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 	u32 *bridge_header = NULL;
47 	struct pci_dev *bridge = NULL;
48 	int bridge_pcix_cap = 0;
49 	int hca_pcie_cap = 0;
50 	int hca_pcix_cap = 0;
51 
52 	u16 devctl;
53 	u16 linkctl;
54 
55 #define MTHCA_RESET_OFFSET 0xf0010
56 #define MTHCA_RESET_VALUE  swab32(1)
57 
58 	/*
59 	 * Reset the chip.  This is somewhat ugly because we have to
60 	 * save off the PCI header before reset and then restore it
61 	 * after the chip reboots.  We skip config space offsets 22
62 	 * and 23 since those have a special meaning.
63 	 *
64 	 * To make matters worse, for Tavor (PCI-X HCA) we have to
65 	 * find the associated bridge device and save off its PCI
66 	 * header as well.
67 	 */
68 
69 	if (!(mdev->mthca_flags & MTHCA_FLAG_PCIE)) {
70 		/* Look for the bridge -- its device ID will be 2 more
71 		   than HCA's device ID. */
72 		while ((bridge = pci_get_device(mdev->pdev->vendor,
73 						mdev->pdev->device + 2,
74 						bridge)) != NULL) {
75 			if (bridge->hdr_type    == PCI_HEADER_TYPE_BRIDGE &&
76 			    bridge->subordinate == mdev->pdev->bus) {
77 				mthca_dbg(mdev, "Found bridge: %s\n",
78 					  pci_name(bridge));
79 				break;
80 			}
81 		}
82 
83 		if (!bridge) {
84 			/*
85 			 * Didn't find a bridge for a Tavor device --
86 			 * assume we're in no-bridge mode and hope for
87 			 * the best.
88 			 */
89 			mthca_warn(mdev, "No bridge found for %s\n",
90 				  pci_name(mdev->pdev));
91 		}
92 
93 	}
94 
95 	/* For Arbel do we need to save off the full 4K PCI Express header?? */
96 	hca_header = kmalloc(256, GFP_KERNEL);
97 	if (!hca_header) {
98 		err = -ENOMEM;
99 		mthca_err(mdev, "Couldn't allocate memory to save HCA "
100 			  "PCI header, aborting.\n");
101 		goto out;
102 	}
103 
104 	for (i = 0; i < 64; ++i) {
105 		if (i == 22 || i == 23)
106 			continue;
107 		if (pci_read_config_dword(mdev->pdev, i * 4, hca_header + i)) {
108 			err = -ENODEV;
109 			mthca_err(mdev, "Couldn't save HCA "
110 				  "PCI header, aborting.\n");
111 			goto out;
112 		}
113 	}
114 
115 	hca_pcix_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_PCIX);
116 	hca_pcie_cap = pci_pcie_cap(mdev->pdev);
117 
118 	if (bridge) {
119 		bridge_header = kmalloc(256, GFP_KERNEL);
120 		if (!bridge_header) {
121 			err = -ENOMEM;
122 			mthca_err(mdev, "Couldn't allocate memory to save HCA "
123 				  "bridge PCI header, aborting.\n");
124 			goto out;
125 		}
126 
127 		for (i = 0; i < 64; ++i) {
128 			if (i == 22 || i == 23)
129 				continue;
130 			if (pci_read_config_dword(bridge, i * 4, bridge_header + i)) {
131 				err = -ENODEV;
132 				mthca_err(mdev, "Couldn't save HCA bridge "
133 					  "PCI header, aborting.\n");
134 				goto out;
135 			}
136 		}
137 		bridge_pcix_cap = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
138 		if (!bridge_pcix_cap) {
139 				err = -ENODEV;
140 				mthca_err(mdev, "Couldn't locate HCA bridge "
141 					  "PCI-X capability, aborting.\n");
142 				goto out;
143 		}
144 	}
145 
146 	/* actually hit reset */
147 	{
148 		void __iomem *reset = ioremap(pci_resource_start(mdev->pdev, 0) +
149 					      MTHCA_RESET_OFFSET, 4);
150 
151 		if (!reset) {
152 			err = -ENOMEM;
153 			mthca_err(mdev, "Couldn't map HCA reset register, "
154 				  "aborting.\n");
155 			goto out;
156 		}
157 
158 		writel(MTHCA_RESET_VALUE, reset);
159 		iounmap(reset);
160 	}
161 
162 	/* Docs say to wait one second before accessing device */
163 	msleep(1000);
164 
