BACKPORT: misc: fastrpc: Update dma_bits for CDSP support on Kaanapali SoC

DSP currently supports 32-bit IOVA (32-bit PA + 4-bit SID) for
both Q6 and user DMA (uDMA) access. This is being upgraded to
34-bit PA + 4-bit SID due to a hardware revision in CDSP for
Kaanapali SoC, which expands the DMA addressable range.
Update DMA bits configuration in the driver to support CDSP on
Kaanapali SoC. Set the default `dma_bits` to 32-bit and update
it to 34-bit based on CDSP and OF matching on the fastrpc node.

Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Kumari Pallavi <[email protected]>
Reviewed-by: Dmitry Baryshkov <[email protected]>
Signed-off-by: Vinayak Katoch <[email protected]>

Author: Kumari Pallavi

drivers/misc/fastrpc.c

@@ -276,6 +276,8 @@ struct fastrpc_session_ctx {
 
 struct fastrpc_soc_data {
 	u32 sid_pos;
+	u32 dma_addr_bits_cdsp;
+	u32 dma_addr_bits_default;
 };
 
 struct fastrpc_channel_ctx {
@@ -2317,6 +2319,7 @@ static int fastrpc_cb_probe(struct platform_device *pdev)
 	int i, sessions = 0;
 	unsigned long flags;
 	int rc;
+	u32 dma_bits;
 
 	cctx = dev_get_drvdata(dev->parent);
 	if (!cctx)
@@ -2330,12 +2333,16 @@ static int fastrpc_cb_probe(struct platform_device *pdev)
 		spin_unlock_irqrestore(&cctx->lock, flags);
 		return -ENOSPC;
 	}
+	dma_bits = cctx->soc_data->dma_addr_bits_default;
 	sess = &cctx->session[cctx->sesscount++];
 	sess->used = false;
 	sess->valid = true;
 	sess->dev = dev;
 	dev_set_drvdata(dev, sess);
 
+	if (cctx->domain_id == CDSP_DOMAIN_ID)
+		dma_bits = cctx->soc_data->dma_addr_bits_cdsp;
+
 	if (of_property_read_u32(dev->of_node, "reg", &sess->sid))
 		dev_info(dev, "FastRPC Session ID not specified in DT\n");
 
@@ -2350,9 +2357,9 @@ static int fastrpc_cb_probe(struct platform_device *pdev)
 		}
 	}
 	spin_unlock_irqrestore(&cctx->lock, flags);
-	rc = dma_set_mask(dev, DMA_BIT_MASK(32));
+	rc = dma_set_mask(dev, DMA_BIT_MASK(dma_bits));
 	if (rc) {
-		dev_err(dev, "32-bit DMA enable failed\n");
+		dev_err(dev, "%u-bit DMA enable failed\n", dma_bits);
 		return rc;
 	}
 
@@ -2439,10 +2446,14 @@ static int fastrpc_get_domain_id(const char *domain)
 
 static const struct fastrpc_soc_data kaanapali_soc_data = {
 	.sid_pos = 56,
+	.dma_addr_bits_cdsp = 34,
+	.dma_addr_bits_default = 32,
 };
 
 static const struct fastrpc_soc_data default_soc_data = {
 	.sid_pos = 32,
+	.dma_addr_bits_cdsp = 32,
+	.dma_addr_bits_default = 32,
 };
 
 static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)