3 files changed, 44 insertions, 1 deletions

diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
index 8471a1fe1dad..d7e966a25583 100644
--- a/drivers/i3c/master/mipi-i3c-hci/core.c
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -276,6 +276,34 @@ static int i3c_hci_daa(struct i3c_master_controller *m)
 	return hci->cmd->perform_daa(hci);
 }
 
+static int i3c_hci_alloc_safe_xfer_buf(struct i3c_hci *hci,
+				       struct hci_xfer *xfer)
+{
+	if (hci->io != &mipi_i3c_hci_dma ||
+	    xfer->data == NULL || !is_vmalloc_addr(xfer->data))
+		return 0;
+
+	if (xfer->rnw)
+		xfer->bounce_buf = kzalloc(xfer->data_len, GFP_KERNEL);
+	else
+		xfer->bounce_buf = kmemdup(xfer->data,
+					   xfer->data_len, GFP_KERNEL);
+
+	return xfer->bounce_buf == NULL ? -ENOMEM : 0;
+}
+
+static void i3c_hci_free_safe_xfer_buf(struct i3c_hci *hci,
+				       struct hci_xfer *xfer)
+{
+	if (hci->io != &mipi_i3c_hci_dma || xfer->bounce_buf == NULL)
+		return;
+
+	if (xfer->rnw)
+		memcpy(xfer->data, xfer->bounce_buf, xfer->data_len);
+
+	kfree(xfer->bounce_buf);
+}
+
 static int i3c_hci_priv_xfers(struct i3c_dev_desc *dev,
 			      struct i3c_priv_xfer *i3c_xfers,
 			      int nxfers)
@@ -309,6 +337,9 @@ static int i3c_hci_priv_xfers(struct i3c_dev_desc *dev,
 		}
 		hci->cmd->prep_i3c_xfer(hci, dev, &xfer[i]);
 		xfer[i].cmd_desc[0] |= CMD_0_ROC;
+		ret = i3c_hci_alloc_safe_xfer_buf(hci, &xfer[i]);
+		if (ret)
+			goto out;
 	}
 	last = i - 1;
 	xfer[last].cmd_desc[0] |= CMD_0_TOC;
@@ -332,6 +363,9 @@ static int i3c_hci_priv_xfers(struct i3c_dev_desc *dev,
 	}
 
 out:
+	for (i = 0; i < nxfers; i++)
+		i3c_hci_free_safe_xfer_buf(hci, &xfer[i]);
+
 	hci_free_xfer(xfer, nxfers);
 	return ret;
 }
@@ -357,6 +391,9 @@ static int i3c_hci_i2c_xfers(struct i2c_dev_desc *dev,
 		xfer[i].rnw = i2c_xfers[i].flags & I2C_M_RD;
 		hci->cmd->prep_i2c_xfer(hci, dev, &xfer[i]);
 		xfer[i].cmd_desc[0] |= CMD_0_ROC;
+		ret = i3c_hci_alloc_safe_xfer_buf(hci, &xfer[i]);
+		if (ret)
+			goto out;
 	}
 	last = i - 1;
 	xfer[last].cmd_desc[0] |= CMD_0_TOC;
@@ -378,6 +415,9 @@ static int i3c_hci_i2c_xfers(struct i2c_dev_desc *dev,
 	}
 
 out:
+	for (i = 0; i < nxfers; i++)
+		i3c_hci_free_safe_xfer_buf(hci, &xfer[i]);
+
 	hci_free_xfer(xfer, nxfers);
 	return ret;
 }
diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
index c805a8497319..4e01a95cc4d0 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dma.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
@@ -362,6 +362,7 @@ static int hci_dma_queue_xfer(struct i3c_hci *hci,
 	struct hci_rh_data *rh;
 	unsigned int i, ring, enqueue_ptr;
 	u32 op1_val, op2_val;
+	void *buf;
 
 	/* For now we only use ring 0 */
 	ring = 0;
@@ -390,9 +391,10 @@ static int hci_dma_queue_xfer(struct i3c_hci *hci,
 
 		/* 2nd and 3rd words of Data Buffer Descriptor Structure */
 		if (xfer->data) {
+			buf = xfer->bounce_buf ? xfer->bounce_buf : xfer->data;
 			xfer->data_dma =
 				dma_map_single(&hci->master.dev,
-					       xfer->data,
+					       buf,
 					       xfer->data_len,
 					       xfer->rnw ?
 						  DMA_FROM_DEVICE :
diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h
index f109923f6c3f..f94d95e024be 100644
--- a/drivers/i3c/master/mipi-i3c-hci/hci.h
+++ b/drivers/i3c/master/mipi-i3c-hci/hci.h
@@ -90,6 +90,7 @@ struct hci_xfer {
 		struct {
 			/* DMA specific */
 			dma_addr_t data_dma;
+			void *bounce_buf;
 			int ring_number;
 			int ring_entry;
 		};