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