tile: expect new initramfs name from hypervisor file system
[pandora-kernel.git] / arch / tile / kernel / sysfs.c
1 /*
2  * Copyright 2011 Tilera Corporation. All Rights Reserved.
3  *
4  *   This program is free software; you can redistribute it and/or
5  *   modify it under the terms of the GNU General Public License
6  *   as published by the Free Software Foundation, version 2.
7  *
8  *   This program is distributed in the hope that it will be useful, but
9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11  *   NON INFRINGEMENT.  See the GNU General Public License for
12  *   more details.
13  *
14  * /sys entry support.
15  */
16
17 #include <linux/sysdev.h>
18 #include <linux/cpu.h>
19 #include <linux/slab.h>
20 #include <linux/smp.h>
21 #include <linux/stat.h>
22 #include <hv/hypervisor.h>
23
24 /* Return a string queried from the hypervisor, truncated to page size. */
25 static ssize_t get_hv_confstr(char *page, int query)
26 {
27         ssize_t n = hv_confstr(query, (unsigned long)page, PAGE_SIZE - 1);
28         n = n < 0 ? 0 : min(n, (ssize_t)PAGE_SIZE - 1) - 1;
29         if (n)
30                 page[n++] = '\n';
31         page[n] = '\0';
32         return n;
33 }
34
35 static ssize_t chip_width_show(struct sysdev_class *dev,
36                                struct sysdev_class_attribute *attr,
37                                char *page)
38 {
39         return sprintf(page, "%u\n", smp_width);
40 }
41 static SYSDEV_CLASS_ATTR(chip_width, 0444, chip_width_show, NULL);
42
43 static ssize_t chip_height_show(struct sysdev_class *dev,
44                                 struct sysdev_class_attribute *attr,
45                                 char *page)
46 {
47         return sprintf(page, "%u\n", smp_height);
48 }
49 static SYSDEV_CLASS_ATTR(chip_height, 0444, chip_height_show, NULL);
50
51 static ssize_t chip_serial_show(struct sysdev_class *dev,
52                                 struct sysdev_class_attribute *attr,
53                                 char *page)
54 {
55         return get_hv_confstr(page, HV_CONFSTR_CHIP_SERIAL_NUM);
56 }
57 static SYSDEV_CLASS_ATTR(chip_serial, 0444, chip_serial_show, NULL);
58
59 static ssize_t chip_revision_show(struct sysdev_class *dev,
60                                   struct sysdev_class_attribute *attr,
61                                   char *page)
62 {
63         return get_hv_confstr(page, HV_CONFSTR_CHIP_REV);
64 }
65 static SYSDEV_CLASS_ATTR(chip_revision, 0444, chip_revision_show, NULL);
66
67
68 static ssize_t type_show(struct sysdev_class *dev,
69                             struct sysdev_class_attribute *attr,
70                             char *page)
71 {
72         return sprintf(page, "tilera\n");
73 }
74 static SYSDEV_CLASS_ATTR(type, 0444, type_show, NULL);
75
76 #define HV_CONF_ATTR(name, conf)                                        \
77         static ssize_t name ## _show(struct sysdev_class *dev,          \
78                                      struct sysdev_class_attribute *attr, \
79                                      char *page)                        \
80         {                                                               \
81                 return get_hv_confstr(page, conf);                      \
82         }                                                               \
83         static SYSDEV_CLASS_ATTR(name, 0444, name ## _show, NULL);
84
85 HV_CONF_ATTR(version,           HV_CONFSTR_HV_SW_VER)
86 HV_CONF_ATTR(config_version,    HV_CONFSTR_HV_CONFIG_VER)
87
88 HV_CONF_ATTR(board_part,        HV_CONFSTR_BOARD_PART_NUM)
89 HV_CONF_ATTR(board_serial,      HV_CONFSTR_BOARD_SERIAL_NUM)
