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From: Siddharth Vadapalli <s-vadapalli@ti.com>
To: <peter.ujfalusi@gmail.com>, <vkoul@kernel.org>
CC: <dmaengine@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>, <srk@ti.com>,
        <vigneshr@ti.com>, <s-vadapalli@ti.com>
Subject: [PATCH v3 4/4] dmaengine: ti: k3-udma-glue: Add function to request RX chan for thread ID
Date: Mon, 18 Dec 2023 11:56:40 +0530
Message-ID: <20231218062640.2338453-5-s-vadapalli@ti.com>
In-Reply-To: <20231218062640.2338453-1-s-vadapalli@ti.com>
References: <20231218062640.2338453-1-s-vadapalli@ti.com>
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The existing function k3_udma_glue_request_remote_rx_chn() supports
requesting an RX DMA channel and flow by the name of the RX DMA channel.
Add support to request RX DMA channel for a given thread ID in the form of
a new function named k3_udma_glue_request_remote_rx_chn_for_thread_id().
Also, export it for use by drivers which are probed by alternate methods
(non device-tree) but still wish to make use of the existing DMA APIs. Such
drivers could be informed about the thread ID corresponding to the RX DMA
channel by RPMsg for example.

Since the new function k3_udma_glue_request_remote_rx_chn_for_thread_id()
reuses most of the code in k3_udma_glue_request_remote_rx_chn(), create a
new function named k3_udma_glue_request_remote_rx_chn_common() for the
common code.

Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
---
Changes since v2:
- Renamed function "k3_udma_glue_request_remote_rx_chn_by_id()" to
  "k3_udma_glue_request_remote_rx_chn_for_thread_id()".
- Updated commit message to reflect function renaming.

Changes since v1:
- Updated commit message indicating the use-case for which the patch is
  being added.

 drivers/dma/ti/k3-udma-glue.c    | 137 ++++++++++++++++++++++---------
 include/linux/dma/k3-udma-glue.h |   5 ++
 2 files changed, 103 insertions(+), 39 deletions(-)

diff --git a/drivers/dma/ti/k3-udma-glue.c b/drivers/dma/ti/k3-udma-glue.c
index a475bbea35ee..c9b93055dc9d 100644
--- a/drivers/dma/ti/k3-udma-glue.c
+++ b/drivers/dma/ti/k3-udma-glue.c
@@ -1073,52 +1073,21 @@ k3_udma_glue_request_rx_chn_priv(struct device *dev, const char *name,
 	return ERR_PTR(ret);
 }
 
-static struct k3_udma_glue_rx_channel *
-k3_udma_glue_request_remote_rx_chn(struct device *dev, const char *name,
-				   struct k3_udma_glue_rx_channel_cfg *cfg)
+static int
+k3_udma_glue_request_remote_rx_chn_common(struct k3_udma_glue_rx_channel *rx_chn,
+					  struct k3_udma_glue_rx_channel_cfg *cfg,
+					  struct device *dev)
 {
-	struct k3_udma_glue_rx_channel *rx_chn;
 	int ret, i;
 
-	if (cfg->flow_id_num <= 0 ||
-	    cfg->flow_id_use_rxchan_id ||
-	    cfg->def_flow_cfg ||
-	    cfg->flow_id_base < 0)
-		return ERR_PTR(-EINVAL);
-
-	/*
-	 * Remote RX channel is under control of Remote CPU core, so
-	 * Linux can only request and manipulate by dedicated RX flows
-	 */
-
-	rx_chn = devm_kzalloc(dev, sizeof(*rx_chn), GFP_KERNEL);
-	if (!rx_chn)
-		return ERR_PTR(-ENOMEM);
-
-	rx_chn->common.dev = dev;
-	rx_chn->common.swdata_size = cfg->swdata_size;
-	rx_chn->remote = true;
-	rx_chn->udma_rchan_id = -1;
-	rx_chn->flow_num = cfg->flow_id_num;
-	rx_chn->flow_id_base = cfg->flow_id_base;
-	rx_chn->psil_paired = false;
-
-	/* parse of udmap channel */
-	ret = of_k3_udma_glue_parse_chn(dev->of_node, name,
-					&rx_chn->common, false);
-	if (ret)
-		goto err;
-
 	rx_chn->common.hdesc_size = cppi5_hdesc_calc_size(rx_chn->common.epib,
 						rx_chn->common.psdata_size,
 						rx_chn->common.swdata_size);
 
