[PATCH 3/9] x86/intel_rdt: Global closid helper to support future fixes

From: Fenghua Yu
Date: Fri Sep 14 2018 - 16:36:30 EST


From: Reinette Chatre <reinette.chatre@xxxxxxxxx>

The number of CLOSIDs supported by a system is the minimum number of
CLOSIDs supported by any of its resources. Care should be taken when
iterating over the CLOSIDs of a resource since it may be that the number
of CLOSIDs supported on the system is less than the number of CLOSIDs
supported by the resource.

Introduce a helper function that can be used to query the number of
CLOSIDs that is supported by all resources, irrespective of how many
CLOSIDs are supported by a particular resource.

Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
arch/x86/kernel/cpu/intel_rdt.h | 1 +
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 7 +++++++
2 files changed, 8 insertions(+)

diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index 8c30772e37ed..b2bbba3c4c7e 100644
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -536,6 +536,7 @@ int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp);
void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp);
struct rdt_domain *get_domain_from_cpu(int cpu, struct rdt_resource *r);
int update_domains(struct rdt_resource *r, int closid);
+int closids_supported(void);
void closid_free(int closid);
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 32e8bbdf2400..b372923eb209 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -97,6 +97,12 @@ void rdt_last_cmd_printf(const char *fmt, ...)
* limited as the number of resources grows.
*/
static int closid_free_map;
+static int closid_free_map_len;
+
+int closids_supported(void)
+{
+ return closid_free_map_len;
+}

static void closid_init(void)
{
@@ -111,6 +117,7 @@ static void closid_init(void)

/* CLOSID 0 is always reserved for the default group */
closid_free_map &= ~1;
+ closid_free_map_len = rdt_min_closid;
}

static int closid_alloc(void)
--
2.19.0