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authorDaniel Baumann <mail@daniel-baumann.ch>2025-06-06 10:05:23 +0000
committerDaniel Baumann <mail@daniel-baumann.ch>2025-06-06 10:05:23 +0000
commit755cc582a2473d06f3a2131d506d0311cc70e9f9 (patch)
tree3efb1ddb8d57bbb4539ac0d229b384871c57820f /hw/openrisc/cputimer.c
parentInitial commit. (diff)
downloadqemu-upstream.tar.xz
qemu-upstream.zip
Adding upstream version 1:7.2+dfsg.upstream/1%7.2+dfsgupstream
Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>
Diffstat (limited to 'hw/openrisc/cputimer.c')
-rw-r--r--hw/openrisc/cputimer.c165
1 files changed, 165 insertions, 0 deletions
diff --git a/hw/openrisc/cputimer.c b/hw/openrisc/cputimer.c
new file mode 100644
index 00000000..10163b39
--- /dev/null
+++ b/hw/openrisc/cputimer.c
@@ -0,0 +1,165 @@
+/*
+ * QEMU OpenRISC timer support
+ *
+ * Copyright (c) 2011-2012 Jia Liu <proljc@gmail.com>
+ * Zhizhou Zhang <etouzh@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "migration/vmstate.h"
+#include "qemu/timer.h"
+#include "sysemu/reset.h"
+
+#define TIMER_PERIOD 50 /* 50 ns period for 20 MHz timer */
+
+/* Tick Timer global state to allow all cores to be in sync */
+typedef struct OR1KTimerState {
+ uint32_t ttcr;
+ uint64_t last_clk;
+} OR1KTimerState;
+
+static OR1KTimerState *or1k_timer;
+
+void cpu_openrisc_count_set(OpenRISCCPU *cpu, uint32_t val)
+{
+ or1k_timer->ttcr = val;
+}
+
+uint32_t cpu_openrisc_count_get(OpenRISCCPU *cpu)
+{
+ return or1k_timer->ttcr;
+}
+
+/* Add elapsed ticks to ttcr */
+void cpu_openrisc_count_update(OpenRISCCPU *cpu)
+{
+ uint64_t now;
+
+ if (!cpu->env.is_counting) {
+ return;
+ }
+ now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+ or1k_timer->ttcr += (uint32_t)((now - or1k_timer->last_clk)
+ / TIMER_PERIOD);
+ or1k_timer->last_clk = now;
+}
+
+/* Update the next timeout time as difference between ttmr and ttcr */
+void cpu_openrisc_timer_update(OpenRISCCPU *cpu)
+{
+ uint32_t wait;
+ uint64_t now, next;
+
+ if (!cpu->env.is_counting) {
+ return;
+ }
+
+ cpu_openrisc_count_update(cpu);
+ now = or1k_timer->last_clk;
+
+ if ((cpu->env.ttmr & TTMR_TP) <= (or1k_timer->ttcr & TTMR_TP)) {
+ wait = TTMR_TP - (or1k_timer->ttcr & TTMR_TP) + 1;
+ wait += cpu->env.ttmr & TTMR_TP;
+ } else {
+ wait = (cpu->env.ttmr & TTMR_TP) - (or1k_timer->ttcr & TTMR_TP);
+ }
+ next = now + (uint64_t)wait * TIMER_PERIOD;
+ timer_mod(cpu->env.timer, next);
+}
+
+void cpu_openrisc_count_start(OpenRISCCPU *cpu)
+{
+ cpu->env.is_counting = 1;
+ cpu_openrisc_count_update(cpu);
+}
+
+void cpu_openrisc_count_stop(OpenRISCCPU *cpu)
+{
+ timer_del(cpu->env.timer);
+ cpu_openrisc_count_update(cpu);
+ cpu->env.is_counting = 0;
+}
+
+static void openrisc_timer_cb(void *opaque)
+{
+ OpenRISCCPU *cpu = opaque;
+
+ if ((cpu->env.ttmr & TTMR_IE) &&
+ timer_expired(cpu->env.timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL))) {
+ CPUState *cs = CPU(cpu);
+
+ cpu->env.ttmr |= TTMR_IP;
+ cs->interrupt_request |= CPU_INTERRUPT_TIMER;
+ }
+
+ switch (cpu->env.ttmr & TTMR_M) {
+ case TIMER_NONE:
+ break;
+ case TIMER_INTR:
+ or1k_timer->ttcr = 0;
+ break;
+ case TIMER_SHOT:
+ cpu_openrisc_count_stop(cpu);
+ break;
+ case TIMER_CONT:
+ break;
+ }
+
+ cpu_openrisc_timer_update(cpu);
+ qemu_cpu_kick(CPU(cpu));
+}
+
+/* Reset the per CPU counter state. */
+static void openrisc_count_reset(void *opaque)
+{
+ OpenRISCCPU *cpu = opaque;
+
+ if (cpu->env.is_counting) {
+ cpu_openrisc_count_stop(cpu);
+ }
+ cpu->env.ttmr = 0x00000000;
+}
+
+/* Reset the global timer state. */
+static void openrisc_timer_reset(void *opaque)
+{
+ or1k_timer->ttcr = 0x00000000;
+ or1k_timer->last_clk = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+}
+
+static const VMStateDescription vmstate_or1k_timer = {
+ .name = "or1k_timer",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT32(ttcr, OR1KTimerState),
+ VMSTATE_UINT64(last_clk, OR1KTimerState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+void cpu_openrisc_clock_init(OpenRISCCPU *cpu)
+{
+ cpu->env.timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &openrisc_timer_cb, cpu);
+
+ qemu_register_reset(openrisc_count_reset, cpu);
+ if (or1k_timer == NULL) {
+ or1k_timer = g_new0(OR1KTimerState, 1);
+ qemu_register_reset(openrisc_timer_reset, cpu);
+ vmstate_register(NULL, 0, &vmstate_or1k_timer, or1k_timer);
+ }
+}