From 2d0b41a3767941b53160c940cdaf596a99f50fb6 Mon Sep 17 00:00:00 2001 From: Shay Drory Date: Tue, 22 Jun 2021 14:20:16 +0300 Subject: net/mlx5: Refcount mlx5_irq with integer Currently, all access to mlx5 IRQs are done undere a lock. Hance, there isn't a reason to have kref in struct mlx5_irq. Switch it to integer. Signed-off-by: Shay Drory Reviewed-by: Parav Pandit Signed-off-by: Saeed Mahameed --- drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c | 65 +++++++++++++++-------- 1 file changed, 44 insertions(+), 21 deletions(-) (limited to 'drivers') diff --git a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c index 717b9f1850ac..60bfcad1873c 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c @@ -32,7 +32,7 @@ struct mlx5_irq { cpumask_var_t mask; char name[MLX5_MAX_IRQ_NAME]; struct mlx5_irq_pool *pool; - struct kref kref; + int refcount; u32 index; int irqn; }; @@ -138,9 +138,8 @@ out: return ret; } -static void irq_release(struct kref *kref) +static void irq_release(struct mlx5_irq *irq) { - struct mlx5_irq *irq = container_of(kref, struct mlx5_irq, kref); struct mlx5_irq_pool *pool = irq->pool; xa_erase(&pool->irqs, irq->index); @@ -159,10 +158,31 @@ static void irq_put(struct mlx5_irq *irq) struct mlx5_irq_pool *pool = irq->pool; mutex_lock(&pool->lock); - kref_put(&irq->kref, irq_release); + irq->refcount--; + if (!irq->refcount) + irq_release(irq); mutex_unlock(&pool->lock); } +static int irq_get_locked(struct mlx5_irq *irq) +{ + lockdep_assert_held(&irq->pool->lock); + if (WARN_ON_ONCE(!irq->refcount)) + return 0; + irq->refcount++; + return 1; +} + +static int irq_get(struct mlx5_irq *irq) +{ + int err; + + mutex_lock(&irq->pool->lock); + err = irq_get_locked(irq); + mutex_unlock(&irq->pool->lock); + return err; +} + static irqreturn_t irq_int_handler(int irq, void *nh) { atomic_notifier_call_chain(nh, 0, NULL); @@ -214,7 +234,7 @@ static struct mlx5_irq *irq_request(struct mlx5_irq_pool *pool, int i) err = -ENOMEM; goto err_cpumask; } - kref_init(&irq->kref); + irq->refcount = 1; irq->index = i; err = xa_err(xa_store(&pool->irqs, irq->index, irq, GFP_KERNEL)); if (err) { @@ -235,18 +255,18 @@ err_req_irq: int mlx5_irq_attach_nb(struct mlx5_irq *irq, struct notifier_block *nb) { - int err; + int ret; - err = kref_get_unless_zero(&irq->kref); - if (WARN_ON_ONCE(!err)) + ret = irq_get(irq); + if (!ret) /* Something very bad happens here, we are enabling EQ * on non-existing IRQ. */ return -ENOENT; - err = atomic_notifier_chain_register(&irq->nh, nb); - if (err) + ret = atomic_notifier_chain_register(&irq->nh, nb); + if (ret) irq_put(irq); - return err; + return ret; } int mlx5_irq_detach_nb(struct mlx5_irq *irq, struct notifier_block *nb) @@ -301,10 +321,9 @@ static struct mlx5_irq *irq_pool_find_least_loaded(struct mlx5_irq_pool *pool, xa_for_each_range(&pool->irqs, index, iter, start, end) { if (!cpumask_equal(iter->mask, affinity)) continue; - if (kref_read(&iter->kref) < pool->min_threshold) + if (iter->refcount < pool->min_threshold) return iter; - if (!irq || kref_read(&iter->kref) < - kref_read(&irq->kref)) + if (!irq || iter->refcount < irq->refcount) irq = iter; } return irq; @@ -319,7 +338,7 @@ static struct mlx5_irq *irq_pool_request_affinity(struct mlx5_irq_pool *pool, mutex_lock(&pool->lock); least_loaded_irq = irq_pool_find_least_loaded(pool, affinity); if (least_loaded_irq && - kref_read(&least_loaded_irq->kref) < pool->min_threshold) + least_loaded_irq->refcount < pool->min_threshold) goto out; new_irq = irq_pool_create_irq(pool, affinity); if (IS_ERR(new_irq)) { @@ -337,11 +356,11 @@ static struct mlx5_irq *irq_pool_request_affinity(struct mlx5_irq_pool *pool, least_loaded_irq = new_irq; goto unlock; out: - kref_get(&least_loaded_irq->kref); - if (kref_read(&least_loaded_irq->kref) > pool->max_threshold) + irq_get_locked(least_loaded_irq); + if (least_loaded_irq->refcount > pool->max_threshold) mlx5_core_dbg(pool->dev, "IRQ %u overloaded, pool_name: %s, %u EQs on this irq\n", least_loaded_irq->irqn, pool->name, - kref_read(&least_loaded_irq->kref) / MLX5_EQ_REFS_PER_IRQ); + least_loaded_irq->refcount / MLX5_EQ_REFS_PER_IRQ); unlock: mutex_unlock(&pool->lock); return least_loaded_irq; @@ -357,7 +376,7 @@ irq_pool_request_vector(struct mlx5_irq_pool *pool, int vecidx, mutex_lock(&pool->lock); irq = xa_load(&pool->irqs, vecidx); if (irq) { - kref_get(&irq->kref); + irq_get_locked(irq); goto unlock; } irq = irq_request(pool, vecidx); @@ -424,7 +443,7 @@ out: return irq; mlx5_core_dbg(dev, "irq %u mapped to cpu %*pbl, %u EQs on this irq\n", irq->irqn, cpumask_pr_args(affinity), - kref_read(&irq->kref) / MLX5_EQ_REFS_PER_IRQ); + irq->refcount / MLX5_EQ_REFS_PER_IRQ); return irq; } @@ -456,8 +475,12 @@ static void irq_pool_free(struct mlx5_irq_pool *pool) struct mlx5_irq *irq; unsigned long index; + /* There are cases in which we are destrying the irq_table before + * freeing all the IRQs, fast teardown for example. Hence, free the irqs + * which might not have been freed. + */ xa_for_each(&pool->irqs, index, irq) - irq_release(&irq->kref); + irq_release(irq); xa_destroy(&pool->irqs); kvfree(pool); } -- cgit