kernel/arch/i386/arch_system.c

   1 /* system dependent functions for use inside the whole kernel. */
   2
   3 #include "kernel/kernel.h"
   4
   5 #include <unistd.h>
   6 #include <ctype.h>
   7 #include <string.h>
   8 #include <machine/cmos.h>
   9 #include <machine/bios.h>
  10 #include <machine/cpu.h>
  11 #include <minix/portio.h>
  12 #include <minix/cpufeature.h>
  13 #include <assert.h>
  14 #include <signal.h>
  15 #include <machine/vm.h>
  16
  17 #include <minix/u64.h>
  18
  19 #include "archconst.h"
  20 #include "arch_proto.h"
  21 #include "serial.h"
  22 #include "oxpcie.h"
  23 #include "direct_utils.h"
  24 #include <machine/multiboot.h>
  25
  26 #include "glo.h"
  27
  28 #ifdef USE_APIC
  29 #include "apic.h"
  30 #endif
  31
  32 #ifdef USE_ACPI
  33 #include "acpi.h"
  34 #endif
  35
  36 static int osfxsr_feature; /* FXSAVE/FXRSTOR instructions support (SSEx) */
  37
  38 /* set MP and NE flags to handle FPU exceptions in native mode. */
  39 #define CR0_MP_NE       0x0022
  40 /* set CR4.OSFXSR[bit 9] if FXSR is supported. */
  41 #define CR4_OSFXSR      (1L<<9)
  42 /* set OSXMMEXCPT[bit 10] if we provide #XM handler. */
  43 #define CR4_OSXMMEXCPT  (1L<<10)
  44
  45 void * k_stacks;
  46
  47 static void ser_debug(int c);
  48 #ifdef CONFIG_SMP
  49 static void ser_dump_proc_cpu(void);
  50 #endif
  51 #if !CONFIG_OXPCIE
  52 static void ser_init(void);
  53 #endif
  54
  55 void fpu_init(void)
  56 {
  57         unsigned short cw, sw;
  58
  59         fninit();
  60         sw = fnstsw();
  61         fnstcw(&cw);
  62
  63         if((sw & 0xff) == 0 &&
  64            (cw & 0x103f) == 0x3f) {
  65                 /* We have some sort of FPU, but don't check exact model.
  66                  * Set CR0_NE and CR0_MP to handle fpu exceptions
  67                  * in native mode. */
  68                 write_cr0(read_cr0() | CR0_MP_NE);
  69                 get_cpulocal_var(fpu_presence) = 1;
  70                 if(_cpufeature(_CPUF_I386_FXSR)) {
  71                         u32_t cr4 = read_cr4() | CR4_OSFXSR; /* Enable FXSR. */
  72
  73                         /* OSXMMEXCPT if supported
  74                          * FXSR feature can be available without SSE
  75                          */
  76                         if(_cpufeature(_CPUF_I386_SSE))
  77                                 cr4 |= CR4_OSXMMEXCPT;
  78
  79                         write_cr4(cr4);
  80                         osfxsr_feature = 1;
  81                 } else {
  82                         osfxsr_feature = 0;
  83                 }
  84         } else {
  85                 /* No FPU presents. */
  86                 get_cpulocal_var(fpu_presence) = 0;
  87                 osfxsr_feature = 0;
  88                 return;
  89         }
  90 }
  91
  92 void save_local_fpu(struct proc *pr, int retain)
  93 {
  94         char *state = pr->p_seg.fpu_state;
  95
  96         /* Save process FPU context. If the 'retain' flag is set, keep the FPU
  97          * state as is. If the flag is not set, the state is undefined upon
  98          * return, and the caller is responsible for reloading a proper state.
