/* 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>
#include <asm/sstate.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_NIAG_PERF, .flags = FLAG_PRE_API },
{ .group = HV_GRP_FIRE_PERF, },
{ .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;
sun4v_sstate_init();
return;
bad:
prom_printf("HVAPI: Cannot register API group "
"%lx with major(%u) minor(%u)\n",
group, major, minor);
prom_halt();
}
