arch/mips/kernel/smp_mt.c

   1 /*
   2  * Copyright (C) 2004, 2005 MIPS Technologies, Inc.  All rights reserved.
   3  *
   4  *  Elizabeth Clarke (beth@mips.com)
   5  *
   6  *  This program is free software; you can distribute it and/or modify it
   7  *  under the terms of the GNU General Public License (Version 2) as
   8  *  published by the Free Software Foundation.
   9  *
  10  *  This program is distributed in the hope it will be useful, but WITHOUT
  11  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  *  for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License along
  16  *  with this program; if not, write to the Free Software Foundation, Inc.,
  17  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  18  *
  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/cpu.h>
  28 #include <asm/processor.h>
  29 #include <asm/system.h>
  30 #include <asm/hardirq.h>
  31 #include <asm/mmu_context.h>
  32 #include <asm/smp.h>
  33 #include <asm/time.h>
  34 #include <asm/mipsregs.h>
  35 #include <asm/mipsmtregs.h>
  36 #include <asm/cacheflush.h>
  37 #include <asm/mips-boards/maltaint.h>
  38
  39 #define MIPS_CPU_IPI_RESCHED_IRQ 0
  40 #define MIPS_CPU_IPI_CALL_IRQ 1
  41
  42 static int cpu_ipi_resched_irq, cpu_ipi_call_irq;
  43
  44 #if 0
  45 static void dump_mtregisters(int vpe, int tc)
  46 {
  47         printk("vpe %d tc %d\n", vpe, tc);
  48
  49         settc(tc);
  50
  51         printk("  c0 status  0x%lx\n", read_vpe_c0_status());
  52         printk("  vpecontrol 0x%lx\n", read_vpe_c0_vpecontrol());
  53         printk("  vpeconf0    0x%lx\n", read_vpe_c0_vpeconf0());
  54         printk("  tcstatus 0x%lx\n", read_tc_c0_tcstatus());
  55         printk("  tcrestart 0x%lx\n", read_tc_c0_tcrestart());
  56         printk("  tcbind 0x%lx\n", read_tc_c0_tcbind());
  57         printk("  tchalt 0x%lx\n", read_tc_c0_tchalt());
  58 }
  59 #endif
  60
  61 void __init sanitize_tlb_entries(void)
  62 {
  63         int i, tlbsiz;
  64         unsigned long mvpconf0, ncpu;
  65
  66         if (!cpu_has_mipsmt)
  67                 return;
  68
  69         set_c0_mvpcontrol(MVPCONTROL_VPC);
  70
  71         back_to_back_c0_hazard();
  72
  73         /* Disable TLB sharing */
  74         clear_c0_mvpcontrol(MVPCONTROL_STLB);
  75
  76         mvpconf0 = read_c0_mvpconf0();
  77
  78         printk(KERN_INFO "MVPConf0 0x%lx TLBS %lx PTLBE %ld\n", mvpconf0,
  79                    (mvpconf0 & MVPCONF0_TLBS) >> MVPCONF0_TLBS_SHIFT,
  80                            (mvpconf0 & MVPCONF0_PTLBE) >> MVPCONF0_PTLBE_SHIFT);
  81
  82         tlbsiz = (mvpconf0 & MVPCONF0_PTLBE) >> MVPCONF0_PTLBE_SHIFT;
  83         ncpu = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
  84
  85         printk(" tlbsiz %d ncpu %ld\n", tlbsiz, ncpu);
  86
  87         if (tlbsiz > 0) {
  88                 /* share them out across the vpe's */
  89                 tlbsiz /= ncpu;
  90
  91                 printk(KERN_INFO "setting Config1.MMU_size to %d\n", tlbsiz);
  92
  93                 for (i = 0; i < ncpu; i++) {
  94                         settc(i);
  95
  96                         if (i == 0)
  97                                 write_c0_config1((read_c0_config1() & ~(0x3f << 25)) | (tlbsiz << 25));
  98                         else
  99                                 write_vpe_c0_config1((read_vpe_c0_config1() & ~(0x3f << 25)) |
 100                                                    (tlbsiz << 25));
 101                 }
 102         }
 103
 104         clear_c0_mvpcontrol(MVPCONTROL_VPC);
 105 }
 106
 107 static void ipi_resched_dispatch (struct pt_regs *regs)
 108 {
 109         do_IRQ(MIPS_CPU_IPI_RESCHED_IRQ, regs);
 110 }
 111
 112 static void ipi_call_dispatch (struct pt_regs *regs)
 113 {
 114         do_IRQ(MIPS_CPU_IPI_CALL_IRQ, regs);
 115 }
 116
 117 irqreturn_t ipi_resched_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 118 {
 119         return IRQ_HANDLED;
 120 }
 121
 122 irqreturn_t ipi_call_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 123 {
