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[Qemu-ppc] [PATCH] booke_ppc: limit booke timer to max when timeout over
From: |
Bharat Bhushan |
Subject: |
[Qemu-ppc] [PATCH] booke_ppc: limit booke timer to max when timeout overflow |
Date: |
Wed, 12 Jun 2013 18:00:50 +0530 |
Limit watchdog and fit timer to maximum timeout value which
qemu timer can support (INT64_MAX). This maximum timeout will be
hundreds of years, so limiting to max timeout is pretty safe.
Signed-off-by: Bharat Bhushan <address@hidden>
---
hw/ppc/ppc_booke.c | 24 ++++++++++++++++++++----
1 files changed, 20 insertions(+), 4 deletions(-)
diff --git a/hw/ppc/ppc_booke.c b/hw/ppc/ppc_booke.c
index e41b036..000c27f 100644
--- a/hw/ppc/ppc_booke.c
+++ b/hw/ppc/ppc_booke.c
@@ -131,17 +131,33 @@ static void booke_update_fixed_timer(CPUPPCState
*env,
struct QEMUTimer *timer)
{
ppc_tb_t *tb_env = env->tb_env;
- uint64_t lapse;
+ uint64_t delta_tick, ticks = 0;
uint64_t tb;
- uint64_t period = 1 << (target_bit + 1);
+ uint64_t period;
uint64_t now;
now = qemu_get_clock_ns(vm_clock);
tb = cpu_ppc_get_tb(tb_env, now, tb_env->tb_offset);
+ period = 1ULL << target_bit;
+ delta_tick = period - (tb & (period - 1));
- lapse = period - ((tb - (1 << target_bit)) & (period - 1));
+ /* the timer triggers only when the selected bit toggles from 0 to 1 */
+ if (tb & period) {
+ ticks = period;
+ }
- *next = now + muldiv64(lapse, get_ticks_per_sec(), tb_env->tb_freq);
+ if (ticks + delta_tick < ticks) {
+ /* Overflow, so assume the biggest number we can express. */
+ ticks = UINT64_MAX;
+ } else {
+ ticks += delta_tick;
+ }
+
+ *next = now + muldiv64(ticks, get_ticks_per_sec(), tb_env->tb_freq);
+ if ((*next < now) || (*next > INT64_MAX)) {
+ /* Overflow, so assume the biggest number the qemu timer supports. */
+ *next = INT64_MAX;
+ }
/* XXX: If expire time is now. We can't run the callback because we don't
* have access to it. So we just set the timer one nanosecond later.
--
1.7.0.4
- [Qemu-ppc] [PATCH] booke_ppc: limit booke timer to max when timeout overflow,
Bharat Bhushan <=