arch/mips/kernel/mips-mt.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * General MIPS MT support routines, usable in AP/SP and SMVP.
   4  * Copyright (C) 2005 Mips Technologies, Inc
   5  */
   6
   7 #include <linux/device.h>
   8 #include <linux/kernel.h>
   9 #include <linux/sched.h>
  10 #include <linux/export.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/security.h>
  13
  14 #include <asm/cpu.h>
  15 #include <asm/processor.h>
  16 #include <linux/atomic.h>
  17 #include <asm/hardirq.h>
  18 #include <asm/mmu_context.h>
  19 #include <asm/mipsmtregs.h>
  20 #include <asm/r4kcache.h>
  21 #include <asm/cacheflush.h>
  22
  23 int vpelimit;
  24
  25 static int __init maxvpes(char *str)
  26 {
  27         get_option(&str, &vpelimit);
  28
  29         return 1;
  30 }
  31
  32 __setup("maxvpes=", maxvpes);
  33
  34 int tclimit;
  35
  36 static int __init maxtcs(char *str)
  37 {
  38         get_option(&str, &tclimit);
  39
  40         return 1;
  41 }
  42
  43 __setup("maxtcs=", maxtcs);
  44
  45 /*
  46  * Dump new MIPS MT state for the core. Does not leave TCs halted.
  47  * Takes an argument which taken to be a pre-call MVPControl value.
  48  */
  49
  50 void mips_mt_regdump(unsigned long mvpctl)
  51 {
  52         unsigned long flags;
  53         unsigned long vpflags;
  54         unsigned long mvpconf0;
  55         int nvpe;
  56         int ntc;
  57         int i;
  58         int tc;
  59         unsigned long haltval;
  60         unsigned long tcstatval;
  61
  62         local_irq_save(flags);
  63         vpflags = dvpe();
  64         printk("=== MIPS MT State Dump ===\n");
  65         printk("-- Global State --\n");
  66         printk("   MVPControl Passed: %08lx\n", mvpctl);
  67         printk("   MVPControl Read: %08lx\n", vpflags);
  68         printk("   MVPConf0 : %08lx\n", (mvpconf0 = read_c0_mvpconf0()));
  69         nvpe = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
  70         ntc = ((mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1;
  71         printk("-- per-VPE State --\n");
  72         for (i = 0; i < nvpe; i++) {
  73                 for (tc = 0; tc < ntc; tc++) {
  74                         settc(tc);
  75                         if ((read_tc_c0_tcbind() & TCBIND_CURVPE) == i) {
  76                                 printk("  VPE %d\n", i);
  77                                 printk("   VPEControl : %08lx\n",
  78                                        read_vpe_c0_vpecontrol());
  79                                 printk("   VPEConf0 : %08lx\n",
  80                                        read_vpe_c0_vpeconf0());
  81                                 printk("   VPE%d.Status : %08lx\n",
  82                                        i, read_vpe_c0_status());
  83                                 printk("   VPE%d.EPC : %08lx %pS\n",
  84                                        i, read_vpe_c0_epc(),
  85                                        (void *) read_vpe_c0_epc());
  86                                 printk("   VPE%d.Cause : %08lx\n",
  87                                        i, read_vpe_c0_cause());
  88                                 printk("   VPE%d.Config7 : %08lx\n",
  89                                        i, read_vpe_c0_config7());
  90                                 break; /* Next VPE */
  91                         }
  92                 }
  93         }
  94         printk("-- per-TC State --\n");
  95         for (tc = 0; tc < ntc; tc++) {
  96                 settc(tc);
  97                 if (read_tc_c0_tcbind() == read_c0_tcbind()) {
  98                         /* Are we dumping ourself?  */
  99                         haltval = 0; /* Then we're not halted, and mustn't be */