 124         smp_call_function_interrupt();
 125
 126         return IRQ_HANDLED;
 127 }
 128
 129 static struct irqaction irq_resched = {
 130         .handler        = ipi_resched_interrupt,
 131         .flags          = SA_INTERRUPT,
 132         .name           = "IPI_resched"
 133 };
 134
 135 static struct irqaction irq_call = {
 136         .handler        = ipi_call_interrupt,
 137         .flags          = SA_INTERRUPT,
 138         .name           = "IPI_call"
 139 };
 140
 141 /*
 142  * Common setup before any secondaries are started
 143  * Make sure all CPU's are in a sensible state before we boot any of the
 144  * secondarys
 145  */
 146 void prom_prepare_cpus(unsigned int max_cpus)
 147 {
 148         unsigned long val;
 149         int i, num;
 150
 151         if (!cpu_has_mipsmt)
 152                 return;
 153
 154         /* disable MT so we can configure */
 155         dvpe();
 156         dmt();
 157
 158         /* Put MVPE's into 'configuration state' */
 159         set_c0_mvpcontrol(MVPCONTROL_VPC);
 160
 161         val = read_c0_mvpconf0();
 162
 163         /* we'll always have more TC's than VPE's, so loop setting everything
 164            to a sensible state */
 165         for (i = 0, num = 0; i <= ((val & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT); i++) {
 166                 settc(i);
 167
 168                 /* VPE's */
 169                 if (i <= ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)) {
 170
 171                         /* deactivate all but vpe0 */
 172                         if (i != 0) {
 173                                 unsigned long tmp = read_vpe_c0_vpeconf0();
 174
 175                                 tmp &= ~VPECONF0_VPA;
 176
 177                                 /* master VPE */
 178                                 tmp |= VPECONF0_MVP;
 179                                 write_vpe_c0_vpeconf0(tmp);
 180
 181                                 /* Record this as available CPU */
 182                                 if (i < max_cpus) {
 183                                         cpu_set(i, phys_cpu_present_map);
 184                                         __cpu_number_map[i]     = ++num;
 185                                         __cpu_logical_map[num]  = i;
 186                                 }
 187                         }
 188
 189                         /* disable multi-threading with TC's */
 190                         write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
 191
 192                         if (i != 0) {
 193                                 write_vpe_c0_status((read_c0_status() & ~(ST0_IM | ST0_IE | ST0_KSU)) | ST0_CU0);
 194                                 write_vpe_c0_cause(read_vpe_c0_cause() & ~CAUSEF_IP);
 195
 196                                 /* set config to be the same as vpe0, particularly kseg0 coherency alg */
 197                                 write_vpe_c0_config( read_c0_config());
 198
 199                                 /* Propagate Config7 */
 200                                 write_vpe_c0_config7(read_c0_config7());
 201                         }
 202
 203                 }
 204
 205                 /* TC's */
 206
 207                 if (i != 0) {
 208                         unsigned long tmp;
 209
 210                         /* bind a TC to each VPE, May as well put all excess TC's
 211                            on the last VPE */
 212                         if ( i >= (((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)+1) )
 213                                 write_tc_c0_tcbind(read_tc_c0_tcbind() | ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) );
 214                         else {
 215                                 write_tc_c0_tcbind( read_tc_c0_tcbind() | i);
 216
 217                                 /* and set XTC */
 218                                 write_vpe_c0_vpeconf0( read_vpe_c0_vpeconf0() | (i << VPECONF0_XTC_SHIFT));
 219                         }
 220
