power: fix thread-safety environment modification

Due to lack of thread safety in exisiting solution
use spinlock mechanism for atomic
modification of power environment related data.

Fixes: 445c6528b5 ("power: common interface for guest and host")
Cc: stable@dpdk.org
Signed-off-by: Marcin Hajkowski <marcinx.hajkowski@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

diff --git a/doc/guides/rel_notes/release_19_05.rst b/doc/guides/rel_notes/release_19_05.rst
index 3c388da..d5ed564 100644 (file)
--- a/doc/guides/rel_notes/release_19_05.rst
+++ b/doc/guides/rel_notes/release_19_05.rst
@@ -229,6 +229,9 @@ API Changes
   ``rte_vfio_container_dma_unmap`` have been extended with an option to
   request mapping or un-mapping to the default vfio container fd.
 
+* power: ``rte_power_set_env`` and ``rte_power_unset_env`` functions
+  have been modified to be thread safe.
+
 
 ABI Changes
 -----------

diff --git a/lib/librte_power/rte_power.c b/lib/librte_power/rte_power.c
index a05fbef..540d69b 100644 (file)
--- a/lib/librte_power/rte_power.c
+++ b/lib/librte_power/rte_power.c
@@ -2,7 +2,7 @@
  * Copyright(c) 2010-2014 Intel Corporation
  */
 
-#include <rte_atomic.h>
+#include <rte_spinlock.h>
 
 #include "rte_power.h"
 #include "power_acpi_cpufreq.h"
@@ -12,7 +12,7 @@
 
 enum power_management_env global_default_env = PM_ENV_NOT_SET;
 
-volatile uint32_t global_env_cfg_status = 0;
+static rte_spinlock_t global_env_cfg_lock = RTE_SPINLOCK_INITIALIZER;
 
 /* function pointers */
 rte_power_freqs_t rte_power_freqs  = NULL;
@@ -30,9 +30,15 @@ rte_power_get_capabilities_t rte_power_get_capabilities;
 int
 rte_power_set_env(enum power_management_env env)
 {
-       if (rte_atomic32_cmpset(&global_env_cfg_status, 0, 1) == 0) {
+       rte_spinlock_lock(&global_env_cfg_lock);
+
+       if (global_default_env != PM_ENV_NOT_SET) {
+               rte_spinlock_unlock(&global_env_cfg_lock);
                return 0;
        }
+
+       int ret = 0;
+
        if (env == PM_ENV_ACPI_CPUFREQ) {
                rte_power_freqs = power_acpi_cpufreq_freqs;
                rte_power_get_freq = power_acpi_cpufreq_get_freq;
@@ -73,18 +79,24 @@ rte_power_set_env(enum power_management_env env)
        } else {
                RTE_LOG(ERR, POWER, "Invalid Power Management Environment(%d) set\n",
                                env);
-               rte_power_unset_env();
-               return -1;
+               ret = -1;
        }
-       global_default_env = env;
-       return 0;
+
+       if (ret == 0)
+               global_default_env = env;
+       else
+               global_default_env = PM_ENV_NOT_SET;
+
+       rte_spinlock_unlock(&global_env_cfg_lock);
+       return ret;
 }
 
 void
 rte_power_unset_env(void)
 {
-       if (rte_atomic32_cmpset(&global_env_cfg_status, 1, 0) != 0)
-               global_default_env = PM_ENV_NOT_SET;
+       rte_spinlock_lock(&global_env_cfg_lock);
+       global_default_env = PM_ENV_NOT_SET;
+       rte_spinlock_unlock(&global_env_cfg_lock);
 }
 
 enum power_management_env

diff --git a/lib/librte_power/rte_power.h b/lib/librte_power/rte_power.h
index dee7af3..47db69f 100644 (file)
--- a/lib/librte_power/rte_power.h
+++ b/lib/librte_power/rte_power.h
@@ -26,7 +26,7 @@ enum power_management_env {PM_ENV_NOT_SET, PM_ENV_ACPI_CPUFREQ, PM_ENV_KVM_VM,
 /**
  * Set the default power management implementation. If this is not called prior
  * to rte_power_init(), then auto-detect of the environment will take place.
- * It is not thread safe.
+ * It is thread safe.
  *
  * @param env
  *  env. The environment in which to initialise Power Management for.