* THE SOFTWARE.
*/
+#include "qemu/osdep.h"
#include "hw/hw.h"
#include "hw/mips/cpudevs.h"
#include "qemu/timer.h"
#include "sysemu/kvm.h"
-#define TIMER_FREQ 100 * 1000 * 1000
+#define TIMER_PERIOD 10 /* 10 ns period for 100 Mhz frequency */
/* XXX: do not use a global */
uint32_t cpu_mips_get_random (CPUMIPSState *env)
{
- static uint32_t lfsr = 1;
+ static uint32_t seed = 1;
static uint32_t prev_idx = 0;
uint32_t idx;
+ uint32_t nb_rand_tlb = env->tlb->nb_tlb - env->CP0_Wired;
+
+ if (nb_rand_tlb == 1) {
+ return env->tlb->nb_tlb - 1;
+ }
+
/* Don't return same value twice, so get another value */
do {
- lfsr = (lfsr >> 1) ^ (-(lfsr & 1u) & 0xd0000001u);
- idx = lfsr % (env->tlb->nb_tlb - env->CP0_Wired) + env->CP0_Wired;
+ /* Use a simple algorithm of Linear Congruential Generator
+ * from ISO/IEC 9899 standard. */
+ seed = 1103515245 * seed + 12345;
+ idx = (seed >> 16) % nb_rand_tlb + env->CP0_Wired;
} while (idx == prev_idx);
prev_idx = idx;
return idx;
uint32_t wait;
now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
- wait = env->CP0_Compare - env->CP0_Count -
- (uint32_t)muldiv64(now, TIMER_FREQ, get_ticks_per_sec());
- next = now + muldiv64(wait, get_ticks_per_sec(), TIMER_FREQ);
+ wait = env->CP0_Compare - env->CP0_Count - (uint32_t)(now / TIMER_PERIOD);
+ next = now + (uint64_t)wait * TIMER_PERIOD;
timer_mod(env->timer, next);
}
cpu_mips_timer_expire(env);
}
- return env->CP0_Count +
- (uint32_t)muldiv64(now, TIMER_FREQ, get_ticks_per_sec());
+ return env->CP0_Count + (uint32_t)(now / TIMER_PERIOD);
}
}
env->CP0_Count = count;
else {
/* Store new count register */
- env->CP0_Count =
- count - (uint32_t)muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
- TIMER_FREQ, get_ticks_per_sec());
+ env->CP0_Count = count -
+ (uint32_t)(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / TIMER_PERIOD);
/* Update timer timer */
cpu_mips_timer_update(env);
}
void cpu_mips_stop_count(CPUMIPSState *env)
{
/* Store the current value */
- env->CP0_Count += (uint32_t)muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
- TIMER_FREQ, get_ticks_per_sec());
+ env->CP0_Count += (uint32_t)(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) /
+ TIMER_PERIOD);
}
static void mips_timer_cb (void *opaque)