aboutsummaryrefslogtreecommitdiff
path: root/target/mips/cp0_timer.c
diff options
context:
space:
mode:
authorPhilippe Mathieu-Daudé <f4bug@amsat.org>2017-09-20 16:49:29 -0300
committerYongbok Kim <yongbok.kim@imgtec.com>2017-09-21 13:24:34 +0100
commit5502b66fc7d0bebd08b9b7017cb7e8b5261c3a2d (patch)
tree49bb5858296ea9d548f781bce5843851608deed6 /target/mips/cp0_timer.c
parentff5667ed53c544c4dc88dcd7cb23cc509c9a55e0 (diff)
mips: move hw/mips/cputimer.c to target/mips/
This timer is a required part of the MIPS32/MIPS64 System Control coprocessor (CP0). Moving it with the other architecture related files will allow an opaque use of CPUMIPSState* in the next commit (introduce "internal.h"). also remove it from 'user' targets, remove an unnecessary include. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Tested-by: Igor Mammedov <imammedo@redhat.com> Tested-by: James Hogan <james.hogan@imgtec.com> Acked-by: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
Diffstat (limited to 'target/mips/cp0_timer.c')
-rw-r--r--target/mips/cp0_timer.c164
1 files changed, 164 insertions, 0 deletions
diff --git a/target/mips/cp0_timer.c b/target/mips/cp0_timer.c
new file mode 100644
index 0000000000..a9a58c5604
--- /dev/null
+++ b/target/mips/cp0_timer.c
@@ -0,0 +1,164 @@
+/*
+ * 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.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/mips/cpudevs.h"
+#include "qemu/timer.h"
+#include "sysemu/kvm.h"
+
+#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 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 {
+ /* 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;
+}
+
+/* MIPS R4K timer */
+static void cpu_mips_timer_update(CPUMIPSState *env)
+{
+ uint64_t now, next;
+ uint32_t wait;
+
+ now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+ wait = env->CP0_Compare - env->CP0_Count - (uint32_t)(now / TIMER_PERIOD);
+ next = now + (uint64_t)wait * TIMER_PERIOD;
+ timer_mod(env->timer, next);
+}
+
+/* Expire the timer. */
+static void cpu_mips_timer_expire(CPUMIPSState *env)
+{
+ cpu_mips_timer_update(env);
+ if (env->insn_flags & ISA_MIPS32R2) {
+ env->CP0_Cause |= 1 << CP0Ca_TI;
+ }
+ qemu_irq_raise(env->irq[(env->CP0_IntCtl >> CP0IntCtl_IPTI) & 0x7]);
+}
+
+uint32_t cpu_mips_get_count (CPUMIPSState *env)
+{
+ if (env->CP0_Cause & (1 << CP0Ca_DC)) {
+ return env->CP0_Count;
+ } else {
+ uint64_t now;
+
+ now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+ if (timer_pending(env->timer)
+ && timer_expired(env->timer, now)) {
+ /* The timer has already expired. */
+ cpu_mips_timer_expire(env);
+ }
+
+ return env->CP0_Count + (uint32_t)(now / TIMER_PERIOD);
+ }
+}
+
+void cpu_mips_store_count (CPUMIPSState *env, uint32_t count)
+{
+ /*
+ * This gets called from cpu_state_reset(), potentially before timer init.
+ * So env->timer may be NULL, which is also the case with KVM enabled so
+ * treat timer as disabled in that case.
+ */
+ if (env->CP0_Cause & (1 << CP0Ca_DC) || !env->timer)
+ env->CP0_Count = count;
+ else {
+ /* Store new count register */
+ 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_store_compare (CPUMIPSState *env, uint32_t value)
+{
+ env->CP0_Compare = value;
+ 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[(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)(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) /
+ TIMER_PERIOD);
+}
+
+static void mips_timer_cb (void *opaque)
+{
+ CPUMIPSState *env;
+
+ env = opaque;
+#if 0
+ qemu_log("%s\n", __func__);
+#endif
+
+ 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 (MIPSCPU *cpu)
+{
+ CPUMIPSState *env = &cpu->env;
+
+ /*
+ * If we're in KVM mode, don't create the periodic timer, that is handled in
+ * kernel.
+ */
+ if (!kvm_enabled()) {
+ env->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &mips_timer_cb, env);
+ }
+}