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
  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         /* Enable VPC */
  70         set_c0_mvpcontrol(MVPCONTROL_VPC);
  71
  72         back_to_back_c0_hazard();
  73
  74         /* Disable TLB sharing */
  75         clear_c0_mvpcontrol(MVPCONTROL_STLB);
  76
  77         mvpconf0 = read_c0_mvpconf0();
  78
  79         printk(KERN_INFO "MVPConf0 0x%lx TLBS %lx PTLBE %ld\n", mvpconf0,
  80                    (mvpconf0 & MVPCONF0_TLBS) >> MVPCONF0_TLBS_SHIFT,
  81                            (mvpconf0 & MVPCONF0_PTLBE) >> MVPCONF0_PTLBE_SHIFT);
  82
  83         tlbsiz = (mvpconf0 & MVPCONF0_PTLBE) >> MVPCONF0_PTLBE_SHIFT;
  84         ncpu = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
  85
  86         printk(" tlbsiz %d ncpu %ld\n", tlbsiz, ncpu);
  87
  88         if (tlbsiz > 0) {
  89                 /* share them out across the vpe's */
  90                 tlbsiz /= ncpu;
  91
  92                 printk(KERN_INFO "setting Config1.MMU_size to %d\n", tlbsiz);
  93
  94                 for (i = 0; i < ncpu; i++) {
  95                         settc(i);
  96
  97                         if (i == 0)
  98                                 write_c0_config1((read_c0_config1() & ~(0x3f << 25)) | (tlbsiz << 25));
  99                         else
 100                                 write_vpe_c0_config1((read_vpe_c0_config1() & ~(0x3f << 25)) |
 101                                                    (tlbsiz << 25));
 102                 }
 103         }
 104
 105         clear_c0_mvpcontrol(MVPCONTROL_VPC);
 106 }
 107
 108 static void ipi_resched_dispatch(void)
 109 {
 110         do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ);
 111 }
 112
 113 static void ipi_call_dispatch(void)
 114 {
 115         do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ);
 116 }
 117
 118 static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
 119 {
 120         return IRQ_HANDLED;
 121 }
 122
 123 static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
 124 {
 125         smp_call_function_interrupt();
 126
 127         return IRQ_HANDLED;
 128 }
 129
 130 static struct irqaction irq_resched = {
 131         .handler        = ipi_resched_interrupt,
 132         .flags          = IRQF_DISABLED,
 133         .name           = "IPI_resched"
 134 };
 135
 136 static struct irqaction irq_call = {
 137         .handler        = ipi_call_interrupt,
 138         .flags          = IRQF_DISABLED,
 139         .name           = "IPI_call"
 140 };
 141
 142 static void __init smp_copy_vpe_config(void)
 143 {
 144         write_vpe_c0_status(
 145                 (read_c0_status() & ~(ST0_IM | ST0_IE | ST0_KSU)) | ST0_CU0);
 146
 147         /* set config to be the same as vpe0, particularly kseg0 coherency alg */
 148         write_vpe_c0_config( read_c0_config());
 149
 150         /* make sure there are no software interrupts pending */
 151         write_vpe_c0_cause(0);
 152
 153         /* Propagate Config7 */
 154         write_vpe_c0_config7(read_c0_config7());
 155
 156         write_vpe_c0_count(read_c0_count());
 157 }
 158
 159 static unsigned int __init smp_vpe_init(unsigned int tc, unsigned int mvpconf0,
 160         unsigned int ncpu)
 161 {
 162         if (tc > ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT))
 163                 return ncpu;
 164
 165         /* Deactivate all but VPE 0 */
 166         if (tc != 0) {
 167                 unsigned long tmp = read_vpe_c0_vpeconf0();
 168
 169                 tmp &= ~VPECONF0_VPA;
 170
 171                 /* master VPE */
 172                 tmp |= VPECONF0_MVP;
 173                 write_vpe_c0_vpeconf0(tmp);
 174
 175                 /* Record this as available CPU */
 176                 cpu_set(tc, phys_cpu_present_map);
 177                 __cpu_number_map[tc]    = ++ncpu;
 178                 __cpu_logical_map[ncpu] = tc;
 179         }
