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
   9 #define pr_fmt(fmt) "ipmi_hotmod: " fmt
  10
  11 #include <linux/moduleparam.h>
  12 #include <linux/ipmi.h>
  13 #include "ipmi_si.h"
  14
  15 static int hotmod_handler(const char *val, const struct kernel_param *kp);
  16
  17 module_param_call(hotmod, hotmod_handler, NULL, NULL, 0200);
  18 MODULE_PARM_DESC(hotmod, "Add and remove interfaces.  See"
  19                  " Documentation/IPMI.txt in the kernel sources for the"
  20                  " gory details.");
  21
  22 /*
  23  * Parms come in as <op1>[:op2[:op3...]].  ops are:
  24  *   add|remove,kcs|bt|smic,mem|i/o,<address>[,<opt1>[,<opt2>[,...]]]
  25  * Options are:
  26  *   rsp=<regspacing>
  27  *   rsi=<regsize>
  28  *   rsh=<regshift>
  29  *   irq=<irq>
  30  *   ipmb=<ipmb addr>
  31  */
  32 enum hotmod_op { HM_ADD, HM_REMOVE };
  33 struct hotmod_vals {
  34         const char *name;
  35         const int  val;
  36 };
  37
  38 static const struct hotmod_vals hotmod_ops[] = {
  39         { "add",        HM_ADD },
  40         { "remove",     HM_REMOVE },
  41         { NULL }
  42 };
  43
  44 static const struct hotmod_vals hotmod_si[] = {
  45         { "kcs",        SI_KCS },
  46         { "smic",       SI_SMIC },
  47         { "bt",         SI_BT },
  48         { NULL }
  49 };
  50
  51 static const struct hotmod_vals hotmod_as[] = {
  52         { "mem",        IPMI_MEM_ADDR_SPACE },
  53         { "i/o",        IPMI_IO_ADDR_SPACE },
  54         { NULL }
  55 };
  56
  57 static int parse_str(const struct hotmod_vals *v, int *val, char *name,
  58                      char **curr)
  59 {
  60         char *s;
  61         int  i;
  62
  63         s = strchr(*curr, ',');
  64         if (!s) {
  65                 pr_warn("No hotmod %s given\n", name);
  66                 return -EINVAL;
  67         }
  68         *s = '\0';
  69         s++;
  70         for (i = 0; v[i].name; i++) {
  71                 if (strcmp(*curr, v[i].name) == 0) {
  72                         *val = v[i].val;
  73                         *curr = s;
  74                         return 0;
  75                 }
  76         }
  77
  78         pr_warn("Invalid hotmod %s '%s'\n", name, *curr);
  79         return -EINVAL;
  80 }
  81
  82 static int check_hotmod_int_op(const char *curr, const char *option,
  83                                const char *name, int *val)
  84 {
  85         char *n;
  86
  87         if (strcmp(curr, name) == 0) {
  88                 if (!option) {
  89                         pr_warn("No option given for '%s'\n", curr);
  90                         return -EINVAL;
  91                 }
  92                 *val = simple_strtoul(option, &n, 0);
  93                 if ((*n != '\0') || (*option == '\0')) {
  94                         pr_warn("Bad option given for '%s'\n", curr);
  95                         return -EINVAL;
  96                 }
  97                 return 1;
  98         }
  99         return 0;
 100 }
 101
 102 static int hotmod_handler(const char *val, const struct kernel_param *kp)
 103 {
 104         char *str = kstrdup(val, GFP_KERNEL);
 105         int  rv;
 106         char *next, *curr, *s, *n, *o;
 107         enum hotmod_op op;
 108         enum si_type si_type;
 109         int  addr_space;
 110         unsigned long addr;
 111         int regspacing;
 112         int regsize;
 113         int regshift;
 114         int irq;
 115         int ipmb;
 116         int ival;
 117         int len;
 118
 119         if (!str)
 120                 return -ENOMEM;
 121
 122         /* Kill any trailing spaces, as we can get a "\n" from echo. */
 123         len = strlen(str);
 124         ival = len - 1;
 125         while ((ival >= 0) && isspace(str[ival])) {
 126                 str[ival] = '\0';
 127                 ival--;
 128         }
 129
 130         for (curr = str; curr; curr = next) {
 131                 regspacing = 1;
 132                 regsize = 1;
 133                 regshift = 0;
 134                 irq = 0;
 135                 ipmb = 0; /* Choose the default if not specified */
 136
 137                 next = strchr(curr, ':');
 138                 if (next) {
 139                         *next = '\0';
 140                         next++;
 141                 }
