[PATCH v5 5/9] x86/intel_pstate: changes in cpufreq_del_cpu for CPU offline

[Wei Wang <wei.w.wang@intel.com>]

We change to NULL the cpufreq_cpu_policy pointer after the call of
cpufreq_driver->exit, because the pointer is still needed in
intel_pstate_set_pstate().

Signed-off-by: Wei Wang <wei.w.wang@intel.com>
---
 xen/drivers/cpufreq/cpufreq.c      | 6 +++---
 xen/include/acpi/cpufreq/cpufreq.h | 7 +++++++
 2 files changed, 10 insertions(+), 3 deletions(-)

 changes in v5:
 1) put this patch prior to the "main body of intel pstate driver", which is 
    one of the acceptable options suggested by the Jan.

diff --git a/xen/drivers/cpufreq/cpufreq.c b/xen/drivers/cpufreq/cpufreq.c
index 0c437d4..5485944 100644
--- a/xen/drivers/cpufreq/cpufreq.c
+++ b/xen/drivers/cpufreq/cpufreq.c
@@ -334,12 +334,11 @@ int cpufreq_del_cpu(unsigned int cpu)
 
     /* for HW_ALL, stop gov for each core of the _PSD domain */
     /* for SW_ALL & SW_ANY, stop gov for the 1st core of the _PSD domain */
-    if (hw_all || (cpumask_weight(cpufreq_dom->map) ==
-                   perf->domain_info.num_processors))
+    if (!policy->internal_gov && (hw_all || (cpumask_weight(cpufreq_dom->map) ==
+                   perf->domain_info.num_processors)))
         __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
 
     cpufreq_statistic_exit(cpu);
-    per_cpu(cpufreq_cpu_policy, cpu) = NULL;
     cpumask_clear_cpu(cpu, policy->cpus);
     cpumask_clear_cpu(cpu, cpufreq_dom->map);
 
@@ -348,6 +347,7 @@ int cpufreq_del_cpu(unsigned int cpu)
         free_cpumask_var(policy->cpus);
         xfree(policy);
     }
+    per_cpu(cpufreq_cpu_policy, cpu) = NULL;
 
     /* for the last cpu of the domain, clean room */
     /* It's safe here to free freq_table, drv_data and policy */
diff --git a/xen/include/acpi/cpufreq/cpufreq.h b/xen/include/acpi/cpufreq/cpufreq.h
index c6976d0..48bd94d 100644
--- a/xen/include/acpi/cpufreq/cpufreq.h
+++ b/xen/include/acpi/cpufreq/cpufreq.h
@@ -53,6 +53,12 @@ struct perf_limits {
     uint32_t min_policy_pct;
 };
 
+struct internal_governor {
+    char *avail_gov;
+    uint32_t gov_num;
+    uint32_t cur_gov;
+};
+
 struct cpufreq_policy {
     cpumask_var_t       cpus;          /* affected CPUs */
     unsigned int        shared_type;   /* ANY or ALL affected CPUs
@@ -66,6 +72,7 @@ struct cpufreq_policy {
                                  * governors are used */
     struct perf_limits  limits;
     struct cpufreq_governor     *governor;
+    struct internal_governor    *internal_gov;
 
     bool_t              resume; /* flag for cpufreq 1st run
                                  * S3 wakeup, hotplug cpu, etc */
-- 
1.9.1