src/system/kernel/arch/x86/timers/x86_apic.cpp

   1 /*
   2  * Copyright 2008, Dustin Howett, dustin.howett@gmail.com. All rights reserved.
   3  * Copyright 2002-2005, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
   4  * Distributed under the terms of the MIT License.
   5  *
   6  * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
   7  * Distributed under the terms of the NewOS License.
   8  */
   9
  10 #include <timer.h>
  11 #include <arch/x86/timer.h>
  12
  13 #include <int.h>
  14 #include <arch/x86/apic.h>
  15
  16 #include <arch/cpu.h>
  17
  18 #include "apic_timer.h"
  19
  20
  21 /* Method Prototypes */
  22 static int apic_timer_get_priority();
  23 static status_t apic_timer_set_hardware_timer(bigtime_t relativeTimeout);
  24 static status_t apic_timer_clear_hardware_timer();
  25 static status_t apic_timer_init(struct kernel_args *args);
  26
  27 static uint32 sApicTicsPerSec = 0;
  28
  29 struct timer_info gAPICTimer = {
  30         "APIC",
  31         &apic_timer_get_priority,
  32         &apic_timer_set_hardware_timer,
  33         &apic_timer_clear_hardware_timer,
  34         &apic_timer_init
  35 };
  36
  37
  38 static int
  39 apic_timer_get_priority()
  40 {
  41         return 3;
  42 }
  43
  44
  45 static int32
  46 apic_timer_interrupt(void *data)
  47 {
  48         return timer_interrupt();
  49 }
  50
  51
  52 #define MIN_TIMEOUT 1
  53
  54 static status_t
  55 apic_timer_set_hardware_timer(bigtime_t relativeTimeout)
  56 {
  57         if (relativeTimeout < MIN_TIMEOUT)
  58                 relativeTimeout = MIN_TIMEOUT;
  59
  60         // calculation should be ok, since it's going to be 64-bit
  61         uint32 ticks = ((relativeTimeout * sApicTicsPerSec) / 1000000);
  62
  63         cpu_status state = disable_interrupts();
  64
  65         uint32 config = apic_lvt_timer() | APIC_LVT_MASKED; // mask the timer
  66         apic_set_lvt_timer(config);
  67
  68         apic_set_lvt_initial_timer_count(0); // zero out the timer
  69
  70         config = apic_lvt_timer() & ~APIC_LVT_MASKED; // unmask the timer
  71         apic_set_lvt_timer(config);
  72
  73         //TRACE_TIMER(("arch_smp_set_apic_timer: config 0x%lx, timeout %Ld, tics/sec %lu, tics %lu\n",
  74         //      config, relativeTimeout, sApicTicsPerSec, ticks));
  75
  76         apic_set_lvt_initial_timer_count(ticks); // start it up
  77
  78         restore_interrupts(state);
  79
  80         return B_OK;
  81 }
  82
  83
  84 static status_t
  85 apic_timer_clear_hardware_timer()
  86 {
  87         cpu_status state = disable_interrupts();
  88
  89         uint32 config = apic_lvt_timer() | APIC_LVT_MASKED;
  90                 // mask the timer
  91         apic_set_lvt_timer(config);
  92
  93         apic_set_lvt_initial_timer_count(0); // zero out the timer
  94
  95         restore_interrupts(state);
  96         return B_OK;
  97 }
  98
  99
 100 static status_t
 101 apic_timer_init(struct kernel_args *args)
 102 {
 103         if (!apic_available())
 104                 return B_ERROR;
 105
 106         sApicTicsPerSec = args->arch_args.apic_time_cv_factor;
 107
 108         reserve_io_interrupt_vectors(1, 0xfb - ARCH_INTERRUPT_BASE,
 109                 INTERRUPT_TYPE_LOCAL_IRQ);
 110         install_io_interrupt_handler(0xfb - ARCH_INTERRUPT_BASE,
 111                 &apic_timer_interrupt, NULL, B_NO_LOCK_VECTOR);
 112
 113         return B_OK;
 114 }
 115
 116
 117 status_t
 118 apic_timer_per_cpu_init(struct kernel_args *args, int32 cpu)
 119 {
 120         /* setup timer */
 121         uint32 config = apic_lvt_timer() & APIC_LVT_TIMER_MASK;
 122         config |= 0xfb | APIC_LVT_MASKED; // vector 0xfb, timer masked
 123         apic_set_lvt_timer(config);
 124
 125         apic_set_lvt_initial_timer_count(0); // zero out the clock
 126
 127         config = apic_lvt_timer_divide_config() & 0xfffffff0;
 128         config |= APIC_TIMER_DIVIDE_CONFIG_1; // clock division by 1
 129         apic_set_lvt_timer_divide_config(config);
 130         return B_OK;
 131 }