[PATCH v2 11/11] xen/cpufreq: Adapt SET/GET_CPUFREQ_CPPC xen_sysctl_pm_op for amd-cppc driver

[Penny Zheng <Penny.Zheng@xxxxxxx>]

Introduce helper set_amd_cppc_para and get_amd_cppc_para to
SET/GET CPPC-related para for amd-cppc/amd-cppc-epp driver.

Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx>
---
v1 -> v2:
- Give the variable des_perf an initializer of 0
- Use the strncmp()s directly in the if()
---
 xen/arch/x86/acpi/cpufreq/amd-cppc.c | 115 +++++++++++++++++++++++++++
 xen/drivers/acpi/pmstat.c            |  20 ++++-
 xen/include/acpi/cpufreq/cpufreq.h   |   5 ++
 3 files changed, 136 insertions(+), 4 deletions(-)

diff --git a/xen/arch/x86/acpi/cpufreq/amd-cppc.c 
b/xen/arch/x86/acpi/cpufreq/amd-cppc.c
index 241cce330b..0e43e32979 100644
--- a/xen/arch/x86/acpi/cpufreq/amd-cppc.c
+++ b/xen/arch/x86/acpi/cpufreq/amd-cppc.c
@@ -35,6 +35,7 @@
 
 static bool __ro_after_init opt_cpufreq_active;
 static uint8_t __read_mostly epp_init;
+static bool __ro_after_init amd_cppc_in_use;
 
 struct amd_cppc_drv_data
 {
@@ -533,6 +534,114 @@ static int cf_check amd_cppc_epp_set_policy(struct 
cpufreq_policy *policy)
     return amd_cppc_epp_update_limit(policy);
 }
 
+int get_amd_cppc_para(unsigned int cpu,
+                      struct xen_cppc_para *cppc_para)
+{
+    const struct amd_cppc_drv_data *data = per_cpu(amd_cppc_drv_data, cpu);
+
+    if ( data == NULL )
+        return -ENODATA;
+
+    cppc_para->features         = 0;
+    cppc_para->lowest           = data->caps.lowest_perf;
+    cppc_para->lowest_nonlinear = data->caps.lowest_nonlinear_perf;
+    cppc_para->nominal          = data->caps.nominal_perf;
+    cppc_para->highest          = data->caps.highest_perf;
+    cppc_para->minimum          = data->req.min_perf;
+    cppc_para->maximum          = data->req.max_perf;
+    cppc_para->desired          = data->req.des_perf;
+    cppc_para->energy_perf      = data->req.epp;
+
+    return 0;
+}
+
+int set_amd_cppc_para(const struct cpufreq_policy *policy,
+                      const struct xen_set_cppc_para *set_cppc)
+{
+    unsigned int cpu = policy->cpu;
+    struct amd_cppc_drv_data *data = per_cpu(amd_cppc_drv_data, cpu);
+    uint8_t max_perf, min_perf, des_perf = 0;
+    int epp = -1;
+
+    if ( data == NULL )
+        return -ENOENT;
+
+    /* Validate all parameters - Disallow reserved bits. */
+    if ( set_cppc->minimum > 255 || set_cppc->maximum > 255 ||
+         set_cppc->desired > 255 || set_cppc->energy_perf > 255 )
+        return -EINVAL;
+
+    /* Only allow values if params bit is set. */
+    if ( (!(set_cppc->set_params & XEN_SYSCTL_CPPC_SET_DESIRED) &&
+          set_cppc->desired) ||
+         (!(set_cppc->set_params & XEN_SYSCTL_CPPC_SET_MINIMUM) &&
+          set_cppc->minimum) ||
+         (!(set_cppc->set_params & XEN_SYSCTL_CPPC_SET_MAXIMUM) &&
+          set_cppc->maximum) ||
+         (!(set_cppc->set_params & XEN_SYSCTL_CPPC_SET_ENERGY_PERF) &&
+          set_cppc->energy_perf) )
+        return -EINVAL;
+
+    /* Activity window not supported */
+    if ( set_cppc->set_params & XEN_SYSCTL_CPPC_SET_ACT_WINDOW )
+        return -EINVAL;
+
+    /* Return if there is nothing to do. */
+    if ( set_cppc->set_params == 0 )
+        return 0;
+
+    /* Apply presets */
+    switch ( set_cppc->set_params & XEN_SYSCTL_CPPC_SET_PRESET_MASK )
+    {
+    case XEN_SYSCTL_CPPC_SET_PRESET_POWERSAVE:
+        if ( set_cppc->set_params & XEN_SYSCTL_CPPC_SET_DESIRED )
+            return -EINVAL;
+        min_perf = data->caps.lowest_perf;
+        max_perf = data->caps.highest_perf;
+        epp = CPPC_ENERGY_PERF_MAX_POWERSAVE;
+        break;
+
+    case XEN_SYSCTL_CPPC_SET_PRESET_PERFORMANCE:
+        if ( set_cppc->set_params & XEN_SYSCTL_CPPC_SET_DESIRED )
+            return -EINVAL;
+        min_perf = data->caps.highest_perf;
+        max_perf = data->caps.highest_perf;
+        epp = CPPC_ENERGY_PERF_MAX_PERFORMANCE;
+        break;
+
+    case XEN_SYSCTL_CPPC_SET_PRESET_BALANCE:
+        if ( set_cppc->set_params & XEN_SYSCTL_CPPC_SET_DESIRED )
+            return -EINVAL;
+        min_perf = data->caps.lowest_perf;
+        max_perf = data->caps.highest_perf;
+        epp = CPPC_ENERGY_PERF_BALANCE;
+        break;
+
+    case XEN_SYSCTL_CPPC_SET_PRESET_NONE:
+        min_perf = data->caps.lowest_nonlinear_perf;
+        max_perf = data->caps.highest_perf;
+        break;
+
+    default:
+        return -EINVAL;
+    }
+
+    /* Further customize presets if needed */
+    if ( set_cppc->set_params & XEN_SYSCTL_CPPC_SET_MINIMUM )
+        min_perf = set_cppc->minimum;
+
+    if ( set_cppc->set_params & XEN_SYSCTL_CPPC_SET_MAXIMUM )
+        max_perf = set_cppc->maximum;
+
+    if ( set_cppc->set_params & XEN_SYSCTL_CPPC_SET_ENERGY_PERF )
+        epp = set_cppc->energy_perf;
+
+    if ( set_cppc->set_params & XEN_SYSCTL_CPPC_SET_DESIRED )
+        des_perf = set_cppc->desired;
+
+    return amd_cppc_write_request(cpu, min_perf, des_perf, max_perf, epp);
+}
+
 static const struct cpufreq_driver __initconst_cf_clobber 
amd_cppc_cpufreq_driver =
 {
     .name   = XEN_AMD_CPPC_DRIVER_NAME,
@@ -551,11 +660,17 @@ static const struct cpufreq_driver  
__initconst_cf_clobber amd_cppc_epp_driver =
     .exit       = amd_cppc_cpufreq_cpu_exit,
 };
 
