reset.c revision 271127 
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/errno.h>
35#include <linux/pci.h>
36#include <linux/delay.h>
37#include <linux/slab.h>
38#include <linux/jiffies.h>
39
40#include "mlx4.h"
41
42int mlx4_reset(struct mlx4_dev *dev)
43{
44	void __iomem *reset;
45	u32 *hca_header = NULL;
46	int pcie_cap;
47	u16 devctl;
48	u16 linkctl;
49	u16 vendor;
50	unsigned long end;
51	u32 sem;
52	int i;
53	int err = 0;
54
55#define MLX4_RESET_BASE		0xf0000
56#define MLX4_RESET_SIZE		  0x400
57#define MLX4_SEM_OFFSET		  0x3fc
58#define MLX4_RESET_OFFSET	   0x10
59#define MLX4_RESET_VALUE	swab32(1)
60
61#define MLX4_SEM_TIMEOUT_JIFFIES	(10 * HZ)
62#define MLX4_RESET_TIMEOUT_JIFFIES	(2 * HZ)
63
64	/*
65	 * Reset the chip.  This is somewhat ugly because we have to
66	 * save off the PCI header before reset and then restore it
67	 * after the chip reboots.  We skip config space offsets 22
68	 * and 23 since those have a special meaning.
69	 */
70
71	/* Do we need to save off the full 4K PCI Express header?? */
72	hca_header = kmalloc(256, GFP_KERNEL);
73	if (!hca_header) {
74		err = -ENOMEM;
75		mlx4_err(dev, "Couldn't allocate memory to save HCA "
76			  "PCI header, aborting.\n");
77		goto out;
78	}
79
80	pcie_cap = pci_find_capability(dev->pdev, PCI_CAP_ID_EXP);
81
82	for (i = 0; i < 64; ++i) {
83		if (i == 22 || i == 23)
84			continue;
85		if (pci_read_config_dword(dev->pdev, i * 4, hca_header + i)) {
86			err = -ENODEV;
87			mlx4_err(dev, "Couldn't save HCA "
88				  "PCI header, aborting.\n");
89			goto out;
90		}
91	}
92
93	reset = ioremap(pci_resource_start(dev->pdev, 0) + MLX4_RESET_BASE,
94			MLX4_RESET_SIZE);
95	if (!reset) {
96		err = -ENOMEM;
97		mlx4_err(dev, "Couldn't map HCA reset register, aborting.\n");
98		goto out;
99	}
100
101	/* grab HW semaphore to lock out flash updates */
102	end = jiffies + MLX4_SEM_TIMEOUT_JIFFIES;
103	do {
104		sem = readl(reset + MLX4_SEM_OFFSET);
105		if (!sem)
106			break;
107
108		msleep(1);
109	} while (time_before(jiffies, end));
110
111	if (sem) {
112		mlx4_err(dev, "Failed to obtain HW semaphore, aborting\n");
113		err = -EAGAIN;
114		iounmap(reset);
115		goto out;
116	}
117
118	/* actually hit reset */
119	writel(MLX4_RESET_VALUE, reset + MLX4_RESET_OFFSET);
120	iounmap(reset);
121
122	/* Docs say to wait one second before accessing device */
123	msleep(2000);
124
125	end = jiffies + MLX4_RESET_TIMEOUT_JIFFIES;
126	do {
127		if (!pci_read_config_word(dev->pdev, PCI_VENDOR_ID, &vendor) &&
128		    vendor != 0xffff)
129			break;
130
131		msleep(1);
132	} while (time_before(jiffies, end));
133
134	if (vendor == 0xffff) {
135		err = -ENODEV;
136		mlx4_err(dev, "PCI device did not come back after reset, "
137			  "aborting.\n");
138		goto out;
139	}
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