arch/all-pc/kernel/apic_ia32.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Intel IA-32 APIC driver.
   6 */
   7
   8 #include <asm/cpu.h>
   9 #include <asm/io.h>
  10 #include <exec/types.h>
  11
  12 #include <inttypes.h>
  13
  14 #include "apic.h"
  15 #include "apic_ia32.h"
  16 #include "kernel_base.h"
  17 #include "kernel_debug.h"
  18 #include "kernel_syscall.h"
  19 #include "kernel_timer.h"
  20
  21 #define D(x)
  22 #define DWAKE(x) /* Badly interferes with AP startup */
  23 /* #define DEBUG_WAIT */
  24
  25 /*
  26  * On i386 platform we need to support various quirks of old APICs.
  27  * x86-64 is free of that crap.
  28  */
  29 #ifdef __i386__
  30 #define CONFIG_LEGACY
  31 #endif
  32
  33 static ULONG DoIPI(IPTR __APICBase, ULONG target, ULONG cmd)
  34 {
  35     ULONG ipisend_timeout, status_ipisend;
  36
  37     D(bug("[IPI] Command 0x%08X to target %u\n", cmd, target));
  38
  39     /*
  40      * Send the IPI.
  41      * First we write target APIC ID into high command register.
  42      * Writing to the low register triggers the IPI itself.
  43      */
  44     APIC_REG(__APICBase, APIC_ICRH) = target << 24;
  45     APIC_REG(__APICBase, APIC_ICRL) = cmd;
  46
  47     D(bug("[IPI] Waiting for IPI to complete "));
  48
  49     for (ipisend_timeout = 1000; ipisend_timeout > 0; ipisend_timeout--)
  50     {
  51         pit_udelay(100);
  52 #ifdef DEBUG_WAIT
  53         if ((ipisend_timeout % 100) == 0)
  54         {
  55             bug(".");
  56         }
  57 #endif
  58         status_ipisend = APIC_REG(__APICBase, APIC_ICRL) & ICR_DS;
  59         /* Delivery status resets to 0 when delivery is done */
  60         if (status_ipisend == 0)
  61             break;
  62     }
  63     D(bug("\n"));
  64     D(bug("[IPI] ... left wait loop (status = 0x%08X)\n", status_ipisend));
  65
  66     return status_ipisend;
  67 }
  68
  69 /**********************************************************
  70                         Driver functions
  71  **********************************************************/
  72
  73 void core_APIC_Init(struct APICData *apic, ULONG cpuNum)
  74 {
  75     IPTR __APICBase = apic->lapicBase;
  76     ULONG apic_ver = APIC_REG(__APICBase, APIC_VERSION);
  77     ULONG maxlvt = APIC_LVT(apic_ver);
  78     ULONG lapic_initial, lapic_final;
  79     WORD pit_final;
  80
  81 #ifdef CONFIG_LEGACY
  82     /* 82489DX doesnt report no. of LVT entries. */
  83     if (!APIC_INTEGRATED(apic_ver))
  84         maxlvt = 2;
  85 #endif
  86
  87     /* Use flat interrupt model with logical destination ID = 1 */
  88     APIC_REG(__APICBase, APIC_DFR) = DFR_FLAT;
  89     APIC_REG(__APICBase, APIC_LDR) = 1 << LDR_ID_SHIFT;
  90
  91     /* Set Task Priority to 'accept all interrupts' */
  92     APIC_REG(__APICBase, APIC_TPR) = 0;
  93
  94     /* Set spurious IRQ vector to 0xFF. APIC enabled, focus check disabled. */
  95     APIC_REG(__APICBase, APIC_SVR) = SVR_ASE|SVR_FCC|0xFF;
  96
  97     /*
  98      * Set LINT0 to external and LINT1 to NMI.
  99      * These are common defaults and they are going to be overriden by ACPI tables.
 100      */
 101     APIC_REG(__APICBase, APIC_LINT0_VEC) = LVT_MT_EXT;
 102     APIC_REG(__APICBase, APIC_LINT1_VEC) = LVT_MT_NMI;
 103
 104 #ifdef CONFIG_LEGACY
 105     /* Due to the Pentium erratum 3AP. */
 106     if (maxlvt > 3)
 107          APIC_REG(__APICBase, APIC_ESR) = 0;
 108 #endif
 109
 110     D(bug("[APIC.%u] _APIC_IA32_init: APIC ESR before enabling vector: %08x\n", cpuNum, APIC_REG(__APICBase, APIC_ESR)));
 111
 112     /* Set APIC error interrupt to fixed vector 0xFE interrupt on APIC error */
 113     APIC_REG(__APICBase, APIC_ERROR_VEC) = 0xfe;
 114
 115     /* spec says clear errors after enabling vector. */
 116     if (maxlvt > 3)
 117          APIC_REG(__APICBase, APIC_ESR) = 0;
 118
 119     D(bug("[APIC.%u] _APIC_IA32_init: APIC ESR after enabling vector: %08x\n", cpuNum, APIC_REG(__APICBase, APIC_ESR)));
 120
 121     /*
 122      * Now the tricky thing - calibrate LAPIC timer frequency.
