split transaction control, aborting.\n");
213 			goto out;
214 		}
215 		/*
216 		 * Bridge control register is at 0x3e, so we'll
217 		 * naturally restore it last in this loop.
218 		 */
219 		for (i = 0; i < 16; ++i) {
220 			if (i * 4 == PCI_COMMAND)
221 				continue;
222 
223 			if (pci_write_config_dword(bridge, i * 4, bridge_header[i])) {
224 				err = -ENODEV;
225 				mthca_err(mdev, "Couldn't restore HCA bridge reg %x, "
226 					  "aborting.\n", i);
227 				goto out;
228 			}
229 		}
230 
231 		if (pci_write_config_dword(bridge, PCI_COMMAND,
232 					   bridge_header[PCI_COMMAND / 4])) {
233 			err = -ENODEV;
234 			mthca_err(mdev, "Couldn't restore HCA bridge COMMAND, "
235 				  "aborting.\n");
236 			goto out;
237 		}
238 	}
239 #endif
240 
241 	if (hca_pcix_cap) {
242 		if (pci_write_config_dword(mdev->pdev, hca_pcix_cap,
243 				 hca_header[hca_pcix_cap / 4])) {
244 			err = -ENODEV;
245 			mthca_err(mdev, "Couldn't restore HCA PCI-X "
246 				  "command register, aborting.\n");
247 			goto out;
248 		}
249 	}
250 
251 	if (hca_pcie_cap) {
252 		devctl = hca_header[(hca_pcie_cap + PCI_EXP_DEVCTL) / 4];
253 		if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_DEVCTL,
254 					   devctl)) {
255 			err = -ENODEV;
256 			mthca_err(mdev, "Couldn't restore HCA PCI Express "
257 				  "Device Control register, aborting.\n");
258 			goto out;
259 		}
260 		linkctl = hca_header[(hca_pcie_cap + PCI_EXP_LNKCTL) / 4];
261 		if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_LNKCTL,
262 					   linkctl)) {
263 			err = -ENODEV;
264 			mthca_err(mdev, "Couldn't restore HCA PCI Express "
265 				  "Link control register, aborting.\n");
266 			goto out;
267 		}
268 	}
269 
270 	for (i = 0; i < 16; ++i) {
271 		if (i * 4 == PCI_COMMAND)
272 			continue;
273 
274 		if (pci_write_config_dword(mdev->pdev, i * 4, hca_header[i])) {
275 			err = -ENODEV;
276 			mthca_err(mdev, "Couldn't restore HCA reg %x, "
277 				  "aborting.\n", i);
278 			goto out;
279 		}
280 	}
281 
282 	if (pci_write_config_dword(mdev->pdev, PCI_COMMAND,
283 				   hca_header[PCI_COMMAND / 4])) {
284 		err = -ENODEV;
285 		mthca_err(mdev, "Couldn't restore HCA COMMAND, "
286 			  "aborting.\n");
287 		goto out;
288 	}
289 
290 out:
291 #ifdef __linux__
292 	if (bridge)
293 		pci_dev_put(bridge);
294 	kfree(bridge_header);
295 #endif
296 	kfree(hca_header);
297 
298 	return err;
299 }
300