hw/riscv: Provide rdtime callback for TCG in CLINT emulation

This patch extends CLINT emulation to provide rdtime callback for
TCG. This rdtime callback will be called wheneven TIME CSRs are
read in privileged modes.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

hw/riscv/sifive_clint.c

@@ -227,7 +227,8 @@ type_init(sifive_clint_register_types)
  * Create CLINT device.
  */
 DeviceState *sifive_clint_create(hwaddr addr, hwaddr size, uint32_t num_harts,
-    uint32_t sip_base, uint32_t timecmp_base, uint32_t time_base)
+    uint32_t sip_base, uint32_t timecmp_base, uint32_t time_base,
+    bool provide_rdtime)
 {
     int i;
     for (i = 0; i < num_harts; i++) {
@@ -236,6 +237,9 @@ DeviceState *sifive_clint_create(hwaddr addr, hwaddr size, uint32_t num_harts,
         if (!env) {
             continue;
         }
+        if (provide_rdtime) {
+            riscv_cpu_set_rdtime_fn(env, cpu_riscv_read_rtc);
+        }
         env->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
                                   &sifive_clint_timer_cb, cpu);
         env->timecmp = 0;

hw/riscv/sifive_e.c

@@ -164,7 +164,7 @@ static void riscv_sifive_e_soc_realize(DeviceState *dev, Error **errp)
         memmap[SIFIVE_E_PLIC].size);
     sifive_clint_create(memmap[SIFIVE_E_CLINT].base,
         memmap[SIFIVE_E_CLINT].size, ms->smp.cpus,
-        SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE);
+        SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE, false);
     create_unimplemented_device("riscv.sifive.e.aon",
         memmap[SIFIVE_E_AON].base, memmap[SIFIVE_E_AON].size);
     sifive_e_prci_create(memmap[SIFIVE_E_PRCI].base);

hw/riscv/sifive_u.c

@@ -549,7 +549,7 @@ static void riscv_sifive_u_soc_realize(DeviceState *dev, Error **errp)
         serial_hd(1), qdev_get_gpio_in(DEVICE(s->plic), SIFIVE_U_UART1_IRQ));
     sifive_clint_create(memmap[SIFIVE_U_CLINT].base,
         memmap[SIFIVE_U_CLINT].size, ms->smp.cpus,
-        SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE);
+        SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE, false);
 
     object_property_set_bool(OBJECT(&s->prci), true, "realized", &err);
     sysbus_mmio_map(SYS_BUS_DEVICE(&s->prci), 0, memmap[SIFIVE_U_PRCI].base);

hw/riscv/spike.c

@@ -227,7 +227,8 @@ static void spike_board_init(MachineState *machine)
 
     /* Core Local Interruptor (timer and IPI) */
     sifive_clint_create(memmap[SPIKE_CLINT].base, memmap[SPIKE_CLINT].size,
-        smp_cpus, SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE);
+        smp_cpus, SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE,
+        false);
 }
 
 static void spike_v1_10_0_board_init(MachineState *machine)
@@ -316,7 +317,8 @@ static void spike_v1_10_0_board_init(MachineState *machine)
 
     /* Core Local Interruptor (timer and IPI) */
     sifive_clint_create(memmap[SPIKE_CLINT].base, memmap[SPIKE_CLINT].size,
-        smp_cpus, SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE);
+        smp_cpus, SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE,
+        false);
 }
 
 static void spike_v1_09_1_board_init(MachineState *machine)
@@ -424,7 +426,8 @@ static void spike_v1_09_1_board_init(MachineState *machine)
 
     /* Core Local Interruptor (timer and IPI) */
     sifive_clint_create(memmap[SPIKE_CLINT].base, memmap[SPIKE_CLINT].size,
-        smp_cpus, SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE);
+        smp_cpus, SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE,
+        false);
 
     g_free(config_string);
 }

hw/riscv/virt.c

@@ -593,7 +593,7 @@ static void riscv_virt_board_init(MachineState *machine)
         memmap[VIRT_PLIC].size);
     sifive_clint_create(memmap[VIRT_CLINT].base,
         memmap[VIRT_CLINT].size, smp_cpus,
-        SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE);
+        SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE, true);
     sifive_test_create(memmap[VIRT_TEST].base);
 
     for (i = 0; i < VIRTIO_COUNT; i++) {

include/hw/riscv/sifive_clint.h

@@ -41,7 +41,8 @@ typedef struct SiFiveCLINTState {
 } SiFiveCLINTState;
 
 DeviceState *sifive_clint_create(hwaddr addr, hwaddr size, uint32_t num_harts,
-    uint32_t sip_base, uint32_t timecmp_base, uint32_t time_base);
+    uint32_t sip_base, uint32_t timecmp_base, uint32_t time_base,
+    bool provide_rdtime);
 
 enum {
     SIFIVE_SIP_BASE     = 0x0,