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          = 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 /*
 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 #ifdef CONFIG_MIPS_MT_FPAFF
 154         /* If we have an FPU, enroll ourselves in the FPU-full mask */
 155         if (cpu_has_fpu)
 156                 cpu_set(0, mt_fpu_cpumask);
 157 #endif /* CONFIG_MIPS_MT_FPAFF */
 158         if (!cpu_has_mipsmt)
 159                 return;
 160
 161         /* disable MT so we can configure */
 162         dvpe();
 163         dmt();
 164
 165         mips_mt_set_cpuoptions();
 166
 167         /* Put MVPE's into 'configuration state' */
 168         set_c0_mvpcontrol(MVPCONTROL_VPC);
 169
 170         val = read_c0_mvpconf0();
 171
 172         /* we'll always have more TC's than VPE's, so loop setting everything
 173            to a sensible state */
 174         for (i = 0, num = 0; i <= ((val & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT); i++) {
 175                 settc(i);
 176
 177                 /* VPE's */
 178                 if (i <= ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)) {
 179
 180                         /* deactivate all but vpe0 */
 181                         if (i != 0) {
 182                                 unsigned long tmp = read_vpe_c0_vpeconf0();
 183
 184                                 tmp &= ~VPECONF0_VPA;
 185
 186                                 /* master VPE */
 187                                 tmp |= VPECONF0_MVP;
 188                                 write_vpe_c0_vpeconf0(tmp);
 189
 190                                 /* Record this as available CPU */
 191                                 cpu_set(i, phys_cpu_present_map);
 192                                 __cpu_number_map[i]     = ++num;
 193                                 __cpu_logical_map[num]  = i;
 194                         }
 195
 196                         /* disable multi-threading with TC's */
 197                         write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
 198
 199                         if (i != 0) {
 200                                 write_vpe_c0_status((read_c0_status() & ~(ST0_IM | ST0_IE | ST0_KSU)) | ST0_CU0);
 201
 202                                 /* set config to be the same as vpe0, particularly kseg0 coherency alg */
 203                                 write_vpe_c0_config( read_c0_config());
 204
 205                                 /* make sure there are no software interrupts pending */
 206                                 write_vpe_c0_cause(0);
 207
 208                                 /* Propagate Config7 */
 209                                 write_vpe_c0_config7(read_c0_config7());
 210                         }
 211
 212                 }
 213
 214                 /* TC's */
 215
 216                 if (i != 0) {
 217                         unsigned long tmp;
 218
 219                         /* bind a TC to each VPE, May as well put all excess TC's
 220                            on the last VPE */
 221                         if ( i >= (((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)+1) )
 222                                 write_tc_c0_tcbind(read_tc_c0_tcbind() | ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) );
 223                         else {
 224                                 write_tc_c0_tcbind( read_tc_c0_tcbind() | i);
 225
 226                                 /* and set XTC */
 227                                 write_vpe_c0_vpeconf0( read_vpe_c0_vpeconf0() | (i << VPECONF0_XTC_SHIFT));
 228                         }
 229
 230                         tmp = read_tc_c0_tcstatus();
 231
 232                         /* mark not allocated and not dynamically allocatable */
 233                         tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
 234                         tmp |= TCSTATUS_IXMT;           /* interrupt exempt */
 235                         write_tc_c0_tcstatus(tmp);
 236
 237                         write_tc_c0_tchalt(TCHALT_H);
 238                 }
 239         }
 240
 241         /* Release config state */
 242         clear_c0_mvpcontrol(MVPCONTROL_VPC);
 243
 244         /* We'll wait until starting the secondaries before starting MVPE */
 245
 246         printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
 247 }
 248
 249 void __init plat_prepare_cpus(unsigned int max_cpus)
 250 {
 251         /* set up ipi interrupts */
 252         if (cpu_has_vint) {
 253                 set_vi_handler (MIPS_CPU_IPI_RESCHED_IRQ, ipi_resched_dispatch);
 254                 set_vi_handler (MIPS_CPU_IPI_CALL_IRQ, ipi_call_dispatch);
 255         }
 256
 257         cpu_ipi_resched_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_RESCHED_IRQ;
 258         cpu_ipi_call_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_CALL_IRQ;
 259
 260         setup_irq(cpu_ipi_resched_irq, &irq_resched);
 261         setup_irq(cpu_ipi_call_irq, &irq_call);
 262
 263         /* need to mark IPI's as IRQ_PER_CPU */
 264         irq_desc[cpu_ipi_resched_irq].status |= IRQ_PER_CPU;
 265         irq_desc[cpu_ipi_call_irq].status |= IRQ_PER_CPU;
 266 }
 267
 268 /*
 269  * Setup the PC, SP, and GP of a secondary processor and start it
 270  * running!
