Merge watchdog driver updates
[linux-2.6] / arch / ppc64 / kernel / hvcserver.c
1 /*
2  * hvcserver.c
3  * Copyright (C) 2004 Ryan S Arnold, IBM Corporation
4  *
5  * PPC64 virtual I/O console server support.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
20  */
21
22 #include <linux/kernel.h>
23 #include <linux/list.h>
24 #include <linux/module.h>
25 #include <asm/hvcall.h>
26 #include <asm/hvcserver.h>
27 #include <asm/io.h>
28
29 #define HVCS_ARCH_VERSION "1.0.0"
30
31 MODULE_AUTHOR("Ryan S. Arnold <rsa@us.ibm.com>");
32 MODULE_DESCRIPTION("IBM hvcs ppc64 API");
33 MODULE_LICENSE("GPL");
34 MODULE_VERSION(HVCS_ARCH_VERSION);
35
36 /*
37  * Convert arch specific return codes into relevant errnos.  The hvcs
38  * functions aren't performance sensitive, so this conversion isn't an
39  * issue.
40  */
41 int hvcs_convert(long to_convert)
42 {
43         switch (to_convert) {
44                 case H_Success:
45                         return 0;
46                 case H_Parameter:
47                         return -EINVAL;
48                 case H_Hardware:
49                         return -EIO;
50                 case H_Busy:
51                 case H_LongBusyOrder1msec:
52                 case H_LongBusyOrder10msec:
53                 case H_LongBusyOrder100msec:
54                 case H_LongBusyOrder1sec:
55                 case H_LongBusyOrder10sec:
56                 case H_LongBusyOrder100sec:
57                         return -EBUSY;
58                 case H_Function: /* fall through */
59                 default:
60                         return -EPERM;
61         }
62 }
63
64 /**
65  * hvcs_free_partner_info - free pi allocated by hvcs_get_partner_info
66  * @head: list_head pointer for an allocated list of partner info structs to
67  *      free.
68  *
69  * This function is used to free the partner info list that was returned by
70  * calling hvcs_get_partner_info().
71  */
72 int hvcs_free_partner_info(struct list_head *head)
73 {
74         struct hvcs_partner_info *pi;
75         struct list_head *element;
76
77         if (!head)
78                 return -EINVAL;
79
80         while (!list_empty(head)) {
81                 element = head->next;
82                 pi = list_entry(element, struct hvcs_partner_info, node);
83                 list_del(element);
84                 kfree(pi);
85         }
86
87         return 0;
88 }
89 EXPORT_SYMBOL(hvcs_free_partner_info);
90
91 /* Helper function for hvcs_get_partner_info */
92 int hvcs_next_partner(uint32_t unit_address,
93                 unsigned long last_p_partition_ID,
94                 unsigned long last_p_unit_address, unsigned long *pi_buff)
95
96 {
97         long retval;
98         retval = plpar_hcall_norets(H_VTERM_PARTNER_INFO, unit_address,
99                         last_p_partition_ID,
100                                 last_p_unit_address, virt_to_phys(pi_buff));
101         return hvcs_convert(retval);
102 }
103
104 /**
105  * hvcs_get_partner_info - Get all of the partner info for a vty-server adapter
106  * @unit_address: The unit_address of the vty-server adapter for which this
107  *      function is fetching partner info.
108  * @head: An initialized list_head pointer to an empty list to use to return the
109  *      list of partner info fetched from the hypervisor to the caller.
110  * @pi_buff: A page sized buffer pre-allocated prior to calling this function
111  *      that is to be used to be used by firmware as an iterator to keep track
112  *      of the partner info retrieval.
113  *
114  * This function returns non-zero on success, or if there is no partner info.
115  *
116  * The pi_buff is pre-allocated prior to calling this function because this
117  * function may be called with a spin_lock held and kmalloc of a page is not
118  * recommended as GFP_ATOMIC.
119  *
120  * The first long of this buffer is used to store a partner unit address.  The
121  * second long is used to store a partner partition ID and starting at
122  * pi_buff[2] is the 79 character Converged Location Code (diff size than the
123  * unsigned longs, hence the casting mumbo jumbo you see later).
124  *
125  * Invocation of this function should always be followed by an invocation of
126  * hvcs_free_partner_info() using a pointer to the SAME list head instance
127  * that was passed as a parameter to this function.
128  */
129 int hvcs_get_partner_info(uint32_t unit_address, struct list_head *head,
130                 unsigned long *pi_buff)
131 {
132         /*
133          * Dealt with as longs because of the hcall interface even though the
134          * values are uint32_t.
