summaryrefslogtreecommitdiffstats
path: root/arch/frv/kernel/sysctl.c
blob: 139628afea1766cf1c60864c2d19443507228e5d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
/* sysctl.c: implementation of /proc/sys files relating to FRV specifically
 *
 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <asm/uaccess.h>

static const char frv_cache_wback[] = "wback";
static const char frv_cache_wthru[] = "wthru";

static void frv_change_dcache_mode(unsigned long newmode)
{
	unsigned long flags, hsr0;

	local_irq_save(flags);

	hsr0 = __get_HSR(0);
	hsr0 &= ~HSR0_DCE;
	__set_HSR(0, hsr0);

	asm volatile("	dcef	@(gr0,gr0),#1	\n"
		     "	membar			\n"
		     : : : "memory"
		     );

	hsr0 = (hsr0 & ~HSR0_CBM) | newmode;
	__set_HSR(0, hsr0);
	hsr0 |= HSR0_DCE;
	__set_HSR(0, hsr0);

	local_irq_restore(flags);

	//printk("HSR0 now %08lx\n", hsr0);
}

/*****************************************************************************/
/*
 * handle requests to dynamically switch the write caching mode delivered by /proc
 */
static int procctl_frv_cachemode(ctl_table *table, int write, struct file *filp,
				 void __user *buffer, size_t *lenp, loff_t *ppos)
{
	unsigned long hsr0;
	char buff[8];
	int len;

	len = *lenp;

	if (write) {
		/* potential state change */
		if (len <= 1 || len > sizeof(buff) - 1)
			return -EINVAL;

		if (copy_from_user(buff, buffer, len) != 0)
			return -EFAULT;

		if (buff[len - 1] == '\n')
			buff[len - 1] = '\0';
		else
			buff[len] = '\0';

		if (strcmp(buff, frv_cache_wback) == 0) {
			/* switch dcache into write-back mode */
			frv_change_dcache_mode(HSR0_CBM_COPY_BACK);
			return 0;
		}

		if (strcmp(buff, frv_cache_wthru) == 0) {
			/* switch dcache into write-through mode */
			frv_change_dcache_mode(HSR0_CBM_WRITE_THRU);
			return 0;
		}

		return -EINVAL;
	}

	/* read the state */
	if (filp->f_pos > 0) {
		*lenp = 0;
		return 0;
	}

	hsr0 = __get_HSR(0);
	switch (hsr0 & HSR0_CBM) {
	case HSR0_CBM_WRITE_THRU:
		memcpy(buff, frv_cache_wthru, sizeof(frv_cache_wthru) - 1);
		buff[sizeof(frv_cache_wthru) - 1] = '\n';
		len = sizeof(frv_cache_wthru);
		break;
	default:
		memcpy(buff, frv_cache_wback, sizeof(frv_cache_wback) - 1);
		buff[sizeof(frv_cache_wback) - 1] = '\n';
		len = sizeof(frv_cache_wback);
		break;
	}

	if (len > *lenp)
		len = *lenp;

	if (copy_to_user(buffer, buff, len) != 0)
		return -EFAULT;

	*lenp = len;
	filp->f_pos = len;
	return 0;

} /* end procctl_frv_cachemode() */

/*****************************************************************************/
/*
 * permit the mm_struct the nominated process is using have its MMU context ID pinned
 */
#ifdef CONFIG_MMU
static int procctl_frv_pin_cxnr(ctl_table *table, int write, struct file *filp,
				void __user *buffer, size_t *lenp, loff_t *ppos)
{
	pid_t pid;
	char buff[16], *p;
	int len;

	len = *lenp;

	if (write) {
		/* potential state change */
		if (len <= 1 || len > sizeof(buff) - 1)
			return -EINVAL;

		if (copy_from_user(buff, buffer, len) != 0)
			return -EFAULT;

		if (buff[len - 1] == '\n')
			buff[len - 1] = '\0';
		else
			buff[len] = '\0';

		pid = simple_strtoul(buff, &p, 10);
		if (*p)
			return -EINVAL;

		return cxn_pin_by_pid(pid);
	}

	/* read the currently pinned CXN */
	if (filp->f_pos > 0) {
		*lenp = 0;
		return 0;
	}

	len = snprintf(buff, sizeof(buff), "%d\n", cxn_pinned);
	if (len > *lenp)
		len = *lenp;

	if (copy_to_user(buffer, buff, len) != 0)
		return -EFAULT;

	*lenp = len;
	filp->f_pos = len;
	return 0;

} /* end procctl_frv_pin_cxnr() */
#endif

/*
 * FR-V specific sysctls
 */
static struct ctl_table frv_table[] =
{
	{
		.ctl_name 	= CTL_UNNUMBERD,
		.procname 	= "cache-mode",
		.data		= NULL,
		.maxlen		= 0,
		.mode		= 0644,
		.proc_handler	= &procctl_frv_cachemode,
	},
#ifdef CONFIG_MMU
	{
		.ctl_name	= CTL_UNNUMBERD,
		.procname	= "pin-cxnr",
		.data		= NULL,
		.maxlen		= 0,
		.mode		= 0644,
		.proc_handler	= &procctl_frv_pin_cxnr
	},
#endif
	{}
};

/*
 * Use a temporary sysctl number. Horrid, but will be cleaned up in 2.6
 * when all the PM interfaces exist nicely.
 */
static struct ctl_table frv_dir_table[] =
{
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "frv",
		.mode 		= 0555,
		.child		= frv_table
	},
	{}
};

/*
 * Initialize power interface
 */
static int __init frv_sysctl_init(void)
{
	register_sysctl_table(frv_dir_table);
	return 0;
}

__initcall(frv_sysctl_init);
OpenPOWER on IntegriCloud