 142
 143                 rv = parse_str(hotmod_ops, &ival, "operation", &curr);
 144                 if (rv)
 145                         break;
 146                 op = ival;
 147
 148                 rv = parse_str(hotmod_si, &ival, "interface type", &curr);
 149                 if (rv)
 150                         break;
 151                 si_type = ival;
 152
 153                 rv = parse_str(hotmod_as, &addr_space, "address space", &curr);
 154                 if (rv)
 155                         break;
 156
 157                 s = strchr(curr, ',');
 158                 if (s) {
 159                         *s = '\0';
 160                         s++;
 161                 }
 162                 addr = simple_strtoul(curr, &n, 0);
 163                 if ((*n != '\0') || (*curr == '\0')) {
 164                         pr_warn("Invalid hotmod address '%s'\n", curr);
 165                         break;
 166                 }
 167
 168                 while (s) {
 169                         curr = s;
 170                         s = strchr(curr, ',');
 171                         if (s) {
 172                                 *s = '\0';
 173                                 s++;
 174                         }
 175                         o = strchr(curr, '=');
 176                         if (o) {
 177                                 *o = '\0';
 178                                 o++;
 179                         }
 180                         rv = check_hotmod_int_op(curr, o, "rsp", &regspacing);
 181                         if (rv < 0)
 182                                 goto out;
 183                         else if (rv)
 184                                 continue;
 185                         rv = check_hotmod_int_op(curr, o, "rsi", &regsize);
 186                         if (rv < 0)
 187                                 goto out;
 188                         else if (rv)
 189                                 continue;
 190                         rv = check_hotmod_int_op(curr, o, "rsh", &regshift);
 191                         if (rv < 0)
 192                                 goto out;
 193                         else if (rv)
 194                                 continue;
 195                         rv = check_hotmod_int_op(curr, o, "irq", &irq);
 196                         if (rv < 0)
 197                                 goto out;
 198                         else if (rv)
 199                                 continue;
 200                         rv = check_hotmod_int_op(curr, o, "ipmb", &ipmb);
 201                         if (rv < 0)
 202                                 goto out;
 203                         else if (rv)
 204                                 continue;
 205
 206                         rv = -EINVAL;
 207                         pr_warn("Invalid hotmod option '%s'\n", curr);
 208                         goto out;
 209                 }
 210
 211                 if (op == HM_ADD) {
 212                         struct si_sm_io io;
 213
 214                         memset(&io, 0, sizeof(io));
 215                         io.addr_source = SI_HOTMOD;
 216                         io.si_type = si_type;
 217                         io.addr_data = addr;
 218                         io.addr_type = addr_space;
 219
 220                         io.addr = NULL;
 221                         io.regspacing = regspacing;
 222                         if (!io.regspacing)
 223                                 io.regspacing = DEFAULT_REGSPACING;
 224                         io.regsize = regsize;
 225                         if (!io.regsize)
 226                                 io.regsize = DEFAULT_REGSIZE;
 227                         io.regshift = regshift;
 228                         io.irq = irq;
 229                         if (io.irq)
 230                                 io.irq_setup = ipmi_std_irq_setup;
 231                         io.slave_addr = ipmb;
 232
 233                         rv = ipmi_si_add_smi(&io);
 234                         if (rv)
 235                                 goto out;
 236                 } else {
 237                         ipmi_si_remove_by_data(addr_space, si_type, addr);
 238                 }
 239         }
 240         rv = len;
 241 out:
 242         kfree(str);
 243         return rv;
 244 }