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 int hvcs_free_partner_info(struct list_head *head)
  65 {
  66         struct hvcs_partner_info *pi;
  67         struct list_head *element;
  68
  69         if (!head) {
  70                 return -EINVAL;
  71         }
  72
  73         while (!list_empty(head)) {
  74                 element = head->next;
  75                 pi = list_entry(element, struct hvcs_partner_info, node);
  76                 list_del(element);
  77                 kfree(pi);
  78         }
  79
  80         return 0;
  81 }
  82 EXPORT_SYMBOL(hvcs_free_partner_info);
  83
  84 /* Helper function for hvcs_get_partner_info */
  85 int hvcs_next_partner(unsigned int unit_address,
  86                 unsigned long last_p_partition_ID,
  87                 unsigned long last_p_unit_address, unsigned long *pi_buff)
  88
  89 {
  90         long retval;
  91         retval = plpar_hcall_norets(H_VTERM_PARTNER_INFO, unit_address,
  92                         last_p_partition_ID,
  93                                 last_p_unit_address, virt_to_phys(pi_buff));
  94         return hvcs_convert(retval);
  95 }
  96
  97 /*
  98  * The unit_address parameter is the unit address of the vty-server vdevice
  99  * in whose partner information the caller is interested.  This function
 100  * uses a pointer to a list_head instance in which to store the partner info.
 101  * This function returns non-zero on success, or if there is no partner info.
 102  *
 103  * Invocation of this function should always be followed by an invocation of
 104  * hvcs_free_partner_info() using a pointer to the SAME list head instance
 105  * that was used to store the partner_info list.
 106  */
 107 int hvcs_get_partner_info(unsigned int unit_address, struct list_head *head,
 108                 unsigned long *pi_buff)
 109 {
 110         /*
 111          * This is a page sized buffer to be passed to hvcall per invocation.
 112          * NOTE: the first long returned is unit_address.  The second long
 113          * returned is the partition ID and starting with pi_buff[2] are
 114          * HVCS_CLC_LENGTH characters, which are diff size than the unsigned
 115          * long, hence the casting mumbojumbo you see later.
 116          */
 117         unsigned long   last_p_partition_ID;
 118         unsigned long   last_p_unit_address;
 119         struct hvcs_partner_info *next_partner_info = NULL;
 120         int more = 1;
 121         int retval;
 122
 123         memset(pi_buff, 0x00, PAGE_SIZE);
 124         /* invalid parameters */
 125         if (!head)
 126                 return -EINVAL;
 127
 128         last_p_partition_ID = last_p_unit_address = ~0UL;
 129         INIT_LIST_HEAD(head);
 130
 131         if (!pi_buff)
 132                 return -ENOMEM;
 133
 134         do {
 135                 retval = hvcs_next_partner(unit_address, last_p_partition_ID,
 136                                 last_p_unit_address, pi_buff);
 137                 if (retval) {
 138                         /*
 139                          * Don't indicate that we've failed if we have
 140                          * any list elements.
 141                          */
 142                         if (!list_empty(head))
 143                                 return 0;
 144                         return retval;
 145                 }
 146
 147                 last_p_partition_ID = pi_buff[0];
 148                 last_p_unit_address = pi_buff[1];
 149
 150                 /* This indicates that there are no further partners */
 151                 if (last_p_partition_ID == ~0UL
 152                                 && last_p_unit_address == ~0UL)
 153                         break;
 154
 155                 /* This is a very small struct and will be freed soon in
 156                  * hvcs_free_partner_info(). */
 157                 next_partner_info = kmalloc(sizeof(struct hvcs_partner_info),
 158                                 GFP_ATOMIC);
 159
 160                 if (!next_partner_info) {
 161                         printk(KERN_WARNING "HVCONSOLE: kmalloc() failed to"
 162                                 " allocate partner info struct.\n");
 163                         hvcs_free_partner_info(head);
 164                         return -ENOMEM;
 165                 }
 166
 167                 next_partner_info->unit_address
 168                         = (unsigned int)last_p_unit_address;
 169                 next_partner_info->partition_ID
 170                         = (unsigned int)last_p_partition_ID;
 171
 172                 /* copy the Null-term char too */
 173                 strncpy(&next_partner_info->location_code[0],
 174                         (char *)&pi_buff[2],
 175                         strlen((char *)&pi_buff[2]) + 1);
 176
 177                 list_add_tail(&(next_partner_info->node), head);
 178                 next_partner_info = NULL;
 179
 180         } while (more);
 181
 182         return 0;
 183 }
 184 EXPORT_SYMBOL(hvcs_get_partner_info);
 185
 186 /*
 187  * If this function is called once and -EINVAL is returned it may
 188  * indicate that the partner info needs to be refreshed for the
 189  * target unit address at which point the caller must invoke
 190  * hvcs_get_partner_info() and then call this function again.  If,
 191  * for a second time, -EINVAL is returned then it indicates that
 192  * there is probably already a partner connection registered to a
 193  * different vty-server@ vdevice.  It is also possible that a second
 194  * -EINVAL may indicate that one of the parms is not valid, for
 195  * instance if the link was removed between the vty-server@ vdevice
 196  * and the vty@ vdevice that you are trying to open.  Don't shoot the
 197  * messenger.  Firmware implemented it this way.
 198  */
 199 int hvcs_register_connection( unsigned int unit_address,
 200                 unsigned int p_partition_ID, unsigned int p_unit_address)
 201 {
 202         long retval;
 203         retval = plpar_hcall_norets(H_REGISTER_VTERM, unit_address,
 204                                 p_partition_ID, p_unit_address);
 205         return hvcs_convert(retval);
 206 }
 207 EXPORT_SYMBOL(hvcs_register_connection);
 208
 209 /*
 210  * If -EBUSY is returned continue to call this function
 211  * until 0 is returned.
 212  */
 213 int hvcs_free_connection(unsigned int unit_address)
 214 {
 215         long retval;
 216         retval = plpar_hcall_norets(H_FREE_VTERM, unit_address);
 217         return hvcs_convert(retval);
 218 }
 219 EXPORT_SYMBOL(hvcs_free_connection);