  99          */
 100
 101         if(!is_fpu())
 102                 return;
 103
 104         assert(state);
 105
 106         if(osfxsr_feature) {
 107                 fxsave(state);
 108         } else {
 109                 fnsave(state);
 110                 if (retain)
 111                         (void) frstor(state);
 112         }
 113 }
 114
 115 void save_fpu(struct proc *pr)
 116 {
 117 #ifdef CONFIG_SMP
 118         if (cpuid != pr->p_cpu) {
 119                 int stopped;
 120
 121                 /* remember if the process was already stopped */
 122                 stopped = RTS_ISSET(pr, RTS_PROC_STOP);
 123
 124                 /* stop the remote process and force its context to be saved */
 125                 smp_schedule_stop_proc_save_ctx(pr);
 126
 127                 /*
 128                  * If the process wasn't stopped let the process run again. The
 129                  * process is kept block by the fact that the kernel cannot run
 130                  * on its cpu
 131                  */
 132                 if (!stopped)
 133                         RTS_UNSET(pr, RTS_PROC_STOP);
 134
 135                 return;
 136         }
 137 #endif
 138
 139         if (get_cpulocal_var(fpu_owner) == pr) {
 140                 disable_fpu_exception();
 141                 save_local_fpu(pr, TRUE /*retain*/);
 142         }
 143 }
 144
 145 /* reserve a chunk of memory for fpu state; every one has to
 146  * be FPUALIGN-aligned.
 147  */
 148 static char fpu_state[NR_PROCS][FPU_XFP_SIZE] __aligned(FPUALIGN);
 149
 150 void arch_proc_reset(struct proc *pr)
 151 {
 152         char *v = NULL;
 153         struct stackframe_s reg;
 154
 155         assert(pr->p_nr < NR_PROCS);
 156
 157         if(pr->p_nr >= 0) {
 158                 v = fpu_state[pr->p_nr];
 159                 /* verify alignment */
 160                 assert(!((vir_bytes)v % FPUALIGN));
 161                 /* initialize state */
 162                 memset(v, 0, FPU_XFP_SIZE);
 163         }
 164
 165         /* Clear process state. */
 166         memset(&reg, 0, sizeof(pr->p_reg));
 167         if(iskerneln(pr->p_nr))
 168                 reg.psw = INIT_TASK_PSW;
 169         else
 170                 reg.psw = INIT_PSW;
 171
 172         pr->p_seg.fpu_state = v;
 173
 174         /* Initialize the fundamentals that are (initially) the same for all
 175          * processes - the segment selectors it gets to use.
 176          */
 177         pr->p_reg.cs = USER_CS_SELECTOR;
 178         pr->p_reg.gs =
 179         pr->p_reg.fs =
 180         pr->p_reg.ss =
 181         pr->p_reg.es =
 182         pr->p_reg.ds = USER_DS_SELECTOR;
 183
 184         /* set full context and make sure it gets restored */
 185         arch_proc_setcontext(pr, &reg, 0);
 186 }
 187
 188 void arch_set_secondary_ipc_return(struct proc *p, u32_t val)
 189 {
 190         p->p_reg.bx = val;
 191 }
 192
 193 int restore_fpu(struct proc *pr)
 194 {
 195         int failed;
 196         char *state = pr->p_seg.fpu_state;
 197
 198         assert(state);
 199
 200         if(!proc_used_fpu(pr)) {
 201                 fninit();
 202                 pr->p_misc_flags |= MF_FPU_INITIALIZED;
 203         } else {
 204                 if(osfxsr_feature) {
 205                         failed = fxrstor(state);
 206                 } else {
 207                         failed = frstor(state);
 208                 }
 209
 210                 if (failed) return EINVAL;
 211         }
 212
 213         return OK;
 214 }
 215
 216 void cpu_identify(void)
 217 {
 218         u32_t eax, ebx, ecx, edx;
 219         unsigned cpu = cpuid;
