From: Michael Kelley <mikel...@microsoft.com>

The synic_initialized flag is part of the global hv_context
structure.  But the Hyper-V synthetic interrupt controller is
fundamentally a per-cpu device, and other synic related
fields are in hv_per_cpu_context.  In a multi-CPU system,
synic_initialized gets set multiple times, making the test in
hv_synic_cleanup() invalid.  Fix this by moving the flag to
hv_per_cpu_context and adjusting the references.

Signed-off-by: Michael Kelley <mikel...@microsoft.com>
---
 drivers/hv/hv.c           | 16 +++++++---------
 drivers/hv/hyperv_vmbus.h |  4 ++--
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 312fe5e..8d4fe0e 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -33,9 +33,7 @@
 #include "hyperv_vmbus.h"
 
 /* The one and only */
-struct hv_context hv_context = {
-       .synic_initialized      = false,
-};
+struct hv_context hv_context;
 
 /*
  * If false, we're using the old mechanism for stimer0 interrupts
@@ -315,7 +313,7 @@ int hv_synic_init(unsigned int cpu)
 
        hv_set_synic_state(sctrl.as_uint64);
 
-       hv_context.synic_initialized = true;
+       hv_cpu->synic_initialized = true;
 
        /*
         * Register the per-cpu clockevent source.
@@ -354,6 +352,8 @@ void hv_synic_clockevents_cleanup(void)
  */
 int hv_synic_cleanup(unsigned int cpu)
 {
+       struct hv_per_cpu_context *hv_cpu
+               = per_cpu_ptr(hv_context.cpu_context, cpu);
        union hv_synic_sint shared_sint;
        union hv_synic_simp simp;
        union hv_synic_siefp siefp;
@@ -362,7 +362,7 @@ int hv_synic_cleanup(unsigned int cpu)
        bool channel_found = false;
        unsigned long flags;
 
-       if (!hv_context.synic_initialized)
+       if (!hv_cpu->synic_initialized)
                return -EFAULT;
 
        /*
@@ -395,12 +395,8 @@ int hv_synic_cleanup(unsigned int cpu)
 
        /* Turn off clockevent device */
        if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE) {
-               struct hv_per_cpu_context *hv_cpu
-                       = this_cpu_ptr(hv_context.cpu_context);
-
                clockevents_unbind_device(hv_cpu->clk_evt, cpu);
                hv_ce_shutdown(hv_cpu->clk_evt);
-               put_cpu_ptr(hv_cpu);
        }
 
        hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
@@ -428,5 +424,7 @@ int hv_synic_cleanup(unsigned int cpu)
        sctrl.enable = 0;
        hv_set_synic_state(sctrl.as_uint64);
 
+       hv_cpu->synic_initialized = false;
+
        return 0;
 }
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 72eaba3..eadd3df 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -202,6 +202,8 @@ enum {
 struct hv_per_cpu_context {
        void *synic_message_page;
        void *synic_event_page;
+       bool synic_initialized;
+
        /*
         * buffer to post messages to the host.
         */
@@ -230,8 +232,6 @@ struct hv_context {
 
        void *tsc_page;
 
-       bool synic_initialized;
-
        struct hv_per_cpu_context __percpu *cpu_context;
 
        /*
-- 
1.8.3.1

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