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c7754d46 DM |
1 | /* hvapi.c: Hypervisor API management. |
2 | * | |
3 | * Copyright (C) 2007 David S. Miller <davem@davemloft.net> | |
4 | */ | |
5 | #include <linux/kernel.h> | |
6 | #include <linux/module.h> | |
7 | #include <linux/init.h> | |
8 | #include <linux/slab.h> | |
9 | ||
10 | #include <asm/hypervisor.h> | |
11 | #include <asm/oplib.h> | |
22d6a1cb | 12 | #include <asm/sstate.h> |
c7754d46 DM |
13 | |
14 | /* If the hypervisor indicates that the API setting | |
15 | * calls are unsupported, by returning HV_EBADTRAP or | |
16 | * HV_ENOTSUPPORTED, we assume that API groups with the | |
17 | * PRE_API flag set are major 1 minor 0. | |
18 | */ | |
19 | struct api_info { | |
20 | unsigned long group; | |
21 | unsigned long major; | |
22 | unsigned long minor; | |
23 | unsigned int refcnt; | |
24 | unsigned int flags; | |
25 | #define FLAG_PRE_API 0x00000001 | |
26 | }; | |
27 | ||
28 | static struct api_info api_table[] = { | |
29 | { .group = HV_GRP_SUN4V, .flags = FLAG_PRE_API }, | |
30 | { .group = HV_GRP_CORE, .flags = FLAG_PRE_API }, | |
31 | { .group = HV_GRP_INTR, }, | |
32 | { .group = HV_GRP_SOFT_STATE, }, | |
33 | { .group = HV_GRP_PCI, .flags = FLAG_PRE_API }, | |
34 | { .group = HV_GRP_LDOM, }, | |
35 | { .group = HV_GRP_SVC_CHAN, .flags = FLAG_PRE_API }, | |
36 | { .group = HV_GRP_NCS, .flags = FLAG_PRE_API }, | |
37 | { .group = HV_GRP_NIAG_PERF, .flags = FLAG_PRE_API }, | |
38 | { .group = HV_GRP_FIRE_PERF, }, | |
39 | { .group = HV_GRP_DIAG, .flags = FLAG_PRE_API }, | |
40 | }; | |
41 | ||
42 | static DEFINE_SPINLOCK(hvapi_lock); | |
43 | ||
44 | static struct api_info *__get_info(unsigned long group) | |
45 | { | |
46 | int i; | |
47 | ||
48 | for (i = 0; i < ARRAY_SIZE(api_table); i++) { | |
49 | if (api_table[i].group == group) | |
50 | return &api_table[i]; | |
51 | } | |
52 | return NULL; | |
53 | } | |
54 | ||
55 | static void __get_ref(struct api_info *p) | |
56 | { | |
57 | p->refcnt++; | |
58 | } | |
59 | ||
60 | static void __put_ref(struct api_info *p) | |
61 | { | |
62 | if (--p->refcnt == 0) { | |
63 | unsigned long ignore; | |
64 | ||
65 | sun4v_set_version(p->group, 0, 0, &ignore); | |
66 | p->major = p->minor = 0; | |
67 | } | |
68 | } | |
69 | ||
70 | /* Register a hypervisor API specification. It indicates the | |
71 | * API group and desired major+minor. | |
72 | * | |
73 | * If an existing API registration exists '0' (success) will | |
74 | * be returned if it is compatible with the one being registered. | |
75 | * Otherwise a negative error code will be returned. | |
76 | * | |
77 | * Otherwise an attempt will be made to negotiate the requested | |
78 | * API group/major/minor with the hypervisor, and errors returned | |
79 | * if that does not succeed. | |
80 | */ | |
81 | int sun4v_hvapi_register(unsigned long group, unsigned long major, | |
82 | unsigned long *minor) | |