165 	/* Now wait for PCI device to start responding again */
166 	{
167 		u32 v;
168 		int c = 0;
169 
170 		for (c = 0; c < 100; ++c) {
171 			if (pci_read_config_dword(bridge ? bridge : mdev->pdev, 0, &v)) {
172 				err = -ENODEV;
173 				mthca_err(mdev, "Couldn't access HCA after reset, "
174 					  "aborting.\n");
175 				goto out;
176 			}
177 
178 			if (v != 0xffffffff)
179 				goto good;
180 
181 			msleep(100);
182 		}
183 
184 		err = -ENODEV;
185 		mthca_err(mdev, "PCI device did not come back after reset, "
186 			  "aborting.\n");
187 		goto out;
188 	}
189 
190 good:
191 	/* Now restore the PCI headers */
192 	if (bridge) {
193 		if (pci_write_config_dword(bridge, bridge_pcix_cap + 0x8,
194 				 bridge_header[(bridge_pcix_cap + 0x8) / 4])) {
195 			err = -ENODEV;
196 			mthca_err(mdev, "Couldn't restore HCA bridge Upstream "
197 				  "split transaction control, aborting.\n");
198 			goto out;
199 		}
200 		if (pci_write_config_dword(bridge, bridge_pcix_cap + 0xc,
201 				 bridge_header[(bridge_pcix_cap + 0xc) / 4])) {
202 			err = -ENODEV;
203 			mthca_err(mdev, "Couldn't restore HCA bridge Downstream "
204 				  "split transaction control, aborting.\n");
205 			goto out;
206 		}
207 		/*
208 		 * Bridge control register is at 0x3e, so we'll
209 		 * naturally restore it last in this loop.
210 		 */
211 		for (i = 0; i < 16; ++i) {
212 			if (i * 4 == PCI_COMMAND)
213 				continue;
214 
215 			if (pci_write_config_dword(bridge, i * 4, bridge_header[i])) {
216 				err = -ENODEV;
217 				mthca_err(mdev, "Couldn't restore HCA bridge reg %x, "
218 					  "aborting.\n", i);
219 				goto out;
220 			}
221 		}
222 
223 		if (pci_write_config_dword(bridge, PCI_COMMAND,
224 					   bridge_header[PCI_COMMAND / 4])) {
225 			err = -ENODEV;
226 			mthca_err(mdev, "Couldn't restore HCA bridge COMMAND, "
227 				  "aborting.\n");
228 			goto out;
229 		}
230 	}
231 
232 	if (hca_pcix_cap) {
233 		if (pci_write_config_dword(mdev->pdev, hca_pcix_cap,
234 				 hca_header[hca_pcix_cap / 4])) {
235 			err = -ENODEV;
236 			mthca_err(mdev, "Couldn't restore HCA PCI-X "
237 				  "command register, aborting.\n");
238 			goto out;
239 		}
240 	}
241 
242 	if (hca_pcie_cap) {
243 		devctl = hca_header[(hca_pcie_cap + PCI_EXP_DEVCTL) / 4];
244 		if (pcie_capability_write_word(mdev->pdev, PCI_EXP_DEVCTL,
245 					       devctl)) {
246 			err = -ENODEV;
247 			mthca_err(mdev, "Couldn't restore HCA PCI Express "
248 				  "Device Control register, aborting.\n");
249 			goto out;
250 		}
251 		linkctl = hca_header[(hca_pcie_cap + PCI_EXP_LNKCTL) / 4];
252 		if (pcie_capability_write_word(mdev->pdev, PCI_EXP_LNKCTL,
253 					       linkctl)) {
254 			err = -ENODEV;
255 			mthca_err(mdev, "Couldn't restore HCA PCI Express "
256 				  "Link control register, aborting.\n");
257 			goto out;
258 		}
259 	}
260 
261 	for (i = 0; i < 16; ++i) {
262 		if (i * 4 == PCI_COMMAND)
263 			continue;
264 
265 		if (pci_write_config_dword(mdev->pdev, i * 4, hca_header[i])) {
266 			err = -ENODEV;
267 			mthca_err(mdev, "Couldn't restore HCA reg %x, "
268 				  "aborting.\n", i);
269 			goto out;
270 		}
271 	}
272 
273 	if (pci_write_config_dword(mdev->pdev, PCI_COMMAND,
274 				   hca_header[PCI_COMMAND / 4])) {
275 		err = -ENODEV;
276 		mthca_err(mdev, "Couldn't restore HCA COMMAND, "
277 			  "aborting.\n");
278 		goto out;
279 	}
280 
281 out:
282 	if (bridge)
283 		pci_dev_put(bridge);
284 	kfree(bridge_header);
285 	kfree(hca_header);
286 
287 	return err;
288 }
289