drivers/char/ipmi/ipmi_si_hotmod.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * ipmi_si_hotmod.c
   4  *
   5  * Handling for dynamically adding/removing IPMI devices through
   6  * a module parameter (and thus sysfs).
   7  */
   8 #include <linux/moduleparam.h>
   9 #include <linux/ipmi.h>
  10 #include "ipmi_si.h"
  11
  12 #define PFX "ipmi_hotmod: "
  13
  14 static int hotmod_handler(const char *val, const struct kernel_param *kp);
  15
  16 module_param_call(hotmod, hotmod_handler, NULL, NULL, 0200);
  17 MODULE_PARM_DESC(hotmod, "Add and remove interfaces.  See"
  18                  " Documentation/IPMI.txt in the kernel sources for the"
  19                  " gory details.");
  20
  21 /*
  22  * Parms come in as <op1>[:op2[:op3...]].  ops are:
  23  *   add|remove,kcs|bt|smic,mem|i/o,<address>[,<opt1>[,<opt2>[,...]]]
  24  * Options are:
  25  *   rsp=<regspacing>
  26  *   rsi=<regsize>
  27  *   rsh=<regshift>
  28  *   irq=<irq>
  29  *   ipmb=<ipmb addr>
  30  */
  31 enum hotmod_op { HM_ADD, HM_REMOVE };
  32 struct hotmod_vals {
  33         const char *name;
  34         const int  val;
  35 };
  36
  37 static const struct hotmod_vals hotmod_ops[] = {
  38         { "add",        HM_ADD },
  39         { "remove",     HM_REMOVE },
  40         { NULL }
  41 };
  42
  43 static const struct hotmod_vals hotmod_si[] = {
  44         { "kcs",        SI_KCS },
  45         { "smic",       SI_SMIC },
  46         { "bt",         SI_BT },
  47         { NULL }
  48 };
  49
  50 static const struct hotmod_vals hotmod_as[] = {
  51         { "mem",        IPMI_MEM_ADDR_SPACE },
  52         { "i/o",        IPMI_IO_ADDR_SPACE },
  53         { NULL }
  54 };
  55
  56 static int parse_str(const struct hotmod_vals *v, int *val, char *name,
  57                      char **curr)
  58 {
  59         char *s;
  60         int  i;
  61
  62         s = strchr(*curr, ',');
  63         if (!s) {
  64                 pr_warn(PFX "No hotmod %s given.\n", name);
  65                 return -EINVAL;
  66         }
  67         *s = '\0';
  68         s++;
  69         for (i = 0; v[i].name; i++) {
  70                 if (strcmp(*curr, v[i].name) == 0) {
  71                         *val = v[i].val;
  72                         *curr = s;
  73                         return 0;
  74                 }
  75         }
  76
  77         pr_warn(PFX "Invalid hotmod %s '%s'\n", name, *curr);
  78         return -EINVAL;
  79 }
  80
  81 static int check_hotmod_int_op(const char *curr, const char *option,
  82                                const char *name, int *val)
  83 {
  84         char *n;
  85
  86         if (strcmp(curr, name) == 0) {
  87                 if (!option) {
  88                         pr_warn(PFX "No option given for '%s'\n", curr);
  89                         return -EINVAL;
  90                 }
  91                 *val = simple_strtoul(option, &n, 0);
  92                 if ((*n != '\0') || (*option == '\0')) {
  93                         pr_warn(PFX "Bad option given for '%s'\n", curr);
  94                         return -EINVAL;
  95                 }
  96                 return 1;
  97         }
  98         return 0;
  99 }
 100
 101 static int hotmod_handler(const char *val, const struct kernel_param *kp)
 102 {
 103         char *str = kstrdup(val, GFP_KERNEL);
 104         int  rv;
 105         char *next, *curr, *s, *n, *o;
 106         enum hotmod_op op;
 107         enum si_type si_type;
 108         int  addr_space;
 109         unsigned long addr;
 110         int regspacing;
 111         int regsize;
 112         int regshift;
 113         int irq;
 114         int ipmb;
 115         int ival;
 116         int len;
 117
 118         if (!str)
 119                 return -ENOMEM;
 120
 121         /* Kill any trailing spaces, as we can get a "\n" from echo. */
 122         len = strlen(str);
 123         ival = len - 1;
 124         while ((ival >= 0) && isspace(str[ival])) {
 125                 str[ival] = '\0';
 126                 ival--;
 127         }
 128
 129         for (curr = str; curr; curr = next) {
 130                 regspacing = 1;
 131                 regsize = 1;
 132                 regshift = 0;
 133                 irq = 0;
 134                 ipmb = 0; /* Choose the default if not specified */
 135
 136                 next = strchr(curr, ':');
 137                 if (next) {