135          */
136         unsigned long   last_p_partition_ID;
137         unsigned long   last_p_unit_address;
138         struct hvcs_partner_info *next_partner_info = NULL;
139         int more = 1;
140         int retval;
141
142         memset(pi_buff, 0x00, PAGE_SIZE);
143         /* invalid parameters */
144         if (!head || !pi_buff)
145                 return -EINVAL;
146
147         last_p_partition_ID = last_p_unit_address = ~0UL;
148         INIT_LIST_HEAD(head);
149
150         do {
151                 retval = hvcs_next_partner(unit_address, last_p_partition_ID,
152                                 last_p_unit_address, pi_buff);
153                 if (retval) {
154                         /*
155                          * Don't indicate that we've failed if we have
156                          * any list elements.
157                          */
158                         if (!list_empty(head))
159                                 return 0;
160                         return retval;
161                 }
162
163                 last_p_partition_ID = pi_buff[0];
164                 last_p_unit_address = pi_buff[1];
165
166                 /* This indicates that there are no further partners */
167                 if (last_p_partition_ID == ~0UL
168                                 && last_p_unit_address == ~0UL)
169                         break;
170
171                 /* This is a very small struct and will be freed soon in
172                  * hvcs_free_partner_info(). */
173                 next_partner_info = kmalloc(sizeof(struct hvcs_partner_info),
174                                 GFP_ATOMIC);
175
176                 if (!next_partner_info) {
177                         printk(KERN_WARNING "HVCONSOLE: kmalloc() failed to"
178                                 " allocate partner info struct.\n");
179                         hvcs_free_partner_info(head);
180                         return -ENOMEM;
181                 }
182
183                 next_partner_info->unit_address
184                         = (unsigned int)last_p_unit_address;
185                 next_partner_info->partition_ID
186                         = (unsigned int)last_p_partition_ID;
187
188                 /* copy the Null-term char too */
189                 strncpy(&next_partner_info->location_code[0],
190                         (char *)&pi_buff[2],
191                         strlen((char *)&pi_buff[2]) + 1);
192
193                 list_add_tail(&(next_partner_info->node), head);
194                 next_partner_info = NULL;
195
196         } while (more);
197
198         return 0;
199 }
200 EXPORT_SYMBOL(hvcs_get_partner_info);
201
202 /**
203  * hvcs_register_connection - establish a connection between this vty-server and
204  *      a vty.
205  * @unit_address: The unit address of the vty-server adapter that is to be
206  *      establish a connection.
207  * @p_partition_ID: The partition ID of the vty adapter that is to be connected.
208  * @p_unit_address: The unit address of the vty adapter to which the vty-server
209  *      is to be connected.
210  *
211  * If this function is called once and -EINVAL is returned it may
212  * indicate that the partner info needs to be refreshed for the
213  * target unit address at which point the caller must invoke
214  * hvcs_get_partner_info() and then call this function again.  If,
215  * for a second time, -EINVAL is returned then it indicates that
216  * there is probably already a partner connection registered to a
217  * different vty-server adapter.  It is also possible that a second
218  * -EINVAL may indicate that one of the parms is not valid, for
219  * instance if the link was removed between the vty-server adapter
220  * and the vty adapter that you are trying to open.  Don't shoot the
221  * messenger.  Firmware implemented it this way.
222  */
223 int hvcs_register_connection( uint32_t unit_address,
224                 uint32_t p_partition_ID, uint32_t p_unit_address)
225 {
226         long retval;
227         retval = plpar_hcall_norets(H_REGISTER_VTERM, unit_address,
228                                 p_partition_ID, p_unit_address);
229         return hvcs_convert(retval);
230 }
231 EXPORT_SYMBOL(hvcs_register_connection);
232
233 /**
234  * hvcs_free_connection - free the connection between a vty-server and vty
235  * @unit_address: The unit address of the vty-server that is to have its
236  *      connection severed.
237  *
238  * This function is used to free the partner connection between a vty-server
239  * adapter and a vty adapter.
240  *
241  * If -EBUSY is returned continue to call this function until 0 is returned.
242  */
243 int hvcs_free_connection(uint32_t unit_address)
244 {
245         long retval;
246         retval = plpar_hcall_norets(H_FREE_VTERM, unit_address);
247         return hvcs_convert(retval);
248 }
249 EXPORT_SYMBOL(hvcs_free_connection);