[PATCH v10 1/5] xen: move xen_setup_runstate_info and get_runstate_snapshot to drivers/xen/time.c

From: Stefano Stabellini
Date: Tue Nov 03 2015 - 11:22:46 EST


Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
CC: konrad.wilk@xxxxxxxxxx

---

Changes in v10:
- rebase
- remove ia64 changes
---
arch/x86/xen/time.c | 76 +----------------------------------------
drivers/xen/Makefile | 2 +-
drivers/xen/time.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++++
include/xen/xen-ops.h | 5 +++
4 files changed, 98 insertions(+), 76 deletions(-)
create mode 100644 drivers/xen/time.c

diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index f1ba6a0..041d4cd 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -32,86 +32,12 @@
#define TIMER_SLOP 100000
#define NS_PER_TICK (1000000000LL / HZ)

-/* runstate info updated by Xen */
-static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate);
-
/* snapshots of runstate info */
static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate_snapshot);

/* unused ns of stolen time */
static DEFINE_PER_CPU(u64, xen_residual_stolen);

-/* return an consistent snapshot of 64-bit time/counter value */
-static u64 get64(const u64 *p)
-{
- u64 ret;
-
- if (BITS_PER_LONG < 64) {
- u32 *p32 = (u32 *)p;
- u32 h, l;
-
- /*
- * Read high then low, and then make sure high is
- * still the same; this will only loop if low wraps
- * and carries into high.
- * XXX some clean way to make this endian-proof?
- */
- do {
- h = p32[1];
- barrier();
- l = p32[0];
- barrier();
- } while (p32[1] != h);
-
- ret = (((u64)h) << 32) | l;
- } else
- ret = *p;
-
- return ret;
-}
-
-/*
- * Runstate accounting
- */
-static void get_runstate_snapshot(struct vcpu_runstate_info *res)
-{
- u64 state_time;
- struct vcpu_runstate_info *state;
-
- BUG_ON(preemptible());
-
- state = this_cpu_ptr(&xen_runstate);
-
- /*
- * The runstate info is always updated by the hypervisor on
- * the current CPU, so there's no need to use anything
- * stronger than a compiler barrier when fetching it.
- */
- do {
- state_time = get64(&state->state_entry_time);
- barrier();
- *res = *state;
- barrier();
- } while (get64(&state->state_entry_time) != state_time);
-}
-
-/* return true when a vcpu could run but has no real cpu to run on */
-bool xen_vcpu_stolen(int vcpu)
-{
- return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable;
-}
-
-void xen_setup_runstate_info(int cpu)
-{
- struct vcpu_register_runstate_memory_area area;
-
- area.addr.v = &per_cpu(xen_runstate, cpu);
-
- if (HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area,
- cpu, &area))
- BUG();
-}
-
static void do_stolen_accounting(void)
{
struct vcpu_runstate_info state;
@@ -119,7 +45,7 @@ static void do_stolen_accounting(void)
s64 runnable, offline, stolen;
cputime_t ticks;

- get_runstate_snapshot(&state);
+ xen_get_runstate_snapshot(&state);

WARN_ON(state.state != RUNSTATE_running);

diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index e293bc5..943fb1c 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -2,7 +2,7 @@ ifeq ($(filter y, $(CONFIG_ARM) $(CONFIG_ARM64)),)
obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o
endif
obj-$(CONFIG_X86) += fallback.o
-obj-y += grant-table.o features.o balloon.o manage.o preempt.o
+obj-y += grant-table.o features.o balloon.o manage.o preempt.o time.o
obj-y += events/
obj-y += xenbus/

diff --git a/drivers/xen/time.c b/drivers/xen/time.c
new file mode 100644
index 0000000..433fe24
--- /dev/null
+++ b/drivers/xen/time.c
@@ -0,0 +1,91 @@
+/*
+ * Xen stolen ticks accounting.
+ */
+#include <linux/kernel.h>
+#include <linux/kernel_stat.h>
+#include <linux/math64.h>
+#include <linux/gfp.h>
+
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/hypercall.h>
+
+#include <xen/events.h>
+#include <xen/features.h>
+#include <xen/interface/xen.h>
+#include <xen/interface/vcpu.h>
+#include <xen/xen-ops.h>
+
+/* runstate info updated by Xen */
+static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate);
+
+/* return an consistent snapshot of 64-bit time/counter value */
+static u64 get64(const u64 *p)
+{
+ u64 ret;
+
+ if (BITS_PER_LONG < 64) {
+ u32 *p32 = (u32 *)p;
+ u32 h, l;
+
+ /*
+ * Read high then low, and then make sure high is
+ * still the same; this will only loop if low wraps
+ * and carries into high.
+ * XXX some clean way to make this endian-proof?
+ */
+ do {
+ h = p32[1];
+ barrier();
+ l = p32[0];
+ barrier();
+ } while (p32[1] != h);
+
+ ret = (((u64)h) << 32) | l;
+ } else
+ ret = *p;
+
+ return ret;
+}
+
+/*
+ * Runstate accounting
+ */
+void xen_get_runstate_snapshot(struct vcpu_runstate_info *res)
+{
+ u64 state_time;
+ struct vcpu_runstate_info *state;
+
+ BUG_ON(preemptible());
+
+ state = this_cpu_ptr(&xen_runstate);
+
+ /*
+ * The runstate info is always updated by the hypervisor on
+ * the current CPU, so there's no need to use anything
+ * stronger than a compiler barrier when fetching it.
+ */
+ do {
+ state_time = get64(&state->state_entry_time);
+ barrier();
+ *res = *state;
+ barrier();
+ } while (get64(&state->state_entry_time) != state_time);
+}
+
+/* return true when a vcpu could run but has no real cpu to run on */
+bool xen_vcpu_stolen(int vcpu)
+{
+ return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable;
+}
+
+void xen_setup_runstate_info(int cpu)
+{
+ struct vcpu_register_runstate_memory_area area;
+
+ area.addr.v = &per_cpu(xen_runstate, cpu);
+
+ if (HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area,
+ cpu, &area))
+ BUG();
+}
+
diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index e4e214a..86abe07 100644
--- a/include/xen/xen-ops.h
+++ b/include/xen/xen-ops.h
@@ -5,6 +5,7 @@
#include <linux/notifier.h>
#include <linux/efi.h>
#include <asm/xen/interface.h>
+#include <xen/interface/vcpu.h>

DECLARE_PER_CPU(struct vcpu_info *, xen_vcpu);

@@ -18,6 +19,10 @@ void xen_arch_suspend(void);
void xen_resume_notifier_register(struct notifier_block *nb);
void xen_resume_notifier_unregister(struct notifier_block *nb);

+bool xen_vcpu_stolen(int vcpu);
+void xen_setup_runstate_info(int cpu);
+void xen_get_runstate_snapshot(struct vcpu_runstate_info *res);
+
int xen_setup_shutdown_event(void);

extern unsigned long *xen_contiguous_bitmap;
--
1.7.10.4

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