1 files changed, 48 insertions, 7 deletions

diff --git a/drivers/crypto/ccp/ccp-dmaengine.c b/drivers/crypto/ccp/ccp-dmaengine.c
index 67155cb21636..b386a7063818 100644
--- a/drivers/crypto/ccp/ccp-dmaengine.c
+++ b/drivers/crypto/ccp/ccp-dmaengine.c
@@ -1,17 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * AMD Cryptographic Coprocessor (CCP) driver
  *
- * Copyright (C) 2016,2017 Advanced Micro Devices, Inc.
+ * Copyright (C) 2016,2019 Advanced Micro Devices, Inc.
  *
  * Author: Gary R Hook <gary.hook@amd.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
 #include <linux/module.h>
 #include <linux/kernel.h>
+#include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
 #include <linux/spinlock.h>
 #include <linux/mutex.h>
@@ -38,6 +36,10 @@ static unsigned int dma_chan_attr = CCP_DMA_DFLT;
 module_param(dma_chan_attr, uint, 0444);
 MODULE_PARM_DESC(dma_chan_attr, "Set DMA channel visibility: 0 (default) = device defaults, 1 = make private, 2 = make public");
 
+static unsigned int dmaengine = 1;
+module_param(dmaengine, uint, 0444);
+MODULE_PARM_DESC(dmaengine, "Register services with the DMA subsystem (any non-zero value, default: 1)");
+
 static unsigned int ccp_get_dma_chan_attr(struct ccp_device *ccp)
 {
 	switch (dma_chan_attr) {
@@ -305,8 +307,7 @@ static dma_cookie_t ccp_tx_submit(struct dma_async_tx_descriptor *tx_desc)
 	spin_lock_irqsave(&chan->lock, flags);
 
 	cookie = dma_cookie_assign(tx_desc);
-	list_del(&desc->entry);
-	list_add_tail(&desc->entry, &chan->pending);
+	list_move_tail(&desc->entry, &chan->pending);
 
 	spin_unlock_irqrestore(&chan->lock, flags);
 
@@ -340,6 +341,7 @@ static struct ccp_dma_desc *ccp_alloc_dma_desc(struct ccp_dma_chan *chan,
 	desc->tx_desc.flags = flags;
 	desc->tx_desc.tx_submit = ccp_tx_submit;
 	desc->ccp = chan->ccp;
+	INIT_LIST_HEAD(&desc->entry);
 	INIT_LIST_HEAD(&desc->pending);
 	INIT_LIST_HEAD(&desc->active);
 	desc->status = DMA_IN_PROGRESS;
@@ -630,6 +632,36 @@ static int ccp_terminate_all(struct dma_chan *dma_chan)
 	return 0;
 }
 
+static void ccp_dma_release(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;
+
+		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);
+	}
+}
+
 int ccp_dmaengine_register(struct ccp_device *ccp)
 {
 	struct ccp_dma_chan *chan;
@@ -640,6 +672,9 @@ int ccp_dmaengine_register(struct ccp_device *ccp)
 	unsigned int i;
 	int ret;
 
+	if (!dmaengine)
+		return 0;
+
 	ccp->ccp_dma_chan = devm_kcalloc(ccp->dev, ccp->cmd_q_count,
 					 sizeof(*(ccp->ccp_dma_chan)),
 					 GFP_KERNEL);
@@ -731,6 +766,7 @@ int ccp_dmaengine_register(struct ccp_device *ccp)
 	return 0;
 
 err_reg:
+	ccp_dma_release(ccp);
 	kmem_cache_destroy(ccp->dma_desc_cache);
 
 err_cache:
@@ -743,7 +779,12 @@ void ccp_dmaengine_unregister(struct ccp_device *ccp)
 {
 	struct dma_device *dma_dev = &ccp->dma_dev;
 
+	if (!dmaengine)
+		return;
+
+	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);