target/mips/cpu: Calculate the CP0 timer period using the CPU frequency

The CP0 timer period is a function of the CPU frequency.
Start using the default values, which will be replaced by
properties in the next commits.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Message-Id: <20201012095804.3335117-10-f4bug@amsat.org>

diff --git a/target/mips/cpu.c b/target/mips/cpu.c
index 84b727fefa8a5b17299a1b06c01008f398ba7942..46188139b7b57d88b93e0b6d80ca1e2d058ea03c 100644 (file)
--- a/target/mips/cpu.c
+++ b/target/mips/cpu.c
@@ -144,13 +144,13 @@ static void mips_cpu_disas_set_info(CPUState *s, disassemble_info *info)
  */
 #define CPU_FREQ_HZ_DEFAULT     200000000
 #define CP0_COUNT_RATE_DEFAULT  2
-#define TIMER_PERIOD_DEFAULT    10  /* 1 / (CPU_FREQ_HZ / CP0_COUNT_RATE) */
 
 static void mips_cp0_period_set(MIPSCPU *cpu)
 {
     CPUMIPSState *env = &cpu->env;
 
-    env->cp0_count_ns = TIMER_PERIOD_DEFAULT;
+    env->cp0_count_ns = muldiv64(NANOSECONDS_PER_SECOND, CP0_COUNT_RATE_DEFAULT,
+                                 CPU_FREQ_HZ_DEFAULT);
 }
 
 static void mips_cpu_realizefn(DeviceState *dev, Error **errp)