pmstat&xenpm: Re-arrage for cpufreq union

Rearrange code now that xen_sysctl_pm_op's get_para fields has the
nested union and struct.  In particular, the scaling governor
information like scaling_available_governors is inside the union, so it
is not always available.  Move those fields (op->u.get_para.u.s.u.*)
together as well as the common fields (ones outside the union like
op->u.get_para.turbo_enabled).

With that, gov_num may be 0, so bounce buffer handling needs
to be modified.

scaling_governor and other fields inside op->u.get_para.u.s.u.* won't be
used for hwp, so this will simplify the change when hwp support is
introduced and re-indents these lines all together.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>

tools/libs/ctrl/xc_pm.c

@@ -221,7 +221,7 @@ int xc_get_cpufreq_para(xc_interface *xch, int cpuid,
     {
         if ( (!user_para->affected_cpus)                    ||
              (!user_para->scaling_available_frequencies)    ||
-             (!user_para->scaling_available_governors) )
+             (user_para->gov_num && !user_para->scaling_available_governors) )
         {
             errno = EINVAL;
             return -1;
@@ -230,12 +230,15 @@ int xc_get_cpufreq_para(xc_interface *xch, int cpuid,
             goto unlock_1;
         if ( xc_hypercall_bounce_pre(xch, scaling_available_frequencies) )
             goto unlock_2;
-        if ( xc_hypercall_bounce_pre(xch, scaling_available_governors) )
+        if ( user_para->gov_num &&
+             xc_hypercall_bounce_pre(xch, scaling_available_governors) )
             goto unlock_3;
 
         set_xen_guest_handle(sys_para->affected_cpus, affected_cpus);
         set_xen_guest_handle(sys_para->scaling_available_frequencies, scaling_available_frequencies);
-        set_xen_guest_handle(sys_para->scaling_available_governors, scaling_available_governors);
+        if ( user_para->gov_num )
+            set_xen_guest_handle(sys_para->scaling_available_governors,
+                                 scaling_available_governors);
     }
 
     sysctl.cmd = XEN_SYSCTL_pm_op;
@@ -317,7 +320,8 @@ int xc_get_cpufreq_para(xc_interface *xch, int cpuid,
     }
 
 unlock_4:
-    xc_hypercall_bounce_post(xch, scaling_available_governors);
+    if ( user_para->gov_num )
+        xc_hypercall_bounce_post(xch, scaling_available_governors);
 unlock_3:
     xc_hypercall_bounce_post(xch, scaling_available_frequencies);
 unlock_2:

tools/misc/xenpm.c

@@ -811,7 +811,8 @@ static int show_cpufreq_para_by_cpuid(xc_interface *xc_handle, int cpuid)
             ret = -ENOMEM;
             goto out;
         }
-        if (!(p_cpufreq->scaling_available_governors =
+        if (p_cpufreq->gov_num &&
+            !(p_cpufreq->scaling_available_governors =
               malloc(p_cpufreq->gov_num * CPUFREQ_NAME_LEN * sizeof(char))))
         {
             fprintf(stderr,

xen/drivers/acpi/pmstat.c

@@ -239,6 +239,18 @@ static int get_cpufreq_para(struct xen_sysctl_pm_op *op)
     if ( ret )
         return ret;
 
+    op->u.get_para.cpuinfo_cur_freq =
+        cpufreq_driver.get ? cpufreq_driver.get(op->cpuid) : policy->cur;
+    op->u.get_para.cpuinfo_max_freq = policy->cpuinfo.max_freq;
+    op->u.get_para.cpuinfo_min_freq = policy->cpuinfo.min_freq;
+    op->u.get_para.turbo_enabled = cpufreq_get_turbo_status(op->cpuid);
+
+    if ( cpufreq_driver.name[0] )
+        strlcpy(op->u.get_para.scaling_driver,
+            cpufreq_driver.name, CPUFREQ_NAME_LEN);
+    else
+        strlcpy(op->u.get_para.scaling_driver, "Unknown", CPUFREQ_NAME_LEN);
+
     if ( !(scaling_available_governors =
            xzalloc_array(char, gov_num * CPUFREQ_NAME_LEN)) )
         return -ENOMEM;
@@ -254,21 +266,10 @@ static int get_cpufreq_para(struct xen_sysctl_pm_op *op)
     if ( ret )
         return ret;
 
-    op->u.get_para.cpuinfo_cur_freq =
-        cpufreq_driver.get ? cpufreq_driver.get(op->cpuid) : policy->cur;
-    op->u.get_para.cpuinfo_max_freq = policy->cpuinfo.max_freq;
-    op->u.get_para.cpuinfo_min_freq = policy->cpuinfo.min_freq;
-
     op->u.get_para.u.s.scaling_cur_freq = policy->cur;
     op->u.get_para.u.s.scaling_max_freq = policy->max;
     op->u.get_para.u.s.scaling_min_freq = policy->min;
 
-    if ( cpufreq_driver.name[0] )
-        strlcpy(op->u.get_para.scaling_driver,
-            cpufreq_driver.name, CPUFREQ_NAME_LEN);
-    else
-        strlcpy(op->u.get_para.scaling_driver, "Unknown", CPUFREQ_NAME_LEN);
-
     if ( policy->governor->name[0] )
         strlcpy(op->u.get_para.u.s.scaling_governor,
             policy->governor->name, CPUFREQ_NAME_LEN);
@@ -291,7 +292,6 @@ static int get_cpufreq_para(struct xen_sysctl_pm_op *op)
             &op->u.get_para.u.s.u.ondemand.sampling_rate,
             &op->u.get_para.u.s.u.ondemand.up_threshold);
     }
-    op->u.get_para.turbo_enabled = cpufreq_get_turbo_status(op->cpuid);
 
     return ret;
 }