arch/ia64/sn/kernel/sn2/sn2_smp.c

   1 /*
   2  * SN2 Platform specific SMP Support
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * Copyright (C) 2000-2005 Silicon Graphics, Inc. All rights reserved.
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/threads.h>
  15 #include <linux/sched.h>
  16 #include <linux/smp.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/irq.h>
  19 #include <linux/mmzone.h>
  20 #include <linux/module.h>
  21 #include <linux/bitops.h>
  22 #include <linux/nodemask.h>
  23 #include <linux/proc_fs.h>
  24 #include <linux/seq_file.h>
  25
  26 #include <asm/processor.h>
  27 #include <asm/irq.h>
  28 #include <asm/sal.h>
  29 #include <asm/system.h>
  30 #include <asm/delay.h>
  31 #include <asm/io.h>
  32 #include <asm/smp.h>
  33 #include <asm/tlb.h>
  34 #include <asm/numa.h>
  35 #include <asm/hw_irq.h>
  36 #include <asm/current.h>
  37 #include <asm/sn/sn_cpuid.h>
  38 #include <asm/sn/sn_sal.h>
  39 #include <asm/sn/addrs.h>
  40 #include <asm/sn/shub_mmr.h>
  41 #include <asm/sn/nodepda.h>
  42 #include <asm/sn/rw_mmr.h>
  43
  44 DEFINE_PER_CPU(struct ptc_stats, ptcstats);
  45 DECLARE_PER_CPU(struct ptc_stats, ptcstats);
  46
  47 static  __cacheline_aligned DEFINE_SPINLOCK(sn2_global_ptc_lock);
  48
  49 void sn2_ptc_deadlock_recovery(short *, short, int, volatile unsigned long *, unsigned long data0,
  50         volatile unsigned long *, unsigned long data1);
  51
  52 #ifdef DEBUG_PTC
  53 /*
  54  * ptctest:
  55  *
  56  *      xyz - 3 digit hex number:
  57  *              x - Force PTC purges to use shub:
  58  *                      0 - no force
  59  *                      1 - force
  60  *              y - interupt enable
  61  *                      0 - disable interrupts
  62  *                      1 - leave interuupts enabled
  63  *              z - type of lock:
  64  *                      0 - global lock
  65  *                      1 - node local lock
  66  *                      2 - no lock
  67  *
  68  *      Note: on shub1, only ptctest == 0 is supported. Don't try other values!
  69  */
  70
  71 static unsigned int sn2_ptctest = 0;
  72
  73 static int __init ptc_test(char *str)
  74 {
  75         get_option(&str, &sn2_ptctest);
  76         return 1;
  77 }
  78 __setup("ptctest=", ptc_test);
  79
  80 static inline int ptc_lock(unsigned long *flagp)
  81 {
  82         unsigned long opt = sn2_ptctest & 255;
  83
  84         switch (opt) {
  85         case 0x00:
  86                 spin_lock_irqsave(&sn2_global_ptc_lock, *flagp);
  87                 break;
  88         case 0x01:
  89                 spin_lock_irqsave(&sn_nodepda->ptc_lock, *flagp);
  90                 break;
  91         case 0x02:
  92                 local_irq_save(*flagp);
  93                 break;
  94         case 0x10:
  95                 spin_lock(&sn2_global_ptc_lock);
  96                 break;
  97         case 0x11:
  98                 spin_lock(&sn_nodepda->ptc_lock);
  99                 break;
 100         case 0x12:
 101                 break;
 102         default:
 103                 BUG();
 104         }
 105         return opt;
 106 }
 107
 108 static inline void ptc_unlock(unsigned long flags, int opt)
 109 {
 110         switch (opt) {
 111         case 0x00:
 112                 spin_unlock_irqrestore(&sn2_global_ptc_lock, flags);
 113                 break;
 114         case 0x01:
 115                 spin_unlock_irqrestore(&sn_nodepda->ptc_lock, flags);
 116                 break;
 117         case 0x02:
 118                 local_irq_restore(flags);
 119                 break;
 120         case 0x10:
 121                 spin_unlock(&sn2_global_ptc_lock);
 122                 break;
