[PATCH 1/5] ARM: arch_timers: switch to physical timers if HYP mode is available

Christoffer Dall
2012-09-15T15:39:03Z

If we're booted in HYP mode, it is possible that we'll run some
kind of virtualized environment. In this case, it is a better to
switch to the physical timers, and leave the virtual timers to
guests.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm/kernel/arch_timer.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index c04c2a6..8a30186 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -25,6 +25,7 @@
#include <asm/arch_timer.h>
#include <asm/system_info.h>
#include <asm/sched_clock.h>
+#include <asm/virt.h>

static unsigned long arch_timer_rate;

@@ -490,10 +491,14 @@ int __init arch_timer_of_register(void)
arch_timer_ppi[i] = irq_of_parse_and_map(np, i);

/*
+ * If HYP mode is available, we know that the physical timer
+ * has been configured to be accessible from PL1. Use it, so
+ * that a guest can use the virtual timer instead.
+ *
* If no interrupt provided for virtual timer, we'll have to
* stick to the physical timer. It'd better be accessible...
*/
- if (!arch_timer_ppi[VIRT_PPI]) {
+ if (is_hyp_mode_available() || !arch_timer_ppi[VIRT_PPI]) {
arch_timer_use_virtual = false;

if (!arch_timer_ppi[PHYS_SECURE_PPI] ||