reset.c revision 219820 
1/*
2 * Copyright (c) 2006, 2007 Cisco Systems, Inc.  All rights reserved.
3 * Copyright (c) 2007, 2008 Mellanox Technologies. All rights reserved.
4 *
5 * This software is available to you under a choice of one of two
6 * licenses.  You may choose to be licensed under the terms of the GNU
7 * General Public License (GPL) Version 2, available from the file
8 * COPYING in the main directory of this source tree, or the
9 * OpenIB.org BSD license below:
10 *
11 *     Redistribution and use in source and binary forms, with or
12 *     without modification, are permitted provided that the following
13 *     conditions are met:
14 *
15 *      - Redistributions of source code must retain the above
16 *        copyright notice, this list of conditions and the following
17 *        disclaimer.
18 *
19 *      - Redistributions in binary form must reproduce the above
20 *        copyright notice, this list of conditions and the following
21 *        disclaimer in the documentation and/or other materials
22 *        provided with the distribution.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31 * SOFTWARE.
32 */
33
34#include <linux/init.h>
35#include <linux/errno.h>
36#include <linux/pci.h>
37#include <linux/delay.h>
38#include <linux/slab.h>
39#include <linux/jiffies.h>
40
41#include "mlx4.h"
42
43int mlx4_reset(struct mlx4_dev *dev)
44{
45	void __iomem *reset;
46	u32 *hca_header = NULL;
47	int pcie_cap;
48	u16 devctl;
49	u16 linkctl;
50	u16 vendor;
51	unsigned long end;
52	u32 sem;
53	int i;
54	int err = 0;
55
56#define MLX4_RESET_BASE		0xf0000
57#define MLX4_RESET_SIZE		  0x400
58#define MLX4_SEM_OFFSET		  0x3fc
59#define MLX4_RESET_OFFSET	   0x10
60#define MLX4_RESET_VALUE	swab32(1)
61
62#define MLX4_SEM_TIMEOUT_JIFFIES	(10 * HZ)
63#define MLX4_RESET_TIMEOUT_JIFFIES	(2 * HZ)
64
65	/*
66	 * Reset the chip.  This is somewhat ugly because we have to
67	 * save off the PCI header before reset and then restore it
68	 * after the chip reboots.  We skip config space offsets 22
69	 * and 23 since those have a special meaning.
70	 */
71
72	/* Do we need to save off the full 4K PCI Express header?? */
73	hca_header = kmalloc(256, GFP_KERNEL);
74	if (!hca_header) {
75		err = -ENOMEM;
76		mlx4_err(dev, "Couldn't allocate memory to save HCA "
77			  "PCI header, aborting.\n");
78		goto out;
79	}
80
81	pcie_cap = pci_find_capability(dev->pdev, PCI_CAP_ID_EXP);
82
83	for (i = 0; i < 64; ++i) {
84		if (i == 22 || i == 23)
85			continue;
86		if (pci_read_config_dword(dev->pdev, i * 4, hca_header + i)) {
87			err = -ENODEV;
88			mlx4_err(dev, "Couldn't save HCA "
89				  "PCI header, aborting.\n");
90			goto out;
91		}
92	}
93
94	reset = ioremap(pci_resource_start(dev->pdev, 0) + MLX4_RESET_BASE,
95			MLX4_RESET_SIZE);
96	if (!reset) {
97		err = -ENOMEM;
98		mlx4_err(dev, "Couldn't map HCA reset register, aborting.\n");
99		goto out;
100	}
101
102	/* grab HW semaphore to lock out flash updates */
103	end = jiffies + MLX4_SEM_TIMEOUT_JIFFIES;
104	do {
105		sem = readl(reset + MLX4_SEM_OFFSET);
106		if (!sem)
107			break;
108
109		msleep(1);
110	} while (time_before(jiffies, end));
111
112	if (sem) {
113		mlx4_err(dev, "Failed to obtain HW semaphore, aborting\n");
114		err = -EAGAIN;
115		iounmap(reset);
116		goto out;
117	}
118
119	/* actually hit reset */
120	writel(MLX4_RESET_VALUE, reset + MLX4_RESET_OFFSET);
121	iounmap(reset);
122
123	/* Docs say to wait one second before accessing device */
124	msleep(1000);
125
126	end = jiffies + MLX4_RESET_TIMEOUT_JIFFIES;
127	do {
128		if (!pci_read_config_word(dev->pdev, PCI_VENDOR_ID, &vendor) &&
129		    vendor != 0xffff)
130			break;
131
132		msleep(1);
133	} while (time_before(jiffies, end));
134
135	if (vendor == 0xffff) {
136		err = -ENODEV;
137		mlx4_err(dev, "PCI device did not come back after reset, "
138			  "aborting.\n");
139		goto out;
140	}
141
142	/* Now restore the PCI headers */
143	if (pcie_cap) {
144		devctl = hca_header[(pcie_cap + PCI_EXP_DEVCTL) / 4];
145		if (pci_write_config_word(dev->pdev, pcie_cap + PCI_EXP_DEVCTL,
146					   devctl)) {
147			err = -ENODEV;
148			mlx4_err(dev, "Couldn't restore HCA PCI Express "
149				 "Device Control register, aborting.\n");
150			goto out;
151		}
152		linkctl = hca_header[(pcie_cap + PCI_EXP_LNKCTL) / 4];
153		if (pci_write_config_word(dev->pdev, pcie_cap + PCI_EXP_LNKCTL,
154					   linkctl)) {
155			err = -ENODEV;
156			mlx4_err(dev, "Couldn't restore HCA PCI Express "
157				 "Link control register, aborting.\n");
158			goto out;
159		}
160	}
161
162	for (i = 0; i < 16; ++i) {
163		if (i * 4 == PCI_COMMAND)
164			continue;
165
166		if (pci_write_config_dword(dev->pdev, i * 4, hca_header[i])) {
167			err = -ENODEV;
168			mlx4_err(dev, "Couldn't restore HCA reg %x, "
169				  "aborting.\n", i);
170			goto out;
171		}
172	}
173
174	if (pci_write_config_dword(dev->pdev, PCI_COMMAND,
175				   hca_header[PCI_COMMAND / 4])) {
176		err = -ENODEV;
177		mlx4_err(dev, "Couldn't restore HCA COMMAND, "
178			  "aborting.\n");
179		goto out;
180	}
181
182out:
183	kfree(hca_header);
184
185	return err;
186}
187