linux-kernel - [PATCH v2 5/8] arch_topology: Check for non-negative value rather than -1 for IDs validity

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Message-Id: <20220518093325.2070336-6-sudeep.holla@arm.com>
Date:   Wed, 18 May 2022 10:33:22 +0100
From:   Sudeep Holla <sudeep.holla@....com>
To:     Atish Patra <atishp@...shpatra.org>, linux-kernel@...r.kernel.org
Cc:     Sudeep Holla <sudeep.holla@....com>,
        Atish Patra <atishp@...osinc.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Morten Rasmussen <morten.rasmussen@....com>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Qing Wang <wangqing@...o.com>,
        linux-arm-kernel@...ts.infradead.org,
        linux-riscv@...ts.infradead.org, Rob Herring <robh+dt@...nel.org>,
        Andy Shevchenko <andy.shevchenko@...il.com>
Subject: [PATCH v2 5/8] arch_topology: Check for non-negative value rather than -1 for IDs validity

Instead of just comparing the cpu topology IDs with -1 to check their
validity, improve that by checking for a valid non-negative value.

Suggested-by: Andy Shevchenko <andy.shevchenko@...il.com>
Signed-off-by: Sudeep Holla <sudeep.holla@....com>
---
 drivers/base/arch_topology.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 77aab5fea46b..be99a78f5b31 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -662,7 +662,7 @@ static int __init parse_dt_topology(void)
 	 * only mark cores described in the DT as possible.
 	 */
 	for_each_possible_cpu(cpu)
-		if (cpu_topology[cpu].package_id == -1)
+		if (cpu_topology[cpu].package_id < 0)
 			ret = -EINVAL;
 
 out_map:
@@ -688,7 +688,7 @@ const struct cpumask *cpu_coregroup_mask(int cpu)
 		/* not numa in package, lets use the package siblings */
 		core_mask = &cpu_topology[cpu].core_sibling;
 	}
-	if (cpu_topology[cpu].llc_id != -1) {
+	if (cpu_topology[cpu].llc_id >= 0) {
 		if (cpumask_subset(&cpu_topology[cpu].llc_sibling, core_mask))
 			core_mask = &cpu_topology[cpu].llc_sibling;
 	}
@@ -719,7 +719,8 @@ void update_siblings_masks(unsigned int cpuid)
 	for_each_online_cpu(cpu) {
 		cpu_topo = &cpu_topology[cpu];
 
-		if (cpu_topo->llc_id != -1 && cpuid_topo->llc_id == cpu_topo->llc_id) {
+		if (cpu_topo->llc_id >= 0 &&
+		    cpuid_topo->llc_id == cpu_topo->llc_id) {
 			cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling);
 			cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling);
 		}
@@ -733,7 +734,7 @@ void update_siblings_masks(unsigned int cpuid)
 		if (cpuid_topo->cluster_id != cpu_topo->cluster_id)
 			continue;
 
-		if (cpuid_topo->cluster_id != -1) {
+		if (cpuid_topo->cluster_id >= 0) {
 			cpumask_set_cpu(cpu, &cpuid_topo->cluster_sibling);
 			cpumask_set_cpu(cpuid, &cpu_topo->cluster_sibling);
 		}
-- 
2.36.1