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/export.h> 7 #include <linux/init.h> 8 9 #include <asm/hypervisor.h> 10 #include <asm/oplib.h> 11 12 /* If the hypervisor indicates that the API setting 13 * calls are unsupported, by returning HV_EBADTRAP or 14 * HV_ENOTSUPPORTED, we assume that API groups with the 15 * PRE_API flag set are major 1 minor 0. 16 */ 17 struct api_info { 18 unsigned long group; 19 unsigned long major; 20 unsigned long minor; 21 unsigned int refcnt; 22 unsigned int flags; 23 #define FLAG_PRE_API 0x00000001 24 }; 25 26 static struct api_info api_table[] = { 27 { .group = HV_GRP_SUN4V, .flags = FLAG_PRE_API }, 28 { .group = HV_GRP_CORE, .flags = FLAG_PRE_API }, 29 { .group = HV_GRP_INTR, }, 30 { .group = HV_GRP_SOFT_STATE, }, 31 { .group = HV_GRP_TM, }, 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 }, 36 { .group = HV_GRP_RNG, }, 37 { .group = HV_GRP_PBOOT, }, 38 { .group = HV_GRP_TPM, }, 39 { .group = HV_GRP_SDIO, }, 40 { .group = HV_GRP_SDIO_ERR, }, 41 { .group = HV_GRP_REBOOT_DATA, }, 42 { .group = HV_GRP_NIAG_PERF, .flags = FLAG_PRE_API }, 43 { .group = HV_GRP_FIRE_PERF, }, 44 { .group = HV_GRP_N2_CPU, }, 45 { .group = HV_GRP_NIU, }, 46 { .group = HV_GRP_VF_CPU, }, 47 { .group = HV_GRP_KT_CPU, }, 48 { .group = HV_GRP_DIAG, .flags = FLAG_PRE_API }, 49 }; 50 51 static DEFINE_SPINLOCK(hvapi_lock); 52 53 static struct api_info *__get_info(unsigned long group) 54 { 55 int i; 56 57 for (i = 0; i < ARRAY_SIZE(api_table); i++) { 58 if (api_table[i].group == group) 59 return &api_table[i]; 60 } 61 return NULL; 62 } 63 64 static void __get_ref(struct api_info *p) 65 { 66 p->refcnt++; 67 } 68 69 static void __put_ref(struct api_info *p) 70 { 71 if (--p->refcnt == 0) { 72 unsigned long ignore; 73 74 sun4v_set_version(p->group, 0, 0, &ignore); 75 p->major = p->minor = 0; 76 } 77 } 78 79 /* Register a hypervisor API specification. It indicates the 80 * API group and desired major+minor. 81 * 82 * If an existing API registration exists '0' (success) will 83 * be returned if it is compatible with the one being registered. 84 * Otherwise a negative error code will be returned. 85 * 86 * Otherwise an attempt will be made to negotiate the requested 87 * API group/major/minor with the hypervisor, and errors returned 88 * if that does not succeed. 89 */ 90 int sun4v_hvapi_register(unsigned long group, unsigned long major, 91 unsigned long *minor) 92 { 93 struct api_info *p; 94 unsigned long flags; 95 int ret; 96 97 spin_lock_irqsave(&hvapi_lock, flags); 98 p = __get_info(group); 99 ret = -EINVAL; 100 if (p) { 101 if (p->refcnt) { 102 ret = -EINVAL; 103 if (p->major == major) { 104 *minor = p->minor; 105 ret = 0; 106 } 107 } else { 108 unsigned long actual_minor; 109 unsigned long hv_ret; 110 111 hv_ret = sun4v_set_version(group, major, *minor, 112 &actual_minor); 113 ret = -EINVAL; 114 if (hv_ret == HV_EOK) { 115 *minor = actual_minor; 116 p->major = major; 117 p->minor = actual_minor; 118 ret = 0; 119 } else if (hv_ret == HV_EBADTRAP || 120 hv_ret == HV_ENOTSUPPORTED) { 121 if (p->flags & FLAG_PRE_API) { 122 if (major == 1) { 123 p->major = 1; 124 p->minor = 0; 125 *minor = 0; 126 ret = 0; 127 } 128 } 129 } 130 } 131 132 if (ret == 0) 133 __get_ref(p); 134 } 135 spin_unlock_irqrestore(&hvapi_lock, flags); 136 137 return ret; 138 } 139 EXPORT_SYMBOL(sun4v_hvapi_register); 140 141 void sun4v_hvapi_unregister(unsigned long group) 142 { 143 struct api_info *p; 144 unsigned long flags; 145 146 spin_lock_irqsave(&hvapi_lock, flags); 147 p = __get_info(group); 148 if (p) 149 __put_ref(p); 150 spin_unlock_irqrestore(&hvapi_lock, flags); 151 } 152 EXPORT_SYMBOL(sun4v_hvapi_unregister); 153 154 int sun4v_hvapi_get(unsigned long group, 155 unsigned long *major, 156 unsigned long *minor) 157 { 158 struct api_info *p; 159 unsigned long flags; 160 int ret; 161 162 spin_lock_irqsave(&hvapi_lock, flags); 163 ret = -EINVAL; 164 p = __get_info(group); 165 if (p && p->refcnt) { 166 *major = p->major; 167 *minor = p->minor; 168 ret = 0; 169 } 170 spin_unlock_irqrestore(&hvapi_lock, flags); 171 172 return ret; 173 } 174 EXPORT_SYMBOL(sun4v_hvapi_get); 175 176 void __init sun4v_hvapi_init(void) 177 { 178 unsigned long group, major, minor; 179 180 group = HV_GRP_SUN4V; 181 major = 1; 182 minor = 0; 183 if (sun4v_hvapi_register(group, major, &minor)) 184 goto bad; 185 186 group = HV_GRP_CORE; 187 major = 1; 188 minor = 1; 189 if (sun4v_hvapi_register(group, major, &minor)) 190 goto bad; 191 192 return; 193 194 bad: 195 prom_printf("HVAPI: Cannot register API group " 196 "%lx with major(%u) minor(%u)\n", 197 group, major, minor); 198 prom_halt(); 199 } 200