diff mbox

[v4,1/5] ARM: arch_timers: switch to physical timers if HYP mode is available

Message ID 20121110154605.3274.70574.stgit@chazy-air (mailing list archive)
State New, archived
Headers show

Commit Message

Christoffer Dall Nov. 10, 2012, 3:46 p.m. UTC 
From: Marc Zyngier <marc.zyngier@arm.com>

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(-)


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Comments

Will Deacon Nov. 23, 2012, 3:18 p.m. UTC | #1 
On Sat, Nov 10, 2012 at 03:46:05PM +0000, Christoffer Dall wrote:
> From: Marc Zyngier <marc.zyngier@arm.com>
> 
> 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>

Seems simple enough.

Reviewed-by: Will Deacon <will.deacon@arm.com>

Will
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diff mbox

Patch

diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index c8ef207..8adcd04 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -26,6 +26,7 @@ 
 #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;
 
@@ -489,10 +490,14 @@  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] ||