[PATCH v2 2/4] powerpc/topology: Update mc/pkg flags based on llc_override

[Shrikanth Hegde]

Update the flags passed for building the scheduler topology based on
llc_override.

SD_SHARE_LLC is used to determine the highest domain where the LLC is.
Also when set at a particular domain, all the child domains are expected
to have it set as well.

Signed-off-by: Shrikanth Hegde <sshegde@xxxxxxxxxxxxx>
---
 arch/powerpc/kernel/smp.c | 41 +++++++++++++++++++++++++++------------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 6b1201ea3572..ca1821dedc98 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -1007,6 +1007,12 @@ static int powerpc_smt_flags(void)
  */
 static __ro_after_init DEFINE_STATIC_KEY_FALSE(splpar_asym_pack);
 
+static int llc_override;
+enum llc_override_values {
+	LLC_OVERRIDE_MC		= 1,
+	LLC_OVERRIDE_PKG	= 2,
+};
+
 /*
  * P9 has a slightly odd architecture where pairs of cores share an L2 cache.
  * This topology makes it *much* cheaper to migrate tasks between adjacent cores
@@ -1021,12 +1027,30 @@ static int powerpc_shared_cache_flags(void)
 	return SD_SHARE_LLC;
 }
 
-static int powerpc_shared_proc_flags(void)
+static int powerpc_mc_flags(void)
 {
+	int flags = 0;
+
 	if (static_branch_unlikely(&splpar_asym_pack))
-		return SD_ASYM_PACKING;
+		flags |= SD_ASYM_PACKING;
 
-	return 0;
+	if (READ_ONCE(llc_override) >= LLC_OVERRIDE_MC)
+		flags |= SD_SHARE_LLC;
+
+	return flags;
+}
+
+static int powerpc_pkg_flags(void)
+{
+	int flags = 0;
+
+	if (static_branch_unlikely(&splpar_asym_pack))
+		flags |= SD_ASYM_PACKING;
+
+	if (READ_ONCE(llc_override) >= LLC_OVERRIDE_PKG)
+		flags |= SD_SHARE_LLC;
+
+	return flags;
 }
 
 /*
@@ -1059,13 +1083,6 @@ static bool has_coregroup_support(void)
 	return coregroup_enabled;
 }
 
-enum llc_override_values {
-	LLC_OVERRIDE_MC		= 1,
-	LLC_OVERRIDE_PKG	= 2,
-};
-
-static int llc_override;
-
 static int __init set_llc_override(char *str)
 {
 	if (!strcasecmp(str, "mc") && has_coregroup_support())
@@ -1759,10 +1776,10 @@ static void __init build_sched_topology(void)
 
 	if (has_coregroup_support()) {
 		powerpc_topology[i++] =
-			SDTL_INIT(tl_mc_mask, powerpc_shared_proc_flags, MC);
+			SDTL_INIT(tl_mc_mask, powerpc_mc_flags, MC);
 	}
 
-	powerpc_topology[i++] = SDTL_INIT(tl_pkg_mask, powerpc_shared_proc_flags, PKG);
+	powerpc_topology[i++] = SDTL_INIT(tl_pkg_mask, powerpc_pkg_flags, PKG);
 
 	/* There must be one trailing NULL entry left.  */
 	BUG_ON(i >= ARRAY_SIZE(powerpc_topology) - 1);
-- 
2.52.0