Merge tag 'tilcdc-4.15-fixes' of https://github.com/jsarha/linux into drm-next

[sfrench/cifs-2.6.git] / arch / powerpc / perf / imc-pmu.c

diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c
index 9ccac86f346385eaa624930f3050cdae62b6b09d..88126245881b3f8e500ab099bbfa4ebba8bf03d9 100644 (file)
--- a/arch/powerpc/perf/imc-pmu.c
+++ b/arch/powerpc/perf/imc-pmu.c
@@ -399,6 +399,20 @@ static void nest_imc_counters_release(struct perf_event *event)
 
        /* Take the mutex lock for this node and then decrement the reference count */
        mutex_lock(&ref->lock);
+       if (ref->refc == 0) {
+               /*
+                * The scenario where this is true is, when perf session is
+                * started, followed by offlining of all cpus in a given node.
+                *
+                * In the cpuhotplug offline path, ppc_nest_imc_cpu_offline()
+                * function set the ref->count to zero, if the cpu which is
+                * about to offline is the last cpu in a given node and make
+                * an OPAL call to disable the engine in that node.
+                *
+                */
+               mutex_unlock(&ref->lock);
+               return;
+       }
        ref->refc--;
        if (ref->refc == 0) {
                rc = opal_imc_counters_stop(OPAL_IMC_COUNTERS_NEST,
@@ -523,8 +537,8 @@ static int core_imc_mem_init(int cpu, int size)
 
        /* We need only vbase for core counters */
        mem_info->vbase = page_address(alloc_pages_node(phys_id,
-                                         GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE,
-                                         get_order(size)));
+                                         GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE |
+                                         __GFP_NOWARN, get_order(size)));
        if (!mem_info->vbase)
                return -ENOMEM;
 
@@ -646,6 +660,20 @@ static void core_imc_counters_release(struct perf_event *event)
                return;
 
        mutex_lock(&ref->lock);
+       if (ref->refc == 0) {
+               /*
+                * The scenario where this is true is, when perf session is
+                * started, followed by offlining of all cpus in a given core.
+                *
+                * In the cpuhotplug offline path, ppc_core_imc_cpu_offline()
+                * function set the ref->count to zero, if the cpu which is
+                * about to offline is the last cpu in a given core and make
+                * an OPAL call to disable the engine in that core.
+                *
+                */
+               mutex_unlock(&ref->lock);
+               return;
+       }
        ref->refc--;
        if (ref->refc == 0) {
                rc = opal_imc_counters_stop(OPAL_IMC_COUNTERS_CORE,
@@ -763,8 +791,8 @@ static int thread_imc_mem_alloc(int cpu_id, int size)
                 * free the memory in cpu offline path.
                 */
                local_mem = page_address(alloc_pages_node(phys_id,
-                                 GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE,
-                                 get_order(size)));
+                                 GFP_KERNEL | __GFP_ZERO | __GFP_THISNODE |
+                                 __GFP_NOWARN, get_order(size)));
                if (!local_mem)
                        return -ENOMEM;
 
@@ -1148,7 +1176,8 @@ static void imc_common_cpuhp_mem_free(struct imc_pmu *pmu_ptr)
        }
 
        /* Only free the attr_groups which are dynamically allocated  */
-       kfree(pmu_ptr->attr_groups[IMC_EVENT_ATTR]->attrs);
+       if (pmu_ptr->attr_groups[IMC_EVENT_ATTR])
+               kfree(pmu_ptr->attr_groups[IMC_EVENT_ATTR]->attrs);
        kfree(pmu_ptr->attr_groups[IMC_EVENT_ATTR]);
        kfree(pmu_ptr);
        return;