 221                         tmp = read_tc_c0_tcstatus();
 222
 223                         /* mark not allocated and not dynamically allocatable */
 224                         tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
 225                         tmp |= TCSTATUS_IXMT;           /* interrupt exempt */
 226                         write_tc_c0_tcstatus(tmp);
 227
 228                         write_tc_c0_tchalt(TCHALT_H);
 229                 }
 230         }
 231
 232         /* Release config state */
 233         clear_c0_mvpcontrol(MVPCONTROL_VPC);
 234
 235         /* We'll wait until starting the secondaries before starting MVPE */
 236
 237         printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
 238
 239         /* set up ipi interrupts */
 240         if (cpu_has_vint) {
 241                 set_vi_handler (MIPS_CPU_IPI_RESCHED_IRQ, ipi_resched_dispatch);
 242                 set_vi_handler (MIPS_CPU_IPI_CALL_IRQ, ipi_call_dispatch);
 243         }
 244
 245         cpu_ipi_resched_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_RESCHED_IRQ;
 246         cpu_ipi_call_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_CALL_IRQ;
 247
 248         setup_irq(cpu_ipi_resched_irq, &irq_resched);
 249         setup_irq(cpu_ipi_call_irq, &irq_call);
 250
 251         /* need to mark IPI's as IRQ_PER_CPU */
 252         irq_desc[cpu_ipi_resched_irq].status |= IRQ_PER_CPU;
 253         irq_desc[cpu_ipi_call_irq].status |= IRQ_PER_CPU;
 254 }
 255
 256 /*
 257  * Setup the PC, SP, and GP of a secondary processor and start it
 258  * running!
 259  * smp_bootstrap is the place to resume from
 260  * __KSTK_TOS(idle) is apparently the stack pointer
 261  * (unsigned long)idle->thread_info the gp
 262  * assumes a 1:1 mapping of TC => VPE
 263  */
 264 void prom_boot_secondary(int cpu, struct task_struct *idle)
 265 {
 266         struct thread_info *gp = task_thread_info(idle);
 267         dvpe();
 268         set_c0_mvpcontrol(MVPCONTROL_VPC);
 269
 270         settc(cpu);
 271
 272         /* restart */
 273         write_tc_c0_tcrestart((unsigned long)&smp_bootstrap);
 274
 275         /* enable the tc this vpe/cpu will be running */
 276         write_tc_c0_tcstatus((read_tc_c0_tcstatus() & ~TCSTATUS_IXMT) | TCSTATUS_A);
 277
 278         write_tc_c0_tchalt(0);
 279
 280         /* enable the VPE */
 281         write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
 282
 283         /* stack pointer */
 284         write_tc_gpr_sp( __KSTK_TOS(idle));
 285
 286         /* global pointer */
 287         write_tc_gpr_gp((unsigned long)gp);
 288
 289         flush_icache_range((unsigned long)gp, (unsigned long)(gp + 1));
 290
 291         /* finally out of configuration and into chaos */
 292         clear_c0_mvpcontrol(MVPCONTROL_VPC);
 293
 294         evpe(EVPE_ENABLE);
 295 }
 296
 297 void prom_init_secondary(void)
 298 {
 299         write_c0_status((read_c0_status() & ~ST0_IM ) |
 300                         (STATUSF_IP0 | STATUSF_IP1 | STATUSF_IP7));
 301 }
 302
 303 void prom_smp_finish(void)
 304 {
 305         write_c0_compare(read_c0_count() + (8* mips_hpt_frequency/HZ));
 306
 307         local_irq_enable();
 308 }
 309
 310 void prom_cpus_done(void)
 311 {
 312 }
 313
 314 void core_send_ipi(int cpu, unsigned int action)
 315 {
 316         int i;
 317         unsigned long flags;
 318         int vpflags;
 319
 320         local_irq_save (flags);
 321
 322         vpflags = dvpe();       /* cant access the other CPU's registers whilst MVPE enabled */
 323
 324         switch (action) {
 325         case SMP_CALL_FUNCTION:
 326                 i = C_SW1;
 327                 break;
 328
 329         case SMP_RESCHEDULE_YOURSELF:
 330         default:
 331                 i = C_SW0;
 332                 break;
 333         }
 334
 335         /* 1:1 mapping of vpe and tc... */
 336         settc(cpu);
 337         write_vpe_c0_cause(read_vpe_c0_cause() | i);
 338         evpe(vpflags);
 339
 340         local_irq_restore(flags);
 341 }