@@ -2460,6 +2460,32 @@ static uint64_t gt_phys_cnt_offset(CPUARMState *env)
return gt_phys_raw_cnt_offset(env);
}
+static uint64_t gt_indirect_access_timer_offset(CPUARMState *env, int timeridx)
+{
+ /*
+ * Return the timer offset to use for indirect accesses to the timer.
+ * This is the Offset value as defined in D12.2.4.1 "Operation of the
+ * CompareValue views of the timers".
+ *
+ * The condition here is not always the same as the condition for
+ * whether to apply an offset register when doing a direct read of
+ * the counter sysreg; those conditions are described in the
+ * access pseudocode for each counter register.
+ */
+ switch (timeridx) {
+ case GTIMER_PHYS:
+ return gt_phys_raw_cnt_offset(env);
+ case GTIMER_VIRT:
+ return env->cp15.cntvoff_el2;
+ case GTIMER_HYP:
+ case GTIMER_SEC:
+ case GTIMER_HYPVIRT:
+ return 0;
+ default:
+ g_assert_not_reached();
+ }
+}
+
static void gt_recalc_timer(ARMCPU *cpu, int timeridx)
{
ARMGenericTimer *gt = &cpu->env.cp15.c14_timer[timeridx];
@@ -2469,8 +2495,7 @@ static void gt_recalc_timer(ARMCPU *cpu, int timeridx)
* Timer enabled: calculate and set current ISTATUS, irq, and
* reset timer to when ISTATUS next has to change
*/
- uint64_t offset = timeridx == GTIMER_VIRT ?
- cpu->env.cp15.cntvoff_el2 : gt_phys_raw_cnt_offset(&cpu->env);
+ uint64_t offset = gt_indirect_access_timer_offset(&cpu->env, timeridx);
uint64_t count = gt_get_countervalue(&cpu->env);
/* Note that this must be unsigned 64 bit arithmetic: */
int istatus = count - offset >= gt->cval;
When we are calculating timer deadlines, the correct definition of whether or not to apply an offset to the physical count is described in the Arm ARM DDI4087 rev L.a section D12.2.4.1. This is different from when the offset should be applied for a direct read of the counter sysreg. We got this right for the EL1 physical timer and for the EL1 virtual timer, but got all the rest wrong: they should be using a zero offset always. Factor the offset calculation out into a function that has a comment documenting exactly which offset it is calculating and which gets the HYP, SEC, and HYPVIRT cases right. Cc: qemu-stable@nongnu.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- target/arm/helper.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-)