hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7YUNJ

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The implementation of ECMDQ equalization based on the number of numa nodes and the number of cores in it is too complicated. Some special application scenarios, such as using maxcpus to limit the number of cores, may not be fully considered. Equalizing ECMDQ by number of cores can greatly simplify code and reduce quality risk.

Fixes: 3965519baff5 ("iommu/arm-smmu-v3: Add support for less than one ECMDQ per core") Signed-off-by: Zhen Lei thunder.leizhen@huawei.com --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 99 +++------------------ 1 file changed, 12 insertions(+), 87 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 1ee14a59a3d66c7..4419d6348f68511 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -4733,104 +4733,29 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool resume)

static int arm_smmu_ecmdq_layout(struct arm_smmu_device *smmu) { - int cpu, node, nr_remain, nr_nodes = 0; - int *nr_ecmdqs; - struct arm_smmu_ecmdq *ecmdq, **ecmdqs; + int cpu, host_cpu; + struct arm_smmu_ecmdq *ecmdq;

ecmdq = devm_alloc_percpu(smmu->dev, *ecmdq); if (!ecmdq) return -ENOMEM; smmu->ecmdq = ecmdq;

- if (num_possible_cpus() <= smmu->nr_ecmdq) { - for_each_possible_cpu(cpu) - *per_cpu_ptr(smmu->ecmdqs, cpu) = per_cpu_ptr(ecmdq, cpu); - - /* A core requires at most one ECMDQ */ + /* A core requires at most one ECMDQ */ + if (num_possible_cpus() < smmu->nr_ecmdq) smmu->nr_ecmdq = num_possible_cpus();

- return 0; - } - - for_each_node(node) - if (nr_cpus_node(node)) - nr_nodes++; - - if (nr_nodes >= smmu->nr_ecmdq) { - dev_err(smmu->dev, "%d ECMDQs is less than %d nodes\n", smmu->nr_ecmdq, nr_nodes); - return -ENOSPC; - } - - nr_ecmdqs = kcalloc(MAX_NUMNODES, sizeof(int), GFP_KERNEL); - if (!nr_ecmdqs) - return -ENOMEM; - - ecmdqs = kcalloc(smmu->nr_ecmdq, sizeof(*ecmdqs), GFP_KERNEL); - if (!ecmdqs) { - kfree(nr_ecmdqs); - return -ENOMEM; - } - - /* [1] Ensure that each node has at least one ECMDQ */ - nr_remain = smmu->nr_ecmdq - nr_nodes; - for_each_node(node) { - /* - * Calculate the number of ECMDQs to be allocated to this node. - * NR_ECMDQS_PER_CPU = nr_remain / num_possible_cpus(); - * When nr_cpus_node(node) is not zero, less than one ECMDQ - * may be left due to truncation rounding. - */ - nr_ecmdqs[node] = nr_cpus_node(node) * nr_remain / num_possible_cpus(); - } - - for_each_node(node) { - if (!nr_cpus_node(node)) - continue; - - nr_remain -= nr_ecmdqs[node]; - - /* An ECMDQ has been reserved for each node at above [1] */ - nr_ecmdqs[node]++; - } - - /* Divide the remaining ECMDQs */ - while (nr_remain) { - for_each_node(node) { - if (!nr_remain) - break; - - if (nr_ecmdqs[node] >= nr_cpus_node(node)) - continue; - - nr_ecmdqs[node]++; - nr_remain--; - } - } - - for_each_node(node) { - int i, round, shared; - - if (!nr_cpus_node(node)) - continue; - - shared = 0; - if (nr_ecmdqs[node] < nr_cpus_node(node)) - shared = 1; - - i = 0; - for_each_cpu(cpu, cpumask_of_node(node)) { - round = i % nr_ecmdqs[node]; - if (i++ < nr_ecmdqs[node]) - ecmdqs[round] = per_cpu_ptr(ecmdq, cpu); - else - ecmdqs[round]->cmdq.shared = shared; - *per_cpu_ptr(smmu->ecmdqs, cpu) = ecmdqs[round]; + for_each_possible_cpu(cpu) { + if (cpu < smmu->nr_ecmdq) { + *per_cpu_ptr(smmu->ecmdqs, cpu) = per_cpu_ptr(smmu->ecmdq, cpu); + } else { + host_cpu = cpu % smmu->nr_ecmdq; + ecmdq = per_cpu_ptr(smmu->ecmdq, host_cpu); + ecmdq->cmdq.shared = 1; + *per_cpu_ptr(smmu->ecmdqs, cpu) = ecmdq; } }

- kfree(nr_ecmdqs); - kfree(ecmdqs); - return 0; }