1 // SPDX-License-Identifier: GPL-2.0
2 /* hvapi.c: Hypervisor API management.
4 * Copyright (C) 2007 David S. Miller <davem@davemloft.net>
6 #include <linux/kernel.h>
7 #include <linux/export.h>
8 #include <linux/init.h>
10 #include <asm/hypervisor.h>
11 #include <asm/oplib.h>
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.
24 #define FLAG_PRE_API 0x00000001
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_TM, },
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_RNG, },
38 { .group = HV_GRP_PBOOT, },
39 { .group = HV_GRP_TPM, },
40 { .group = HV_GRP_SDIO, },
41 { .group = HV_GRP_SDIO_ERR, },
42 { .group = HV_GRP_REBOOT_DATA, },
43 { .group = HV_GRP_ATU, .flags = FLAG_PRE_API },
44 { .group = HV_GRP_NIAG_PERF, .flags = FLAG_PRE_API },
45 { .group = HV_GRP_FIRE_PERF, },
46 { .group = HV_GRP_N2_CPU, },
47 { .group = HV_GRP_NIU, },
48 { .group = HV_GRP_VF_CPU, },
49 { .group = HV_GRP_KT_CPU, },
50 { .group = HV_GRP_VT_CPU, },
51 { .group = HV_GRP_T5_CPU, },
52 { .group = HV_GRP_DIAG, .flags = FLAG_PRE_API },
53 { .group = HV_GRP_M7_PERF, },
56 static DEFINE_SPINLOCK(hvapi_lock);
58 static struct api_info *__get_info(unsigned long group)
62 for (i = 0; i < ARRAY_SIZE(api_table); i++) {
63 if (api_table[i].group == group)
69 static void __get_ref(struct api_info *p)
74 static void __put_ref(struct api_info *p)
76 if (--p->refcnt == 0) {
79 sun4v_set_version(p->group, 0, 0, &ignore);
80 p->major = p->minor = 0;
84 /* Register a hypervisor API specification. It indicates the
85 * API group and desired major+minor.
87 * If an existing API registration exists '0' (success) will
88 * be returned if it is compatible with the one being registered.
89 * Otherwise a negative error code will be returned.
91 * Otherwise an attempt will be made to negotiate the requested
92 * API group/major/minor with the hypervisor, and errors returned
93 * if that does not succeed.
95 int sun4v_hvapi_register(unsigned long group, unsigned long major,
102 spin_lock_irqsave(&hvapi_lock, flags);
103 p = __get_info(group);
108 if (p->major == major) {
113 unsigned long actual_minor;
114 unsigned long hv_ret;
116 hv_ret = sun4v_set_version(group, major, *minor,
119 if (hv_ret == HV_EOK) {
120 *minor = actual_minor;
122 p->minor = actual_minor;
124 } else if (hv_ret == HV_EBADTRAP ||
125 hv_ret == HV_ENOTSUPPORTED) {
126 if (p->flags & FLAG_PRE_API) {
140 spin_unlock_irqrestore(&hvapi_lock, flags);
144 EXPORT_SYMBOL(sun4v_hvapi_register);
146 void sun4v_hvapi_unregister(unsigned long group)
151 spin_lock_irqsave(&hvapi_lock, flags);
152 p = __get_info(group);
155 spin_unlock_irqrestore(&hvapi_lock, flags);
157 EXPORT_SYMBOL(sun4v_hvapi_unregister);
159 int sun4v_hvapi_get(unsigned long group,
160 unsigned long *major,
161 unsigned long *minor)
167 spin_lock_irqsave(&hvapi_lock, flags);
169 p = __get_info(group);
170 if (p && p->refcnt) {
175 spin_unlock_irqrestore(&hvapi_lock, flags);
179 EXPORT_SYMBOL(sun4v_hvapi_get);
181 void __init sun4v_hvapi_init(void)
183 unsigned long group, major, minor;
185 group = HV_GRP_SUN4V;
188 if (sun4v_hvapi_register(group, major, &minor))
194 if (sun4v_hvapi_register(group, major, &minor))
200 prom_printf("HVAPI: Cannot register API group "
201 "%lx with major(%lu) minor(%lu)\n",
202 group, major, minor);