 138                         *next = '\0';
 139                         next++;
 140                 }
 141
 142                 rv = parse_str(hotmod_ops, &ival, "operation", &curr);
 143                 if (rv)
 144                         break;
 145                 op = ival;
 146
 147                 rv = parse_str(hotmod_si, &ival, "interface type", &curr);
 148                 if (rv)
 149                         break;
 150                 si_type = ival;
 151
 152                 rv = parse_str(hotmod_as, &addr_space, "address space", &curr);
 153                 if (rv)
 154                         break;
 155
 156                 s = strchr(curr, ',');
 157                 if (s) {
 158                         *s = '\0';
 159                         s++;
 160                 }
 161                 addr = simple_strtoul(curr, &n, 0);
 162                 if ((*n != '\0') || (*curr == '\0')) {
 163                         pr_warn(PFX "Invalid hotmod address '%s'\n", curr);
 164                         break;
 165                 }
 166
 167                 while (s) {
 168                         curr = s;
 169                         s = strchr(curr, ',');
 170                         if (s) {
 171                                 *s = '\0';
 172                                 s++;
 173                         }
 174                         o = strchr(curr, '=');
 175                         if (o) {
 176                                 *o = '\0';
 177                                 o++;
 178                         }
 179                         rv = check_hotmod_int_op(curr, o, "rsp", &regspacing);
 180                         if (rv < 0)
 181                                 goto out;
 182                         else if (rv)
 183                                 continue;
 184                         rv = check_hotmod_int_op(curr, o, "rsi", &regsize);
 185                         if (rv < 0)
 186                                 goto out;
 187                         else if (rv)
 188                                 continue;
 189                         rv = check_hotmod_int_op(curr, o, "rsh", &regshift);
 190                         if (rv < 0)
 191                                 goto out;
 192                         else if (rv)
 193                                 continue;
 194                         rv = check_hotmod_int_op(curr, o, "irq", &irq);
 195                         if (rv < 0)
 196                                 goto out;
 197                         else if (rv)
 198                                 continue;
 199                         rv = check_hotmod_int_op(curr, o, "ipmb", &ipmb);
 200                         if (rv < 0)
 201                                 goto out;
 202                         else if (rv)
 203                                 continue;
 204
 205                         rv = -EINVAL;
 206                         pr_warn(PFX "Invalid hotmod option '%s'\n", curr);
 207                         goto out;
 208                 }
 209
 210                 if (op == HM_ADD) {
 211                         struct si_sm_io io;
 212
 213                         memset(&io, 0, sizeof(io));
 214                         io.addr_source = SI_HOTMOD;
 215                         io.si_type = si_type;
 216                         io.addr_data = addr;
 217                         io.addr_type = addr_space;
 218
 219                         io.addr = NULL;
 220                         io.regspacing = regspacing;
 221                         if (!io.regspacing)
 222                                 io.regspacing = DEFAULT_REGSPACING;
 223                         io.regsize = regsize;
 224                         if (!io.regsize)
 225                                 io.regsize = DEFAULT_REGSIZE;
 226                         io.regshift = regshift;
 227                         io.irq = irq;
 228                         if (io.irq)
 229                                 io.irq_setup = ipmi_std_irq_setup;
 230                         io.slave_addr = ipmb;
 231
 232                         rv = ipmi_si_add_smi(&io);
 233                         if (rv)
 234                                 goto out;
 235                 } else {
 236                         ipmi_si_remove_by_data(addr_space, si_type, addr);
 237                 }
 238         }
 239         rv = len;
 240 out:
 241         kfree(str);
 242         return rv;
 243 }