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authorAlexander Graf <agraf@suse.de>2009-11-02 12:02:31 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-11-05 16:51:05 +1100
commit544c6761bb05a1dd19a39cb9bed096273f9bdb36 (patch)
tree66fde2d24a61c3be4712ac2701263aca04f26ebb /arch/powerpc/kvm
parentc8240bd6f0b4b1b21ffd36dd44114d05c7afe0c0 (diff)
downloadblackbird-op-linux-544c6761bb05a1dd19a39cb9bed096273f9bdb36.tar.gz
blackbird-op-linux-544c6761bb05a1dd19a39cb9bed096273f9bdb36.zip
Use hrtimers for the decrementer
Following S390's good example we should use hrtimers for the decrementer too! This patch converts the timer from the old mechanism to hrtimers. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kvm')
-rw-r--r--arch/powerpc/kvm/emulate.c18
-rw-r--r--arch/powerpc/kvm/powerpc.c20
2 files changed, 29 insertions, 9 deletions
diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index 1ec5e07b81eb..4a9ac6640fad 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -18,7 +18,7 @@
*/
#include <linux/jiffies.h>
-#include <linux/timer.h>
+#include <linux/hrtimer.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kvm_host.h>
@@ -79,12 +79,13 @@ static int kvmppc_dec_enabled(struct kvm_vcpu *vcpu)
void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
{
- unsigned long nr_jiffies;
+ unsigned long dec_nsec;
+ pr_debug("mtDEC: %x\n", vcpu->arch.dec);
#ifdef CONFIG_PPC64
/* POWER4+ triggers a dec interrupt if the value is < 0 */
if (vcpu->arch.dec & 0x80000000) {
- del_timer(&vcpu->arch.dec_timer);
+ hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
kvmppc_core_queue_dec(vcpu);
return;
}
@@ -94,12 +95,15 @@ void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
* that's how we convert the guest DEC value to the number of
* host ticks. */
+ hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
+ dec_nsec = vcpu->arch.dec;
+ dec_nsec *= 1000;
+ dec_nsec /= tb_ticks_per_usec;
+ hrtimer_start(&vcpu->arch.dec_timer, ktime_set(0, dec_nsec),
+ HRTIMER_MODE_REL);
vcpu->arch.dec_jiffies = get_tb();
- nr_jiffies = vcpu->arch.dec / tb_ticks_per_jiffy;
- mod_timer(&vcpu->arch.dec_timer,
- get_jiffies_64() + nr_jiffies);
} else {
- del_timer(&vcpu->arch.dec_timer);
+ hrtimer_try_to_cancel(&vcpu->arch.dec_timer);
}
}
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index a06ecc3401fd..692c3709011e 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -23,6 +23,7 @@
#include <linux/kvm_host.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
+#include <linux/hrtimer.h>
#include <linux/fs.h>
#include <asm/cputable.h>
#include <asm/uaccess.h>
@@ -208,10 +209,25 @@ static void kvmppc_decrementer_func(unsigned long data)
}
}
+/*
+ * low level hrtimer wake routine. Because this runs in hardirq context
+ * we schedule a tasklet to do the real work.
+ */
+enum hrtimer_restart kvmppc_decrementer_wakeup(struct hrtimer *timer)
+{
+ struct kvm_vcpu *vcpu;
+
+ vcpu = container_of(timer, struct kvm_vcpu, arch.dec_timer);
+ tasklet_schedule(&vcpu->arch.tasklet);
+
+ return HRTIMER_NORESTART;
+}
+
int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
{
- setup_timer(&vcpu->arch.dec_timer, kvmppc_decrementer_func,
- (unsigned long)vcpu);
+ hrtimer_init(&vcpu->arch.dec_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
+ tasklet_init(&vcpu->arch.tasklet, kvmppc_decrementer_func, (ulong)vcpu);
+ vcpu->arch.dec_timer.function = kvmppc_decrementer_wakeup;
return 0;
}
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