[PATCH v2 06/13] cpufreq: Export HWP parameters to userspace

[Jason Andryuk <jandryuk@gmail.com>]

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

We need the 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.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
---
v2:
Style fixes
Don't bump XEN_SYSCTL_INTERFACE_VERSION
Drop cpufreq.h comment divider
Expand xen_hwp_para comment
Add HWP activity window mantissa/exponent defines
Handle union rename
Add const to get_hwp_para
Remove hw_ prefix from xen_hwp_para members
Use XEN_HWP_GOVERNOR
Use per_cpu for hwp_drv_data
---
 xen/arch/x86/acpi/cpufreq/hwp.c    | 25 +++++++++++++++++++++++++
 xen/drivers/acpi/pmstat.c          |  5 +++++
 xen/include/acpi/cpufreq/cpufreq.h |  2 ++
 xen/include/public/sysctl.h        | 26 ++++++++++++++++++++++++++
 4 files changed, 58 insertions(+)

diff --git a/xen/arch/x86/acpi/cpufreq/hwp.c b/xen/arch/x86/acpi/cpufreq/hwp.c
index 405cbae334..233089b6c9 100644
--- a/xen/arch/x86/acpi/cpufreq/hwp.c
+++ b/xen/arch/x86/acpi/cpufreq/hwp.c
@@ -500,6 +500,31 @@ static const struct cpufreq_driver __initconstrel hwp_cpufreq_driver =
     .update = hwp_cpufreq_update,
 };
 
+int get_hwp_para(const struct cpufreq_policy *policy,
+                 struct xen_hwp_para *hwp_para)
+{
+    unsigned int cpu = policy->cpu;
+    const struct hwp_drv_data *data = per_cpu(hwp_drv_data, cpu);
+
+    if ( data == NULL )
+        return -EINVAL;
+
+    hwp_para->features        =
+        (feature_hwp_activity_window ? XEN_SYSCTL_HWP_FEAT_ACT_WINDOW  : 0) |
+        (feature_hwp_energy_perf     ? XEN_SYSCTL_HWP_FEAT_ENERGY_PERF : 0);
+    hwp_para->lowest          = data->hw.lowest;
+    hwp_para->most_efficient  = data->hw.most_efficient;
+    hwp_para->guaranteed      = data->hw.guaranteed;
+    hwp_para->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 __init hwp_register_driver(void)
 {
     return cpufreq_register_driver(&hwp_cpufreq_driver);
diff --git a/xen/drivers/acpi/pmstat.c b/xen/drivers/acpi/pmstat.c
index 1bae635101..67fd9dabd4 100644
--- a/xen/drivers/acpi/pmstat.c
+++ b/xen/drivers/acpi/pmstat.c
@@ -290,6 +290,11 @@ 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 ( !strncasecmp(op->u.get_para.scaling_governor, XEN_HWP_GOVERNOR,
+                      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 29a712a4f1..92b4c7e79c 100644
--- a/xen/include/acpi/cpufreq/cpufreq.h
+++ b/xen/include/acpi/cpufreq/cpufreq.h
@@ -247,5 +247,7 @@ void intel_feature_detect(struct cpufreq_policy *policy);
 
 extern bool opt_cpufreq_hwp;
 extern bool opt_cpufreq_hdc;
+int get_hwp_para(const 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 3d6dd14377..12a7a7db29 100644
--- a/xen/include/public/sysctl.h
+++ b/xen/include/public/sysctl.h
@@ -316,6 +316,31 @@ struct xen_ondemand {
     uint32_t up_threshold;
 };
 
+struct xen_hwp_para {
+    /*
+     * bits 6:0   - 7bit mantissa
+     * bits 9:7   - 3bit base-10 exponent
+     * btis 15:10 - Unused - must be 0
+     */
+#define HWP_ACT_WINDOW_MANTISSA_MASK  0x7f
+#define HWP_ACT_WINDOW_EXPONENT_MASK  0x7
+#define HWP_ACT_WINDOW_EXPONENT_SHIFT 7
+    uint16_t activity_window;
+    /* energy_perf range 0-255 if 1. Otherwise 0-15 */
+#define XEN_SYSCTL_HWP_FEAT_ENERGY_PERF (1 << 0)
+    /* activity_window supported if 1 */
+#define XEN_SYSCTL_HWP_FEAT_ACT_WINDOW  (1 << 1)
+    uint8_t features; /* bit flags for features */
+    uint8_t lowest;
+    uint8_t most_efficient;
+    uint8_t guaranteed;
+    uint8_t highest;
+    uint8_t minimum;
+    uint8_t maximum;
+    uint8_t desired;
+    uint8_t energy_perf;
+};
+
 #define XEN_HWP_GOVERNOR "hwp-internal"
 /*
  * cpufreq para name of this structure named
@@ -348,6 +373,7 @@ 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;
-- 
2.37.1