 180
 181         /* Disable multi-threading with TC's */
 182         write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
 183
 184         if (tc != 0)
 185                 smp_copy_vpe_config();
 186
 187         return ncpu;
 188 }
 189
 190 static void __init smp_tc_init(unsigned int tc, unsigned int mvpconf0)
 191 {
 192         unsigned long tmp;
 193
 194         if (!tc)
 195                 return;
 196
 197         /* bind a TC to each VPE, May as well put all excess TC's
 198            on the last VPE */
 199         if (tc >= (((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)+1))
 200                 write_tc_c0_tcbind(read_tc_c0_tcbind() | ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT));
 201         else {
 202                 write_tc_c0_tcbind(read_tc_c0_tcbind() | tc);
 203
 204                 /* and set XTC */
 205                 write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | (tc << VPECONF0_XTC_SHIFT));
 206         }
 207
 208         tmp = read_tc_c0_tcstatus();
 209
 210         /* mark not allocated and not dynamically allocatable */
 211         tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
 212         tmp |= TCSTATUS_IXMT;           /* interrupt exempt */
 213         write_tc_c0_tcstatus(tmp);
 214
 215         write_tc_c0_tchalt(TCHALT_H);
 216 }
 217
 218 /*
 219  * Common setup before any secondaries are started
 220  * Make sure all CPU's are in a sensible state before we boot any of the
 221  * secondarys
 222  */
 223 void __init plat_smp_setup(void)
 224 {
 225         unsigned int mvpconf0, ntc, tc, ncpu = 0;
 226
 227 #ifdef CONFIG_MIPS_MT_FPAFF
 228         /* If we have an FPU, enroll ourselves in the FPU-full mask */
 229         if (cpu_has_fpu)
 230                 cpu_set(0, mt_fpu_cpumask);
 231 #endif /* CONFIG_MIPS_MT_FPAFF */
 232         if (!cpu_has_mipsmt)
 233                 return;
 234
 235         /* disable MT so we can configure */
 236         dvpe();
 237         dmt();
 238
 239         mips_mt_set_cpuoptions();
 240
 241         /* Put MVPE's into 'configuration state' */
 242         set_c0_mvpcontrol(MVPCONTROL_VPC);
 243
 244         mvpconf0 = read_c0_mvpconf0();
 245         ntc = (mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT;
 246
 247         /* we'll always have more TC's than VPE's, so loop setting everything
 248            to a sensible state */
 249         for (tc = 0; tc <= ntc; tc++) {
 250                 settc(tc);
 251
 252                 smp_tc_init(tc, mvpconf0);
 253                 ncpu = smp_vpe_init(tc, mvpconf0, ncpu);
 254         }
 255
 256         /* Release config state */
 257         clear_c0_mvpcontrol(MVPCONTROL_VPC);
 258
 259         /* We'll wait until starting the secondaries before starting MVPE */
 260
 261         printk(KERN_INFO "Detected %i available secondary CPU(s)\n", ncpu);
 262 }
 263
 264 void __init plat_prepare_cpus(unsigned int max_cpus)
 265 {
 266         /* set up ipi interrupts */
 267         if (cpu_has_vint) {
 268                 set_vi_handler(MIPS_CPU_IPI_RESCHED_IRQ, ipi_resched_dispatch);
 269                 set_vi_handler(MIPS_CPU_IPI_CALL_IRQ, ipi_call_dispatch);
 270         }
 271
 272         cpu_ipi_resched_irq = MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ;
 273         cpu_ipi_call_irq = MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ;
 274
 275         setup_irq(cpu_ipi_resched_irq, &irq_resched);
 276         setup_irq(cpu_ipi_call_irq, &irq_call);
 277
 278         /* need to mark IPI's as IRQ_PER_CPU */
 279         irq_desc[cpu_ipi_resched_irq].status |= IRQ_PER_CPU;
 280         set_irq_handler(cpu_ipi_resched_irq, handle_percpu_irq);
 281         irq_desc[cpu_ipi_call_irq].status |= IRQ_PER_CPU;
 282         set_irq_handler(cpu_ipi_call_irq, handle_percpu_irq);
 283 }
 284
 285 /*
 286  * Setup the PC, SP, and GP of a secondary processor and start it
 287  * running!
