[Xen-devel] [PATCH v2 4/9] x86/intel_pstate: add new policy fields and a new driver interface

[Wei Wang <wei.w.wang@xxxxxxxxx>]

In order to better support future Intel processors, intel_pstate
changes to use percentage values to tune P-states. The intel_pstate
driver uses its own internal governor, and it is recorded in the
"policy->policy" field. The setpolicy driver interface is used to
configure the intel_pstate internal policy. The __cpufreq_set_policy
needs to be intercepted to use the setpolicy driver if it exists.

Signed-off-by: Wei Wang <wei.w.wang@xxxxxxxxx>
---
 xen/drivers/cpufreq/utility.c      |  5 +++++
 xen/include/acpi/cpufreq/cpufreq.h | 11 +++++++++++
 2 files changed, 16 insertions(+)

diff --git a/xen/drivers/cpufreq/utility.c b/xen/drivers/cpufreq/utility.c
index 519f862..04f88c2 100644
--- a/xen/drivers/cpufreq/utility.c
+++ b/xen/drivers/cpufreq/utility.c
@@ -456,6 +456,11 @@ int __cpufreq_set_policy(struct cpufreq_policy *data,
 
     data->min = policy->min;
     data->max = policy->max;
+    data->min_perf_pct = policy->min_perf_pct;
+    data->max_perf_pct = policy->max_perf_pct;
+
+    if (cpufreq_driver->setpolicy)
+        return cpufreq_driver->setpolicy(data);
 
     if (policy->governor != data->governor) {
         /* save old, working values */
diff --git a/xen/include/acpi/cpufreq/cpufreq.h 
b/xen/include/acpi/cpufreq/cpufreq.h
index f96c3e4..67c9be2 100644
--- a/xen/include/acpi/cpufreq/cpufreq.h
+++ b/xen/include/acpi/cpufreq/cpufreq.h
@@ -52,6 +52,10 @@ struct cpufreq_policy {
     unsigned int        max;    /* in kHz */
     unsigned int        cur;    /* in kHz, only needed if cpufreq
                                  * governors are used */
+    int                 min_perf_pct; /* min performance in percentage */
+    int                 max_perf_pct; /* max performance in percentage */
+    int                 turbo_pct;
+    unsigned int        policy;
     struct cpufreq_governor     *governor;
 
     bool_t              resume; /* flag for cpufreq 1st run
@@ -87,6 +91,12 @@ struct cpufreq_freqs {
  *                          CPUFREQ GOVERNORS                        *
  *********************************************************************/
 
+/* the four internal governors used in intel_pstate */
+#define CPUFREQ_POLICY_POWERSAVE        (1)
+#define CPUFREQ_POLICY_PERFORMANCE      (2)
+#define CPUFREQ_POLICY_USERSPACE        (3)
+#define CPUFREQ_POLICY_ONDEMAND         (4)
+
 #define CPUFREQ_GOV_START  1
 #define CPUFREQ_GOV_STOP   2
 #define CPUFREQ_GOV_LIMITS 3
@@ -145,6 +155,7 @@ struct cpufreq_driver {
     char   name[CPUFREQ_NAME_LEN];
     int    (*init)(struct cpufreq_policy *policy);
     int    (*verify)(struct cpufreq_policy *policy);
+    int    (*setpolicy)(struct cpufreq_policy *policy);
     int    (*update)(int cpuid, struct cpufreq_policy *policy);
     int    (*target)(struct cpufreq_policy *policy,
                      unsigned int target_freq,
-- 
1.9.1


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