 123      * In fact we could simply query CPU's clock frequency, but... x86 sucks. There's no
 124      * unified way to get it on whatever CPU. Intel has own way, AMD has own way... Etc... Which, additionally,
 125      * varies between CPU generations.
 126      *
 127      * The idea behing the calibration is to run the timer once, and see how much ticks passes in some defined
 128      * period of time. Then calculate a proportion.
 129      * We use 8253 PIT as our reference.
 130      * This calibrarion algorighm is based on NetBSD one.
 131      */
 132
 133     /* Set the timer to one-shot mode, no interrupt, 1:1 divisor */
 134     APIC_REG(__APICBase, APIC_TIMER_VEC) = LVT_MASK;
 135     APIC_REG(__APICBase, APIC_TIMER_DIV) = TIMER_DIV_1;
 136     APIC_REG(__APICBase, APIC_TIMER_ICR) = 0x80000000;  /* Just some very large value */
 137
 138     /*
 139      * Now wait for 11931 PIT ticks, which is equal to 10 milliseconds.
 140      * We don't use pit_udelay() here, because for improved accuracy we need to sample LAPIC timer counter twice,
 141      * before and after our actual delay (PIT setup also takes up some time, so LAPIC will count away from its
 142      * initial value).
 143      */
 144     pit_start(11931);
 145     lapic_initial = APIC_REG(__APICBase, APIC_TIMER_CCR);
 146
 147     pit_final   = pit_wait(11931);
 148     lapic_final = APIC_REG(__APICBase, APIC_TIMER_CCR);
 149
 150     /*
 151      * TODO: Upon exit from pit_wait() pit_final contains negated number of excessive ticks after 10ms has passed.
 152      * This can be used to improve calibration quality (currently we report 265 mHz instead of 266).
 153      */
 154     D(bug("[APIC.%u] LAPIC counted from %u to %u in 10ms (%u ticks)\n", cpuNum, lapic_initial, lapic_final, 11931 - pit_final));
 155     (void)pit_final; // Unused if not debugging - suppress compiler warning
 156
 157     apic->cores[cpuNum].timerFreq = (lapic_initial - lapic_final) * 100;
 158     D(bug("[APIC.%u] LAPIC frequency should be %u Hz (%u mHz)\n", cpuNum, apic->cores[cpuNum].timerFreq, apic->cores[cpuNum].timerFreq / 1000000));
 159 }
 160
 161 UBYTE core_APIC_GetID(IPTR _APICBase)
 162 {
 163     UBYTE _apic_id;
 164
 165     /* The actual ID is in 8 most significant bits */
 166     _apic_id = APIC_REG(_APICBase, APIC_ID) >> APIC_ID_SHIFT;
 167     D(bug("[APIC] _APIC_IA32_GetID: APIC ID %d\n", _apic_id));
 168
 169     return _apic_id;
 170 }
 171
 172 void core_APIC_AckIntr(void)
 173 {
 174     /* Write zero to EOI of current APIC */
 175     IPTR apic_base = core_APIC_GetBase();
 176
 177     APIC_REG(apic_base, APIC_EOI) = 0;
 178 }
 179
 180 ULONG core_APIC_Wake(APTR wake_apicstartrip, UBYTE wake_apicid, IPTR __APICBase)
 181 {
 182     ULONG status_ipisend, status_ipirecv;
 183     ULONG start_count;
 184 #ifdef CONFIG_LEGACY
 185     ULONG apic_ver = APIC_REG(__APICBase, APIC_VERSION);
 186 #endif
 187
 188     D(bug("[APIC] _APIC_IA32_wake(0x%02X @ %p)\n", wake_apicid, wake_apicstartrip));
 189     D(bug("[APIC] _APIC_IA32_wake: APIC ID 0x%02X Base @ %p\n", core_APIC_GetID(__APICBase), __APICBase));
 190
 191 #ifdef CONFIG_LEGACY
 192     /*
 193      * Check if we have old 82489DX discrete APIC (version & 0xF0 == 0).
 194      * This APIC needs different startup procedure. It doesn't support STARTUP IPI
 195      * because old CPUs didn't have INIT signal. They jump to BIOS ROM boot code
 196      * immediately after INIT IPI. In order to run the bootstrap, a BIOS warm reset
 197      * magic has to be used there.
 198      */
 199     if (!APIC_INTEGRATED(apic_ver))
 200     {
 201         /*
 202          * BIOS warm reset magic, part one.
 203          * Write real-mode bootstrap routine address to 40:67 (real-mode address) location.
 204          * This is standard feature of IBM PC AT BIOS. If a warm reset condition is detected,
 205          * the BIOS jumps to the given address.
 206          */
 207         D(bug("[APIC] Setting BIOS vector for trampoline @ %p ..\n", wake_apicstartrip));
 208         *((volatile unsigned short *)0x469) = (IPTR)wake_apicstartrip >> 4;
 209         *((volatile unsigned short *)0x467) = 0; /* Actually wake_apicstartrip & 0x0F, it's page-aligned. */
 210
 211         /*
 212          * BIOS warm reset magic, part two.
