From 5c59f6c246249f4c03281d0ab02b81f38f65b398 Mon Sep 17 00:00:00 2001
From: Aurelien Jarno <aurelien@aurel32.net>
Date: Tue, 15 Sep 2009 00:30:41 +0200
Subject: [PATCH] Fix Linux task preemption on Versatile board
Backport from master:
Recent versions of the Linux kernel will not preempt CPU-intensive
tasks unless the clock used by sched_clock() works. On -M versatilepb
that's the 24MHz timer in the system controller. It's a very simple
timer, so implement it.
Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
hw/arm_sysctl.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/hw/arm_sysctl.c b/hw/arm_sysctl.c
index 62222a1ab3b..06661d8e756 100644
--- a/hw/arm_sysctl.c
+++ b/hw/arm_sysctl.c
@@ -8,6 +8,7 @@
*/
#include "hw.h"
+#include "qemu-timer.h"
#include "primecell.h"
#include "sysemu.h"
@@ -70,8 +71,7 @@ static uint32_t arm_sysctl_read(void *opaque, target_phys_addr_t offset)
case 0x58: /* BOOTCS */
return 0;
case 0x5c: /* 24MHz */
- /* ??? not implemented. */
- return 0;
+ return muldiv64(qemu_get_clock(vm_clock), 24000000, ticks_per_sec);
case 0x60: /* MISC */
return 0;
case 0x84: /* PROCID0 */
--
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