This patch enables multithread TCG for OpenRISC. Since the or1k shared
syncrhonized timer can be updated from each vCPU via helpers we use a
mutex to synchronize updates.
Signed-off-by: Stafford Horne <sho...@gmail.com>
---
configs/targets/or1k-softmmu.mak | 1 +
hw/openrisc/cputimer.c | 17 +++++++++++++++++
target/openrisc/cpu.h | 3 +++
target/openrisc/sys_helper.c | 11 +++++++++--
4 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/configs/targets/or1k-softmmu.mak b/configs/targets/or1k-softmmu.mak
index 263e970870..432f855a30 100644
--- a/configs/targets/or1k-softmmu.mak
+++ b/configs/targets/or1k-softmmu.mak
@@ -1,3 +1,4 @@
TARGET_ARCH=openrisc
+TARGET_SUPPORTS_MTTCG=y
TARGET_BIG_ENDIAN=y
TARGET_NEED_FDT=y
diff --git a/hw/openrisc/cputimer.c b/hw/openrisc/cputimer.c
index 4dbba3a3d4..2298eff8b9 100644
--- a/hw/openrisc/cputimer.c
+++ b/hw/openrisc/cputimer.c
@@ -43,6 +43,23 @@ uint32_t cpu_openrisc_count_get(OpenRISCCPU *cpu)
return or1k_timer->ttcr;
}
+/*
+ * Check to see if calling cpu_openrisc_count_update will
+ * actually advance the time.
+ *
+ * Used in hot spots to avoid taking expensive locks.
+ */
+bool cpu_openrisc_timer_has_advanced(OpenRISCCPU *cpu)
+{
+ uint64_t now;
+
+ if (!cpu->env.is_counting) {
+ return false;
+ }
+ now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+ return (now - or1k_timer->last_clk) >= TIMER_PERIOD;
+}
+
/* Add elapsed ticks to ttcr */
void cpu_openrisc_count_update(OpenRISCCPU *cpu)
{
diff --git a/target/openrisc/cpu.h b/target/openrisc/cpu.h
index b9584f10d4..5354d681f5 100644
--- a/target/openrisc/cpu.h
+++ b/target/openrisc/cpu.h
@@ -25,6 +25,8 @@
#include "hw/core/cpu.h"
#include "qom/object.h"
+#define TCG_GUEST_DEFAULT_MO (0)
+
#define TYPE_OPENRISC_CPU "or1k-cpu"
OBJECT_DECLARE_CPU_TYPE(OpenRISCCPU, OpenRISCCPUClass, OPENRISC_CPU)
@@ -333,6 +335,7 @@ void cpu_openrisc_pic_init(OpenRISCCPU *cpu);
/* hw/openrisc_timer.c */
void cpu_openrisc_clock_init(OpenRISCCPU *cpu);
+bool cpu_openrisc_timer_has_advanced(OpenRISCCPU *cpu);
uint32_t cpu_openrisc_count_get(OpenRISCCPU *cpu);
void cpu_openrisc_count_set(OpenRISCCPU *cpu, uint32_t val);
void cpu_openrisc_count_update(OpenRISCCPU *cpu);
diff --git a/target/openrisc/sys_helper.c b/target/openrisc/sys_helper.c
index 48674231e7..7c0d3d6187 100644
--- a/target/openrisc/sys_helper.c
+++ b/target/openrisc/sys_helper.c
@@ -145,6 +145,7 @@ void HELPER(mtspr)(CPUOpenRISCState *env, target_ulong spr,
target_ulong rb)
break;
case TO_SPR(10, 0): /* TTMR */
{
+ qemu_mutex_lock_iothread();
if ((env->ttmr & TTMR_M) ^ (rb & TTMR_M)) {
switch (rb & TTMR_M) {
case TIMER_NONE:
@@ -168,14 +169,16 @@ void HELPER(mtspr)(CPUOpenRISCState *env, target_ulong
spr, target_ulong rb)
env->ttmr = rb & ~TTMR_IP;
cs->interrupt_request &= ~CPU_INTERRUPT_TIMER;
}
-
cpu_openrisc_timer_update(cpu);
+ qemu_mutex_unlock_iothread();
}
break;
case TO_SPR(10, 1): /* TTCR */
+ qemu_mutex_lock_iothread();
cpu_openrisc_count_set(cpu, rb);
cpu_openrisc_timer_update(cpu);
+ qemu_mutex_unlock_iothread();
break;
#endif
@@ -303,7 +306,11 @@ target_ulong HELPER(mfspr)(CPUOpenRISCState *env,
target_ulong rd,
return env->ttmr;
case TO_SPR(10, 1): /* TTCR */
- cpu_openrisc_count_update(cpu);
+ if (cpu_openrisc_timer_has_advanced(cpu)) {
+ qemu_mutex_lock_iothread();
+ cpu_openrisc_count_update(cpu);
+ qemu_mutex_unlock_iothread();
+ }
return cpu_openrisc_count_get(cpu);
#endif
--
2.36.1
