summaryrefslogtreecommitdiff
path: root/arch/powerpc/platforms/pseries/hvcserver.c
blob: fcf4b4cbeaf331aa7986b0b705bc4bbe2148ee7b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
/*
 * hvcserver.c
 * Copyright (C) 2004 Ryan S Arnold, IBM Corporation
 *
 * PPC64 virtual I/O console server support.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/slab.h>

#include <asm/hvcall.h>
#include <asm/hvcserver.h>
#include <asm/io.h>

#define HVCS_ARCH_VERSION "1.0.0"

MODULE_AUTHOR("Ryan S. Arnold <rsa@us.ibm.com>");
MODULE_DESCRIPTION("IBM hvcs ppc64 API");
MODULE_LICENSE("GPL");
MODULE_VERSION(HVCS_ARCH_VERSION);

/*
 * Convert arch specific return codes into relevant errnos.  The hvcs
 * functions aren't performance sensitive, so this conversion isn't an
 * issue.
 */
static int hvcs_convert(long to_convert)
{
	switch (to_convert) {
		case H_SUCCESS:
			return 0;
		case H_PARAMETER:
			return -EINVAL;
		case H_HARDWARE:
			return -EIO;
		case H_BUSY:
		case H_LONG_BUSY_ORDER_1_MSEC:
		case H_LONG_BUSY_ORDER_10_MSEC:
		case H_LONG_BUSY_ORDER_100_MSEC:
		case H_LONG_BUSY_ORDER_1_SEC:
		case H_LONG_BUSY_ORDER_10_SEC:
		case H_LONG_BUSY_ORDER_100_SEC:
			return -EBUSY;
		case H_FUNCTION: /* fall through */
		default:
			return -EPERM;
	}
}

/**
 * hvcs_free_partner_info - free pi allocated by hvcs_get_partner_info
 * @head: list_head pointer for an allocated list of partner info structs to
 *	free.
 *
 * This function is used to free the partner info list that was returned by
 * calling hvcs_get_partner_info().
 */
int hvcs_free_partner_info(struct list_head *head)
{
	struct hvcs_partner_info *pi;
	struct list_head *element;

	if (!head)
		return -EINVAL;

	while (!list_empty(head)) {
		element = head->next;
		pi = list_entry(element, struct hvcs_partner_info, node);
		list_del(element);
		kfree(pi);
	}

	return 0;
}
EXPORT_SYMBOL(hvcs_free_partner_info);

/* Helper function for hvcs_get_partner_info */
static int hvcs_next_partner(uint32_t unit_address,
		unsigned long last_p_partition_ID,
		unsigned long last_p_unit_address, unsigned long *pi_buff)

{
	long retval;
	retval = plpar_hcall_norets(H_VTERM_PARTNER_INFO, unit_address,
			last_p_partition_ID,
				last_p_unit_address, virt_to_phys(pi_buff));
	return hvcs_convert(retval);
}

/**
 * hvcs_get_partner_info - Get all of the partner info for a vty-server adapter
 * @unit_address: The unit_address of the vty-server adapter for which this
 *	function is fetching partner info.
 * @head: An initialized list_head pointer to an empty list to use to return the
 *	list of partner info fetched from the hypervisor to the caller.
 * @pi_buff: A page sized buffer pre-allocated prior to calling this function
 *	that is to be used to be used by firmware as an iterator to keep track
 *	of the partner info retrieval.
 *
 * This function returns non-zero on success, or if there is no partner info.
 *
 * The pi_buff is pre-allocated prior to calling this function because this
 * function may be called with a spin_lock held and kmalloc of a page is not
 * recommended as GFP_ATOMIC.
 *
 * The first long of this buffer is used to store a partner unit address.  The
 * second long is used to store a partner partition ID and starting at
 * pi_buff[2] is the 79 character Converged Location Code (diff size than the
 * unsigned longs, hence the casting mumbo jumbo you see later).
 *
 * Invocation of this function should always be followed by an invocation of
 * hvcs_free_partner_info() using a pointer to the SAME list head instance
 * that was passed as a parameter to this function.
 */
int hvcs_get_partner_info(uint32_t unit_address, struct list_head *head,
		unsigned long *pi_buff)
{
	/*
	 * Dealt with as longs because of the hcall interface even though the
	 * values are uint32_t.
	 */
	unsigned long	last_p_partition_ID;
	unsigned long	last_p_unit_address;
	struct hvcs_partner_info *next_partner_info = NULL;
	int more = 1;
	int retval;