 123         case 0x11:
 124                 spin_unlock(&sn_nodepda->ptc_lock);
 125                 break;
 126         case 0x12:
 127                 break;
 128         default:
 129                 BUG();
 130         }
 131 }
 132 #else
 133
 134 #define sn2_ptctest     0
 135
 136 static inline int ptc_lock(unsigned long *flagp)
 137 {
 138         spin_lock_irqsave(&sn2_global_ptc_lock, *flagp);
 139         return 0;
 140 }
 141
 142 static inline void ptc_unlock(unsigned long flags, int opt)
 143 {
 144         spin_unlock_irqrestore(&sn2_global_ptc_lock, flags);
 145 }
 146 #endif
 147
 148 struct ptc_stats {
 149         unsigned long ptc_l;
 150         unsigned long change_rid;
 151         unsigned long shub_ptc_flushes;
 152         unsigned long nodes_flushed;
 153         unsigned long deadlocks;
 154         unsigned long lock_itc_clocks;
 155         unsigned long shub_itc_clocks;
 156         unsigned long shub_itc_clocks_max;
 157 };
 158
 159 static inline unsigned long wait_piowc(void)
 160 {
 161         volatile unsigned long *piows, zeroval;
 162         unsigned long ws;
 163
 164         piows = pda->pio_write_status_addr;
 165         zeroval = pda->pio_write_status_val;
 166         do {
 167                 cpu_relax();
 168         } while (((ws = *piows) & SH_PIO_WRITE_STATUS_PENDING_WRITE_COUNT_MASK) != zeroval);
 169         return ws;
 170 }
 171
 172 void sn_tlb_migrate_finish(struct mm_struct *mm)
 173 {
 174         if (mm == current->mm)
 175                 flush_tlb_mm(mm);
 176 }
 177
 178 /**
 179  * sn2_global_tlb_purge - globally purge translation cache of virtual address range
 180  * @start: start of virtual address range
 181  * @end: end of virtual address range
 182  * @nbits: specifies number of bytes to purge per instruction (num = 1<<(nbits & 0xfc))
 183  *
 184  * Purges the translation caches of all processors of the given virtual address
 185  * range.
 186  *
 187  * Note:
 188  *      - cpu_vm_mask is a bit mask that indicates which cpus have loaded the context.
 189  *      - cpu_vm_mask is converted into a nodemask of the nodes containing the
 190  *        cpus in cpu_vm_mask.
 191  *      - if only one bit is set in cpu_vm_mask & it is the current cpu,
 192  *        then only the local TLB needs to be flushed. This flushing can be done
 193  *        using ptc.l. This is the common case & avoids the global spinlock.
 194  *      - if multiple cpus have loaded the context, then flushing has to be
 195  *        done with ptc.g/MMRs under protection of the global ptc_lock.
 196  */
 197
 198 void
 199 sn2_global_tlb_purge(unsigned long start, unsigned long end,
 200                      unsigned long nbits)
 201 {
 202         int i, opt, shub1, cnode, mynasid, cpu, lcpu = 0, nasid, flushed = 0;
 203         volatile unsigned long *ptc0, *ptc1;
 204         unsigned long itc, itc2, flags, data0 = 0, data1 = 0;
 205         struct mm_struct *mm = current->active_mm;
 206         short nasids[MAX_NUMNODES], nix;
 207         nodemask_t nodes_flushed;
 208
 209         nodes_clear(nodes_flushed);
 210         i = 0;
 211
 212         for_each_cpu_mask(cpu, mm->cpu_vm_mask) {
 213                 cnode = cpu_to_node(cpu);
 214                 node_set(cnode, nodes_flushed);
 215                 lcpu = cpu;
 216                 i++;
 217         }
 218
 219         preempt_disable();
 220
 221         if (likely(i == 1 && lcpu == smp_processor_id())) {
 222                 do {
 223                         ia64_ptcl(start, nbits << 2);
 224                         start += (1UL << nbits);
 225                 } while (start < end);
 226                 ia64_srlz_i();
 227                 __get_cpu_var(ptcstats).ptc_l++;
