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 (struct pt_regs *regs)
 110 {
 111         do_IRQ(MIPSCPU_INT_BASE + MIPS_CPU_IPI_RESCHED_IRQ, regs);
 112 }
 113
 114 static void ipi_call_dispatch (struct pt_regs *regs)
 115 {
 116         do_IRQ(MIPSCPU_INT_BASE + MIPS_CPU_IPI_CALL_IRQ, regs);
 117 }
 118
 119 irqreturn_t ipi_resched_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 120 {
 121         return IRQ_HANDLED;
 122 }
 123
 124 irqreturn_t ipi_call_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 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          = SA_INTERRUPT,
 134         .name           = "IPI_resched"
 135 };
 136
 137 static struct irqaction irq_call = {
 138         .handler        = ipi_call_interrupt,
 139         .flags          = SA_INTERRUPT,
 140         .name           = "IPI_call"
 141 };
 142
 143 /*
 144  * Common setup before any secondaries are started
 145  * Make sure all CPU's are in a sensible state before we boot any of the
 146  * secondarys
 147  */
 148 void plat_smp_setup(void)
 149 {
 150         unsigned long val;
 151         int i, num;
 152
 153         if (!cpu_has_mipsmt)
 154                 return;
 155
 156         /* disable MT so we can configure */
 157         dvpe();
 158         dmt();
 159
 160         mips_mt_set_cpuoptions();
 161
 162         /* Put MVPE's into 'configuration state' */
 163         set_c0_mvpcontrol(MVPCONTROL_VPC);
 164
 165         val = read_c0_mvpconf0();
 166
 167         /* we'll always have more TC's than VPE's, so loop setting everything
 168            to a sensible state */
 169         for (i = 0, num = 0; i <= ((val & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT); i++) {
 170                 settc(i);
 171
 172                 /* VPE's */
 173                 if (i <= ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)) {
 174
 175                         /* deactivate all but vpe0 */
 176                         if (i != 0) {
 177                                 unsigned long tmp = read_vpe_c0_vpeconf0();
 178
 179                                 tmp &= ~VPECONF0_VPA;
 180
 181                                 /* master VPE */
 182                                 tmp |= VPECONF0_MVP;
 183                                 write_vpe_c0_vpeconf0(tmp);
 184
 185                                 /* Record this as available CPU */
 186                                 cpu_set(i, phys_cpu_present_map);
 187                                 __cpu_number_map[i]     = ++num;
 188                                 __cpu_logical_map[num]  = i;
 189                         }
 190
 191                         /* disable multi-threading with TC's */
 192                         write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
 193
 194                         if (i != 0) {
 195                                 write_vpe_c0_status((read_c0_status() & ~(ST0_IM | ST0_IE | ST0_KSU)) | ST0_CU0);
 196
 197                                 /* set config to be the same as vpe0, particularly kseg0 coherency alg */
 198                                 write_vpe_c0_config( read_c0_config());
 199
 200                                 /* make sure there are no software interrupts pending */
 201                                 write_vpe_c0_cause(read_vpe_c0_cause() & ~(C_SW1|C_SW0));
 202
 203                                 /* Propagate Config7 */
 204                                 write_vpe_c0_config7(read_c0_config7());
 205                         }
 206
 207                 }
 208
 209                 /* TC's */
 210
 211                 if (i != 0) {
 212                         unsigned long tmp;
 213
 214                         /* bind a TC to each VPE, May as well put all excess TC's
 215                            on the last VPE */
 216                         if ( i >= (((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)+1) )
 217                                 write_tc_c0_tcbind(read_tc_c0_tcbind() | ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) );
 218                         else {
 219                                 write_tc_c0_tcbind( read_tc_c0_tcbind() | i);
 220
 221                                 /* and set XTC */