 100                         tcstatval = flags; /* And pre-dump TCStatus is flags */
 101                         printk("  TC %d (current TC with VPE EPC above)\n", tc);
 102                 } else {
 103                         haltval = read_tc_c0_tchalt();
 104                         write_tc_c0_tchalt(1);
 105                         tcstatval = read_tc_c0_tcstatus();
 106                         printk("  TC %d\n", tc);
 107                 }
 108                 printk("   TCStatus : %08lx\n", tcstatval);
 109                 printk("   TCBind : %08lx\n", read_tc_c0_tcbind());
 110                 printk("   TCRestart : %08lx %pS\n",
 111                        read_tc_c0_tcrestart(), (void *) read_tc_c0_tcrestart());
 112                 printk("   TCHalt : %08lx\n", haltval);
 113                 printk("   TCContext : %08lx\n", read_tc_c0_tccontext());
 114                 if (!haltval)
 115                         write_tc_c0_tchalt(0);
 116         }
 117         printk("===========================\n");
 118         evpe(vpflags);
 119         local_irq_restore(flags);
 120 }
 121
 122 static int mt_opt_norps;
 123 static int mt_opt_rpsctl = -1;
 124 static int mt_opt_nblsu = -1;
 125 static int mt_opt_forceconfig7;
 126 static int mt_opt_config7 = -1;
 127
 128 static int __init rps_disable(char *s)
 129 {
 130         mt_opt_norps = 1;
 131         return 1;
 132 }
 133 __setup("norps", rps_disable);
 134
 135 static int __init rpsctl_set(char *str)
 136 {
 137         get_option(&str, &mt_opt_rpsctl);
 138         return 1;
 139 }
 140 __setup("rpsctl=", rpsctl_set);
 141
 142 static int __init nblsu_set(char *str)
 143 {
 144         get_option(&str, &mt_opt_nblsu);
 145         return 1;
 146 }
 147 __setup("nblsu=", nblsu_set);
 148
 149 static int __init config7_set(char *str)
 150 {
 151         get_option(&str, &mt_opt_config7);
 152         mt_opt_forceconfig7 = 1;
 153         return 1;
 154 }
 155 __setup("config7=", config7_set);
 156
 157 /* Experimental cache flush control parameters that should go away some day */
 158 int mt_protiflush;
 159 int mt_protdflush;
 160 int mt_n_iflushes = 1;
 161 int mt_n_dflushes = 1;
 162
 163 static int __init set_protiflush(char *s)
 164 {
 165         mt_protiflush = 1;
 166         return 1;
 167 }
 168 __setup("protiflush", set_protiflush);
 169
 170 static int __init set_protdflush(char *s)
 171 {
 172         mt_protdflush = 1;
 173         return 1;
 174 }
 175 __setup("protdflush", set_protdflush);
 176
 177 static int __init niflush(char *s)
 178 {
 179         get_option(&s, &mt_n_iflushes);
 180         return 1;
 181 }
 182 __setup("niflush=", niflush);
 183
 184 static int __init ndflush(char *s)
 185 {
 186         get_option(&s, &mt_n_dflushes);
 187         return 1;
 188 }
 189 __setup("ndflush=", ndflush);
 190
 191 static unsigned int itc_base;
 192
 193 static int __init set_itc_base(char *str)
 194 {
 195         get_option(&str, &itc_base);
 196         return 1;
 197 }
 198
 199 __setup("itcbase=", set_itc_base);
 200
 201 void mips_mt_set_cpuoptions(void)
 202 {
 203         unsigned int oconfig7 = read_c0_config7();
 204         unsigned int nconfig7 = oconfig7;
 205
 206         if (mt_opt_norps) {
 207                 printk("\"norps\" option deprecated: use \"rpsctl=\"\n");
 208         }
 209         if (mt_opt_rpsctl >= 0) {
 210                 printk("34K return prediction stack override set to %d.\n",
 211                         mt_opt_rpsctl);
 212                 if (mt_opt_rpsctl)
 213                         nconfig7 |= (1 << 2);
 214                 else
 215                         nconfig7 &= ~(1 << 2);
 216         }
 217         if (mt_opt_nblsu >= 0) {
 218                 printk("34K ALU/LSU sync override set to %d.\n", mt_opt_nblsu);
