diff options
Diffstat (limited to 'arch/sparc/kernel/hvapi.c')
| -rw-r--r-- | arch/sparc/kernel/hvapi.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/arch/sparc/kernel/hvapi.c b/arch/sparc/kernel/hvapi.c new file mode 100644 index 00000000000..1d272c3b574 --- /dev/null +++ b/arch/sparc/kernel/hvapi.c @@ -0,0 +1,193 @@ +/* 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 <linux/slab.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_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_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_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(); +} |