David S. Miller | c7754d4 | 2007-05-15 17:03:54 -0700 | [diff] [blame] | 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> |
| 12 | |
| 13 | /* If the hypervisor indicates that the API setting |
| 14 | * calls are unsupported, by returning HV_EBADTRAP or |
| 15 | * HV_ENOTSUPPORTED, we assume that API groups with the |
| 16 | * PRE_API flag set are major 1 minor 0. |
| 17 | */ |
| 18 | struct api_info { |
| 19 | unsigned long group; |
| 20 | unsigned long major; |
| 21 | unsigned long minor; |
| 22 | unsigned int refcnt; |
| 23 | unsigned int flags; |
| 24 | #define FLAG_PRE_API 0x00000001 |
| 25 | }; |
| 26 | |
| 27 | static struct api_info api_table[] = { |
| 28 | { .group = HV_GRP_SUN4V, .flags = FLAG_PRE_API }, |
| 29 | { .group = HV_GRP_CORE, .flags = FLAG_PRE_API }, |
| 30 | { .group = HV_GRP_INTR, }, |
| 31 | { .group = HV_GRP_SOFT_STATE, }, |
| 32 | { .group = HV_GRP_PCI, .flags = FLAG_PRE_API }, |
| 33 | { .group = HV_GRP_LDOM, }, |
| 34 | { .group = HV_GRP_SVC_CHAN, .flags = FLAG_PRE_API }, |
| 35 | { .group = HV_GRP_NCS, .flags = FLAG_PRE_API }, |
David S. Miller | 432e876 | 2008-07-18 00:43:52 -0700 | [diff] [blame] | 36 | { .group = HV_GRP_RNG, }, |
David S. Miller | c7754d4 | 2007-05-15 17:03:54 -0700 | [diff] [blame] | 37 | { .group = HV_GRP_NIAG_PERF, .flags = FLAG_PRE_API }, |
| 38 | { .group = HV_GRP_FIRE_PERF, }, |
David S. Miller | 432e876 | 2008-07-18 00:43:52 -0700 | [diff] [blame] | 39 | { .group = HV_GRP_N2_CPU, }, |
| 40 | { .group = HV_GRP_NIU, }, |
| 41 | { .group = HV_GRP_VF_CPU, }, |
David S. Miller | c7754d4 | 2007-05-15 17:03:54 -0700 | [diff] [blame] | 42 | { .group = HV_GRP_DIAG, .flags = FLAG_PRE_API }, |
| 43 | }; |
| 44 | |
| 45 | static DEFINE_SPINLOCK(hvapi_lock); |
| 46 | |
| 47 | static struct api_info *__get_info(unsigned long group) |
| 48 | { |
| 49 | int i; |
| 50 | |
| 51 | for (i = 0; i < ARRAY_SIZE(api_table); i++) { |
| 52 | if (api_table[i].group == group) |
| 53 | return &api_table[i]; |
| 54 | } |
| 55 | return NULL; |
| 56 | } |
| 57 | |
| 58 | static void __get_ref(struct api_info *p) |
| 59 | { |
| 60 | p->refcnt++; |
| 61 | } |
| 62 | |
| 63 | static void __put_ref(struct api_info *p) |
| 64 | { |
| 65 | if (--p->refcnt == 0) { |
| 66 | unsigned long ignore; |
| 67 | |
| 68 | sun4v_set_version(p->group, 0, 0, &ignore); |
| 69 | p->major = p->minor = 0; |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | /* Register a hypervisor API specification. It indicates the |
| 74 | * API group and desired major+minor. |
| 75 | * |
| 76 | * If an existing API registration exists '0' (success) will |
| 77 | * be returned if it is compatible with the one being registered. |
| 78 | * Otherwise a negative error code will be returned. |
| 79 | * |
| 80 | * Otherwise an attempt will be made to negotiate the requested |
| 81 | * API group/major/minor with the hypervisor, and errors returned |
| 82 | * if that does not succeed. |
| 83 | */ |
| 84 | int sun4v_hvapi_register(unsigned long group, unsigned long major, |
| 85 | unsigned long *minor) |
| 86 | { |
