[deliverable/linux.git] / arch / sparc64 / kernel / hvapi.c

/* 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_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;

	sun4v_sstate_init();

	return;

bad:
	prom_printf("HVAPI: Cannot register API group "
		    "%lx with major(%u) minor(%u)\n",
		    group, major, minor);
	prom_halt();
}
Commit	Line	Data
c7754d46 DM	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>
22d6a1cb	12	#include <asm/sstate.h>
c7754d46 DM	13
	14	/* If the hypervisor indicates that the API setting
	15	* calls are unsupported, by returning HV_EBADTRAP or
	16	* HV_ENOTSUPPORTED, we assume that API groups with the
	17	* PRE_API flag set are major 1 minor 0.
	18	*/
	19	struct api_info {
	20	unsigned long group;
	21	unsigned long major;
	22	unsigned long minor;
	23	unsigned int refcnt;
	24	unsigned int flags;
	25	#define FLAG_PRE_API 0x00000001
	26	};
	27
	28	static struct api_info api_table[] = {
	29	{ .group = HV_GRP_SUN4V, .flags = FLAG_PRE_API },
	30	{ .group = HV_GRP_CORE, .flags = FLAG_PRE_API },
	31	{ .group = HV_GRP_INTR, },
	32	{ .group = HV_GRP_SOFT_STATE, },
	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 },
432e8765	37	{ .group = HV_GRP_RNG, },
c7754d46 DM	38	{ .group = HV_GRP_NIAG_PERF, .flags = FLAG_PRE_API },
c7754d46 DM	39	{ .group = HV_GRP_FIRE_PERF, },
432e8765 DM	40	{ .group = HV_GRP_N2_CPU, },
	41	{ .group = HV_GRP_NIU, },
	42	{ .group = HV_GRP_VF_CPU, },
c7754d46 DM	43	{ .group = HV_GRP_DIAG, .flags = FLAG_PRE_API },
	44	};
	45
	46	static DEFINE_SPINLOCK(hvapi_lock);
	47
	48	static struct api_info *__get_info(unsigned long group)
	49	{
	50	int i;
	51
	52	for (i = 0; i < ARRAY_SIZE(api_table); i++) {
	53	if (api_table[i].group == group)
	54	return &api_table[i];
	55	}
	56	return NULL;
	57	}
	58
	59	static void __get_ref(struct api_info *p)
	60	{
	61	p->refcnt++;
	62	}
	63
	64	static void __put_ref(struct api_info *p)
	65	{
	66	if (--p->refcnt == 0) {
	67	unsigned long ignore;
	68
	69	sun4v_set_version(p->group, 0, 0, &ignore);
	70	p->major = p->minor = 0;
	71	}
	72	}
	73
	74	/* Register a hypervisor API specification. It indicates the
	75	* API group and desired major+minor.
	76	*
	77	* If an existing API registration exists '0' (success) will
	78	* be returned if it is compatible with the one being registered.
	79	* Otherwise a negative error code will be returned.
	80	*
	81	* Otherwise an attempt will be made to negotiate the requested
	82	* API group/major/minor with the hypervisor, and errors returned
	83	* if that does not succeed.
	84	*/
	85	int sun4v_hvapi_register(unsigned long group, unsigned long major,
	86	unsigned long *minor)
	87	{
	88	struct api_info *p;
	89	unsigned long flags;
	90	int ret;
	91
	92	spin_lock_irqsave(&hvapi_lock, flags);
	93	p = __get_info(group);
	94	ret = -EINVAL;
	95	if (p) {
	96	if (p->refcnt) {
	97	ret = -EINVAL;
	98	if (p->major == major) {
	99	*minor = p->minor;
	100	ret = 0;
	101	}
	102	} else {
	103	unsigned long actual_minor;
	104	unsigned long hv_ret;
	105
	106	hv_ret = sun4v_set_version(group, major, *minor,
107	&actual_minor);
108	ret = -EINVAL;
109	if (hv_ret == HV_EOK) {
110	*minor = actual_minor;
111	p->major = major;
112	p->minor = actual_minor;
113	ret = 0;
114	} else if (hv_ret == HV_EBADTRAP \|\|
36b48973	115	hv_ret == HV_ENOTSUPPORTED) {
c7754d46 DM	116	if (p->flags & FLAG_PRE_API) {
	117	if (major == 1) {
	118	p->major = 1;
	119	p->minor = 0;
	120	*minor = 0;
	121	ret = 0;
	122	}
	123	}
	124	}
	125	}
	126
	127	if (ret == 0)
	128	__get_ref(p);
	129	}
	130	spin_unlock_irqrestore(&hvapi_lock, flags);
	131
	132	return ret;
	133	}
	134	EXPORT_SYMBOL(sun4v_hvapi_register);
	135
	136	void sun4v_hvapi_unregister(unsigned long group)
	137	{
	138	struct api_info *p;
	139	unsigned long flags;
	140
	141	spin_lock_irqsave(&hvapi_lock, flags);
	142	p = __get_info(group);
	143	if (p)
	144	__put_ref(p);
	145	spin_unlock_irqrestore(&hvapi_lock, flags);
	146	}
	147	EXPORT_SYMBOL(sun4v_hvapi_unregister);
	148
	149	int sun4v_hvapi_get(unsigned long group,
	150	unsigned long *major,
	151	unsigned long *minor)
	152	{
	153	struct api_info *p;
	154	unsigned long flags;
	155	int ret;
	156
	157	spin_lock_irqsave(&hvapi_lock, flags);
	158	ret = -EINVAL;
	159	p = __get_info(group);
	160	if (p && p->refcnt) {
	161	*major = p->major;
	162	*minor = p->minor;
	163	ret = 0;
	164	}
	165	spin_unlock_irqrestore(&hvapi_lock, flags);
	166
	167	return ret;
	168	}
	169	EXPORT_SYMBOL(sun4v_hvapi_get);
	170
	171	void __init sun4v_hvapi_init(void)
	172	{
	173	unsigned long group, major, minor;
	174
	175	group = HV_GRP_SUN4V;
	176	major = 1;
	177	minor = 0;
	178	if (sun4v_hvapi_register(group, major, &minor))
	179	goto bad;
180
181	group = HV_GRP_CORE;
182	major = 1;
183	minor = 1;
184	if (sun4v_hvapi_register(group, major, &minor))
185	goto bad;
186
22d6a1cb DM	187	sun4v_sstate_init();
22d6a1cb DM	188
c7754d46 DM	189	return;
	190
	191	bad:
	192	prom_printf("HVAPI: Cannot register API group "
	193	"%lx with major(%u) minor(%u)\n",
	194	group, major, minor);
	195	prom_halt();
	196	}