arch/mips/kernel/smp-mt.c

   1 /*
   2  *  This program is free software; you can distribute it and/or modify it
   3  *  under the terms of the GNU General Public License (Version 2) as
   4  *  published by the Free Software Foundation.
   5  *
   6  *  This program is distributed in the hope it will be useful, but WITHOUT
   7  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   8  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   9  *  for more details.
  10  *
  11  *  You should have received a copy of the GNU General Public License along
  12  *  with this program; if not, write to the Free Software Foundation, Inc.,
  13  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  14  *
  15  * Copyright (C) 2004, 05, 06 MIPS Technologies, Inc.
  16  *    Elizabeth Clarke (beth@mips.com)
  17  *    Ralf Baechle (ralf@linux-mips.org)
  18  * Copyright (C) 2006 Ralf Baechle (ralf@linux-mips.org)
  19  */
  20 #include <linux/kernel.h>
  21 #include <linux/sched.h>
  22 #include <linux/cpumask.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/compiler.h>
  25
  26 #include <asm/atomic.h>
  27 #include <asm/cacheflush.h>
  28 #include <asm/cpu.h>
  29 #include <asm/processor.h>
  30 #include <asm/system.h>
  31 #include <asm/hardirq.h>
  32 #include <asm/mmu_context.h>
  33 #include <asm/smp.h>
  34 #include <asm/time.h>
  35 #include <asm/mipsregs.h>
  36 #include <asm/mipsmtregs.h>
  37 #include <asm/mips_mt.h>
  38 #include <asm/mips-boards/maltaint.h>  /* This is f*cking wrong */
  39
  40 #define MIPS_CPU_IPI_RESCHED_IRQ 0
  41 #define MIPS_CPU_IPI_CALL_IRQ 1
  42
  43 static int cpu_ipi_resched_irq, cpu_ipi_call_irq;
  44
  45 #if 0
  46 static void dump_mtregisters(int vpe, int tc)
  47 {
  48         printk("vpe %d tc %d\n", vpe, tc);
  49
  50         settc(tc);
  51
  52         printk("  c0 status  0x%lx\n", read_vpe_c0_status());
  53         printk("  vpecontrol 0x%lx\n", read_vpe_c0_vpecontrol());
  54         printk("  vpeconf0    0x%lx\n", read_vpe_c0_vpeconf0());
  55         printk("  tcstatus 0x%lx\n", read_tc_c0_tcstatus());
  56         printk("  tcrestart 0x%lx\n", read_tc_c0_tcrestart());
  57         printk("  tcbind 0x%lx\n", read_tc_c0_tcbind());
  58         printk("  tchalt 0x%lx\n", read_tc_c0_tchalt());
  59 }
  60 #endif
  61
  62 void __init sanitize_tlb_entries(void)
  63 {
  64         int i, tlbsiz;
  65         unsigned long mvpconf0, ncpu;
  66
  67         if (!cpu_has_mipsmt)
  68                 return;
  69
  70         /* Enable VPC */
  71         set_c0_mvpcontrol(MVPCONTROL_VPC);
  72
  73         back_to_back_c0_hazard();
  74
  75         /* Disable TLB sharing */
  76         clear_c0_mvpcontrol(MVPCONTROL_STLB);
  77
  78         mvpconf0 = read_c0_mvpconf0();
  79
  80         printk(KERN_INFO "MVPConf0 0x%lx TLBS %lx PTLBE %ld\n", mvpconf0,
  81                    (mvpconf0 & MVPCONF0_TLBS) >> MVPCONF0_TLBS_SHIFT,
  82                            (mvpconf0 & MVPCONF0_PTLBE) >> MVPCONF0_PTLBE_SHIFT);
  83
  84         tlbsiz = (mvpconf0 & MVPCONF0_PTLBE) >> MVPCONF0_PTLBE_SHIFT;
  85         ncpu = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
  86
  87         printk(" tlbsiz %d ncpu %ld\n", tlbsiz, ncpu);
  88
  89         if (tlbsiz > 0) {
  90                 /* share them out across the vpe's */
  91                 tlbsiz /= ncpu;
  92
  93                 printk(KERN_INFO "setting Config1.MMU_size to %d\n", tlbsiz);
  94
  95                 for (i = 0; i < ncpu; i++) {
  96                         settc(i);
  97
  98                         if (i == 0)
  99                                 write_c0_config1((read_c0_config1() & ~(0x3f << 25)) | (tlbsiz << 25));
 100                         else
 101                                 write_vpe_c0_config1((read_vpe_c0_config1() & ~(0x3f << 25)) |
 102                                                    (tlbsiz << 25));
 103                 }
 104         }
 105
 106         clear_c0_mvpcontrol(MVPCONTROL_VPC);
 107 }
 108
 109 static void ipi_resched_dispatch(void)
 110 {
 111         do_IRQ(MIPSCPU_INT_BASE + MIPS_CPU_IPI_RESCHED_IRQ);
 112 }
 113
 114 static void ipi_call_dispatch(void)
 115 {
 116         do_IRQ(MIPSCPU_INT_BASE + MIPS_CPU_IPI_CALL_IRQ);
 117 }
 118
 119 static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
 120 {