 220
 221         eax = 0;
 222         _cpuid(&eax, &ebx, &ecx, &edx);
 223
 224         if (ebx == INTEL_CPUID_GEN_EBX && ecx == INTEL_CPUID_GEN_ECX &&
 225                         edx == INTEL_CPUID_GEN_EDX) {
 226                 cpu_info[cpu].vendor = CPU_VENDOR_INTEL;
 227         } else if (ebx == AMD_CPUID_GEN_EBX && ecx == AMD_CPUID_GEN_ECX &&
 228                         edx == AMD_CPUID_GEN_EDX) {
 229                 cpu_info[cpu].vendor = CPU_VENDOR_AMD;
 230         } else
 231                 cpu_info[cpu].vendor = CPU_VENDOR_UNKNOWN;
 232
 233         if (eax == 0)
 234                 return;
 235
 236         eax = 1;
 237         _cpuid(&eax, &ebx, &ecx, &edx);
 238
 239         cpu_info[cpu].family = (eax >> 8) & 0xf;
 240         if (cpu_info[cpu].family == 0xf)
 241                 cpu_info[cpu].family += (eax >> 20) & 0xff;
 242         cpu_info[cpu].model = (eax >> 4) & 0xf;
 243         if (cpu_info[cpu].model == 0xf || cpu_info[cpu].model == 0x6)
 244                 cpu_info[cpu].model += ((eax >> 16) & 0xf) << 4 ;
 245         cpu_info[cpu].stepping = eax & 0xf;
 246         cpu_info[cpu].flags[0] = ecx;
 247         cpu_info[cpu].flags[1] = edx;
 248 }
 249
 250 void arch_init(void)
 251 {
 252         k_stacks = (void*) &k_stacks_start;
 253         assert(!((vir_bytes) k_stacks % K_STACK_SIZE));
 254
 255 #ifndef CONFIG_SMP
 256         /*
 257          * use stack 0 and cpu id 0 on a single processor machine, SMP
 258          * configuration does this in smp_init() for all cpus at once
 259          */
 260         tss_init(0, get_k_stack_top(0));
 261 #endif
 262
 263 #if !CONFIG_OXPCIE
 264         ser_init();
 265 #endif
 266
 267 #ifdef USE_ACPI
 268         acpi_init();
 269 #endif
 270
 271 #if defined(USE_APIC) && !defined(CONFIG_SMP)
 272         if (config_no_apic) {
 273                 BOOT_VERBOSE(printf("APIC disabled, using legacy PIC\n"));
 274         }
 275         else if (!apic_single_cpu_init()) {
 276                 BOOT_VERBOSE(printf("APIC not present, using legacy PIC\n"));
 277         }
 278 #endif
 279
 280         /* Reserve some BIOS ranges */
 281         cut_memmap(&kinfo, BIOS_MEM_BEGIN, BIOS_MEM_END);
 282         cut_memmap(&kinfo, BASE_MEM_TOP, UPPER_MEM_END);
 283 }
 284
 285 /*===========================================================================*
 286  *                              do_ser_debug                                 *
 287  *===========================================================================*/
 288 void do_ser_debug()
 289 {
 290         u8_t c, lsr;
 291
 292 #if CONFIG_OXPCIE
 293         {
 294                 int oxin;
 295                 if((oxin = oxpcie_in()) >= 0)
 296                 ser_debug(oxin);
 297         }
 298 #endif
 299
 300         lsr= inb(COM1_LSR);
 301         if (!(lsr & LSR_DR))
 302                 return;
 303         c = inb(COM1_RBR);
 304         ser_debug(c);
 305 }
 306
 307 static void ser_dump_queue_cpu(unsigned cpu)
 308 {
 309         int q;
 310         struct proc ** rdy_head;
 311
 312         rdy_head = get_cpu_var(cpu, run_q_head);
 313
 314         for(q = 0; q < NR_SCHED_QUEUES; q++) {
 315                 struct proc *p;
 316                 if(rdy_head[q])  {
 317                         printf("%2d: ", q);
 318                         for(p = rdy_head[q]; p; p = p->p_nextready) {
 319                                 printf("%s / %d  ", p->p_name, p->p_endpoint);
 320                         }
 321                         printf("\n");
 322                 }
 323         }
 324 }
 325
 326 static void ser_dump_queues(void)
 327 {
