drivers/target/target_core_hba.c

Source file repositories/reference/linux-study-clean/drivers/target/target_core_hba.c

File Facts

System
Linux kernel
Corpus path
drivers/target/target_core_hba.c
Extension
.c
Size
4082 bytes
Lines
179
Domain
Driver Families
Bucket
drivers/target
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (!strcmp(old->ops->name, ops->name)) {
			pr_err("backend %s already registered.\n", ops->name);
			mutex_unlock(&backend_mutex);
			kfree(tb);
			return -EEXIST;
		}
	}
	target_setup_backend_cits(tb);
	list_add_tail(&tb->list, &backend_list);
	mutex_unlock(&backend_mutex);

	pr_debug("TCM: Registered subsystem plugin: %s struct module: %p\n",
			ops->name, ops->owner);
	return 0;
}
EXPORT_SYMBOL(transport_backend_register);

void target_backend_unregister(const struct target_backend_ops *ops)
{
	struct target_backend *tb;

	mutex_lock(&backend_mutex);
	list_for_each_entry(tb, &backend_list, list) {
		if (tb->ops == ops) {
			list_del(&tb->list);
			mutex_unlock(&backend_mutex);
			/*
			 * Wait for any outstanding backend driver ->rcu_head
			 * callbacks to complete post TBO->free_device() ->
			 * call_rcu(), before allowing backend driver module
			 * unload of target_backend_ops->owner to proceed.
			 */
			rcu_barrier();
			kfree(tb);
			return;
		}
	}
	mutex_unlock(&backend_mutex);
}
EXPORT_SYMBOL(target_backend_unregister);

static struct target_backend *core_get_backend(const char *name)
{
	struct target_backend *tb;

	mutex_lock(&backend_mutex);
	list_for_each_entry(tb, &backend_list, list) {
		if (!strcmp(tb->ops->name, name))
			goto found;
	}
	mutex_unlock(&backend_mutex);
	return NULL;
found:
	if (tb->ops->owner && !try_module_get(tb->ops->owner))
		tb = NULL;
	mutex_unlock(&backend_mutex);
	return tb;
}

struct se_hba *
core_alloc_hba(const char *plugin_name, u32 plugin_dep_id, u32 hba_flags)
{
	struct se_hba *hba;
	int ret = 0;

	hba = kzalloc_obj(*hba);
	if (!hba) {
		pr_err("Unable to allocate struct se_hba\n");
		return ERR_PTR(-ENOMEM);
	}

	spin_lock_init(&hba->device_lock);
	mutex_init(&hba->hba_access_mutex);

	hba->hba_index = scsi_get_new_index(SCSI_INST_INDEX);
	hba->hba_flags |= hba_flags;

	hba->backend = core_get_backend(plugin_name);
	if (!hba->backend) {
		ret = -EINVAL;
		goto out_free_hba;
	}

	ret = hba->backend->ops->attach_hba(hba, plugin_dep_id);
	if (ret < 0)
		goto out_module_put;

	spin_lock(&hba_lock);
	hba->hba_id = hba_id_counter++;
	list_add_tail(&hba->hba_node, &hba_list);

Annotation

Implementation Notes