 288  * smp_bootstrap is the place to resume from
 289  * __KSTK_TOS(idle) is apparently the stack pointer
 290  * (unsigned long)idle->thread_info the gp
 291  * assumes a 1:1 mapping of TC => VPE
 292  */
 293 void prom_boot_secondary(int cpu, struct task_struct *idle)
 294 {
 295         struct thread_info *gp = task_thread_info(idle);
 296         dvpe();
 297         set_c0_mvpcontrol(MVPCONTROL_VPC);
 298
 299         settc(cpu);
 300
 301         /* restart */
 302         write_tc_c0_tcrestart((unsigned long)&smp_bootstrap);
 303
 304         /* enable the tc this vpe/cpu will be running */
 305         write_tc_c0_tcstatus((read_tc_c0_tcstatus() & ~TCSTATUS_IXMT) | TCSTATUS_A);
 306
 307         write_tc_c0_tchalt(0);
 308
 309         /* enable the VPE */
 310         write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
 311
 312         /* stack pointer */
 313         write_tc_gpr_sp( __KSTK_TOS(idle));
 314
 315         /* global pointer */
 316         write_tc_gpr_gp((unsigned long)gp);
 317
 318         flush_icache_range((unsigned long)gp,
 319                            (unsigned long)(gp + sizeof(struct thread_info)));
 320
 321         /* finally out of configuration and into chaos */
 322         clear_c0_mvpcontrol(MVPCONTROL_VPC);
 323
 324         evpe(EVPE_ENABLE);
 325 }
 326
 327 void prom_init_secondary(void)
 328 {
 329         write_c0_status((read_c0_status() & ~ST0_IM ) |
 330                         (STATUSF_IP0 | STATUSF_IP1 | STATUSF_IP7));
 331 }
 332
 333 void prom_smp_finish(void)
 334 {
 335         write_c0_compare(read_c0_count() + (8* mips_hpt_frequency/HZ));
 336
 337 #ifdef CONFIG_MIPS_MT_FPAFF
 338         /* If we have an FPU, enroll ourselves in the FPU-full mask */
 339         if (cpu_has_fpu)
 340                 cpu_set(smp_processor_id(), mt_fpu_cpumask);
 341 #endif /* CONFIG_MIPS_MT_FPAFF */
 342
 343         local_irq_enable();
 344 }
 345
 346 void prom_cpus_done(void)
 347 {
 348 }
 349
 350 void core_send_ipi(int cpu, unsigned int action)
 351 {
 352         int i;
 353         unsigned long flags;
 354         int vpflags;
 355
 356         local_irq_save (flags);
 357
 358         vpflags = dvpe();       /* cant access the other CPU's registers whilst MVPE enabled */
 359
 360         switch (action) {
 361         case SMP_CALL_FUNCTION:
 362                 i = C_SW1;
 363                 break;
 364
 365         case SMP_RESCHEDULE_YOURSELF:
 366         default:
 367                 i = C_SW0;
 368                 break;
 369         }
 370
 371         /* 1:1 mapping of vpe and tc... */
 372         settc(cpu);
 373         write_vpe_c0_cause(read_vpe_c0_cause() | i);
 374         evpe(vpflags);
 375
 376         local_irq_restore(flags);
 377 }