crypto: ccp - Failure on re-initialization due to duplicate sysfs filename

The following warning appears during the CCP module re-initialization:

[ 140.965403] sysfs: cannot create duplicate filename
'/devices/pci0000:00/0000:00:07.1/0000:03:00.2/dma/dma0chan0'
[ 140.975736] CPU: 0 PID: 388 Comm: kworker/0:2 Kdump: loaded Not
tainted 6.2.0-0.rc2.18.eln124.x86_64 #1
[ 140.985185] Hardware name: HPE ProLiant DL325 Gen10/ProLiant DL325
Gen10, BIOS A41 07/17/2020
[ 140.993761] Workqueue: events work_for_cpu_fn
[ 140.998151] Call Trace:
[ 141.000613] <TASK>
[ 141.002726] dump_stack_lvl+0x33/0x46
[ 141.006415] sysfs_warn_dup.cold+0x17/0x23
[ 141.010542] sysfs_create_dir_ns+0xba/0xd0
[ 141.014670] kobject_add_internal+0xba/0x260
[ 141.018970] kobject_add+0x81/0xb0
[ 141.022395] device_add+0xdc/0x7e0
[ 141.025822] ? complete_all+0x20/0x90
[ 141.029510] __dma_async_device_channel_register+0xc9/0x130
[ 141.035119] dma_async_device_register+0x19e/0x3b0
[ 141.039943] ccp_dmaengine_register+0x334/0x3f0 [ccp]
[ 141.045042] ccp5_init+0x662/0x6a0 [ccp]
[ 141.049000] ? devm_kmalloc+0x40/0xd0
[ 141.052688] ccp_dev_init+0xbb/0xf0 [ccp]
[ 141.056732] ? __pci_set_master+0x56/0xd0
[ 141.060768] sp_init+0x70/0x90 [ccp]
[ 141.064377] sp_pci_probe+0x186/0x1b0 [ccp]
[ 141.068596] local_pci_probe+0x41/0x80
[ 141.072374] work_for_cpu_fn+0x16/0x20
[ 141.076145] process_one_work+0x1c8/0x380
[ 141.080181] worker_thread+0x1ab/0x380
[ 141.083953] ? __pfx_worker_thread+0x10/0x10
[ 141.088250] kthread+0xda/0x100
[ 141.091413] ? __pfx_kthread+0x10/0x10
[ 141.095185] ret_from_fork+0x2c/0x50
[ 141.098788] </TASK>
[ 141.100996] kobject_add_internal failed for dma0chan0 with -EEXIST,
don't try to register things with the same name in the same directory.
[ 141.113703] ccp 0000:03:00.2: ccp initialization failed

The /dma/dma0chan0 sysfs file is not removed since dma_chan object
has been released in ccp_dma_release() before releasing dma device.
A correct procedure would be: release dma channels first => unregister
dma device => release ccp dma object.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=216888
Fixes: 68dbe80f5b51 ("crypto: ccp - Release dma channels before dmaengine unrgister")
Tested-by: Vladis Dronov <[e-mail]>
Signed-off-by: Koba Ko <[e-mail]>
Reviewed-by: Vladis Dronov <[e-mail]>
Acked-by: Tom Lendacky <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

drivers/crypto/ccp/ccp-dmaengine.c

···
 		chan = ccp->ccp_dma_chan + i;
 		dma_chan = &chan->dma_chan;
 
-		if (dma_chan->client_count)
-			dma_release_channel(dma_chan);
-
 		tasklet_kill(&chan->cleanup_tasklet);
 		list_del_rcu(&dma_chan->device_node);
+	}
+}
+
+static void ccp_dma_release_channels(struct ccp_device *ccp)
+{
+	struct ccp_dma_chan *chan;
+	struct dma_chan *dma_chan;
+	unsigned int i;
+
+	for (i = 0; i < ccp->cmd_q_count; i++) {
+		chan = ccp->ccp_dma_chan + i;
+		dma_chan = &chan->dma_chan;
+
+		if (dma_chan->client_count)
+			dma_release_channel(dma_chan);
 	}
 }
 
···
 	if (!dmaengine)
 		return;
 
-	ccp_dma_release(ccp);
+	ccp_dma_release_channels(ccp);
 	dma_async_device_unregister(dma_dev);
+	ccp_dma_release(ccp);
 
 	kmem_cache_destroy(ccp->dma_desc_cache);
 	kmem_cache_destroy(ccp->dma_cmd_cache);