 228                 preempt_enable();
 229                 return;
 230         }
 231
 232         if (atomic_read(&mm->mm_users) == 1) {
 233                 flush_tlb_mm(mm);
 234                 __get_cpu_var(ptcstats).change_rid++;
 235                 preempt_enable();
 236                 return;
 237         }
 238
 239         itc = ia64_get_itc();
 240         nix = 0;
 241         for_each_node_mask(cnode, nodes_flushed)
 242                 nasids[nix++] = cnodeid_to_nasid(cnode);
 243
 244         shub1 = is_shub1();
 245         if (shub1) {
 246                 data0 = (1UL << SH1_PTC_0_A_SHFT) |
 247                         (nbits << SH1_PTC_0_PS_SHFT) |
 248                         ((ia64_get_rr(start) >> 8) << SH1_PTC_0_RID_SHFT) |
 249                         (1UL << SH1_PTC_0_START_SHFT);
 250                 ptc0 = (long *)GLOBAL_MMR_PHYS_ADDR(0, SH1_PTC_0);
 251                 ptc1 = (long *)GLOBAL_MMR_PHYS_ADDR(0, SH1_PTC_1);
 252         } else {
 253                 data0 = (1UL << SH2_PTC_A_SHFT) |
 254                         (nbits << SH2_PTC_PS_SHFT) |
 255                         (1UL << SH2_PTC_START_SHFT);
 256                 ptc0 = (long *)GLOBAL_MMR_PHYS_ADDR(0, SH2_PTC +
 257                         ((ia64_get_rr(start) >> 8) << SH2_PTC_RID_SHFT) );
 258                 ptc1 = NULL;
 259         }
 260
 261
 262         mynasid = get_nasid();
 263
 264         itc = ia64_get_itc();
 265         opt = ptc_lock(&flags);
 266         itc2 = ia64_get_itc();
 267         __get_cpu_var(ptcstats).lock_itc_clocks += itc2 - itc;
 268         __get_cpu_var(ptcstats).shub_ptc_flushes++;
 269         __get_cpu_var(ptcstats).nodes_flushed += nix;
 270
 271         do {
 272                 if (shub1)
 273                         data1 = start | (1UL << SH1_PTC_1_START_SHFT);
 274                 else
 275                         data0 = (data0 & ~SH2_PTC_ADDR_MASK) | (start & SH2_PTC_ADDR_MASK);
 276                 for (i = 0; i < nix; i++) {
 277                         nasid = nasids[i];
 278                         if ((!(sn2_ptctest & 3)) && unlikely(nasid == mynasid)) {
 279                                 ia64_ptcga(start, nbits << 2);
 280                                 ia64_srlz_i();
 281                         } else {
 282                                 ptc0 = CHANGE_NASID(nasid, ptc0);
 283                                 if (ptc1)
 284                                         ptc1 = CHANGE_NASID(nasid, ptc1);
 285                                 pio_atomic_phys_write_mmrs(ptc0, data0, ptc1,
 286                                                            data1);
 287                                 flushed = 1;
 288                         }
 289                 }
 290                 if (flushed
 291                     && (wait_piowc() &
 292                                 (SH_PIO_WRITE_STATUS_WRITE_DEADLOCK_MASK))) {
 293                         sn2_ptc_deadlock_recovery(nasids, nix, mynasid, ptc0, data0, ptc1, data1);
 294                 }
 295
 296                 start += (1UL << nbits);
 297
 298         } while (start < end);
 299
 300         itc2 = ia64_get_itc() - itc2;
 301         __get_cpu_var(ptcstats).shub_itc_clocks += itc2;
 302         if (itc2 > __get_cpu_var(ptcstats).shub_itc_clocks_max)
 303                 __get_cpu_var(ptcstats).shub_itc_clocks_max = itc2;
 304
 305         ptc_unlock(flags, opt);
 306
 307         preempt_enable();
 308 }
 309
 310 /*
 311  * sn2_ptc_deadlock_recovery
 312  *
 313  * Recover from PTC deadlocks conditions. Recovery requires stepping thru each
 314  * TLB flush transaction.  The recovery sequence is somewhat tricky & is
 315  * coded in assembly language.
