[PATCH v2 3/4] misc: fastrpc: add extended context bank support

[Vinayak Katoch]

Detect extended context banks by the presence of iommu-ranges on the
context bank node. Register them in a separate ext_cb array so the
mapping layer can direct large allocations into the wider IOVA window.

Signed-off-by: Vinayak Katoch <vinayak.katoch@xxxxxxxxxxxxxxxx>
---
 drivers/misc/fastrpc.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 5c7bb56cf46d..d40cdcd5dec3 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -307,6 +307,8 @@ struct fastrpc_channel_ctx {
 	struct qcom_scm_vmperm vmperms[FASTRPC_MAX_VMIDS];
 	struct rpmsg_device *rpdev;
 	struct fastrpc_session_ctx session[FASTRPC_MAX_SESSIONS];
+	struct fastrpc_session_ctx **ext_cb;
+	int ext_cb_count;
 	spinlock_t lock;
 	struct idr ctx_idr;
 	struct list_head users;
@@ -538,9 +540,13 @@ static int fastrpc_remote_heap_alloc(struct fastrpc_user *fl, struct device *dev
 static void fastrpc_channel_ctx_free(struct kref *ref)
 {
 	struct fastrpc_channel_ctx *cctx;
+	int i;
 
 	cctx = container_of(ref, struct fastrpc_channel_ctx, refcount);
 
+	for (i = 0; i < cctx->ext_cb_count; i++)
+		kfree(cctx->ext_cb[i]);
+	kfree(cctx->ext_cb);
 	idr_destroy(&cctx->ctx_idr);
 	kfree(cctx);
 }
@@ -2343,6 +2349,7 @@ static int fastrpc_cb_init(struct platform_device *pdev)
 	u32 dma_bits;
 	u32 sid = 0;
 	int rc;
+	bool is_extended_cb = false;
 
 	cctx = dev_get_drvdata(dev->parent);
 	if (!cctx)
@@ -2352,6 +2359,43 @@ static int fastrpc_cb_init(struct platform_device *pdev)
 				       of_n_addr_cells(dev->of_node) - 1, &sid))
 		dev_info(dev, "FastRPC Session ID not specified in DT\n");
 
+	if (of_property_present(dev->of_node, "iommu-ranges"))
+		is_extended_cb = true;
+
+	if (is_extended_cb) {
+		struct fastrpc_session_ctx **new_ext;
+
+		sess = kzalloc_obj(*sess);
+		if (!sess)
+			return -ENOMEM;
+
+		rc = dma_set_mask(dev, DMA_BIT_MASK(40));
+		if (rc) {
+			dev_err(dev, "40-bit DMA enable failed\n");
+			kfree(sess);
+			return rc;
+		}
+
+		new_ext = krealloc(cctx->ext_cb,
+				   (cctx->ext_cb_count + 1) * sizeof(*cctx->ext_cb),
+				   GFP_KERNEL);
+		if (!new_ext) {
+			kfree(sess);
+			return -ENOMEM;
+		}
+
+		spin_lock_irqsave(&cctx->lock, flags);
+		cctx->ext_cb = new_ext;
+		sess->valid = true;
+		sess->dev = dev;
+		sess->sid = sid;
+		dev_set_drvdata(dev, sess);
+		cctx->ext_cb[cctx->ext_cb_count++] = sess;
+		spin_unlock_irqrestore(&cctx->lock, flags);
+
+		return 0;
+	}
+
 	spin_lock_irqsave(&cctx->lock, flags);
 	if (cctx->sesscount >= FASTRPC_MAX_SESSIONS) {
 		spin_unlock_irqrestore(&cctx->lock, flags);
@@ -2391,6 +2435,8 @@ static void fastrpc_cb_devices_destroy(struct rpmsg_device *rpdev)
 	spin_lock_irqsave(&cctx->lock, flags);
 	for (i = 0; i < cctx->sesscount; i++)
 		cctx->session[i].valid = false;
+	for (i = 0; i < cctx->ext_cb_count; i++)
+		cctx->ext_cb[i]->valid = false;
 	spin_unlock_irqrestore(&cctx->lock, flags);
 
 	for_each_available_child_of_node(rdev->of_node, np) {

-- 
2.34.1