 222                                 write_vpe_c0_vpeconf0( read_vpe_c0_vpeconf0() | (i << VPECONF0_XTC_SHIFT));
 223                         }
 224
 225                         tmp = read_tc_c0_tcstatus();
 226
 227                         /* mark not allocated and not dynamically allocatable */
 228                         tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
 229                         tmp |= TCSTATUS_IXMT;           /* interrupt exempt */
 230                         write_tc_c0_tcstatus(tmp);
 231
 232                         write_tc_c0_tchalt(TCHALT_H);
 233                 }
 234         }
 235
 236         /* Release config state */
 237         clear_c0_mvpcontrol(MVPCONTROL_VPC);
 238
 239         /* We'll wait until starting the secondaries before starting MVPE */
 240
 241         printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
 242 }
 243
 244 void __init plat_prepare_cpus(unsigned int max_cpus)
 245 {
 246         /* set up ipi interrupts */
 247         if (cpu_has_vint) {
 248                 set_vi_handler (MIPS_CPU_IPI_RESCHED_IRQ, ipi_resched_dispatch);
 249                 set_vi_handler (MIPS_CPU_IPI_CALL_IRQ, ipi_call_dispatch);
 250         }
 251
 252         cpu_ipi_resched_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_RESCHED_IRQ;
 253         cpu_ipi_call_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_CALL_IRQ;
 254
 255         setup_irq(cpu_ipi_resched_irq, &irq_resched);
 256         setup_irq(cpu_ipi_call_irq, &irq_call);
 257
 258         /* need to mark IPI's as IRQ_PER_CPU */
 259         irq_desc[cpu_ipi_resched_irq].status |= IRQ_PER_CPU;
 260         irq_desc[cpu_ipi_call_irq].status |= IRQ_PER_CPU;
 261 }
 262
 263 /*
 264  * Setup the PC, SP, and GP of a secondary processor and start it
 265  * running!
 266  * smp_bootstrap is the place to resume from
 267  * __KSTK_TOS(idle) is apparently the stack pointer
 268  * (unsigned long)idle->thread_info the gp
 269  * assumes a 1:1 mapping of TC => VPE
 270  */
 271 void prom_boot_secondary(int cpu, struct task_struct *idle)
 272 {
 273         struct thread_info *gp = task_thread_info(idle);
 274         dvpe();
 275         set_c0_mvpcontrol(MVPCONTROL_VPC);
 276
 277         settc(cpu);
 278
 279         /* restart */
 280         write_tc_c0_tcrestart((unsigned long)&smp_bootstrap);
 281
 282         /* enable the tc this vpe/cpu will be running */
 283         write_tc_c0_tcstatus((read_tc_c0_tcstatus() & ~TCSTATUS_IXMT) | TCSTATUS_A);
 284
 285         write_tc_c0_tchalt(0);
 286
 287         /* enable the VPE */
 288         write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
 289
 290         /* stack pointer */
 291         write_tc_gpr_sp( __KSTK_TOS(idle));
 292
 293         /* global pointer */
 294         write_tc_gpr_gp((unsigned long)gp);
 295
 296         flush_icache_range((unsigned long)gp,
 297                            (unsigned long)(gp + sizeof(struct thread_info)));
 298
 299         /* finally out of configuration and into chaos */
 300         clear_c0_mvpcontrol(MVPCONTROL_VPC);
 301
 302         evpe(EVPE_ENABLE);
 303 }
 304
 305 void prom_init_secondary(void)
 306 {
 307         write_c0_status((read_c0_status() & ~ST0_IM ) |
 308                         (STATUSF_IP0 | STATUSF_IP1 | STATUSF_IP7));
 309 }
 310
 311 void prom_smp_finish(void)
 312 {
 313         write_c0_compare(read_c0_count() + (8* mips_hpt_frequency/HZ));
 314
 315         local_irq_enable();
 316 }
 317
 318 void prom_cpus_done(void)
 319 {
 320 }
 321
 322 void core_send_ipi(int cpu, unsigned int action)
 323 {
 324         int i;
 325         unsigned long flags;
 326         int vpflags;
 327
 328         local_irq_save (flags);
 329
 330         vpflags = dvpe();       /* cant access the other CPU's registers whilst MVPE enabled */
 331
 332         switch (action) {
 333         case SMP_CALL_FUNCTION:
 334                 i = C_SW1;
 335                 break;
 336
 337         case SMP_RESCHEDULE_YOURSELF:
 338         default:
 339                 i = C_SW0;
 340                 break;
 341         }
 342
 343         /* 1:1 mapping of vpe and tc... */
 344         settc(cpu);
 345         write_vpe_c0_cause(read_vpe_c0_cause() | i);
 346         evpe(vpflags);
 347
 348         local_irq_restore(flags);
 349 }