 328 #ifdef CONFIG_SMP
 329         unsigned cpu;
 330
 331         printf("--- run queues ---\n");
 332         for (cpu = 0; cpu < ncpus; cpu++) {
 333                 printf("CPU %d :\n", cpu);
 334                 ser_dump_queue_cpu(cpu);
 335         }
 336 #else
 337         ser_dump_queue_cpu(0);
 338 #endif
 339 }
 340
 341 #ifdef CONFIG_SMP
 342 static void dump_bkl_usage(void)
 343 {
 344         unsigned cpu;
 345
 346         printf("--- BKL usage ---\n");
 347         for (cpu = 0; cpu < ncpus; cpu++) {
 348                 printf("cpu %3d kernel ticks 0x%x%08x bkl ticks 0x%x%08x succ %d tries %d\n", cpu,
 349                                 ex64hi(kernel_ticks[cpu]),
 350                                 ex64lo(kernel_ticks[cpu]),
 351                                 ex64hi(bkl_ticks[cpu]),
 352                                 ex64lo(bkl_ticks[cpu]),
 353                                 bkl_succ[cpu], bkl_tries[cpu]);
 354         }
 355 }
 356
 357 static void reset_bkl_usage(void)
 358 {
 359         memset(kernel_ticks, 0, sizeof(kernel_ticks));
 360         memset(bkl_ticks, 0, sizeof(bkl_ticks));
 361         memset(bkl_tries, 0, sizeof(bkl_tries));
 362         memset(bkl_succ, 0, sizeof(bkl_succ));
 363 }
 364 #endif
 365
 366 static void ser_debug(const int c)
 367 {
 368         serial_debug_active = 1;
 369
 370         switch(c)
 371         {
 372         case 'Q':
 373                 minix_shutdown(NULL);
 374                 NOT_REACHABLE;
 375 #ifdef CONFIG_SMP
 376         case 'B':
 377                 dump_bkl_usage();
 378                 break;
 379         case 'b':
 380                 reset_bkl_usage();
 381                 break;
 382 #endif
 383         case '1':
 384                 ser_dump_proc();
 385                 break;
 386         case '2':
 387                 ser_dump_queues();
 388                 break;
 389 #ifdef CONFIG_SMP
 390         case '4':
 391                 ser_dump_proc_cpu();
 392                 break;
 393 #endif
 394 #if DEBUG_TRACE
 395 #define TOGGLECASE(ch, flag)                            \
 396         case ch: {                                      \
 397                 if(verboseflags & flag) {               \
 398                         verboseflags &= ~flag;          \
 399                         printf("%s disabled\n", #flag); \
 400                 } else {                                \
 401                         verboseflags |= flag;           \
 402                         printf("%s enabled\n", #flag);  \
 403                 }                                       \
 404                 break;                                  \
 405                 }
 406         TOGGLECASE('8', VF_SCHEDULING)
 407         TOGGLECASE('9', VF_PICKPROC)
 408 #endif
 409 #ifdef USE_APIC
 410         case 'I':
 411                 dump_apic_irq_state();
 412                 break;
 413 #endif
 414         }
 415         serial_debug_active = 0;
 416 }
 417
 418 #if DEBUG_SERIAL
 419 void ser_dump_proc()
 420 {
 421         struct proc *pp;
 422
 423         for (pp= BEG_PROC_ADDR; pp < END_PROC_ADDR; pp++)
 424         {
 425                 if (isemptyp(pp))
 426                         continue;
 427                 print_proc_recursive(pp);
 428         }
 429 }
 430
 431 #ifdef CONFIG_SMP
 432 static void ser_dump_proc_cpu(void)
 433 {
 434         struct proc *pp;
 435         unsigned cpu;
 436
 437         for (cpu = 0; cpu < ncpus; cpu++) {
 438                 printf("CPU %d processes : \n", cpu);
 439                 for (pp= BEG_USER_ADDR; pp < END_PROC_ADDR; pp++) {
