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

/* hvapi.c: Hypervisor API management.
 *
 * Copyright (C) 2007 David S. Miller <davem@davemloft.net>
 */
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/init.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_TM,					},
	{ .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_PBOOT,				},
	{ .group = HV_GRP_TPM,					},
	{ .group = HV_GRP_SDIO,					},
	{ .group = HV_GRP_SDIO_ERR,				},
	{ .group = HV_GRP_REBOOT_DATA,				},
	{ .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_KT_CPU,				},
	{ .group = HV_GRP_VT_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(%lu) minor(%lu)\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>
066bcaca	6	#include <linux/export.h>
c7754d46	7	#include <linux/init.h>
c7754d46 DM	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, },
e2eb9f81	31	{ .group = HV_GRP_TM, },
c7754d46 DM	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 },
432e8765	36	{ .group = HV_GRP_RNG, },
e2eb9f81 DM	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, },
c7754d46 DM	42	{ .group = HV_GRP_NIAG_PERF, .flags = FLAG_PRE_API },
c7754d46 DM	43	{ .group = HV_GRP_FIRE_PERF, },
432e8765 DM	44	{ .group = HV_GRP_N2_CPU, },
	45	{ .group = HV_GRP_NIU, },
	46	{ .group = HV_GRP_VF_CPU, },
15e3608d	47	{ .group = HV_GRP_KT_CPU, },
8c79bfa5	48	{ .group = HV_GRP_VT_CPU, },
c7754d46 DM	49	{ .group = HV_GRP_DIAG, .flags = FLAG_PRE_API },
	50	};
	51
	52	static DEFINE_SPINLOCK(hvapi_lock);
	53
	54	static struct api_info *__get_info(unsigned long group)
	55	{
	56	int i;
	57
	58	for (i = 0; i < ARRAY_SIZE(api_table); i++) {
	59	if (api_table[i].group == group)
	60	return &api_table[i];
	61	}
	62	return NULL;
	63	}
	64
	65	static void __get_ref(struct api_info *p)
	66	{
	67	p->refcnt++;
	68	}
	69
	70	static void __put_ref(struct api_info *p)
	71	{
	72	if (--p->refcnt == 0) {
	73	unsigned long ignore;
	74
	75	sun4v_set_version(p->group, 0, 0, &ignore);
	76	p->major = p->minor = 0;
	77	}
	78	}
	79
	80	/* Register a hypervisor API specification. It indicates the
	81	* API group and desired major+minor.
	82	*
	83	* If an existing API registration exists '0' (success) will
	84	* be returned if it is compatible with the one being registered.
	85	* Otherwise a negative error code will be returned.
	86	*
	87	* Otherwise an attempt will be made to negotiate the requested
	88	* API group/major/minor with the hypervisor, and errors returned
	89	* if that does not succeed.
	90	*/
	91	int sun4v_hvapi_register(unsigned long group, unsigned long major,
	92	unsigned long *minor)
	93	{
	94	struct api_info *p;
	95	unsigned long flags;
	96	int ret;
	97
	98	spin_lock_irqsave(&hvapi_lock, flags);
	99	p = __get_info(group);
	100	ret = -EINVAL;
	101	if (p) {
	102	if (p->refcnt) {
	103	ret = -EINVAL;
	104	if (p->major == major) {
	105	*minor = p->minor;
	106	ret = 0;
	107	}
	108	} else {
	109	unsigned long actual_minor;
	110	unsigned long hv_ret;
	111
	112	hv_ret = sun4v_set_version(group, major, *minor,
113	&actual_minor);
114	ret = -EINVAL;
115	if (hv_ret == HV_EOK) {
116	*minor = actual_minor;
117	p->major = major;
118	p->minor = actual_minor;
119	ret = 0;
120	} else if (hv_ret == HV_EBADTRAP \|\|
36b48973	121	hv_ret == HV_ENOTSUPPORTED) {
c7754d46 DM	122	if (p->flags & FLAG_PRE_API) {
	123	if (major == 1) {
	124	p->major = 1;
	125	p->minor = 0;
	126	*minor = 0;
	127	ret = 0;
	128	}
	129	}
	130	}
	131	}
	132
	133	if (ret == 0)
	134	__get_ref(p);
	135	}
	136	spin_unlock_irqrestore(&hvapi_lock, flags);
	137
	138	return ret;
	139	}
	140	EXPORT_SYMBOL(sun4v_hvapi_register);
	141
	142	void sun4v_hvapi_unregister(unsigned long group)
	143	{
	144	struct api_info *p;
	145	unsigned long flags;
	146
	147	spin_lock_irqsave(&hvapi_lock, flags);
	148	p = __get_info(group);
	149	if (p)
	150	__put_ref(p);
	151	spin_unlock_irqrestore(&hvapi_lock, flags);
	152	}
	153	EXPORT_SYMBOL(sun4v_hvapi_unregister);
	154
	155	int sun4v_hvapi_get(unsigned long group,
	156	unsigned long *major,
	157	unsigned long *minor)
	158	{
	159	struct api_info *p;
	160	unsigned long flags;
	161	int ret;
	162
	163	spin_lock_irqsave(&hvapi_lock, flags);
	164	ret = -EINVAL;
	165	p = __get_info(group);
	166	if (p && p->refcnt) {
	167	*major = p->major;
	168	*minor = p->minor;
	169	ret = 0;
	170	}
	171	spin_unlock_irqrestore(&hvapi_lock, flags);
	172
	173	return ret;
	174	}
	175	EXPORT_SYMBOL(sun4v_hvapi_get);
	176
	177	void __init sun4v_hvapi_init(void)
	178	{
	179	unsigned long group, major, minor;
	180
	181	group = HV_GRP_SUN4V;
	182	major = 1;
	183	minor = 0;
	184	if (sun4v_hvapi_register(group, major, &minor))
	185	goto bad;
186
187	group = HV_GRP_CORE;
188	major = 1;
189	minor = 1;
190	if (sun4v_hvapi_register(group, major, &minor))
191	goto bad;
192
193	return;
194
195	bad:
196	prom_printf("HVAPI: Cannot register API group "
5da444aa	197	"%lx with major(%lu) minor(%lu)\n",
c7754d46 DM	198	group, major, minor);
	199	prom_halt();
	200	}