-#include "vl.h"
+/*
+ * QEMU MIPS timer support
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
-void cpu_mips_irqctrl_init (void)
-{
-}
+#include "hw.h"
+#include "mips_cpudevs.h"
+#include "qemu-timer.h"
+
+#define TIMER_FREQ 100 * 1000 * 1000
/* XXX: do not use a global */
-uint32_t cpu_mips_get_random (CPUState *env)
+uint32_t cpu_mips_get_random (CPUMIPSState *env)
{
- static uint32_t seed = 0;
+ static uint32_t lfsr = 1;
+ static uint32_t prev_idx = 0;
uint32_t idx;
- seed = seed * 314159 + 1;
- idx = (seed >> 16) % (MIPS_TLB_NB - env->CP0_Wired) + env->CP0_Wired;
+ /* 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;
+ } while (idx == prev_idx);
+ prev_idx = idx;
return idx;
}
/* MIPS R4K timer */
-uint32_t cpu_mips_get_count (CPUState *env)
+static void cpu_mips_timer_update(CPUMIPSState *env)
{
- return env->CP0_Count +
- (uint32_t)muldiv64(qemu_get_clock(vm_clock),
- 100 * 1000 * 1000, ticks_per_sec);
+ uint64_t now, next;
+ uint32_t wait;
+
+ now = qemu_get_clock_ns(vm_clock);
+ 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);
+ qemu_mod_timer(env->timer, next);
}
-void cpu_mips_store_count (CPUState *env, uint32_t count)
+/* Expire the timer. */
+static void cpu_mips_timer_expire(CPUMIPSState *env)
{
- uint64_t now, next;
- uint32_t tmp;
- uint32_t compare = env->CP0_Compare;
-
- tmp = count;
- if (count == compare)
- tmp++;
- now = qemu_get_clock(vm_clock);
- next = now + muldiv64(compare - tmp, ticks_per_sec, 100 * 1000 * 1000);
- if (next == now)
- next++;
-#if 0
- if (logfile) {
- fprintf(logfile, "%s: 0x%08" PRIx64 " %08x %08x => 0x%08" PRIx64 "\n",
- __func__, now, count, compare, next - now);
+ cpu_mips_timer_update(env);
+ if (env->insn_flags & ISA_MIPS32R2) {
+ env->CP0_Cause |= 1 << CP0Ca_TI;
}
-#endif
- /* Store new count and compare registers */
- env->CP0_Compare = compare;
- env->CP0_Count =
- count - (uint32_t)muldiv64(now, 100 * 1000 * 1000, ticks_per_sec);
- /* Adjust timer */
- qemu_mod_timer(env->timer, next);
+ qemu_irq_raise(env->irq[(env->CP0_IntCtl >> CP0IntCtl_IPTI) & 0x7]);
}
-static void cpu_mips_update_count (CPUState *env, uint32_t count)
+uint32_t cpu_mips_get_count (CPUMIPSState *env)
{
- if (env->CP0_Cause & (1 << CP0Ca_DC))
- return;
+ if (env->CP0_Cause & (1 << CP0Ca_DC)) {
+ return env->CP0_Count;
+ } else {
+ uint64_t now;
+
+ now = qemu_get_clock_ns(vm_clock);
+ if (qemu_timer_pending(env->timer)
+ && qemu_timer_expired(env->timer, now)) {
+ /* The timer has already expired. */
+ cpu_mips_timer_expire(env);
+ }
+
+ return env->CP0_Count +
+ (uint32_t)muldiv64(now, TIMER_FREQ, get_ticks_per_sec());
+ }
+}
- cpu_mips_store_count(env, count);
+void cpu_mips_store_count (CPUMIPSState *env, uint32_t count)
+{
+ if (env->CP0_Cause & (1 << CP0Ca_DC))
+ env->CP0_Count = count;
+ else {
+ /* Store new count register */
+ env->CP0_Count =
+ count - (uint32_t)muldiv64(qemu_get_clock_ns(vm_clock),
+ TIMER_FREQ, get_ticks_per_sec());
+ /* Update timer timer */
+ cpu_mips_timer_update(env);
+ }
}
-void cpu_mips_store_compare (CPUState *env, uint32_t value)
+void cpu_mips_store_compare (CPUMIPSState *env, uint32_t value)
{
env->CP0_Compare = value;
- cpu_mips_update_count(env, cpu_mips_get_count(env));
- if ((env->CP0_Config0 & (0x7 << CP0C0_AR)) == (1 << CP0C0_AR))
+ if (!(env->CP0_Cause & (1 << CP0Ca_DC)))
+ cpu_mips_timer_update(env);
+ if (env->insn_flags & ISA_MIPS32R2)
env->CP0_Cause &= ~(1 << CP0Ca_TI);
- qemu_irq_lower(env->irq[7]);
+ qemu_irq_lower(env->irq[(env->CP0_IntCtl >> CP0IntCtl_IPTI) & 0x7]);
+}
+
+void cpu_mips_start_count(CPUMIPSState *env)
+{
+ cpu_mips_store_count(env, env->CP0_Count);
+}
+
+void cpu_mips_stop_count(CPUMIPSState *env)
+{
+ /* Store the current value */
+ env->CP0_Count += (uint32_t)muldiv64(qemu_get_clock_ns(vm_clock),
+ TIMER_FREQ, get_ticks_per_sec());
}
static void mips_timer_cb (void *opaque)
{
- CPUState *env;
+ CPUMIPSState *env;
env = opaque;
#if 0
- if (logfile) {
- fprintf(logfile, "%s\n", __func__);
- }
+ qemu_log("%s\n", __func__);
#endif
- cpu_mips_update_count(env, cpu_mips_get_count(env));
- if ((env->CP0_Config0 & (0x7 << CP0C0_AR)) == (1 << CP0C0_AR))
- env->CP0_Cause |= 1 << CP0Ca_TI;
- qemu_irq_raise(env->irq[7]);
+
+ if (env->CP0_Cause & (1 << CP0Ca_DC))
+ return;
+
+ /* ??? This callback should occur when the counter is exactly equal to
+ the comparator value. Offset the count by one to avoid immediately
+ retriggering the callback before any virtual time has passed. */
+ env->CP0_Count++;
+ cpu_mips_timer_expire(env);
+ env->CP0_Count--;
}
-void cpu_mips_clock_init (CPUState *env)
+void cpu_mips_clock_init (CPUMIPSState *env)
{
- env->timer = qemu_new_timer(vm_clock, &mips_timer_cb, env);
+ env->timer = qemu_new_timer_ns(vm_clock, &mips_timer_cb, env);
env->CP0_Compare = 0;
- cpu_mips_update_count(env, 1);
+ cpu_mips_store_count(env, 1);
}
projects / qemu.git / blobdiff