Commit a33239be authored by Alexander Gordeev's avatar Alexander Gordeev
Browse files

s390/topology: honour nr_cpu_ids when adding CPUs 



When SMT thread CPUs are added to CPU masks the nr_cpu_ids
limit is not checked and could be exceeded. This leads to
a warning for example if CONFIG_DEBUG_PER_CPU_MAPS is set
and the command line parameter nr_cpus is set to 1.

Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
parent b1b0d5ae

arch/s390/kernel/topology.c

+17 −15
Original line number Diff line number Diff line
@@ -95,7 +95,7 @@ static void cpu_group_map(cpumask_t *dst, struct mask_info *info, unsigned int c 
static void cpu_thread_map(cpumask_t *dst, unsigned int cpu)

{

	static cpumask_t mask;

	int i;

	unsigned int max_cpu;



	cpumask_clear(&mask);

	if (!cpumask_test_cpu(cpu, &cpu_setup_mask))
@@ -104,9 +104,10 @@ static void cpu_thread_map(cpumask_t *dst, unsigned int cpu) 
	if (topology_mode != TOPOLOGY_MODE_HW)

		goto out;

	cpu -= cpu % (smp_cpu_mtid + 1);

	for (i = 0; i <= smp_cpu_mtid; i++) {

		if (cpumask_test_cpu(cpu + i, &cpu_setup_mask))

			cpumask_set_cpu(cpu + i, &mask);

	max_cpu = min(cpu + smp_cpu_mtid, nr_cpu_ids - 1);

	for (; cpu <= max_cpu; cpu++) {

		if (cpumask_test_cpu(cpu, &cpu_setup_mask))

			cpumask_set_cpu(cpu, &mask);

	}

out:

	cpumask_copy(dst, &mask);
@@ -123,25 +124,26 @@ static void add_cpus_to_mask(struct topology_core *tl_core, 
	unsigned int core;



	for_each_set_bit(core, &tl_core->mask, TOPOLOGY_CORE_BITS) {

		unsigned int rcore;

		int lcpu, i;

		unsigned int max_cpu, rcore;

		int cpu;



		rcore = TOPOLOGY_CORE_BITS - 1 - core + tl_core->origin;

		lcpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);

		if (lcpu < 0)

		cpu = smp_find_processor_id(rcore << smp_cpu_mt_shift);

		if (cpu < 0)

			continue;

		for (i = 0; i <= smp_cpu_mtid; i++) {

			topo = &cpu_topology[lcpu + i];

		max_cpu = min(cpu + smp_cpu_mtid, nr_cpu_ids - 1);

		for (; cpu <= max_cpu; cpu++) {

			topo = &cpu_topology[cpu];

			topo->drawer_id = drawer->id;

			topo->book_id = book->id;

			topo->socket_id = socket->id;

			topo->core_id = rcore;

			topo->thread_id = lcpu + i;

			topo->thread_id = cpu;

			topo->dedicated = tl_core->d;

			cpumask_set_cpu(lcpu + i, &drawer->mask);

			cpumask_set_cpu(lcpu + i, &book->mask);

			cpumask_set_cpu(lcpu + i, &socket->mask);

			smp_cpu_set_polarization(lcpu + i, tl_core->pp);

			cpumask_set_cpu(cpu, &drawer->mask);

			cpumask_set_cpu(cpu, &book->mask);

			cpumask_set_cpu(cpu, &socket->mask);

			smp_cpu_set_polarization(cpu, tl_core->pp);

		}

	}

}