muldiv64() is used to convert microseconds into CPU ticks. But it is not clear and not commented. This patch uses macro to clearly identify what is used: time, CPU frequency and ticks. For an elapsed time and a given frequency, we compute how many ticks we have.
Signed-off-by: Laurent Vivier <[email protected]> --- v2: replace "arm: remove muldiv64()" target-arm/helper.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/target-arm/helper.c b/target-arm/helper.c index 7df1f06..4455761 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -12,6 +12,8 @@ #include <zlib.h> /* For crc32 */ #include "exec/semihost.h" +#define ARM_CPU_FREQ 1000000000 /* FIXME: 1 GHz, should be configurable */ + #ifndef CONFIG_USER_ONLY static inline bool get_phys_addr(CPUARMState *env, target_ulong address, int access_type, ARMMMUIdx mmu_idx, @@ -678,8 +680,8 @@ void pmccntr_sync(CPUARMState *env) { uint64_t temp_ticks; - temp_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), - get_ticks_per_sec(), 1000000); + temp_ticks = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), + ARM_CPU_FREQ, NANOSECONDS_PER_SECOND); if (env->cp15.c9_pmcr & PMCRD) { /* Increment once every 64 processor clock cycles */ @@ -717,8 +719,8 @@ static uint64_t pmccntr_read(CPUARMState *env, const ARMCPRegInfo *ri) return env->cp15.c15_ccnt; } - total_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), - get_ticks_per_sec(), 1000000); + total_ticks = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), + ARM_CPU_FREQ, NANOSECONDS_PER_SECOND); if (env->cp15.c9_pmcr & PMCRD) { /* Increment once every 64 processor clock cycles */ @@ -738,8 +740,8 @@ static void pmccntr_write(CPUARMState *env, const ARMCPRegInfo *ri, return; } - total_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), - get_ticks_per_sec(), 1000000); + total_ticks = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), + ARM_CPU_FREQ, NANOSECONDS_PER_SECOND); if (env->cp15.c9_pmcr & PMCRD) { /* Increment once every 64 processor clock cycles */ -- 2.1.0
