1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/crypto/ccp/ccp-dmaengine.c b/drivers/crypto/ccp/ccp-dmaengine.c
index 8d0eeb46d4a2..e00be01fbf5a 100644
--- a/drivers/crypto/ccp/ccp-dmaengine.c
+++ b/drivers/crypto/ccp/ccp-dmaengine.c
@@ -10,6 +10,7 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/dmaengine.h>
 #include <linux/spinlock.h>
@@ -25,6 +26,37 @@
         (mask == 0) ? 64 : fls64(mask); \
 })
 
+/* The CCP as a DMA provider can be configured for public or private
+ * channels. Default is specified in the vdata for the device (PCI ID).
+ * This module parameter will override for all channels on all devices:
+ *   dma_chan_attr = 0x2 to force all channels public
+ *                 = 0x1 to force all channels private
+ *                 = 0x0 to defer to the vdata setting
+ *                 = any other value: warning, revert to 0x0
+ */
+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");
+
+unsigned int ccp_get_dma_chan_attr(struct ccp_device *ccp)
+{
+        switch (dma_chan_attr) {
+        case CCP_DMA_DFLT:
+                return ccp->vdata->dma_chan_attr;
+
+        case CCP_DMA_PRIV:
+                return DMA_PRIVATE;
+
+        case CCP_DMA_PUB:
+                return 0;
+
+        default:
+                dev_info_once(ccp->dev, "Invalid value for dma_chan_attr: %d\n",
+                              dma_chan_attr);
+                return ccp->vdata->dma_chan_attr;
+        }
+}
+
 static void ccp_free_cmd_resources(struct ccp_device *ccp,
                                    struct list_head *list)
 {
@@ -675,6 +707,15 @@ int ccp_dmaengine_register(struct ccp_device *ccp)
         dma_cap_set(DMA_SG, dma_dev->cap_mask);
         dma_cap_set(DMA_INTERRUPT, dma_dev->cap_mask);
 
+        /* The DMA channels for this device can be set to public or private,
+         * and overridden by the module parameter dma_chan_attr.
+         * Default: according to the value in vdata (dma_chan_attr=0)
+         * dma_chan_attr=0x1: all channels private (override vdata)
+         * dma_chan_attr=0x2: all channels public (override vdata)
+         */
+        if (ccp_get_dma_chan_attr(ccp) == DMA_PRIVATE)
+                dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
+
         INIT_LIST_HEAD(&dma_dev->channels);
         for (i = 0; i < ccp->cmd_q_count; i++) {
                 chan = ccp->ccp_dma_chan + i;