| 87 | struct api_info *p; |
| 88 | unsigned long flags; |
| 89 | int ret; |
| 90 | |
| 91 | spin_lock_irqsave(&hvapi_lock, flags); |
| 92 | p = __get_info(group); |
| 93 | ret = -EINVAL; |
| 94 | if (p) { |
| 95 | if (p->refcnt) { |
| 96 | ret = -EINVAL; |
| 97 | if (p->major == major) { |
| 98 | *minor = p->minor; |
| 99 | ret = 0; |
| 100 | } |
| 101 | } else { |
| 102 | unsigned long actual_minor; |
| 103 | unsigned long hv_ret; |
| 104 | |
| 105 | hv_ret = sun4v_set_version(group, major, *minor, |
| 106 | &actual_minor); |
| 107 | ret = -EINVAL; |
| 108 | if (hv_ret == HV_EOK) { |
| 109 | *minor = actual_minor; |
| 110 | p->major = major; |
| 111 | p->minor = actual_minor; |
| 112 | ret = 0; |
| 113 | } else if (hv_ret == HV_EBADTRAP || |
David S. Miller | 36b4897 | 2007-05-25 00:33:49 -0700 | [diff] [blame] | 114 | hv_ret == HV_ENOTSUPPORTED) { |
David S. Miller | c7754d4 | 2007-05-15 17:03:54 -0700 | [diff] [blame] | 115 | if (p->flags & FLAG_PRE_API) { |
| 116 | if (major == 1) { |
| 117 | p->major = 1; |
| 118 | p->minor = 0; |
| 119 | *minor = 0; |
| 120 | ret = 0; |
| 121 | } |
| 122 | } |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | if (ret == 0) |
| 127 | __get_ref(p); |
| 128 | } |
| 129 | spin_unlock_irqrestore(&hvapi_lock, flags); |
| 130 | |
| 131 | return ret; |
| 132 | } |
| 133 | EXPORT_SYMBOL(sun4v_hvapi_register); |
| 134 | |
| 135 | void sun4v_hvapi_unregister(unsigned long group) |
| 136 | { |
| 137 | struct api_info *p; |
| 138 | unsigned long flags; |
| 139 | |
| 140 | spin_lock_irqsave(&hvapi_lock, flags); |
| 141 | p = __get_info(group); |
| 142 | if (p) |
| 143 | __put_ref(p); |
| 144 | spin_unlock_irqrestore(&hvapi_lock, flags); |
| 145 | } |
| 146 | EXPORT_SYMBOL(sun4v_hvapi_unregister); |
| 147 | |
| 148 | int sun4v_hvapi_get(unsigned long group, |
| 149 | unsigned long *major, |
| 150 | unsigned long *minor) |
| 151 | { |
| 152 | struct api_info *p; |
| 153 | unsigned long flags; |
| 154 | int ret; |
| 155 | |
| 156 | spin_lock_irqsave(&hvapi_lock, flags); |
| 157 | ret = -EINVAL; |
| 158 | p = __get_info(group); |
| 159 | if (p && p->refcnt) { |
| 160 | *major = p->major; |
| 161 | *minor = p->minor; |
| 162 | ret = 0; |
| 163 | } |
| 164 | spin_unlock_irqrestore(&hvapi_lock, flags); |
| 165 | |
| 166 | return ret; |
| 167 | } |
| 168 | EXPORT_SYMBOL(sun4v_hvapi_get); |
| 169 | |
| 170 | void __init sun4v_hvapi_init(void) |
| 171 | { |
| 172 | unsigned long group, major, minor; |
| 173 | |
| 174 | group = HV_GRP_SUN4V; |
| 175 | major = 1; |
| 176 | minor = 0; |
| 177 | if (sun4v_hvapi_register(group, major, &minor)) |
| 178 | goto bad; |
| 179 | |
| 180 | group = HV_GRP_CORE; |
| 181 | major = 1; |
| 182 | minor = 1; |
| 183 | if (sun4v_hvapi_register(group, major, &minor)) |
| 184 | goto bad; |
| 185 | |
David S. Miller | c7754d4 | 2007-05-15 17:03:54 -0700 | [diff] [blame] | 186 | return; |
| 187 | |
| 188 | bad: |
| 189 | prom_printf("HVAPI: Cannot register API group " |
| 190 | "%lx with major(%u) minor(%u)\n", |
| 191 | group, major, minor); |
| 192 | prom_halt(); |
| 193 | } |