83 | { | |
84 | struct api_info *p; | |
85 | unsigned long flags; | |
86 | int ret; | |
87 | ||
88 | spin_lock_irqsave(&hvapi_lock, flags); | |
89 | p = __get_info(group); | |
90 | ret = -EINVAL; | |
91 | if (p) { | |
92 | if (p->refcnt) { | |
93 | ret = -EINVAL; | |
94 | if (p->major == major) { | |
95 | *minor = p->minor; | |
96 | ret = 0; | |
97 | } | |
98 | } else { | |
99 | unsigned long actual_minor; | |
100 | unsigned long hv_ret; | |
101 | ||
102 | hv_ret = sun4v_set_version(group, major, *minor, | |
103 | &actual_minor); | |
104 | ret = -EINVAL; | |
105 | if (hv_ret == HV_EOK) { | |
106 | *minor = actual_minor; | |
107 | p->major = major; | |
108 | p->minor = actual_minor; | |
109 | ret = 0; | |
110 | } else if (hv_ret == HV_EBADTRAP || | |
36b48973 | 111 | hv_ret == HV_ENOTSUPPORTED) { |
c7754d46 DM |
112 | if (p->flags & FLAG_PRE_API) { |
113 | if (major == 1) { | |
114 | p->major = 1; | |
115 | p->minor = 0; | |
116 | *minor = 0; | |
117 | ret = 0; | |
118 | } | |
119 | } | |
120 | } | |
121 | } | |
122 | ||
123 | if (ret == 0) | |
124 | __get_ref(p); | |
125 | } | |
126 | spin_unlock_irqrestore(&hvapi_lock, flags); | |
127 | ||
128 | return ret; | |
129 | } | |
130 | EXPORT_SYMBOL(sun4v_hvapi_register); | |
131 | ||
132 | void sun4v_hvapi_unregister(unsigned long group) | |
133 | { | |
134 | struct api_info *p; | |
135 | unsigned long flags; | |
136 | ||
137 | spin_lock_irqsave(&hvapi_lock, flags); | |
138 | p = __get_info(group); | |
139 | if (p) | |
140 | __put_ref(p); | |
141 | spin_unlock_irqrestore(&hvapi_lock, flags); | |
142 | } | |
143 | EXPORT_SYMBOL(sun4v_hvapi_unregister); | |
144 | ||
145 | int sun4v_hvapi_get(unsigned long group, | |
146 | unsigned long *major, | |
147 | unsigned long *minor) | |
148 | { | |
149 | struct api_info *p; | |
150 | unsigned long flags; | |
151 | int ret; | |
152 | ||
153 | spin_lock_irqsave(&hvapi_lock, flags); | |
154 | ret = -EINVAL; | |
155 | p = __get_info(group); | |
156 | if (p && p->refcnt) { | |
157 | *major = p->major; | |
158 | *minor = p->minor; | |
159 | ret = 0; | |
160 | } | |
161 | spin_unlock_irqrestore(&hvapi_lock, flags); | |
162 | ||
163 | return ret; | |
164 | } | |
165 | EXPORT_SYMBOL(sun4v_hvapi_get); | |
166 | ||
167 | void __init sun4v_hvapi_init(void) | |
168 | { | |
169 | unsigned long group, major, minor; | |
170 | ||
171 | group = HV_GRP_SUN4V; | |
172 | major = 1; | |
173 | minor = 0; | |
174 | if (sun4v_hvapi_register(group, major, &minor)) | |
175 | goto bad; | |
176 | ||
177 | group = HV_GRP_CORE; | |
178 | major = 1; | |
179 | minor = 1; | |
180 | if (sun4v_hvapi_register(group, major, &minor)) | |
181 | goto bad; | |
182 | ||
22d6a1cb DM |
183 | sun4v_sstate_init(); |
184 | ||
c7754d46 DM |
185 | return; |
186 | ||
187 | bad: | |
188 | prom_printf("HVAPI: Cannot register API group " | |
189 | "%lx with major(%u) minor(%u)\n", | |
190 | group, major, minor); | |
191 | prom_halt(); | |
192 | } |