x86/intel_rdt: Associate mode with each RDT resource group

Each RDT resource group is associated with a mode that will reflect
the level of sharing of its allocations. The default, shareable, will be
associated with each resource group on creation since it is zero and
resource groups are created with kzalloc. The managing of the mode of a
resource group will follow. The default resource group always remain
though so ensure that it is reset to the default mode when the resctrl
filesystem is unmounted.

Also introduce a utility that can be used to determine the mode of a
resource group when it is searched for based on its class of service.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: tony.luck@intel.com
Cc: vikas.shivappa@linux.intel.com
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: dave.hansen@intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/797e4e1de4e4fcdf5b5e0039354d6a28079e2015.1529706536.git.reinette.chatre@intel.com

diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index fef254e85da41a2e59ff2ac8d72b94e519a12046..482dd6d3b8c5c82584f9c31cd8bafd59f2ab0798 100644 (file)
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -122,6 +122,7 @@ struct mongroup {
  * @type:                      indicates type of this rdtgroup - either
  *                             monitor only or ctrl_mon group
  * @mon:                       mongroup related data
+ * @mode:                      mode of resource group
  */
 struct rdtgroup {
        struct kernfs_node      *kn;
@@ -132,6 +133,7 @@ struct rdtgroup {
        atomic_t                waitcount;
        enum rdt_group_type     type;
        struct mongroup         mon;
+       enum rdtgrp_mode        mode;
 };
 
 /* rdtgroup.flags */
@@ -461,6 +463,7 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
                                char *buf, size_t nbytes, loff_t off);
 int rdtgroup_schemata_show(struct kernfs_open_file *of,
                           struct seq_file *s, void *v);
+enum rdtgrp_mode rdtgroup_mode_by_closid(int closid);
 struct rdt_domain *get_domain_from_cpu(int cpu, struct rdt_resource *r);
 int alloc_rmid(void);
 void free_rmid(u32 rmid);

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index fa668f9670625975ca4de28e973f87f742ad74f1..4a72061df7cdebf1233b11c6f5f5f447602a99b0 100644 (file)
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -126,6 +126,27 @@ static void closid_free(int closid)
        closid_free_map |= 1 << closid;
 }
 
+/**
+ * rdtgroup_mode_by_closid - Return mode of resource group with closid
+ * @closid: closid if the resource group
+ *
+ * Each resource group is associated with a @closid. Here the mode
+ * of a resource group can be queried by searching for it using its closid.
+ *
+ * Return: mode as &enum rdtgrp_mode of resource group with closid @closid
+ */
+enum rdtgrp_mode rdtgroup_mode_by_closid(int closid)
+{
+       struct rdtgroup *rdtgrp;
+
+       list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
+               if (rdtgrp->closid == closid)
+                       return rdtgrp->mode;
+       }
+
+       return RDT_NUM_MODES;
+}
+
 /* set uid and gid of rdtgroup dirs and files to that of the creator */
 static int rdtgroup_kn_set_ugid(struct kernfs_node *kn)
 {
@@ -1491,6 +1512,7 @@ static void rdt_kill_sb(struct super_block *sb)
                reset_all_ctrls(r);
        cdp_disable_all();
        rmdir_all_sub();
+       rdtgroup_default.mode = RDT_MODE_SHAREABLE;
        static_branch_disable_cpuslocked(&rdt_alloc_enable_key);
        static_branch_disable_cpuslocked(&rdt_mon_enable_key);
        static_branch_disable_cpuslocked(&rdt_enable_key);