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/init.h>
34#include <linux/errno.h>
35#include <linux/pci.h>
36#include <linux/delay.h>
37#include <linux/slab.h>
38
39#include "mthca_dev.h"
40#include "mthca_cmd.h"
41
42int mthca_reset(struct mthca_dev *mdev)
43{
44	int i;
45	int err = 0;
46	u32 *hca_header    = NULL;
47	u32 *bridge_header = NULL;
48	struct pci_dev *bridge = NULL;
49	int bridge_pcix_cap = 0;
50	int hca_pcie_cap = 0;
51	int hca_pcix_cap = 0;
52
53	u16 devctl;
54	u16 linkctl;
55
56#define MTHCA_RESET_OFFSET 0xf0010
57#define MTHCA_RESET_VALUE  swab32(1)
58
59	/*
60	 * Reset the chip.  This is somewhat ugly because we have to
61	 * save off the PCI header before reset and then restore it
62	 * after the chip reboots.  We skip config space offsets 22
63	 * and 23 since those have a special meaning.
64	 *
65	 * To make matters worse, for Tavor (PCI-X HCA) we have to
66	 * find the associated bridge device and save off its PCI
67	 * header as well.
68	 */
69
70	if (!(mdev->mthca_flags & MTHCA_FLAG_PCIE)) {
71		/* Look for the bridge -- its device ID will be 2 more
72		   than HCA's device ID. */
73#ifdef __linux__
74		while ((bridge = pci_get_device(mdev->pdev->vendor,
75						mdev->pdev->device + 2,
76						bridge)) != NULL) {
77			if (bridge->hdr_type    == PCI_HEADER_TYPE_BRIDGE &&
78			    bridge->subordinate == mdev->pdev->bus) {
79				mthca_dbg(mdev, "Found bridge: %s\n",
80					  pci_name(bridge));
81				break;
82			}
83		}
84
85		if (!bridge) {
86			/*
87			 * Didn't find a bridge for a Tavor device --
88			 * assume we're in no-bridge mode and hope for
89			 * the best.
90			 */
91			mthca_warn(mdev, "No bridge found for %s\n",
92				  pci_name(mdev->pdev));
93		}
94#else
95		mthca_warn(mdev, "Reset on PCI-X is not supported.\n");
96		goto out;
97
98#endif
99	}
100
101	/* For Arbel do we need to save off the full 4K PCI Express header?? */
102	hca_header = kmalloc(256, GFP_KERNEL);
103	if (!hca_header) {
104		err = -ENOMEM;
105		mthca_err(mdev, "Couldn't allocate memory to save HCA "
106			  "PCI header, aborting.\n");
107		goto out;
108	}
109
110	for (i = 0; i < 64; ++i) {
111		if (i == 22 || i == 23)
112			continue;
113		if (pci_read_config_dword(mdev->pdev, i * 4, hca_header + i)) {
114			err = -ENODEV;
115			mthca_err(mdev, "Couldn't save HCA "
116				  "PCI header, aborting.\n");
117			goto out;
118		}
119	}
120
121	hca_pcix_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_PCIX);
122	hca_pcie_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_EXP);
123
124#ifdef __linux__
125	if (bridge) {
126		bridge_header = kmalloc(256, GFP_KERNEL);
127		if (!bridge_header) {
128			err = -ENOMEM;
129			mthca_err(mdev, "Couldn't allocate memory to save HCA "
130				  "bridge PCI header, aborting.\n");
131			goto out;
132		}
133
134		for (i = 0; i < 64; ++i) {
135			if (i == 22 || i == 23)
136				continue;
137			if (pci_read_config_dword(bridge, i * 4, bridge_header + i)) {
138				err = -ENODEV;
139				mthca_err(mdev, "Couldn't save HCA bridge "
140					  "PCI header, aborting.\n");
141				goto out;
142			}
143		}
144		bridge_pcix_cap = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
145		if (!bridge_pcix_cap) {
146				err = -ENODEV;
147				mthca_err(mdev, "Couldn't locate HCA bridge "
148					  "PCI-X capability, aborting.\n");
149				goto out;
150		}
151	}
152#endif
153
154	/* actually hit reset */
155	{
156		void __iomem *reset = ioremap(pci_resource_start(mdev->pdev, 0) +
157					      MTHCA_RESET_OFFSET, 4);
158
159		if (!reset) {
160			err = -ENOMEM;
161			mthca_err(mdev, "Couldn't map HCA reset register, "
162				  "aborting.\n");
163			goto out;
164		}
165
166		writel(MTHCA_RESET_VALUE, reset);
167		iounmap(reset);
168	}
169
170	/* Docs say to wait one second before accessing device */
171	msleep(1000);
172
173	/* Now wait for PCI device to start responding again */
174	{
175		u32 v;
176		int c = 0;
177
178		for (c = 0; c < 100; ++c) {
179			if (pci_read_config_dword(bridge ? bridge : mdev->pdev, 0, &v)) {
180				err = -ENODEV;
181				mthca_err(mdev, "Couldn't access HCA after reset, "
182					  "aborting.\n");
183				goto out;
184			}
185
186			if (v != 0xffffffff)
187				goto good;
188
189			msleep(100);
190		}
191
192		err = -ENODEV;
193		mthca_err(mdev, "PCI device did not come back after reset, "
194			  "aborting.\n");
195		goto out;
196	}
197
198good:
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
240	if (hca_pcix_cap) {
241		if (pci_write_config_dword(mdev->pdev, hca_pcix_cap,
242				 hca_header[hca_pcix_cap / 4])) {
243			err = -ENODEV;
244			mthca_err(mdev, "Couldn't restore HCA PCI-X "
245				  "command register, aborting.\n");
246			goto out;
247		}
248	}
249
250	if (hca_pcie_cap) {
251		devctl = hca_header[(hca_pcie_cap + PCI_EXP_DEVCTL) / 4];
252		if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_DEVCTL,
253					   devctl)) {
254			err = -ENODEV;
255			mthca_err(mdev, "Couldn't restore HCA PCI Express "
256				  "Device Control register, aborting.\n");
257			goto out;
258		}
259		linkctl = hca_header[(hca_pcie_cap + PCI_EXP_LNKCTL) / 4];
260		if (pci_write_config_word(mdev->pdev, hca_pcie_cap + PCI_EXP_LNKCTL,
261					   linkctl)) {
262			err = -ENODEV;
263			mthca_err(mdev, "Couldn't restore HCA PCI Express "
264				  "Link control register, aborting.\n");
265			goto out;
266		}
267	}
268
269	for (i = 0; i < 16; ++i) {
270		if (i * 4 == PCI_COMMAND)
271			continue;
272
273		if (pci_write_config_dword(mdev->pdev, i * 4, hca_header[i])) {
274			err = -ENODEV;
275			mthca_err(mdev, "Couldn't restore HCA reg %x, "
276				  "aborting.\n", i);
277			goto out;
278		}
279	}
280
281	if (pci_write_config_dword(mdev->pdev, PCI_COMMAND,
282				   hca_header[PCI_COMMAND / 4])) {
283		err = -ENODEV;
284		mthca_err(mdev, "Couldn't restore HCA COMMAND, "
285			  "aborting.\n");
286		goto out;
287	}
288
289out:
290#ifdef __linux__
291	if (bridge)
292		pci_dev_put(bridge);
293#endif
294	kfree(bridge_header);
295	kfree(hca_header);
296
297	return err;
298}
299