kernel/arch/powerpc/platforms/pseries/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 <linux/slab.h>
  26 #include <linux/string.h>
  27
  28 #include <asm/hvcall.h>
  29 #include <asm/hvcserver.h>
  30 #include <asm/io.h>
  31
  32 #define HVCS_ARCH_VERSION "1.0.0"
  33
  34 MODULE_AUTHOR("Ryan S. Arnold <rsa@us.ibm.com>");
  35 MODULE_DESCRIPTION("IBM hvcs ppc64 API");
  36 MODULE_LICENSE("GPL");
  37 MODULE_VERSION(HVCS_ARCH_VERSION);
  38
  39 /*
  40  * Convert arch specific return codes into relevant errnos.  The hvcs
  41  * functions aren't performance sensitive, so this conversion isn't an
  42  * issue.
  43  */
  44 static int hvcs_convert(long to_convert)
  45 {
  46         switch (to_convert) {
  47                 case H_SUCCESS:
  48                         return 0;
  49                 case H_PARAMETER:
  50                         return -EINVAL;
  51                 case H_HARDWARE:
  52                         return -EIO;
  53                 case H_BUSY:
  54                 case H_LONG_BUSY_ORDER_1_MSEC:
  55                 case H_LONG_BUSY_ORDER_10_MSEC:
  56                 case H_LONG_BUSY_ORDER_100_MSEC:
  57                 case H_LONG_BUSY_ORDER_1_SEC:
  58                 case H_LONG_BUSY_ORDER_10_SEC:
  59                 case H_LONG_BUSY_ORDER_100_SEC:
  60                         return -EBUSY;
  61                 case H_FUNCTION: /* fall through */
  62                 default:
  63                         return -EPERM;
  64         }
  65 }
  66
  67 /**
  68  * hvcs_free_partner_info - free pi allocated by hvcs_get_partner_info
  69  * @head: list_head pointer for an allocated list of partner info structs to
  70  *      free.
  71  *
  72  * This function is used to free the partner info list that was returned by
  73  * calling hvcs_get_partner_info().
  74  */
  75 int hvcs_free_partner_info(struct list_head *head)
  76 {
  77         struct hvcs_partner_info *pi;
  78         struct list_head *element;
  79
  80         if (!head)
  81                 return -EINVAL;
  82
  83         while (!list_empty(head)) {
  84                 element = head->next;
  85                 pi = list_entry(element, struct hvcs_partner_info, node);
  86                 list_del(element);
  87                 kfree(pi);
  88         }
  89
  90         return 0;
  91 }
  92 EXPORT_SYMBOL(hvcs_free_partner_info);
  93
  94 /* Helper function for hvcs_get_partner_info */
  95 static int hvcs_next_partner(uint32_t unit_address,
  96                 unsigned long last_p_partition_ID,
  97                 unsigned long last_p_unit_address, unsigned long *pi_buff)
  98
  99 {
 100         long retval;
 101         retval = plpar_hcall_norets(H_VTERM_PARTNER_INFO, unit_address,
 102                         last_p_partition_ID,
 103                                 last_p_unit_address, virt_to_phys(pi_buff));
 104         return hvcs_convert(retval);
 105 }
 106
 107 /**
 108  * hvcs_get_partner_info - Get all of the partner info for a vty-server adapter
 109  * @unit_address: The unit_address of the vty-server adapter for which this
 110  *      function is fetching partner info.
 111  * @head: An initialized list_head pointer to an empty list to use to return the
 112  *      list of partner info fetched from the hypervisor to the caller.
 113  * @pi_buff: A page sized buffer pre-allocated prior to calling this function
 114  *      that is to be used to be used by firmware as an iterator to keep track
 115  *      of the partner info retrieval.
 116  *
 117  * This function returns non-zero on success, or if there is no partner info.
 118  *
 119  * The pi_buff is pre-allocated prior to calling this function because this
 120  * function may be called with a spin_lock held and kmalloc of a page is not
 121  * recommended as GFP_ATOMIC.
 122  *
 123  * The first long of this buffer is used to store a partner unit address.  The
 124  * second long is used to store a partner partition ID and starting at
 125  * pi_buff[2] is the 79 character Converged Location Code (diff size than the
 126  * unsigned longs, hence the casting mumbo jumbo you see later).
 127  *
 128  * Invocation of this function should always be followed by an invocation of
 129  * hvcs_free_partner_info() using a pointer to the SAME list head instance
 130  * that was passed as a parameter to this function.
 131  */
 132 int hvcs_get_partner_info(uint32_t unit_address, struct list_head *head,
 133                 unsigned long *pi_buff)
 134 {
 135         /*
 136          * Dealt with as longs because of the hcall interface even though the
 137          * values are uint32_t.
