[PATCH 1/2] EDAC/device: simplify info allocation

Rosen Penev
2026-04-30T22:01:07Z

Use a flexible array member to combine info and instance allocations.
Simplifies allocation slightly.

Add __counted_by for extra runtime analysis. Move counting variable
assignment to after allocation as kzalloc_flex already does with GCC >=
15.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
drivers/edac/edac_device.c | 23 ++++++++---------------
drivers/edac/edac_device.h | 4 +---
2 files changed, 9 insertions(+), 18 deletions(-)

diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
index cf0d3c2dfc04..9c21997a50e0 100644
--- a/drivers/edac/edac_device.c
+++ b/drivers/edac/edac_device.c
@@ -58,31 +58,25 @@ edac_device_alloc_ctl_info(unsigned pvt_sz, char *dev_name, unsigned nr_instance
char *blk_name, unsigned nr_blocks, unsigned off_val,
int device_index)
{
- struct edac_device_block *dev_blk, *blk_p, *blk;
+ struct edac_device_block *blk_p, *blk;
struct edac_device_instance *dev_inst, *inst;
struct edac_device_ctl_info *dev_ctl;
unsigned instance, block;
+ size_t alloc_size;
void *pvt;
int err;

edac_dbg(4, "instances=%d blocks=%d\n", nr_instances, nr_blocks);

- dev_ctl = kzalloc_obj(struct edac_device_ctl_info);
+ alloc_size = struct_size(dev_ctl, instances, nr_instances);
+ alloc_size += sizeof(*dev_ctl->blocks) * nr_instances * nr_blocks;
+ dev_ctl = kzalloc(alloc_size, GFP_KERNEL);
if (!dev_ctl)
return NULL;

- dev_inst = kzalloc_objs(struct edac_device_instance, nr_instances);
- if (!dev_inst)
- goto free;
-
- dev_ctl->instances = dev_inst;
-
- dev_blk = kzalloc_objs(struct edac_device_block,
- nr_instances * nr_blocks);
- if (!dev_blk)
- goto free;
+ dev_ctl->nr_instances = nr_instances;

- dev_ctl->blocks = dev_blk;
+ dev_ctl->blocks = (struct edac_device_block *)(dev_ctl->instances + nr_instances);

if (pvt_sz) {
pvt = kzalloc(pvt_sz, GFP_KERNEL);
@@ -93,7 +87,6 @@ edac_device_alloc_ctl_info(unsigned pvt_sz, char *dev_name, unsigned nr_instance
}

dev_ctl->dev_idx = device_index;
- dev_ctl->nr_instances = nr_instances;

/* Default logging of CEs and UEs */
dev_ctl->log_ce = 1;
@@ -107,7 +100,7 @@ edac_device_alloc_ctl_info(unsigned pvt_sz, char *dev_name, unsigned nr_instance
inst = &dev_inst[instance];
inst->ctl = dev_ctl;
inst->nr_blocks = nr_blocks;
- blk_p = &dev_blk[instance * nr_blocks];
+ blk_p = &dev_ctl->blocks[instance * nr_blocks];
inst->blocks = blk_p;

/* name of this instance */
diff --git a/drivers/edac/edac_device.h b/drivers/edac/edac_device.h
index 24c1921aa490..4562461a3e8f 100644
--- a/drivers/edac/edac_device.h
+++ b/drivers/edac/edac_device.h
@@ -203,7 +203,6 @@ struct edac_device_ctl_info {
* and the array of those instances
*/
u32 nr_instances;
- struct edac_device_instance *instances;
struct edac_device_block *blocks;

/* Event counters for the this whole EDAC Device */
@@ -213,6 +212,7 @@ struct edac_device_ctl_info {
* device this structure controls
*/
struct kobject kobj;
+ struct edac_device_instance instances[] __counted_by(nr_instances);
};

/* To get from the instance's wq to the beginning of the ctl structure */
@@ -341,8 +341,6 @@ static inline void __edac_device_free_ctl_info(struct edac_device_ctl_info *ci)
{
if (ci) {
kfree(ci->pvt_info);
- kfree(ci->blocks);
- kfree(ci->instances);
kfree(ci);
}
}
--
2.54.0