[PATCH] gpio: mockup: allocate lines with main struct

From: Rosen Penev

Date: Wed Mar 18 2026 - 20:06:26 EST


Remove no longer needed kcalloc to simplify allocation.

Added __counted_by along with a counting variable to get extra runtime
analysis.

Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
---
drivers/gpio/gpio-mockup.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index a7d69f3835c1..a907ce28cbbb 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -52,10 +52,11 @@ struct gpio_mockup_line_status {

struct gpio_mockup_chip {
struct gpio_chip gc;
- struct gpio_mockup_line_status *lines;
struct irq_domain *irq_sim_domain;
struct dentry *dbg_dir;
struct mutex lock;
+ int nr_lines;
+ struct gpio_mockup_line_status lines[] __counted_by(nr_lines);
};

struct gpio_mockup_dbgfs_private {
@@ -436,15 +437,18 @@ static int gpio_mockup_probe(struct platform_device *pdev)
if (rv)
name = dev_name(dev);

- chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+ chip = devm_kzalloc(dev, struct_size(chip, lines, ngpio), GFP_KERNEL);
if (!chip)
return -ENOMEM;

- mutex_init(&chip->lock);
+ chip->nr_lines = ngpio;

gc = &chip->gc;
- gc->base = base;
gc->ngpio = ngpio;
+ gc->base = base;
+
+ mutex_init(&chip->lock);
+
gc->label = name;
gc->owner = THIS_MODULE;
gc->parent = dev;
@@ -460,11 +464,6 @@ static int gpio_mockup_probe(struct platform_device *pdev)
gc->request = gpio_mockup_request;
gc->free = gpio_mockup_free;

- chip->lines = devm_kcalloc(dev, gc->ngpio,
- sizeof(*chip->lines), GFP_KERNEL);
- if (!chip->lines)
- return -ENOMEM;
-
for (i = 0; i < gc->ngpio; i++)
chip->lines[i].dir = GPIO_LINE_DIRECTION_IN;

--
2.53.0