 440                         if (isemptyp(pp) || pp->p_cpu != cpu)
 441                                 continue;
 442                         print_proc(pp);
 443                 }
 444         }
 445 }
 446 #endif
 447
 448 #endif /* DEBUG_SERIAL */
 449
 450 #if SPROFILE
 451
 452 int arch_init_profile_clock(const u32_t freq)
 453 {
 454   int r;
 455   /* Set CMOS timer frequency. */
 456   outb(RTC_INDEX, RTC_REG_A);
 457   outb(RTC_IO, RTC_A_DV_OK | freq);
 458   /* Enable CMOS timer interrupts. */
 459   outb(RTC_INDEX, RTC_REG_B);
 460   r = inb(RTC_IO);
 461   outb(RTC_INDEX, RTC_REG_B);
 462   outb(RTC_IO, r | RTC_B_PIE);
 463   /* Mandatory read of CMOS register to enable timer interrupts. */
 464   outb(RTC_INDEX, RTC_REG_C);
 465   inb(RTC_IO);
 466
 467   return CMOS_CLOCK_IRQ;
 468 }
 469
 470 void arch_stop_profile_clock(void)
 471 {
 472   int r;
 473   /* Disable CMOS timer interrupts. */
 474   outb(RTC_INDEX, RTC_REG_B);
 475   r = inb(RTC_IO);
 476   outb(RTC_INDEX, RTC_REG_B);
 477   outb(RTC_IO, r & ~RTC_B_PIE);
 478 }
 479
 480 void arch_ack_profile_clock(void)
 481 {
 482   /* Mandatory read of CMOS register to re-enable timer interrupts. */
 483   outb(RTC_INDEX, RTC_REG_C);
 484   inb(RTC_IO);
 485 }
 486
 487 #endif
 488
 489 void arch_do_syscall(struct proc *proc)
 490 {
 491   /* do_ipc assumes that it's running because of the current process */
 492   assert(proc == get_cpulocal_var(proc_ptr));
 493   /* Make the system call, for real this time. */
 494   proc->p_reg.retreg =
 495           do_ipc(proc->p_reg.cx, proc->p_reg.retreg, proc->p_reg.bx);
 496 }
 497
 498 struct proc * arch_finish_switch_to_user(void)
 499 {
 500         char * stk;
 501         struct proc * p;
 502
 503 #ifdef CONFIG_SMP
 504         stk = (char *)tss[cpuid].sp0;
 505 #else
 506         stk = (char *)tss[0].sp0;
 507 #endif
 508         /* set pointer to the process to run on the stack */
 509         p = get_cpulocal_var(proc_ptr);
 510         *((reg_t *)stk) = (reg_t) p;
 511
 512         /* make sure IF is on in FLAGS so that interrupts won't be disabled
 513          * once p's context is restored. this should not be possible.
 514          */
 515         assert(p->p_reg.psw & (1L << 9));
 516
 517         return p;
 518 }
 519
 520 void arch_proc_setcontext(struct proc *p, struct stackframe_s *state, int isuser)
 521 {
 522         if(isuser) {
 523                 /* Restore user bits of psw from sc, maintain system bits
 524                  * from proc.
 525                  */
 526                 state->psw  =  (state->psw & X86_FLAGS_USER) |
 527                         (p->p_reg.psw & ~X86_FLAGS_USER);
 528         }
 529
 530         /* someone wants to totally re-initialize process state */
 531         assert(sizeof(p->p_reg) == sizeof(*state));
 532         memcpy(&p->p_reg, state, sizeof(*state));
 533
 534         /* further code is instructed to not touch the context
 535          * any more
 536          */
 537         p->p_misc_flags |= MF_CONTEXT_SET;
 538
 539         /* on x86 this requires returning using iret (KTS_INT)
 540          * so that the full context is restored instead of relying on
 541          * the userspace doing it (as it would do on SYSEXIT).
 542          * as ESP and EIP are also reset, userspace won't try to
 543          * restore bogus context after returning.
 544          *
 545          * if the process is not blocked, or the kernel will ignore
 546          * our trap style, we needn't panic but things will probably
 547          * not go well for the process (restored context will be ignored)
 548          * and the situation should be debugged.