	memset(pi_buff, 0x00, PAGE_SIZE);
	/* invalid parameters */
	if (!head || !pi_buff)
		return -EINVAL;

	last_p_partition_ID = last_p_unit_address = ~0UL;
	INIT_LIST_HEAD(head);

	do {
		retval = hvcs_next_partner(unit_address, last_p_partition_ID,
				last_p_unit_address, pi_buff);
		if (retval) {
			/*
			 * Don't indicate that we've failed if we have
			 * any list elements.
			 */
			if (!list_empty(head))
				return 0;
			return retval;
		}

		last_p_partition_ID = pi_buff[0];
		last_p_unit_address = pi_buff[1];

		/* This indicates that there are no further partners */
		if (last_p_partition_ID == ~0UL
				&& last_p_unit_address == ~0UL)
			break;

		/* This is a very small struct and will be freed soon in
		 * hvcs_free_partner_info(). */
		next_partner_info = kmalloc(sizeof(struct hvcs_partner_info),
				GFP_ATOMIC);

		if (!next_partner_info) {
			printk(KERN_WARNING "HVCONSOLE: kmalloc() failed to"
				" allocate partner info struct.\n");
			hvcs_free_partner_info(head);
			return -ENOMEM;
		}

		next_partner_info->unit_address
			= (unsigned int)last_p_unit_address;
		next_partner_info->partition_ID
			= (unsigned int)last_p_partition_ID;

		/* copy the Null-term char too */
		strncpy(&next_partner_info->location_code[0],
			(char *)&pi_buff[2],
			strlen((char *)&pi_buff[2]) + 1);

		list_add_tail(&(next_partner_info->node), head);
		next_partner_info = NULL;

	} while (more);

	return 0;
}
EXPORT_SYMBOL(hvcs_get_partner_info);

/**
 * hvcs_register_connection - establish a connection between this vty-server and
 *	a vty.
 * @unit_address: The unit address of the vty-server adapter that is to be
 *	establish a connection.
 * @p_partition_ID: The partition ID of the vty adapter that is to be connected.
 * @p_unit_address: The unit address of the vty adapter to which the vty-server
 *	is to be connected.
 *
 * If this function is called once and -EINVAL is returned it may
 * indicate that the partner info needs to be refreshed for the
 * target unit address at which point the caller must invoke
 * hvcs_get_partner_info() and then call this function again.  If,
 * for a second time, -EINVAL is returned then it indicates that
 * there is probably already a partner connection registered to a
 * different vty-server adapter.  It is also possible that a second
 * -EINVAL may indicate that one of the parms is not valid, for
 * instance if the link was removed between the vty-server adapter
 * and the vty adapter that you are trying to open.  Don't shoot the
 * messenger.  Firmware implemented it this way.
 */
int hvcs_register_connection( uint32_t unit_address,
		uint32_t p_partition_ID, uint32_t p_unit_address)
{
	long retval;
	retval = plpar_hcall_norets(H_REGISTER_VTERM, unit_address,
				p_partition_ID, p_unit_address);
	return hvcs_convert(retval);
}
EXPORT_SYMBOL(hvcs_register_connection);

/**
 * hvcs_free_connection - free the connection between a vty-server and vty
 * @unit_address: The unit address of the vty-server that is to have its
 *	connection severed.
 *
 * This function is used to free the partner connection between a vty-server
 * adapter and a vty adapter.
 *
 * If -EBUSY is returned continue to call this function until 0 is returned.
 */
int hvcs_free_connection(uint32_t unit_address)
{
	long retval;
	retval = plpar_hcall_norets(H_FREE_VTERM, unit_address);
	return hvcs_convert(retval);
}
EXPORT_SYMBOL(hvcs_free_connection);