 121         return IRQ_HANDLED;
 122 }
 123
 124 static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
 125 {
 126         smp_call_function_interrupt();
 127
 128         return IRQ_HANDLED;
 129 }
 130
 131 static struct irqaction irq_resched = {
 132         .handler        = ipi_resched_interrupt,
 133         .flags          = IRQF_DISABLED,
 134         .name           = "IPI_resched"
 135 };
 136
 137 static struct irqaction irq_call = {
 138         .handler        = ipi_call_interrupt,
 139         .flags          = IRQF_DISABLED,
 140         .name           = "IPI_call"
 141 };
 142
 143 static void __init smp_copy_vpe_config(void)
 144 {
 145         write_vpe_c0_status(
 146                 (read_c0_status() & ~(ST0_IM | ST0_IE | ST0_KSU)) | ST0_CU0);
 147
 148         /* set config to be the same as vpe0, particularly kseg0 coherency alg */
 149         write_vpe_c0_config( read_c0_config());
 150
 151         /* make sure there are no software interrupts pending */
 152         write_vpe_c0_cause(0);
 153
 154         /* Propagate Config7 */
 155         write_vpe_c0_config7(read_c0_config7());
 156
 157         write_vpe_c0_count(read_c0_count());
 158 }
 159
 160 static unsigned int __init smp_vpe_init(unsigned int tc, unsigned int mvpconf0,
 161         unsigned int ncpu)
 162 {
 163         if (tc > ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT))
 164                 return ncpu;
 165
 166         /* Deactivate all but VPE 0 */
 167         if (tc != 0) {
 168                 unsigned long tmp = read_vpe_c0_vpeconf0();
 169
 170                 tmp &= ~VPECONF0_VPA;
 171
 172                 /* master VPE */
 173                 tmp |= VPECONF0_MVP;
 174                 write_vpe_c0_vpeconf0(tmp);
 175
 176                 /* Record this as available CPU */
 177                 cpu_set(tc, phys_cpu_present_map);
 178                 __cpu_number_map[tc]    = ++ncpu;
 179                 __cpu_logical_map[ncpu] = tc;
 180         }
 181
 182         /* Disable multi-threading with TC's */
 183         write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
 184
 185         if (tc != 0)
 186                 smp_copy_vpe_config();
 187
 188         return ncpu;
 189 }
 190
 191 static void __init smp_tc_init(unsigned int tc, unsigned int mvpconf0)
 192 {
 193         unsigned long tmp;
 194
 195         if (!tc)
 196                 return;
 197
 198         /* bind a TC to each VPE, May as well put all excess TC's
 199            on the last VPE */
 200         if (tc >= (((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)+1))
 201                 write_tc_c0_tcbind(read_tc_c0_tcbind() | ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT));
 202         else {
 203                 write_tc_c0_tcbind(read_tc_c0_tcbind() | tc);
 204
 205                 /* and set XTC */
 206                 write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | (tc << VPECONF0_XTC_SHIFT));
 207         }
 208
 209         tmp = read_tc_c0_tcstatus();
 210
 211         /* mark not allocated and not dynamically allocatable */
 212         tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
 213         tmp |= TCSTATUS_IXMT;           /* interrupt exempt */
 214         write_tc_c0_tcstatus(tmp);
 215
 216         write_tc_c0_tchalt(TCHALT_H);
 217 }
 218
 219 /*
 220  * Common setup before any secondaries are started
 221  * Make sure all CPU's are in a sensible state before we boot any of the
 222  * secondarys
 223  */
 224 void __init plat_smp_setup(void)
 225 {
 226         unsigned int mvpconf0, ntc, tc, ncpu = 0;
 227
 228 #ifdef CONFIG_MIPS_MT_FPAFF
 229         /* If we have an FPU, enroll ourselves in the FPU-full mask */
 230         if (cpu_has_fpu)
 231                 cpu_set(0, mt_fpu_cpumask);
 232 #endif /* CONFIG_MIPS_MT_FPAFF */
 233         if (!cpu_has_mipsmt)
 234                 return;
 235
 236         /* disable MT so we can configure */
 237         dvpe();
 238         dmt();
 239
 240         mips_mt_set_cpuoptions();
 241
 242         /* Put MVPE's into 'configuration state' */
 243         set_c0_mvpcontrol(MVPCONTROL_VPC);
 244
 245         mvpconf0 = read_c0_mvpconf0();
 246         ntc = (mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT;
 247
 248         /* we'll always have more TC's than VPE's, so loop setting everything