 549          */
 550         if(!(p->p_rts_flags)) {
 551                 printf("WARNINIG: setting full context of runnable process\n");
 552                 print_proc(p);
 553                 util_stacktrace();
 554         }
 555         if(p->p_seg.p_kern_trap_style == KTS_NONE)
 556                 printf("WARNINIG: setting full context of out-of-kernel process\n");
 557         p->p_seg.p_kern_trap_style = KTS_FULLCONTEXT;
 558 }
 559
 560 void restore_user_context(struct proc *p)
 561 {
 562         int trap_style = p->p_seg.p_kern_trap_style;
 563 #if 0
 564 #define TYPES 10
 565         static int restores[TYPES], n = 0;
 566
 567         if(trap_style >= 0 && trap_style < TYPES)
 568                 restores[trap_style]++;
 569
 570         if(!(n++ % 500000)) {
 571                 int t;
 572                 for(t = 0; t < TYPES; t++)
 573                         if(restores[t])
 574                                 printf("%d: %d   ", t, restores[t]);
 575                 printf("\n");
 576         }
 577 #endif
 578
 579         p->p_seg.p_kern_trap_style = KTS_NONE;
 580
 581         if(trap_style == KTS_SYSENTER) {
 582                 restore_user_context_sysenter(p);
 583                 NOT_REACHABLE;
 584         }
 585
 586         if(trap_style == KTS_SYSCALL) {
 587                 restore_user_context_syscall(p);
 588                 NOT_REACHABLE;
 589         }
 590
 591         switch(trap_style) {
 592                 case KTS_NONE:
 593                         panic("no entry trap style known");
 594                 case KTS_INT_HARD:
 595                 case KTS_INT_UM:
 596                 case KTS_FULLCONTEXT:
 597                 case KTS_INT_ORIG:
 598                         restore_user_context_int(p);
 599                         NOT_REACHABLE;
 600                 default:
 601                         panic("unknown trap style recorded");
 602                         NOT_REACHABLE;
 603         }
 604
 605         NOT_REACHABLE;
 606 }
 607
 608 void fpu_sigcontext(struct proc *pr, struct sigframe *fr, struct sigcontext *sc)
 609 {
 610         int fp_error;
 611
 612         if (osfxsr_feature) {
 613                 fp_error = sc->sc_fpu_state.xfp_regs.fp_status &
 614                         ~sc->sc_fpu_state.xfp_regs.fp_control;
 615         } else {
 616                 fp_error = sc->sc_fpu_state.fpu_regs.fp_status &
 617                         ~sc->sc_fpu_state.fpu_regs.fp_control;
 618         }
 619
 620         if (fp_error & 0x001) {      /* Invalid op */
 621                 /*
 622                  * swd & 0x240 == 0x040: Stack Underflow
 623                  * swd & 0x240 == 0x240: Stack Overflow
 624                  * User must clear the SF bit (0x40) if set
 625                  */
 626                 fr->sf_code = FPE_FLTINV;
 627         } else if (fp_error & 0x004) {
 628                 fr->sf_code = FPE_FLTDIV; /* Divide by Zero */
 629         } else if (fp_error & 0x008) {
 630                 fr->sf_code = FPE_FLTOVF; /* Overflow */
 631         } else if (fp_error & 0x012) {
 632                 fr->sf_code = FPE_FLTUND; /* Denormal, Underflow */
 633         } else if (fp_error & 0x020) {
 634                 fr->sf_code = FPE_FLTRES; /* Precision */
 635         } else {
 636                 fr->sf_code = 0;  /* XXX - probably should be used for FPE_INTOVF or
 637                                   * FPE_INTDIV */
 638         }
 639 }
 640
 641 reg_t arch_get_sp(struct proc *p) { return p->p_reg.sp; }
 642
 643 #if !CONFIG_OXPCIE
 644 static void ser_init(void)
 645 {
 646         unsigned char lcr;
 647         unsigned divisor;
 648
 649         /* keep BIOS settings if cttybaud is not set */
 650         if (kinfo.serial_debug_baud <= 0) return;
 651
 652         /* set DLAB to make baud accessible */
 653         lcr = LCR_8BIT | LCR_1STOP | LCR_NPAR;
 654         outb(COM1_LCR, lcr | LCR_DLAB);
 655
 656         /* set baud rate */
 657         divisor = UART_BASE_FREQ / kinfo.serial_debug_baud;
 658         if (divisor < 1) divisor = 1;
 659         if (divisor > 65535) divisor = 65535;
 660
 661         outb(COM1_DLL, divisor & 0xff);
 662         outb(COM1_DLM, (divisor >> 8) & 0xff);
 663
 664         /* clear DLAB */
 665         outb(COM1_LCR, lcr);
 666 }
 667 #endif
 668