aboutsummaryrefslogtreecommitdiff
path: root/arch/sparc/kernel/hvapi.c
blob: c2d055d8ba9e273ed8e996c7133b553e75ffcbc7 (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
/* hvapi.c: Hypervisor API management.
 *
 * Copyright (C) 2007 David S. Miller <davem@davemloft.net>
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>

#include <asm/hypervisor.h>
#include <asm/oplib.h>

/* If the hypervisor indicates that the API setting
 * calls are unsupported, by returning HV_EBADTRAP or
 * HV_ENOTSUPPORTED, we assume that API groups with the
 * PRE_API flag set are major 1 minor 0.
 */
struct api_info {
	unsigned long group;
	unsigned long major;
	unsigned long minor;
	unsigned int refcnt;
	unsigned int flags;
#define FLAG_PRE_API		0x00000001
};

static struct api_info api_table[] = {
	{ .group = HV_GRP_SUN4V,	.flags = FLAG_PRE_API	},
	{ .group = HV_GRP_CORE,		.flags = FLAG_PRE_API	},
	{ .group = HV_GRP_INTR,					},
	{ .group = HV_GRP_SOFT_STATE,				},
	{ .group = HV_GRP_TM,					},
	{ .group = HV_GRP_PCI,		.flags = FLAG_PRE_API	},
	{ .group = HV_GRP_LDOM,					},
	{ .group = HV_GRP_SVC_CHAN,	.flags = FLAG_PRE_API	},
	{ .group = HV_GRP_NCS,		.flags = FLAG_PRE_API	},
	{ .group = HV_GRP_RNG,					},
	{ .group = HV_GRP_PBOOT,				},
	{ .group = HV_GRP_TPM,					},
	{ .group = HV_GRP_SDIO,					},
	{ .group = HV_GRP_SDIO_ERR,				},
	{ .group = HV_GRP_REBOOT_DATA,				},
	{ .group = HV_GRP_NIAG_PERF,	.flags = FLAG_PRE_API	},
	{ .group = HV_GRP_FIRE_PERF,				},
	{ .group = HV_GRP_N2_CPU,				},
	{ .group = HV_GRP_NIU,					},
	{ .group = HV_GRP_VF_CPU,				},
	{ .group = HV_GRP_KT_CPU,				},
	{ .group = HV_GRP_DIAG,		.flags = FLAG_PRE_API	},
};

static DEFINE_SPINLOCK(hvapi_lock);

static struct api_info *__get_info(unsigned long group)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(api_table); i++) {
		if (api_table[i].group == group)
			return &api_table[i];
	}
	return NULL;
}

static void __get_ref(struct api_info *p)
{
	p->refcnt++;
}

static void __put_ref(struct api_info *p)
{
	if (--p->refcnt == 0) {
		unsigned long ignore;

		sun4v_set_version(p->group, 0, 0, &ignore);
		p->major = p->minor = 0;
	}
}

/* Register a hypervisor API specification.  It indicates the
 * API group and desired major+minor.
 *
 * If an existing API registration exists '0' (success) will
 * be returned if it is compatible with the one being registered.
 * Otherwise a negative error code will be returned.
 *
 * Otherwise an attempt will be made to negotiate the requested
 * API group/major/minor with the hypervisor, and errors returned
 * if that does not succeed.
 */
int sun4v_hvapi_register(unsigned long group, unsigned long major,
			 unsigned long *minor)
{
	struct api_info *p;
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&hvapi_lock, flags);
	p = __get_info(group);
	ret = -EINVAL;
	if (p) {
		if (p->refcnt) {
			ret = -EINVAL;
			if (p->major == major) {
				*minor = p->minor;
				ret = 0;
			}
		} else {
			unsigned long actual_minor;
			unsigned long hv_ret;

			hv_ret = sun4v_set_version(group, major, *minor,
						   &actual_minor);
			ret = -EINVAL;
			if (hv_ret == HV_EOK) {
				*minor = actual_minor;
				p->major = major;
				p->minor = actual_minor;
				ret = 0;
			} else if (hv_ret == HV_EBADTRAP ||
				   hv_ret == HV_ENOTSUPPORTED) {
				if (p->flags & FLAG_PRE_API) {
					if (major == 1) {
						p->major = 1;
						p->minor = 0;
						*minor = 0;
						ret = 0;
					}
				}
			}
		}

		if (ret == 0)
			__get_ref(p);
	}
	spin_unlock_irqrestore(&hvapi_lock, flags);

	return ret;
}
EXPORT_SYMBOL(sun4v_hvapi_register);

void sun4v_hvapi_unregister(unsigned long group)
{
	struct api_info *p;
	unsigned long flags;

	spin_lock_irqsave(&hvapi_lock, flags);
	p = __get_info(group);
	if (p)
		__put_ref(p);
	spin_unlock_irqrestore(&hvapi_lock, flags);
}
EXPORT_SYMBOL(sun4v_hvapi_unregister);

int sun4v_hvapi_get(unsigned long group,
		    unsigned long *major,
		    unsigned long *minor)
{
	struct api_info *p;
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&hvapi_lock, flags);
	ret = -EINVAL;
	p = __get_info(group);
	if (p && p->refcnt) {
		*major = p->major;
		*minor = p->minor;
		ret = 0;
	}
	spin_unlock_irqrestore(&hvapi_lock, flags);

	return ret;
}
EXPORT_SYMBOL(sun4v_hvapi_get);

void __init sun4v_hvapi_init(void)
{
	unsigned long group, major, minor;

	group = HV_GRP_SUN4V;
	major = 1;
	minor = 0;
	if (sun4v_hvapi_register(group, major, &minor))
		goto bad;

	group = HV_GRP_CORE;
	major = 1;
	minor = 1;
	if (sun4v_hvapi_register(group, major, &minor))
		goto bad;

	return;

bad:
	prom_printf("HVAPI: Cannot register API group "
		    "%lx with major(%u) minor(%u)\n",
		    group, major, minor);
	prom_halt();
}