 316  */
 317 void sn2_ptc_deadlock_recovery(short *nasids, short nix, int mynasid, volatile unsigned long *ptc0, unsigned long data0,
 318         volatile unsigned long *ptc1, unsigned long data1)
 319 {
 320         extern void sn2_ptc_deadlock_recovery_core(volatile unsigned long *, unsigned long,
 321                 volatile unsigned long *, unsigned long, volatile unsigned long *, unsigned long);
 322         short nasid, i;
 323         unsigned long *piows, zeroval;
 324
 325         __get_cpu_var(ptcstats).deadlocks++;
 326
 327         piows = (unsigned long *) pda->pio_write_status_addr;
 328         zeroval = pda->pio_write_status_val;
 329
 330         for (i=0; i < nix; i++) {
 331                 nasid = nasids[i];
 332                 if (!(sn2_ptctest & 3) && nasid == mynasid)
 333                         continue;
 334                 ptc0 = CHANGE_NASID(nasid, ptc0);
 335                 if (ptc1)
 336                         ptc1 = CHANGE_NASID(nasid, ptc1);
 337                 sn2_ptc_deadlock_recovery_core(ptc0, data0, ptc1, data1, piows, zeroval);
 338         }
 339
 340 }
 341
 342 /**
 343  * sn_send_IPI_phys - send an IPI to a Nasid and slice
 344  * @nasid: nasid to receive the interrupt (may be outside partition)
 345  * @physid: physical cpuid to receive the interrupt.
 346  * @vector: command to send
 347  * @delivery_mode: delivery mechanism
 348  *
 349  * Sends an IPI (interprocessor interrupt) to the processor specified by
 350  * @physid
 351  *
 352  * @delivery_mode can be one of the following
 353  *
 354  * %IA64_IPI_DM_INT - pend an interrupt
 355  * %IA64_IPI_DM_PMI - pend a PMI
 356  * %IA64_IPI_DM_NMI - pend an NMI
 357  * %IA64_IPI_DM_INIT - pend an INIT interrupt
 358  */
 359 void sn_send_IPI_phys(int nasid, long physid, int vector, int delivery_mode)
 360 {
 361         long val;
 362         unsigned long flags = 0;
 363         volatile long *p;
 364
 365         p = (long *)GLOBAL_MMR_PHYS_ADDR(nasid, SH_IPI_INT);
 366         val = (1UL << SH_IPI_INT_SEND_SHFT) |
 367             (physid << SH_IPI_INT_PID_SHFT) |
 368             ((long)delivery_mode << SH_IPI_INT_TYPE_SHFT) |
 369             ((long)vector << SH_IPI_INT_IDX_SHFT) |
 370             (0x000feeUL << SH_IPI_INT_BASE_SHFT);
 371
 372         mb();
 373         if (enable_shub_wars_1_1()) {
 374                 spin_lock_irqsave(&sn2_global_ptc_lock, flags);
 375         }
 376         pio_phys_write_mmr(p, val);
 377         if (enable_shub_wars_1_1()) {
 378                 wait_piowc();
 379                 spin_unlock_irqrestore(&sn2_global_ptc_lock, flags);
 380         }
 381
 382 }
 383
 384 EXPORT_SYMBOL(sn_send_IPI_phys);
 385
 386 /**
 387  * sn2_send_IPI - send an IPI to a processor
 388  * @cpuid: target of the IPI
 389  * @vector: command to send
 390  * @delivery_mode: delivery mechanism
 391  * @redirect: redirect the IPI?
