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);