diff options
| author | Johan Hovold | 2023-02-13 11:42:50 +0100 |
|---|---|---|
| committer | Marc Zyngier | 2023-02-13 19:31:24 +0000 |
| commit | 47d1932f37de99bae3345bb93f098ac8750ab0fb (patch) | |
| tree | d63790a43dd16739bb2c1dbb1c89d16d02967ecb /kernel | |
| parent | 8932c32c3053accd50702b36e944ac2016cd103c (diff) | |
irqdomain: Drop revmap mutex
The revmap mutex is essentially only used to maintain the integrity of
the radix tree during updates (lookups use RCU).
As the global irq_domain_mutex is now held in all paths that update the
revmap structures there is strictly no longer any need for the dedicated
mutex, which can be removed.
Drop the revmap mutex and add lockdep assertions to the revmap helpers
to make sure that the global lock is always held when updating the
revmap.
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230213104302.17307-9-johan+linaro@kernel.org
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/irq/irqdomain.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index a6d1b108b8f7..c7113e776543 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -206,7 +206,6 @@ static struct irq_domain *__irq_domain_create(struct fwnode_handle *fwnode, /* Fill structure */ INIT_RADIX_TREE(&domain->revmap_tree, GFP_KERNEL); - mutex_init(&domain->revmap_mutex); domain->ops = ops; domain->host_data = host_data; domain->hwirq_max = hwirq_max; @@ -526,30 +525,30 @@ static bool irq_domain_is_nomap(struct irq_domain *domain) static void irq_domain_clear_mapping(struct irq_domain *domain, irq_hw_number_t hwirq) { + lockdep_assert_held(&irq_domain_mutex); + if (irq_domain_is_nomap(domain)) return; - mutex_lock(&domain->revmap_mutex); if (hwirq < domain->revmap_size) rcu_assign_pointer(domain->revmap[hwirq], NULL); else radix_tree_delete(&domain->revmap_tree, hwirq); - mutex_unlock(&domain->revmap_mutex); } static void irq_domain_set_mapping(struct irq_domain *domain, irq_hw_number_t hwirq, struct irq_data *irq_data) { + lockdep_assert_held(&irq_domain_mutex); + if (irq_domain_is_nomap(domain)) return; - mutex_lock(&domain->revmap_mutex); if (hwirq < domain->revmap_size) rcu_assign_pointer(domain->revmap[hwirq], irq_data); else radix_tree_insert(&domain->revmap_tree, hwirq, irq_data); - mutex_unlock(&domain->revmap_mutex); } static void irq_domain_disassociate(struct irq_domain *domain, unsigned int irq) @@ -1580,11 +1579,12 @@ static void irq_domain_fix_revmap(struct irq_data *d) { void __rcu **slot; + lockdep_assert_held(&irq_domain_mutex); + if (irq_domain_is_nomap(d->domain)) return; /* Fix up the revmap. */ - mutex_lock(&d->domain->revmap_mutex); if (d->hwirq < d->domain->revmap_size) { /* Not using radix tree */ rcu_assign_pointer(d->domain->revmap[d->hwirq], d); @@ -1593,7 +1593,6 @@ static void irq_domain_fix_revmap(struct irq_data *d) if (slot) radix_tree_replace_slot(&d->domain->revmap_tree, slot, d); } - mutex_unlock(&d->domain->revmap_mutex); } /** |