 219                 if (mt_opt_nblsu)
 220                         nconfig7 |= (1 << 5);
 221                 else
 222                         nconfig7 &= ~(1 << 5);
 223         }
 224         if (mt_opt_forceconfig7) {
 225                 printk("CP0.Config7 forced to 0x%08x.\n", mt_opt_config7);
 226                 nconfig7 = mt_opt_config7;
 227         }
 228         if (oconfig7 != nconfig7) {
 229                 __asm__ __volatile("sync");
 230                 write_c0_config7(nconfig7);
 231                 ehb();
 232                 printk("Config7: 0x%08x\n", read_c0_config7());
 233         }
 234
 235         /* Report Cache management debug options */
 236         if (mt_protiflush)
 237                 printk("I-cache flushes single-threaded\n");
 238         if (mt_protdflush)
 239                 printk("D-cache flushes single-threaded\n");
 240         if (mt_n_iflushes != 1)
 241                 printk("I-Cache Flushes Repeated %d times\n", mt_n_iflushes);
 242         if (mt_n_dflushes != 1)
 243                 printk("D-Cache Flushes Repeated %d times\n", mt_n_dflushes);
 244
 245         if (itc_base != 0) {
 246                 /*
 247                  * Configure ITC mapping.  This code is very
 248                  * specific to the 34K core family, which uses
 249                  * a special mode bit ("ITC") in the ErrCtl
 250                  * register to enable access to ITC control
 251                  * registers via cache "tag" operations.
 252                  */
 253                 unsigned long ectlval;
 254                 unsigned long itcblkgrn;
 255
 256                 /* ErrCtl register is known as "ecc" to Linux */
 257                 ectlval = read_c0_ecc();
 258                 write_c0_ecc(ectlval | (0x1 << 26));
 259                 ehb();
 260 #define INDEX_0 (0x80000000)
 261 #define INDEX_8 (0x80000008)
 262                 /* Read "cache tag" for Dcache pseudo-index 8 */
 263                 cache_op(Index_Load_Tag_D, INDEX_8);
 264                 ehb();
 265                 itcblkgrn = read_c0_dtaglo();
 266                 itcblkgrn &= 0xfffe0000;
 267                 /* Set for 128 byte pitch of ITC cells */
 268                 itcblkgrn |= 0x00000c00;
 269                 /* Stage in Tag register */
 270                 write_c0_dtaglo(itcblkgrn);
 271                 ehb();
 272                 /* Write out to ITU with CACHE op */
 273                 cache_op(Index_Store_Tag_D, INDEX_8);
 274                 /* Now set base address, and turn ITC on with 0x1 bit */
 275                 write_c0_dtaglo((itc_base & 0xfffffc00) | 0x1 );
 276                 ehb();
 277                 /* Write out to ITU with CACHE op */
 278                 cache_op(Index_Store_Tag_D, INDEX_0);
 279                 write_c0_ecc(ectlval);
 280                 ehb();
 281                 printk("Mapped %ld ITC cells starting at 0x%08x\n",
 282                         ((itcblkgrn & 0x7fe00000) >> 20), itc_base);
 283         }
 284 }
 285
 286 /*
 287  * Function to protect cache flushes from concurrent execution
 288  * depends on MP software model chosen.
 289  */
 290
 291 void mt_cflush_lockdown(void)
 292 {
 293         /* FILL IN VSMP and AP/SP VERSIONS HERE */
 294 }
 295
 296 void mt_cflush_release(void)
 297 {
 298         /* FILL IN VSMP and AP/SP VERSIONS HERE */
 299 }
 300
 301 struct class *mt_class;
 302
 303 static int __init mt_init(void)
 304 {
 305         struct class *mtc;
 306
 307         mtc = class_create(THIS_MODULE, "mt");
 308         if (IS_ERR(mtc))
 309                 return PTR_ERR(mtc);
 310
 311         mt_class = mtc;
 312
 313         return 0;
 314 }
 315
 316 subsys_initcall(mt_init);