 271  * smp_bootstrap is the place to resume from
 272  * __KSTK_TOS(idle) is apparently the stack pointer
 273  * (unsigned long)idle->thread_info the gp
 274  * assumes a 1:1 mapping of TC => VPE
 275  */
 276 void prom_boot_secondary(int cpu, struct task_struct *idle)
 277 {
 278         struct thread_info *gp = task_thread_info(idle);
 279         dvpe();
 280         set_c0_mvpcontrol(MVPCONTROL_VPC);
 281
 282         settc(cpu);
 283
 284         /* restart */
 285         write_tc_c0_tcrestart((unsigned long)&smp_bootstrap);
 286
 287         /* enable the tc this vpe/cpu will be running */
 288         write_tc_c0_tcstatus((read_tc_c0_tcstatus() & ~TCSTATUS_IXMT) | TCSTATUS_A);
 289
 290         write_tc_c0_tchalt(0);
 291
 292         /* enable the VPE */
 293         write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
 294
 295         /* stack pointer */
 296         write_tc_gpr_sp( __KSTK_TOS(idle));
 297
 298         /* global pointer */
 299         write_tc_gpr_gp((unsigned long)gp);
 300
 301         flush_icache_range((unsigned long)gp,
 302                            (unsigned long)(gp + sizeof(struct thread_info)));
 303
 304         /* finally out of configuration and into chaos */
 305         clear_c0_mvpcontrol(MVPCONTROL_VPC);
 306
 307         evpe(EVPE_ENABLE);
 308 }
 309
 310 void prom_init_secondary(void)
 311 {
 312         write_c0_status((read_c0_status() & ~ST0_IM ) |
 313                         (STATUSF_IP0 | STATUSF_IP1 | STATUSF_IP7));
 314 }
 315
 316 void prom_smp_finish(void)
 317 {
 318         write_c0_compare(read_c0_count() + (8* mips_hpt_frequency/HZ));
 319
 320 #ifdef CONFIG_MIPS_MT_FPAFF
 321         /* If we have an FPU, enroll ourselves in the FPU-full mask */
 322         if (cpu_has_fpu)
 323                 cpu_set(smp_processor_id(), mt_fpu_cpumask);
 324 #endif /* CONFIG_MIPS_MT_FPAFF */
 325
 326         local_irq_enable();
 327 }
 328
 329 void prom_cpus_done(void)
 330 {
 331 }
 332
 333 void core_send_ipi(int cpu, unsigned int action)
 334 {
 335         int i;
 336         unsigned long flags;
 337         int vpflags;
 338
 339         local_irq_save (flags);
 340
 341         vpflags = dvpe();       /* cant access the other CPU's registers whilst MVPE enabled */
 342
 343         switch (action) {
 344         case SMP_CALL_FUNCTION:
 345                 i = C_SW1;
 346                 break;
 347
 348         case SMP_RESCHEDULE_YOURSELF:
 349         default:
 350                 i = C_SW0;
 351                 break;
 352         }
 353
 354         /* 1:1 mapping of vpe and tc... */
 355         settc(cpu);
 356         write_vpe_c0_cause(read_vpe_c0_cause() | i);
 357         evpe(vpflags);
 358
 359         local_irq_restore(flags);
 360 }