+bool amd_cppc_active(void)
+{
+    return amd_cppc_in_use;
+}
+
 int __init amd_cppc_register_driver(void)
 {
     if ( !cpu_has_cppc )
         return -ENODEV;
 
+    amd_cppc_in_use = true;
     if ( !opt_cpufreq_active )
         return cpufreq_register_driver(&amd_cppc_cpufreq_driver);
     else
diff --git a/xen/drivers/acpi/pmstat.c b/xen/drivers/acpi/pmstat.c
index df309e27b4..46899d99d7 100644
--- a/xen/drivers/acpi/pmstat.c
+++ b/xen/drivers/acpi/pmstat.c
@@ -258,7 +258,16 @@ static int get_cpufreq_para(struct xen_sysctl_pm_op *op)
          !strncmp(op->u.get_para.scaling_driver, XEN_HWP_DRIVER_NAME,
                   CPUFREQ_NAME_LEN) )
         ret = get_hwp_para(policy->cpu, &op->u.get_para.u.cppc_para);
-    else
+    else if ( !strncmp(op->u.get_para.scaling_driver, XEN_AMD_CPPC_DRIVER_NAME,
+                       CPUFREQ_NAME_LEN) ||
+              !strncmp(op->u.get_para.scaling_driver, 
XEN_AMD_CPPC_EPP_DRIVER_NAME,
+                       CPUFREQ_NAME_LEN) )
+        ret = get_amd_cppc_para(policy->cpu, &op->u.get_para.u.cppc_para);
+
+    if ( strncmp(op->u.get_para.scaling_driver, XEN_HWP_DRIVER_NAME,
+                 CPUFREQ_NAME_LEN) &&
+         strncmp(op->u.get_para.scaling_driver, XEN_AMD_CPPC_EPP_DRIVER_NAME,
+                 CPUFREQ_NAME_LEN) )
     {
         if ( !(scaling_available_governors =
                xzalloc_array(char, gov_num * CPUFREQ_NAME_LEN)) )
@@ -414,10 +423,13 @@ static int set_cpufreq_cppc(struct xen_sysctl_pm_op *op)
     if ( !policy || !policy->governor )
         return -ENOENT;
 
-    if ( !hwp_active() )
-        return -EOPNOTSUPP;
+    if ( hwp_active() )
+        return set_hwp_para(policy, &op->u.set_cppc);
+
+    if ( amd_cppc_active() )
+        return set_amd_cppc_para(policy, &op->u.set_cppc);
 
-    return set_hwp_para(policy, &op->u.set_cppc);
+    return -EOPNOTSUPP;
 }
 
 int do_pm_op(struct xen_sysctl_pm_op *op)
diff --git a/xen/include/acpi/cpufreq/cpufreq.h 
b/xen/include/acpi/cpufreq/cpufreq.h
index fb42d61567..cc5a248193 100644
--- a/xen/include/acpi/cpufreq/cpufreq.h
+++ b/xen/include/acpi/cpufreq/cpufreq.h
@@ -292,5 +292,10 @@ int acpi_cpufreq_register(void);
 
 int amd_cppc_cmdline_parse(const char *s, const char *e);
 int amd_cppc_register_driver(void);
+bool amd_cppc_active(void);
+int get_amd_cppc_para(unsigned int cpu,
+                      struct xen_cppc_para *cppc_para);
+int set_amd_cppc_para(const struct cpufreq_policy *policy,
+                      const struct xen_set_cppc_para *set_cppc);
 
 #endif /* __XEN_CPUFREQ_PM_H__ */
-- 
2.34.1