 213          * This writes 0x0A into CMOS RAM, location 0x0F. This signals a warm reset condition to BIOS,
 214          * making part one work.
 215          */
 216         D(bug("[APIC] Setting warm reset code ..\n"));
 217         outb(0xf, 0x70);
 218         outb(0xa, 0x71);
 219     }
 220 #endif
 221
 222     /* Flush TLB (we are supervisor here) */
 223     wrcr(cr3, rdcr(cr3));
 224
 225     /* First we send the INIT command (reset the core). Vector must be zero for this. */
 226     status_ipisend = DoIPI(__APICBase, wake_apicid, ICR_INT_LEVELTRIG | ICR_INT_ASSERT | ICR_DM_INIT);
 227     if (status_ipisend)
 228     {
 229         D(bug("[APIC] Error asserting INIT\n"));
 230         return status_ipisend;
 231     }
 232
 233     /* Deassert INIT after a small delay */
 234     pit_udelay(10 * 1000);
 235
 236     /* Deassert INIT */
 237     status_ipisend = DoIPI(__APICBase, wake_apicid, ICR_INT_LEVELTRIG | ICR_DM_INIT);
 238     if (status_ipisend)
 239     {
 240         D(bug("[APIC] Error deasserting INIT\n"));
 241         return status_ipisend;
 242     }
 243
 244     /* memory barrier */
 245     asm volatile("mfence":::"memory");
 246
 247 #ifdef CONFIG_LEGACY
 248     /* If it's 82489DX, we are done. */
 249     if (!APIC_INTEGRATED(apic_ver))
 250     {
 251         DWAKE(bug("[APIC] _APIC_IA32_wake: 82489DX detected, wakeup done\n"));
 252         return 0;
 253     }
 254 #endif
 255
 256     /*
 257      * Perform IPI STARTUP loop.
 258      * According to official Intel specification, this must be done twice.
 259      * It's not explained why. ;-)
 260      */
 261     for (start_count = 1; start_count <= 2; start_count++)
 262     {
 263         D(bug("[APIC] _APIC_IA32_wake: Attempting STARTUP .. %d\n", start_count));
 264
 265         /* Clear any pending error condition */
 266         APIC_REG(__APICBase, APIC_ESR) = 0;
 267
 268         /*
 269          * Send STARTUP IPI.
 270          * The processor starts up at CS = (vector << 16) and IP = 0.
 271          */
 272         status_ipisend = DoIPI(__APICBase, wake_apicid, ICR_DM_STARTUP | ((IPTR)wake_apicstartrip >> 12));
 273
 274         /* Allow the target APIC to accept the IPI */
 275         pit_udelay(200);
 276
 277 #ifdef CONFIG_LEGACY
 278         /* Pentium erratum 3AP quirk */
 279         if (APIC_LVT(apic_ver) > 3)
 280             APIC_REG(__APICBase, APIC_ESR) = 0;
 281 #endif
 282
 283         status_ipirecv = APIC_REG(__APICBase, APIC_ESR) & 0xEF;
 284
 285         /*
 286          * EXPERIMENTAL:
 287          * On my machine (macmini 3,1, as OS X system profiler says), the core starts up from first
 288          * attempt. The second attempt ends up in error (according to the documentation, the STARTUP
 289          * can be accepted only once, while the core in RESET or INIT state, and first STARTUP, if
 290          * succesful, brings the core out of this state).
 291          * Here we try to detect this condition. If the core accepted STARTUP, we suggest that it has
 292          * started up, and break the loop.
 293          * A topic at osdev.org forum (http://forum.osdev.org/viewtopic.php?f=1&t=23018)
 294          * also tells about some problems with double STARTUP. According to it, the second STARTUP can
 295          * manage to re-run the core from the given address, leaving it in 64-bit mode, causing it to crash.
 296          *
 297          * If startup problems pops up (the core doesn't respond and AROS halts at "Launching APIC no X" stage),
 298          * the following two variations of this algorithm can be tried:
 299          * a) Always send STARTUP twice, but signal error condition only if both attempts failed.
 300          * b) Send first STARTUP, abort on error. Allow second attempt to fail and ignore its result.
 301          *
 302          *                                                              Sonic <pavel_fedin@mail.ru>
 303          */
 304         if (!status_ipisend && !status_ipirecv)
 305             break;
 306     }
 307
 308     DWAKE(bug("[APIC] _APIC_IA32_wake: STARTUP run status 0x%08X, error 0x%08X\n", status_ipisend, status_ipirecv));
 309
 310     /*
 311      * We return nonzero on error.
 312      * Actually least significant byte of this value holds ESR value, and 12th bit
 313      * holds delivery status flag from DoIPI() routine. It will be '1' if we got
 314      * stuck at sending phase.
 315      */
 316     return (status_ipisend | status_ipirecv);
 317 }