 392  *
 393  * Sends an IPI (InterProcessor Interrupt) to the processor specified by
 394  * @cpuid.  @vector specifies the command to send, while @delivery_mode can
 395  * be one of the following
 396  *
 397  * %IA64_IPI_DM_INT - pend an interrupt
 398  * %IA64_IPI_DM_PMI - pend a PMI
 399  * %IA64_IPI_DM_NMI - pend an NMI
 400  * %IA64_IPI_DM_INIT - pend an INIT interrupt
 401  */
 402 void sn2_send_IPI(int cpuid, int vector, int delivery_mode, int redirect)
 403 {
 404         long physid;
 405         int nasid;
 406
 407         physid = cpu_physical_id(cpuid);
 408         nasid = cpuid_to_nasid(cpuid);
 409
 410         /* the following is used only when starting cpus at boot time */
 411         if (unlikely(nasid == -1))
 412                 ia64_sn_get_sapic_info(physid, &nasid, NULL, NULL);
 413
 414         sn_send_IPI_phys(nasid, physid, vector, delivery_mode);
 415 }
 416
 417 #ifdef CONFIG_PROC_FS
 418
 419 #define PTC_BASENAME    "sgi_sn/ptc_statistics"
 420
 421 static void *sn2_ptc_seq_start(struct seq_file *file, loff_t * offset)
 422 {
 423         if (*offset < NR_CPUS)
 424                 return offset;
 425         return NULL;
 426 }
 427
 428 static void *sn2_ptc_seq_next(struct seq_file *file, void *data, loff_t * offset)
 429 {
 430         (*offset)++;
 431         if (*offset < NR_CPUS)
 432                 return offset;
 433         return NULL;
 434 }
 435
 436 static void sn2_ptc_seq_stop(struct seq_file *file, void *data)
 437 {
 438 }
 439
 440 static int sn2_ptc_seq_show(struct seq_file *file, void *data)
 441 {
 442         struct ptc_stats *stat;
 443         int cpu;
 444
 445         cpu = *(loff_t *) data;
 446
 447         if (!cpu) {
 448                 seq_printf(file, "# ptc_l change_rid shub_ptc_flushes shub_nodes_flushed deadlocks lock_nsec shub_nsec shub_nsec_max\n");
 449                 seq_printf(file, "# ptctest %d\n", sn2_ptctest);
 450         }
 451
 452         if (cpu < NR_CPUS && cpu_online(cpu)) {
 453                 stat = &per_cpu(ptcstats, cpu);
 454                 seq_printf(file, "cpu %d %ld %ld %ld %ld %ld %ld %ld %ld\n", cpu, stat->ptc_l,
 455                                 stat->change_rid, stat->shub_ptc_flushes, stat->nodes_flushed,
 456                                 stat->deadlocks,
 457                                 1000 * stat->lock_itc_clocks / per_cpu(cpu_info, cpu).cyc_per_usec,
 458                                 1000 * stat->shub_itc_clocks / per_cpu(cpu_info, cpu).cyc_per_usec,
 459                                 1000 * stat->shub_itc_clocks_max / per_cpu(cpu_info, cpu).cyc_per_usec);
 460         }
 461
 462         return 0;
 463 }
 464
 465 static struct seq_operations sn2_ptc_seq_ops = {
 466         .start = sn2_ptc_seq_start,
 467         .next = sn2_ptc_seq_next,
 468         .stop = sn2_ptc_seq_stop,
 469         .show = sn2_ptc_seq_show
 470 };
 471
 472 int sn2_ptc_proc_open(struct inode *inode, struct file *file)
 473 {
 474         return seq_open(file, &sn2_ptc_seq_ops);
 475 }
 476
 477 static struct file_operations proc_sn2_ptc_operations = {
 478         .open = sn2_ptc_proc_open,
 479         .read = seq_read,
 480         .llseek = seq_lseek,
 481         .release = seq_release,
 482 };
 483
 484 static struct proc_dir_entry *proc_sn2_ptc;
 485
 486 static int __init sn2_ptc_init(void)
 487 {
 488         if (!(proc_sn2_ptc = create_proc_entry(PTC_BASENAME, 0444, NULL))) {
 489                 printk(KERN_ERR "unable to create %s proc entry", PTC_BASENAME);
 490                 return -EINVAL;
 491         }
 492         proc_sn2_ptc->proc_fops = &proc_sn2_ptc_operations;
 493         spin_lock_init(&sn2_global_ptc_lock);
 494         return 0;
 495 }
 496
 497 static void __exit sn2_ptc_exit(void)
 498 {
 499         remove_proc_entry(PTC_BASENAME, NULL);
 500 }
 501
 502 module_init(sn2_ptc_init);
 503 module_exit(sn2_ptc_exit);
 504 #endif /* CONFIG_PROC_FS */
 505