[RFC 06/12] cpufreq: Export HWP parameters to userspace

[Jason Andryuk <jandryuk@xxxxxxxxx>]

Extend xen_get_cpufreq_para to return hwp parameters.  These match the
hardware rather closely.

We need the hw_features bitmask to indicated fields supported by the
actual hardware.

The use of uint8_t parameters matches the hardware size.  uint32_t
entries grows the sysctl_t past the build assertion in setup.c.  The
uint8_t ranges are supported across multiple generations, so hopefully
they won't change.

Increment XEN_SYSCTL_INTERFACE_VERSION for the new fields.

Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>
---
 xen/arch/x86/acpi/cpufreq/hwp.c    | 24 ++++++++++++++++++++++++
 xen/drivers/acpi/pmstat.c          |  6 ++++++
 xen/include/acpi/cpufreq/cpufreq.h |  3 +++
 xen/include/public/sysctl.h        | 20 +++++++++++++++++++-
 4 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/acpi/cpufreq/hwp.c b/xen/arch/x86/acpi/cpufreq/hwp.c
index f8e6fdbd41..92222d6d85 100644
--- a/xen/arch/x86/acpi/cpufreq/hwp.c
+++ b/xen/arch/x86/acpi/cpufreq/hwp.c
@@ -523,6 +523,30 @@ static const struct cpufreq_driver __initconstrel 
hwp_cpufreq_driver =
     .update = hwp_cpufreq_update,
 };
 
+int get_hwp_para(struct cpufreq_policy *policy, struct xen_hwp_para *hwp_para)
+{
+    unsigned int cpu = policy->cpu;
+    struct hwp_drv_data *data = hwp_drv_data[cpu];
+
+    if ( data == NULL )
+        return -EINVAL;
+
+    hwp_para->hw_feature        =
+        feature_hwp_activity_window ? XEN_SYSCTL_HWP_FEAT_ACT_WINDOW  : 0 |
+        feature_hwp_energy_perf     ? XEN_SYSCTL_HWP_FEAT_ENERGY_PERF : 0;
+    hwp_para->hw_lowest         = data->hw_lowest;
+    hwp_para->hw_most_efficient = data->hw_most_efficient;
+    hwp_para->hw_guaranteed     = data->hw_guaranteed;
+    hwp_para->hw_highest        = data->hw_highest;
+    hwp_para->minimum           = data->minimum;
+    hwp_para->maximum           = data->maximum;
+    hwp_para->energy_perf       = data->energy_perf;
+    hwp_para->activity_window   = data->activity_window;
+    hwp_para->desired           = data->desired;
+
+    return 0;
+}
+
 int hwp_register_driver(void)
 {
     int ret;
diff --git a/xen/drivers/acpi/pmstat.c b/xen/drivers/acpi/pmstat.c
index 2f528f9ca3..4c6ae5d768 100644
--- a/xen/drivers/acpi/pmstat.c
+++ b/xen/drivers/acpi/pmstat.c
@@ -290,6 +290,12 @@ static int get_cpufreq_para(struct xen_sysctl_pm_op *op)
             &op->u.get_para.u.ondemand.sampling_rate,
             &op->u.get_para.u.ondemand.up_threshold);
     }
+
+    if ( !strnicmp(op->u.get_para.scaling_governor,
+                   "hwp-internal", CPUFREQ_NAME_LEN) )
+    {
+        ret = get_hwp_para(policy, &op->u.get_para.u.hwp_para);
+    }
     op->u.get_para.turbo_enabled = cpufreq_get_turbo_status(op->cpuid);
 
     return ret;
diff --git a/xen/include/acpi/cpufreq/cpufreq.h 
b/xen/include/acpi/cpufreq/cpufreq.h
index b91859ce5d..42146ca2cf 100644
--- a/xen/include/acpi/cpufreq/cpufreq.h
+++ b/xen/include/acpi/cpufreq/cpufreq.h
@@ -246,4 +246,7 @@ int write_userspace_scaling_setspeed(unsigned int cpu, 
unsigned int freq);
 void cpufreq_dbs_timer_suspend(void);
 void cpufreq_dbs_timer_resume(void);
 
+/********************** hwp hypercall helper *************************/
+int get_hwp_para(struct cpufreq_policy *policy, struct xen_hwp_para *hwp_para);
+
 #endif /* __XEN_CPUFREQ_PM_H__ */
diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h
index 039ccf885c..1a6c6397ea 100644
--- a/xen/include/public/sysctl.h
+++ b/xen/include/public/sysctl.h
@@ -35,7 +35,7 @@
 #include "domctl.h"
 #include "physdev.h"
 
-#define XEN_SYSCTL_INTERFACE_VERSION 0x00000013
+#define XEN_SYSCTL_INTERFACE_VERSION 0x00000014
 
 /*
  * Read console content from Xen buffer ring.
@@ -301,6 +301,23 @@ struct xen_ondemand {
     uint32_t up_threshold;
 };
 
+struct xen_hwp_para {
+    uint16_t activity_window; /* 7bit mantissa and 3bit exponent */
+#define XEN_SYSCTL_HWP_FEAT_ENERGY_PERF (1 << 0) /* energy_perf range 0-255 if
+                                                    1. Otherwise 0-15 */
+#define XEN_SYSCTL_HWP_FEAT_ACT_WINDOW  (1 << 1) /* activity_window supported
+                                                    if 1 */
+    uint8_t hw_feature; /* bit flags for features */
+    uint8_t hw_lowest;
+    uint8_t hw_most_efficient;
+    uint8_t hw_guaranteed;
+    uint8_t hw_highest;
+    uint8_t minimum;
+    uint8_t maximum;
+    uint8_t desired;
+    uint8_t energy_perf;
+};
+
 /*
  * cpufreq para name of this structure named
  * same as sysfs file name of native linux
@@ -332,6 +349,7 @@ struct xen_get_cpufreq_para {
     union {
         struct  xen_userspace userspace;
         struct  xen_ondemand ondemand;
+        struct  xen_hwp_para hwp_para;
     } u;
 
     int32_t turbo_enabled;
-- 
2.29.2