90 HV_CONF_ATTR(board_revision,    HV_CONFSTR_BOARD_REV)
91 HV_CONF_ATTR(board_description, HV_CONFSTR_BOARD_DESC)
92 HV_CONF_ATTR(mezz_part,         HV_CONFSTR_MEZZ_PART_NUM)
93 HV_CONF_ATTR(mezz_serial,       HV_CONFSTR_MEZZ_SERIAL_NUM)
94 HV_CONF_ATTR(mezz_revision,     HV_CONFSTR_MEZZ_REV)
95 HV_CONF_ATTR(mezz_description,  HV_CONFSTR_MEZZ_DESC)
96 HV_CONF_ATTR(switch_control,    HV_CONFSTR_SWITCH_CONTROL)
97
98 static struct attribute *board_attrs[] = {
99         &attr_board_part.attr,
100         &attr_board_serial.attr,
101         &attr_board_revision.attr,
102         &attr_board_description.attr,
103         &attr_mezz_part.attr,
104         &attr_mezz_serial.attr,
105         &attr_mezz_revision.attr,
106         &attr_mezz_description.attr,
107         &attr_switch_control.attr,
108         NULL
109 };
110
111 static struct attribute_group board_attr_group = {
112         .name   = "board",
113         .attrs  = board_attrs,
114 };
115
116
117 static struct bin_attribute hvconfig_bin;
118
119 static ssize_t
120 hvconfig_bin_read(struct file *filp, struct kobject *kobj,
121                   struct bin_attribute *bin_attr,
122                   char *buf, loff_t off, size_t count)
123 {
124         static size_t size;
125
126         /* Lazily learn the true size (minus the trailing NUL). */
127         if (size == 0)
128                 size = hv_confstr(HV_CONFSTR_HV_CONFIG, 0, 0) - 1;
129
130         /* Check and adjust input parameters. */
131         if (off > size)
132                 return -EINVAL;
133         if (count > size - off)
134                 count = size - off;
135
136         if (count) {
137                 /* Get a copy of the hvc and copy out the relevant portion. */
138                 char *hvc;
139
140                 size = off + count;
141                 hvc = kmalloc(size, GFP_KERNEL);
142                 if (hvc == NULL)
143                         return -ENOMEM;
144                 hv_confstr(HV_CONFSTR_HV_CONFIG, (unsigned long)hvc, size);
145                 memcpy(buf, hvc + off, count);
146                 kfree(hvc);
147         }
148
149         return count;
150 }
151
152 static int __init create_sysfs_entries(void)
153 {
154         struct sysdev_class *cls = &cpu_sysdev_class;
155         int err = 0;
156
157 #define create_cpu_attr(name)                                           \
158         if (!err)                                                       \
159                 err = sysfs_create_file(&cls->kset.kobj, &attr_##name.attr);
160         create_cpu_attr(chip_width);
161         create_cpu_attr(chip_height);
162         create_cpu_attr(chip_serial);
163         create_cpu_attr(chip_revision);
164
165 #define create_hv_attr(name)                                            \
166         if (!err)                                                       \
167                 err = sysfs_create_file(hypervisor_kobj, &attr_##name.attr);
168         create_hv_attr(type);
169         create_hv_attr(version);
170         create_hv_attr(config_version);
171
172         if (!err)
173                 err = sysfs_create_group(hypervisor_kobj, &board_attr_group);
174
175         if (!err) {
176                 sysfs_bin_attr_init(&hvconfig_bin);
177                 hvconfig_bin.attr.name = "hvconfig";
178                 hvconfig_bin.attr.mode = S_IRUGO;
179                 hvconfig_bin.read = hvconfig_bin_read;
180                 hvconfig_bin.size = PAGE_SIZE;
181                 err = sysfs_create_bin_file(hypervisor_kobj, &hvconfig_bin);
182         }
183
184         return err;
185 }
186 subsys_initcall(create_sysfs_entries);