 138          */
 139         unsigned long   last_p_partition_ID;
 140         unsigned long   last_p_unit_address;
 141         struct hvcs_partner_info *next_partner_info = NULL;
 142         int more = 1;
 143         int retval;
 144
 145         memset(pi_buff, 0x00, PAGE_SIZE);
 146         /* invalid parameters */
 147         if (!head || !pi_buff)
 148                 return -EINVAL;
 149
 150         last_p_partition_ID = last_p_unit_address = ~0UL;
 151         INIT_LIST_HEAD(head);
 152
 153         do {
 154                 retval = hvcs_next_partner(unit_address, last_p_partition_ID,
 155                                 last_p_unit_address, pi_buff);
 156                 if (retval) {
 157                         /*
 158                          * Don't indicate that we've failed if we have
 159                          * any list elements.
 160                          */
 161                         if (!list_empty(head))
 162                                 return 0;
 163                         return retval;
 164                 }
 165
 166                 last_p_partition_ID = be64_to_cpu(pi_buff[0]);
 167                 last_p_unit_address = be64_to_cpu(pi_buff[1]);
 168
 169                 /* This indicates that there are no further partners */
 170                 if (last_p_partition_ID == ~0UL
 171                                 && last_p_unit_address == ~0UL)
 172                         break;
 173
 174                 /* This is a very small struct and will be freed soon in
 175                  * hvcs_free_partner_info(). */
 176                 next_partner_info = kmalloc(sizeof(struct hvcs_partner_info),
 177                                 GFP_ATOMIC);
 178
 179                 if (!next_partner_info) {
 180                         printk(KERN_WARNING "HVCONSOLE: kmalloc() failed to"
 181                                 " allocate partner info struct.\n");
 182                         hvcs_free_partner_info(head);
 183                         return -ENOMEM;
 184                 }
 185
 186                 next_partner_info->unit_address
 187                         = (unsigned int)last_p_unit_address;
 188                 next_partner_info->partition_ID
 189                         = (unsigned int)last_p_partition_ID;
 190
 191                 /* copy the Null-term char too */
 192                 strlcpy(&next_partner_info->location_code[0],
 193                         (char *)&pi_buff[2],
 194                         sizeof(next_partner_info->location_code));
 195
 196                 list_add_tail(&(next_partner_info->node), head);
 197                 next_partner_info = NULL;
 198
 199         } while (more);
 200
 201         return 0;
 202 }
 203 EXPORT_SYMBOL(hvcs_get_partner_info);
 204
 205 /**
 206  * hvcs_register_connection - establish a connection between this vty-server and
 207  *      a vty.
 208  * @unit_address: The unit address of the vty-server adapter that is to be
 209  *      establish a connection.
 210  * @p_partition_ID: The partition ID of the vty adapter that is to be connected.
 211  * @p_unit_address: The unit address of the vty adapter to which the vty-server
 212  *      is to be connected.
 213  *
 214  * If this function is called once and -EINVAL is returned it may
 215  * indicate that the partner info needs to be refreshed for the
 216  * target unit address at which point the caller must invoke
 217  * hvcs_get_partner_info() and then call this function again.  If,
 218  * for a second time, -EINVAL is returned then it indicates that
 219  * there is probably already a partner connection registered to a
 220  * different vty-server adapter.  It is also possible that a second
 221  * -EINVAL may indicate that one of the parms is not valid, for
 222  * instance if the link was removed between the vty-server adapter
 223  * and the vty adapter that you are trying to open.  Don't shoot the
 224  * messenger.  Firmware implemented it this way.
 225  */
 226 int hvcs_register_connection( uint32_t unit_address,
 227                 uint32_t p_partition_ID, uint32_t p_unit_address)
 228 {
 229         long retval;
 230         retval = plpar_hcall_norets(H_REGISTER_VTERM, unit_address,
 231                                 p_partition_ID, p_unit_address);
 232         return hvcs_convert(retval);
 233 }
 234 EXPORT_SYMBOL(hvcs_register_connection);
 235
 236 /**
 237  * hvcs_free_connection - free the connection between a vty-server and vty
 238  * @unit_address: The unit address of the vty-server that is to have its
 239  *      connection severed.
 240  *
 241  * This function is used to free the partner connection between a vty-server
 242  * adapter and a vty adapter.
 243  *
 244  * If -EBUSY is returned continue to call this function until 0 is returned.
 245  */
 246 int hvcs_free_connection(uint32_t unit_address)
 247 {
 248         long retval;
 249         retval = plpar_hcall_norets(H_FREE_VTERM, unit_address);
 250         return hvcs_convert(retval);
 251 }
 252 EXPORT_SYMBOL(hvcs_free_connection);