[PATCH 10/15] hv: switch to cpuhp state machine for synic init/cleanup

From: kys
Date: Thu Dec 01 2016 - 10:34:54 EST


From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

To make it possible to online/offline CPUs switch to cpuhp infrastructure
for doing hv_synic_init()/hv_synic_cleanup().

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
---
drivers/hv/hv.c | 15 +++++++--------
drivers/hv/hyperv_vmbus.h | 4 ++--
drivers/hv/vmbus_drv.c | 19 +++++++++++--------
3 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index c11393c..b3f6a1b 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -495,7 +495,7 @@ void hv_synic_free(void)
* retrieve the initialized message and event pages. Otherwise, we create and
* initialize the message and event pages.
*/
-void hv_synic_init(void *arg)
+int hv_synic_init(unsigned int cpu)
{
u64 version;
union hv_synic_simp simp;
@@ -504,10 +504,8 @@ void hv_synic_init(void *arg)
union hv_synic_scontrol sctrl;
u64 vp_index;

- int cpu = smp_processor_id();
-
if (!hv_context.hypercall_page)
- return;
+ return -EFAULT;

/* Check the version */
rdmsrl(HV_X64_MSR_SVERSION, version);
@@ -562,7 +560,7 @@ void hv_synic_init(void *arg)
HV_TIMER_FREQUENCY,
HV_MIN_DELTA_TICKS,
HV_MAX_MAX_DELTA_TICKS);
- return;
+ return 0;
}

/*
@@ -582,16 +580,15 @@ void hv_synic_clockevents_cleanup(void)
/*
* hv_synic_cleanup - Cleanup routine for hv_synic_init().
*/
-void hv_synic_cleanup(void *arg)
+int hv_synic_cleanup(unsigned int cpu)
{
union hv_synic_sint shared_sint;
union hv_synic_simp simp;
union hv_synic_siefp siefp;
union hv_synic_scontrol sctrl;
- int cpu = smp_processor_id();

if (!hv_context.synic_initialized)
- return;
+ return -EFAULT;

/* Turn off clockevent device */
if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE) {
@@ -623,4 +620,6 @@ void hv_synic_cleanup(void *arg)
rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
sctrl.enable = 0;
wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
+
+ return 0;
}
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 27982df..83beea7 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -505,9 +505,9 @@ extern int hv_post_message(union hv_connection_id connection_id,

extern void hv_synic_free(void);

-extern void hv_synic_init(void *irqarg);
+extern int hv_synic_init(unsigned int cpu);

-extern void hv_synic_cleanup(void *arg);
+extern int hv_synic_cleanup(unsigned int cpu);

extern void hv_synic_clockevents_cleanup(void);

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 1730ac0..cafd273 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -49,6 +49,7 @@

static struct completion probe_event;

+static int hyperv_cpuhp_online;

static void hyperv_report_panic(struct pt_regs *regs)
{
@@ -850,7 +851,12 @@ static int vmbus_bus_init(void)
* Initialize the per-cpu interrupt state and
* connect to the host.
*/
- on_each_cpu(hv_synic_init, NULL, 1);
+ ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/hyperv:online",
+ hv_synic_init, hv_synic_cleanup);
+ if (ret < 0)
+ goto err_alloc;
+ hyperv_cpuhp_online = ret;
+
ret = vmbus_connect();
if (ret)
goto err_connect;
@@ -872,7 +878,7 @@ static int vmbus_bus_init(void)
return 0;

err_connect:
- on_each_cpu(hv_synic_cleanup, NULL, 1);
+ cpuhp_remove_state(hyperv_cpuhp_online);
err_alloc:
hv_synic_free();
hv_remove_vmbus_irq();
@@ -1326,12 +1332,9 @@ static int vmbus_acpi_add(struct acpi_device *device)

static void hv_kexec_handler(void)
{
- int cpu;
-
hv_synic_clockevents_cleanup();
vmbus_initiate_unload(false);
- for_each_online_cpu(cpu)
- smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
+ cpuhp_remove_state(hyperv_cpuhp_online);
hv_cleanup(false);
};

@@ -1343,7 +1346,7 @@ static void hv_crash_handler(struct pt_regs *regs)
* doing the cleanup for current CPU only. This should be sufficient
* for kdump.
*/
- hv_synic_cleanup(NULL);
+ hv_synic_cleanup(smp_processor_id());
hv_cleanup(true);
};

@@ -1407,8 +1410,8 @@ static void __exit vmbus_exit(void)
hv_cleanup(false);
for_each_online_cpu(cpu) {
tasklet_kill(hv_context.event_dpc[cpu]);
- smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
}
+ cpuhp_remove_state(hyperv_cpuhp_online);
hv_synic_free();
acpi_bus_unregister_driver(&vmbus_acpi_driver);
if (vmbus_proto_version > VERSION_WIN7)
--
1.7.4.1