[PATCH v1 1/1] irqdomain: Check virq for 0 before use in irq_dispose_mapping()

From: Andy Shevchenko
Date: Tue Aug 22 2023 - 09:51:47 EST


It's a bit hard to read the logic since we use virq before checking
it for 0. Rearrange the code to make it better to understand.

This, in particular, should clearly answer the question whether caller
need to perform this check or not, and we have plenty places for both
variants, confirming a confusion.

Fun fact that the new code is shorter:

Function old new delta
irq_dispose_mapping 278 271 -7
Total: Before=11625, After=11618, chg -0.06%

when compiled by GCC on Debian for x86_64.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
kernel/irq/irqdomain.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 0bdef4fe925b..26f1be63d622 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -903,10 +903,11 @@ EXPORT_SYMBOL_GPL(irq_create_of_mapping);
*/
void irq_dispose_mapping(unsigned int virq)
{
- struct irq_data *irq_data = irq_get_irq_data(virq);
+ struct irq_data *irq_data;
struct irq_domain *domain;

- if (!virq || !irq_data)
+ irq_data = virq ? irq_get_irq_data(virq) : NULL;
+ if (!irq_data)
return;

domain = irq_data->domain;
--
2.40.0.1.gaa8946217a0b