[PATCH] x86/cpufreq: allocate processor_pminfo[] dynamically

[Jan Beulich <jbeulich@xxxxxxxx>]

There's no need to have a NR_CPUS-dimensioned static array there.

As ordering of pre-SMP initcalls isn't well-defined, allocate the array
from both cpufreq_presmp_init() and cpufreq_register_driver().

Alongside adding a few NULL checks, drop a redundant one from
get_cpufreq_para().

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/drivers/acpi/pm-op.c
+++ b/xen/drivers/acpi/pm-op.c
@@ -104,8 +104,7 @@ static int get_cpufreq_para(struct xen_s
     pmpt = processor_pminfo[op->cpuid];
     policy = per_cpu(cpufreq_cpu_policy, op->cpuid);
 
-    if ( !pmpt ||
-         ((pmpt->init & XEN_PX_INIT) && !pmpt->perf.states) ||
+    if ( ((pmpt->init & XEN_PX_INIT) && !pmpt->perf.states) ||
          /* Avoid NULL deref of pmpt->perf.states[] */
          ((pmpt->init & XEN_CPPC_INIT) && pmpt->perf.state_count) ||
          !policy || !policy->governor )
@@ -369,7 +368,7 @@ int do_pm_op(struct xen_sysctl_pm_op *op
 
     if ( op->cpuid >= nr_cpu_ids || !cpu_online(op->cpuid) )
         return -EINVAL;
-    pmpt = processor_pminfo[op->cpuid];
+    pmpt = processor_pminfo ? processor_pminfo[op->cpuid] : NULL;
 
     switch ( op->cmd & PM_PARA_CATEGORY_MASK )
     {
--- a/xen/drivers/acpi/pmstat.c
+++ b/xen/drivers/acpi/pmstat.c
@@ -227,7 +227,7 @@ int do_get_pm_info(struct xen_sysctl_get
 
     if ( !op || (op->cpuid >= nr_cpu_ids) || !cpu_online(op->cpuid) )
         return -EINVAL;
-    pmpt = processor_pminfo[op->cpuid];
+    pmpt = processor_pminfo ? processor_pminfo[op->cpuid] : NULL;
 
     switch ( op->type & PMSTAT_CATEGORY_MASK )
     {
--- a/xen/drivers/cpufreq/cpufreq.c
+++ b/xen/drivers/cpufreq/cpufreq.c
@@ -218,7 +218,7 @@ int cpufreq_limit_change(unsigned int cp
     struct cpufreq_policy policy;
 
     if (!cpu_online(cpu) || !(data = per_cpu(cpufreq_cpu_policy, cpu)) ||
-        !processor_pminfo[cpu])
+        !processor_pminfo || !processor_pminfo[cpu])
         return -ENODEV;
 
     perf = &processor_pminfo[cpu]->perf;
@@ -273,7 +273,7 @@ int cpufreq_add_cpu(unsigned int cpu)
     unsigned int shared_type;
 
     /* to protect the case when Px was not controlled by xen */
-    if ( !processor_pminfo[cpu] || !cpu_online(cpu) )
+    if ( !processor_pminfo || !processor_pminfo[cpu] || !cpu_online(cpu) )
         return -EINVAL;
 
     if ( !(processor_pminfo[cpu]->init & (XEN_PX_INIT | XEN_CPPC_INIT)) )
@@ -448,7 +448,7 @@ int cpufreq_del_cpu(unsigned int cpu)
     const struct xen_psd_package *domain_info;
 
     /* to protect the case when Px was not controlled by xen */
-    if ( !processor_pminfo[cpu] || !cpu_online(cpu) )
+    if ( !processor_pminfo || !processor_pminfo[cpu] || !cpu_online(cpu) )
         return -EINVAL;
 
     if ( !(processor_pminfo[cpu]->init & (XEN_PX_INIT | XEN_CPPC_INIT)) )
@@ -563,6 +563,9 @@ int set_px_pminfo(uint32_t acpi_id, stru
     struct processor_pminfo *pmpt;
     struct processor_performance *pxpt;
 
+    if ( !processor_pminfo )
+        return -ENOMEM;
+
     cpu = get_cpu_id(acpi_id);
     if ( cpu < 0 || !perf )
     {
@@ -726,6 +729,9 @@ int set_cppc_pminfo(unsigned int acpi_id
     int ret = 0, cpu_id;
     struct processor_pminfo *pm_info;
 
+    if ( !processor_pminfo )
+        return -ENOMEM;
+
     cpu_id = get_cpu_id(acpi_id);
     if ( cpu_id < 0 )
     {
@@ -947,6 +953,11 @@ static struct notifier_block cpu_nfb = {
 
 static int __init cf_check cpufreq_presmp_init(void)
 {
+    if ( !processor_pminfo )
+        processor_pminfo = xvzalloc_array(struct processor_pminfo *, 
nr_cpu_ids);
+    if ( !processor_pminfo )
+        return -ENOMEM;
+
     register_cpu_notifier(&cpu_nfb);
     return 0;
 }
@@ -954,6 +965,11 @@ presmp_initcall(cpufreq_presmp_init);
 
 int __init cpufreq_register_driver(const struct cpufreq_driver *driver_data)
 {
+    if ( !processor_pminfo )
+        processor_pminfo = xvzalloc_array(struct processor_pminfo *, 
nr_cpu_ids);
+    if ( !processor_pminfo )
+        return -ENOMEM;
+
    if ( !driver_data || !driver_data->init ||
         !driver_data->verify || !driver_data->exit ||
         (!driver_data->target == !driver_data->setpolicy) )
--- a/xen/drivers/cpufreq/utility.c
+++ b/xen/drivers/cpufreq/utility.c
@@ -32,7 +32,7 @@
 #include <public/sysctl.h>
 
 struct cpufreq_driver __read_mostly cpufreq_driver;
-struct processor_pminfo *__read_mostly processor_pminfo[NR_CPUS];
+struct processor_pminfo **__read_mostly processor_pminfo;
 DEFINE_PER_CPU_READ_MOSTLY(struct cpufreq_policy *, cpufreq_cpu_policy);
 
 /*********************************************************************
--- a/xen/include/acpi/cpufreq/processor_perf.h
+++ b/xen/include/acpi/cpufreq/processor_perf.h
@@ -59,7 +59,7 @@ struct processor_pminfo {
     uint32_t init;
 };
 
-extern struct processor_pminfo *processor_pminfo[NR_CPUS];
+extern struct processor_pminfo **processor_pminfo;
 
 struct px_stat {
     uint8_t total;        /* total Px states */