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

[Rosen Penev <rosenp@gmail.com>]

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