kern/arch/riscv/time.c

   1 #include <arch/time.h>
   2 #include <ros/common.h>
   3 #include <trap.h>
   4 #include <arch/arch.h>
   5 #include <stdio.h>
   6 #include <assert.h>
   7 #include <ros/procinfo.h>
   8
   9 void
  10 timer_init(void)
  11 {
  12         __proc_global_info.tsc_freq = TSC_HZ;
  13         cprintf("TSC Frequency: %llu\n", __proc_global_info.tsc_freq);
  14 }
  15
  16 void
  17 set_core_timer(uint32_t usec, bool periodic)
  18 {
  19         // we could implement periodic timers using one-shot timers,
  20         // but for now we only support one-shot
  21         assert(!periodic);
  22
  23         if (usec)
  24         {
  25                 uint32_t clocks =  (uint64_t)usec*TSC_HZ/1000000;
  26
  27                 int8_t irq_state = 0;
  28                 disable_irqsave(&irq_state);
  29
  30                 mtpcr(PCR_COUNT, 0);
  31                 mtpcr(PCR_COMPARE, clocks);
  32                 mtpcr(PCR_SR, mfpcr(PCR_SR) | (1 << (IRQ_TIMER+SR_IM_SHIFT)));
  33
  34                 enable_irqsave(&irq_state);
  35         }
  36         else
  37         {
  38                 mtpcr(PCR_SR, mfpcr(PCR_SR) & ~(1 << (IRQ_TIMER+SR_IM_SHIFT)));
  39         }
  40 }
  41
  42 void
  43 udelay(uint64_t usec)
  44 {
  45         if (__proc_global_info.tsc_freq != 0)
  46         {
  47                 uint64_t start, end, now;
  48
  49                 start = read_tsc();
  50                 end = start + (__proc_global_info.tsc_freq * usec) / 1000000;
  51
  52                 do
  53                 {
  54                         cpu_relax();
  55                         now = read_tsc();
  56                 } while (now < end || (now > start && end < start));
  57         }
  58         else panic("udelay() was called before timer_init(), moron!");
  59 }
  60
  61 uint64_t read_persistent_clock(void)
  62 {
  63         return 1242129600 * 1000000000UL; /* nanwan's birthday */
  64 }