 249            to a sensible state */
 250         for (tc = 0; tc <= ntc; tc++) {
 251                 settc(tc);
 252
 253                 smp_tc_init(tc, mvpconf0);
 254                 ncpu = smp_vpe_init(tc, mvpconf0, ncpu);
 255         }
 256
 257         /* Release config state */
 258         clear_c0_mvpcontrol(MVPCONTROL_VPC);
 259
 260         /* We'll wait until starting the secondaries before starting MVPE */
 261
 262         printk(KERN_INFO "Detected %i available secondary CPU(s)\n", ncpu);
 263 }
 264
 265 void __init plat_prepare_cpus(unsigned int max_cpus)
 266 {
 267         /* set up ipi interrupts */
 268         if (cpu_has_vint) {
 269                 set_vi_handler(MIPS_CPU_IPI_RESCHED_IRQ, ipi_resched_dispatch);
 270                 set_vi_handler(MIPS_CPU_IPI_CALL_IRQ, ipi_call_dispatch);
 271         }
 272
 273         cpu_ipi_resched_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_RESCHED_IRQ;
 274         cpu_ipi_call_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_CALL_IRQ;
 275
 276         setup_irq(cpu_ipi_resched_irq, &irq_resched);
 277         setup_irq(cpu_ipi_call_irq, &irq_call);
 278
 279         /* need to mark IPI's as IRQ_PER_CPU */
 280         irq_desc[cpu_ipi_resched_irq].status |= IRQ_PER_CPU;
 281         set_irq_handler(cpu_ipi_resched_irq, handle_percpu_irq);
 282         irq_desc[cpu_ipi_call_irq].status |= IRQ_PER_CPU;
 283         set_irq_handler(cpu_ipi_call_irq, handle_percpu_irq);
 284 }
 285
 286 /*
 287  * Setup the PC, SP, and GP of a secondary processor and start it
 288  * running!
 289  * smp_bootstrap is the place to resume from
 290  * __KSTK_TOS(idle) is apparently the stack pointer
 291  * (unsigned long)idle->thread_info the gp
 292  * assumes a 1:1 mapping of TC => VPE
 293  */
 294 void prom_boot_secondary(int cpu, struct task_struct *idle)
 295 {
 296         struct thread_info *gp = task_thread_info(idle);
 297         dvpe();
 298         set_c0_mvpcontrol(MVPCONTROL_VPC);
 299
 300         settc(cpu);
 301
 302         /* restart */
 303         write_tc_c0_tcrestart((unsigned long)&smp_bootstrap);
 304
 305         /* enable the tc this vpe/cpu will be running */
 306         write_tc_c0_tcstatus((read_tc_c0_tcstatus() & ~TCSTATUS_IXMT) | TCSTATUS_A);
 307
 308         write_tc_c0_tchalt(0);
 309
 310         /* enable the VPE */
 311         write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
 312
 313         /* stack pointer */
 314         write_tc_gpr_sp( __KSTK_TOS(idle));
 315
 316         /* global pointer */
 317         write_tc_gpr_gp((unsigned long)gp);
 318
 319         flush_icache_range((unsigned long)gp,
 320                            (unsigned long)(gp + sizeof(struct thread_info)));
 321
 322         /* finally out of configuration and into chaos */
 323         clear_c0_mvpcontrol(MVPCONTROL_VPC);
 324
 325         evpe(EVPE_ENABLE);
 326 }
 327
 328 void prom_init_secondary(void)
 329 {
 330         write_c0_status((read_c0_status() & ~ST0_IM ) |
 331                         (STATUSF_IP0 | STATUSF_IP1 | STATUSF_IP7));
 332 }
 333
 334 void prom_smp_finish(void)
 335 {
 336         write_c0_compare(read_c0_count() + (8* mips_hpt_frequency/HZ));
 337
 338 #ifdef CONFIG_MIPS_MT_FPAFF
 339         /* If we have an FPU, enroll ourselves in the FPU-full mask */
 340         if (cpu_has_fpu)
 341                 cpu_set(smp_processor_id(), mt_fpu_cpumask);
 342 #endif /* CONFIG_MIPS_MT_FPAFF */
 343
 344         local_irq_enable();
 345 }
 346
 347 void prom_cpus_done(void)
 348 {
 349 }
 350
 351 void core_send_ipi(int cpu, unsigned int action)
 352 {
 353         int i;
 354         unsigned long flags;
 355         int vpflags;
 356
 357         local_irq_save (flags);
 358
 359         vpflags = dvpe();       /* cant access the other CPU's registers whilst MVPE enabled */
 360
 361         switch (action) {
 362         case SMP_CALL_FUNCTION:
 363                 i = C_SW1;
 364                 break;
 365
 366         case SMP_RESCHEDULE_YOURSELF:
 367         default:
 368                 i = C_SW0;
 369                 break;
 370         }
 371
 372         /* 1:1 mapping of vpe and tc... */
 373         settc(cpu);
 374         write_vpe_c0_cause(read_vpe_c0_cause() | i);
 375         evpe(vpflags);
 376
 377         local_irq_restore(flags);
 378 }