target/loongarch: Add constant timer support

Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220606124333.2060567-25-yangxiaojuan@loongson.cn>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

diff --git a/target/loongarch/constant_timer.c b/target/loongarch/constant_timer.c
new file mode 100644 (file)
index 0000000..1851f53
--- /dev/null
+++ b/target/loongarch/constant_timer.c
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * QEMU LoongArch constant timer support
+ *
+ * Copyright (c) 2021 Loongson Technology Corporation Limited
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/timer.h"
+#include "cpu.h"
+#include "internals.h"
+#include "cpu-csr.h"
+
+#define TIMER_PERIOD                10 /* 10 ns period for 100 MHz frequency */
+#define CONSTANT_TIMER_TICK_MASK    0xfffffffffffcUL
+#define CONSTANT_TIMER_ENABLE       0x1UL
+
+uint64_t cpu_loongarch_get_constant_timer_counter(LoongArchCPU *cpu)
+{
+    return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / TIMER_PERIOD;
+}
+
+uint64_t cpu_loongarch_get_constant_timer_ticks(LoongArchCPU *cpu)
+{
+    uint64_t now, expire;
+
+    now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+    expire = timer_expire_time_ns(&cpu->timer);
+
+    return (expire - now) / TIMER_PERIOD;
+}
+
+void cpu_loongarch_store_constant_timer_config(LoongArchCPU *cpu,
+                                               uint64_t value)
+{
+    CPULoongArchState *env = &cpu->env;
+    uint64_t now, next;
+
+    env->CSR_TCFG = value;
+    if (value & CONSTANT_TIMER_ENABLE) {
+        now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+        next = now + (value & CONSTANT_TIMER_TICK_MASK) * TIMER_PERIOD;
+        timer_mod(&cpu->timer, next);
+    } else {
+        timer_del(&cpu->timer);
+    }
+}
+
+void loongarch_constant_timer_cb(void *opaque)
+{
+    LoongArchCPU *cpu  = opaque;
+    CPULoongArchState *env = &cpu->env;
+    uint64_t now, next;
+
+    if (FIELD_EX64(env->CSR_TCFG, CSR_TCFG, PERIODIC)) {
+        now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+        next = now + (env->CSR_TCFG & CONSTANT_TIMER_TICK_MASK) * TIMER_PERIOD;
+        timer_mod(&cpu->timer, next);
+    } else {
+        env->CSR_TCFG = FIELD_DP64(env->CSR_TCFG, CSR_TCFG, EN, 0);
+    }
+
+    loongarch_cpu_set_irq(opaque, IRQ_TIMER, 1);
+}

diff --git a/target/loongarch/cpu.c b/target/loongarch/cpu.c
index 01a0b4878a72ef1b879052079f5ff7cde6b590b7..5ec0ba1cfaa732596926cd4b560b20730c4ee700 100644 (file)
--- a/target/loongarch/cpu.c
+++ b/target/loongarch/cpu.c
@@ -495,6 +495,8 @@ static void loongarch_cpu_init(Object *obj)
 
     cpu_set_cpustate_pointers(cpu);
     qdev_init_gpio_in(DEVICE(cpu), loongarch_cpu_set_irq, N_IRQS);
+    timer_init_ns(&cpu->timer, QEMU_CLOCK_VIRTUAL,
+                  &loongarch_constant_timer_cb, cpu);
 }
 
 static ObjectClass *loongarch_cpu_class_by_name(const char *cpu_model)

diff --git a/target/loongarch/cpu.h b/target/loongarch/cpu.h
index b983ce241c590d6f85318892791c2bcd2f4d3ffd..2081902f2e4d5005765dfd107a17fe712d144999 100644 (file)
--- a/target/loongarch/cpu.h
+++ b/target/loongarch/cpu.h
@@ -11,6 +11,7 @@
 #include "exec/cpu-defs.h"
 #include "fpu/softfloat-types.h"
 #include "hw/registerfields.h"
+#include "qemu/timer.h"
 
 #define TCG_GUEST_DEFAULT_MO (0)
 
@@ -185,6 +186,8 @@ extern const char * const regnames[32];
 extern const char * const fregnames[32];
 
 #define N_IRQS      13
+#define IRQ_TIMER   11
+#define IRQ_IPI     12
 
 #define LOONGARCH_STLB         2048 /* 2048 STLB */
 #define LOONGARCH_MTLB         64   /* 64 MTLB */
@@ -295,6 +298,7 @@ struct ArchCPU {
 
     CPUNegativeOffsetState neg;
     CPULoongArchState env;
+    QEMUTimer timer;
 };
 
 #define TYPE_LOONGARCH_CPU "loongarch-cpu"

diff --git a/target/loongarch/internals.h b/target/loongarch/internals.h
index 69183e8bb50a150045b5a8add56bc5f49bc27b8f..4b1bcd7c0f4093d50acc5eeff5f9808f3a7b7ca5 100644 (file)
--- a/target/loongarch/internals.h
+++ b/target/loongarch/internals.h
@@ -32,6 +32,12 @@ extern const VMStateDescription vmstate_loongarch_cpu;
 
 void loongarch_cpu_set_irq(void *opaque, int irq, int level);
 
+void loongarch_constant_timer_cb(void *opaque);
+uint64_t cpu_loongarch_get_constant_timer_counter(LoongArchCPU *cpu);
+uint64_t cpu_loongarch_get_constant_timer_ticks(LoongArchCPU *cpu);
+void cpu_loongarch_store_constant_timer_config(LoongArchCPU *cpu,
+                                               uint64_t value);
+
 bool loongarch_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
                             MMUAccessType access_type, int mmu_idx,
                             bool probe, uintptr_t retaddr);

diff --git a/target/loongarch/meson.build b/target/loongarch/meson.build
index 435cc759991dacdbdb681d74732328509a8429cb..04e15ba1e39dc63302cb9ed7c25ce6243f3f31c4 100644 (file)
--- a/target/loongarch/meson.build
+++ b/target/loongarch/meson.build
@@ -18,6 +18,7 @@ loongarch_softmmu_ss = ss.source_set()
 loongarch_softmmu_ss.add(files(
   'machine.c',
   'tlb_helper.c',
+  'constant_timer.c',
 ))
 
 loongarch_ss.add_all(when: 'CONFIG_TCG', if_true: [loongarch_tcg_ss])