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 
42 int 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 PCI header, aborting\n");
76 		goto out;
77 	}
78 
79 	pcie_cap = pci_pcie_cap(dev->pdev);
80 
81 	for (i = 0; i < 64; ++i) {
82 		if (i == 22 || i == 23)
83 			continue;
84 		if (pci_read_config_dword(dev->pdev, i * 4, hca_header + i)) {
85 			err = -ENODEV;
86 			mlx4_err(dev, "Couldn't save HCA PCI header, aborting\n");
87 			goto out;
88 		}
89 	}
90 
91 	reset = ioremap(pci_resource_start(dev->pdev, 0) + MLX4_RESET_BASE,
92 			MLX4_RESET_SIZE);
93 	if (!reset) {
94 		err = -ENOMEM;
95 		mlx4_err(dev, "Couldn't map HCA reset register, aborting\n");
96 		goto out;
97 	}
98 
99 	/* grab HW semaphore to lock out flash updates */
100 	end = jiffies + MLX4_SEM_TIMEOUT_JIFFIES;
101 	do {
102 		sem = readl(reset + MLX4_SEM_OFFSET);
103 		if (!sem)
104 			break;
105 
106 		msleep(1);
107 	} while (time_before(jiffies, end));
108 
109 	if (sem) {
110 		mlx4_err(dev, "Failed to obtain HW semaphore, aborting\n");
111 		err = -EAGAIN;
112 		iounmap(reset);
113 		goto out;
114 	}
115 
116 	/* actually hit reset */
117 	writel(MLX4_RESET_VALUE, reset + MLX4_RESET_OFFSET);
118 	iounmap(reset);
119 
120 	/* Docs say to wait one second before accessing device */
121 	msleep(1000);
122 
123 	end = jiffies + MLX4_RESET_TIMEOUT_JIFFIES;
124 	do {
125 		if (!pci_read_config_word(dev->pdev, PCI_VENDOR_ID, &vendor) &&
126 		    vendor != 0xffff)
127 			break;
128 
129 		msleep(1);
130 	} while (time_before(jiffies, end));
131 
132 	if (vendor == 0xffff) {
133 		err = -ENODEV;
134 		mlx4_err(dev, "PCI device did not come back after reset, aborting\n");
135 		goto out;
136 	}
137 
138 	/* Now restore the PCI headers */
139 	if (pcie_cap) {
140 		devctl = hca_header[(pcie_cap + PCI_EXP_DEVCTL) / 4];
141 		if (pcie_capability_write_word(dev->pdev, PCI_EXP_DEVCTL,
142 					       devctl)) {
143 			err = -ENODEV;
144 			mlx4_err(dev, "Couldn't restore HCA PCI Express Device Control register, aborting\n");
145 			goto out;
146 		}
147 		linkctl = hca_header[(pcie_cap + PCI_EXP_LNKCTL) / 4];
148 		if (pcie_capability_write_word(dev->pdev, PCI_EXP_LNKCTL,
149 					       linkctl)) {
150 			err = -ENODEV;
151 			mlx4_err(dev, "Couldn't restore HCA PCI Express Link control register, aborting\n");
152 			goto out;
153 		}
154 	}
155 
156 	for (i = 0; i < 16; ++i) {
157 		if (i * 4 == PCI_COMMAND)
158 			continue;
159 
160 		if (pci_write_config_dword(dev->pdev, i * 4, hca_header[i])) {
161 			err = -ENODEV;
162 			mlx4_err(dev, "Couldn't restore HCA reg %x, aborting\n",
163 				 i);
164 			goto out;
165 		}
166 	}
167 
168 	if (pci_write_config_dword(dev->pdev, PCI_COMMAND,
169 				   hca_header[PCI_COMMAND / 4])) {
170 		err = -ENODEV;
171 		mlx4_err(dev, "Couldn't restore HCA COMMAND, aborting\n");
172 		goto out;
173 	}
174 
175 out:
176 	kfree(hca_header);
177 
178 	return err;
179 }
180