summaryrefslogtreecommitdiff
path: root/drivers/xen/time.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/xen/time.c')
-rw-r--r--drivers/xen/time.c72
1 files changed, 70 insertions, 2 deletions
diff --git a/drivers/xen/time.c b/drivers/xen/time.c
index a63fedbdcbe9..3e741cd1409c 100644
--- a/drivers/xen/time.c
+++ b/drivers/xen/time.c
@@ -6,6 +6,7 @@
#include <linux/kernel_stat.h>
#include <linux/math64.h>
#include <linux/gfp.h>
+#include <linux/slab.h>
#include <asm/paravirt.h>
#include <asm/xen/hypervisor.h>
@@ -20,6 +21,8 @@
/* runstate info updated by Xen */
static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate);
+static DEFINE_PER_CPU(u64[4], old_runstate_time);
+
/* return an consistent snapshot of 64-bit time/counter value */
static u64 get64(const u64 *p)
{
@@ -48,8 +51,8 @@ static u64 get64(const u64 *p)
return ret;
}
-static void xen_get_runstate_snapshot_cpu(struct vcpu_runstate_info *res,
- unsigned int cpu)
+static void xen_get_runstate_snapshot_cpu_delta(
+ struct vcpu_runstate_info *res, unsigned int cpu)
{
u64 state_time;
struct vcpu_runstate_info *state;
@@ -67,6 +70,71 @@ static void xen_get_runstate_snapshot_cpu(struct vcpu_runstate_info *res,
(state_time & XEN_RUNSTATE_UPDATE));
}
+static void xen_get_runstate_snapshot_cpu(struct vcpu_runstate_info *res,
+ unsigned int cpu)
+{
+ int i;
+
+ xen_get_runstate_snapshot_cpu_delta(res, cpu);
+
+ for (i = 0; i < 4; i++)
+ res->time[i] += per_cpu(old_runstate_time, cpu)[i];
+}
+
+void xen_manage_runstate_time(int action)
+{
+ static struct vcpu_runstate_info *runstate_delta;
+ struct vcpu_runstate_info state;
+ int cpu, i;
+
+ switch (action) {
+ case -1: /* backup runstate time before suspend */
+ if (unlikely(runstate_delta))
+ pr_warn_once("%s: memory leak as runstate_delta is not NULL\n",
+ __func__);
+
+ runstate_delta = kmalloc_array(num_possible_cpus(),
+ sizeof(*runstate_delta),
+ GFP_ATOMIC);
+ if (unlikely(!runstate_delta)) {
+ pr_warn("%s: failed to allocate runstate_delta\n",
+ __func__);
+ return;
+ }
+
+ for_each_possible_cpu(cpu) {
+ xen_get_runstate_snapshot_cpu_delta(&state, cpu);
+ memcpy(runstate_delta[cpu].time, state.time,
+ sizeof(runstate_delta[cpu].time));
+ }
+
+ break;
+
+ case 0: /* backup runstate time after resume */
+ if (unlikely(!runstate_delta)) {
+ pr_warn("%s: cannot accumulate runstate time as runstate_delta is NULL\n",
+ __func__);
+ return;
+ }
+
+ for_each_possible_cpu(cpu) {
+ for (i = 0; i < 4; i++)
+ per_cpu(old_runstate_time, cpu)[i] +=
+ runstate_delta[cpu].time[i];
+ }
+
+ break;
+
+ default: /* do not accumulate runstate time for checkpointing */
+ break;
+ }
+
+ if (action != -1 && runstate_delta) {
+ kfree(runstate_delta);
+ runstate_delta = NULL;
+ }
+}
+
/*
* Runstate accounting
*/