x86/intel_rdt/mba_sc: Enable/disable MBA software controller

[linux-2.6-block.git] / arch / x86 / kernel / cpu / intel_rdt_rdtgroup.c

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index fca759d272a1783e76d86dfa38e213d167f39ade..440025446239b2ab29330e116cab10281a4e262a 100644 (file)
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -1005,6 +1005,11 @@ static void l2_qos_cfg_update(void *arg)
        wrmsrl(IA32_L2_QOS_CFG, *enable ? L2_QOS_CDP_ENABLE : 0ULL);
 }
 
+static inline bool is_mba_linear(void)
+{
+       return rdt_resources_all[RDT_RESOURCE_MBA].membw.delay_linear;
+}
+
 static int set_cache_qos_cfg(int level, bool enable)
 {
        void (*update)(void *arg);
@@ -1041,6 +1046,25 @@ static int set_cache_qos_cfg(int level, bool enable)
        return 0;
 }
 
+/*
+ * Enable or disable the MBA software controller
+ * which helps user specify bandwidth in MBps.
+ * MBA software controller is supported only if
+ * MBM is supported and MBA is in linear scale.
+ */
+static int set_mba_sc(bool mba_sc)
+{
+       struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_MBA];
+
+       if (!is_mbm_enabled() || !is_mba_linear() ||
+           mba_sc == is_mba_sc(r))
+               return -EINVAL;
+
+       r->membw.mba_sc = mba_sc;
+
+       return 0;
+}
+
 static int cdp_enable(int level, int data_type, int code_type)
 {
        struct rdt_resource *r_ldata = &rdt_resources_all[data_type];
@@ -1123,6 +1147,10 @@ static int parse_rdtgroupfs_options(char *data)
                        ret = cdpl2_enable();
                        if (ret)
                                goto out;
+               } else if (!strcmp(token, "mba_MBps")) {
+                       ret = set_mba_sc(true);
+                       if (ret)
+                               goto out;
                } else {
                        ret = -EINVAL;
                        goto out;
@@ -1445,6 +1473,8 @@ static void rdt_kill_sb(struct super_block *sb)
        cpus_read_lock();
        mutex_lock(&rdtgroup_mutex);
 
+       set_mba_sc(false);
+
        /*Put everything back to default values. */
        for_each_alloc_enabled_rdt_resource(r)
                reset_all_ctrls(r);