 	rx_chn->flows = devm_kcalloc(dev, rx_chn->flow_num,
 				     sizeof(*rx_chn->flows), GFP_KERNEL);
-	if (!rx_chn->flows) {
-		ret = -ENOMEM;
-		goto err;
-	}
+	if (!rx_chn->flows)
+		return -ENOMEM;
 
 	rx_chn->common.chan_dev.class = &k3_udma_glue_devclass;
 	rx_chn->common.chan_dev.parent = xudma_get_device(rx_chn->common.udmax);
@@ -1129,7 +1098,7 @@ k3_udma_glue_request_remote_rx_chn(struct device *dev, const char *name,
 		dev_err(dev, "Channel Device registration failed %d\n", ret);
 		put_device(&rx_chn->common.chan_dev);
 		rx_chn->common.chan_dev.parent = NULL;
-		goto err;
+		return ret;
 	}
 
 	if (xudma_is_pktdma(rx_chn->common.udmax)) {
@@ -1141,19 +1110,109 @@ k3_udma_glue_request_remote_rx_chn(struct device *dev, const char *name,
 
 	ret = k3_udma_glue_allocate_rx_flows(rx_chn, cfg);
 	if (ret)
-		goto err;
+		return ret;
 
 	for (i = 0; i < rx_chn->flow_num; i++)
 		rx_chn->flows[i].udma_rflow_id = rx_chn->flow_id_base + i;
 
 	k3_udma_glue_dump_rx_chn(rx_chn);
 
+	return 0;
+}
+
+static struct k3_udma_glue_rx_channel *
+k3_udma_glue_request_remote_rx_chn(struct device *dev, const char *name,
+				   struct k3_udma_glue_rx_channel_cfg *cfg)
+{
+	struct k3_udma_glue_rx_channel *rx_chn;
+	int ret;
+
+	if (cfg->flow_id_num <= 0 ||
+	    cfg->flow_id_use_rxchan_id ||
+	    cfg->def_flow_cfg ||
+	    cfg->flow_id_base < 0)
+		return ERR_PTR(-EINVAL);
+
+	/*
+	 * Remote RX channel is under control of Remote CPU core, so
+	 * Linux can only request and manipulate by dedicated RX flows
+	 */
+
+	rx_chn = devm_kzalloc(dev, sizeof(*rx_chn), GFP_KERNEL);
+	if (!rx_chn)
+		return ERR_PTR(-ENOMEM);
+
+	rx_chn->common.dev = dev;
+	rx_chn->common.swdata_size = cfg->swdata_size;
+	rx_chn->remote = true;
+	rx_chn->udma_rchan_id = -1;
+	rx_chn->flow_num = cfg->flow_id_num;
+	rx_chn->flow_id_base = cfg->flow_id_base;
+	rx_chn->psil_paired = false;
+
+	/* parse of udmap channel */
+	ret = of_k3_udma_glue_parse_chn(dev->of_node, name,
+					&rx_chn->common, false);
+	if (ret)
+		goto err;
+
+	ret = k3_udma_glue_request_remote_rx_chn_common(rx_chn, cfg, dev);
+	if (ret)
+		goto err;
+
+	return rx_chn;
+
+err:
+	k3_udma_glue_release_rx_chn(rx_chn);
+	return ERR_PTR(ret);
+}
+
+struct k3_udma_glue_rx_channel *
+k3_udma_glue_request_remote_rx_chn_for_thread_id(struct device *dev,
+						 struct k3_udma_glue_rx_channel_cfg *cfg,
+						 struct device_node *udmax_np, u32 thread_id)
+{
+	struct k3_udma_glue_rx_channel *rx_chn;
+	int ret;
+
+	if (cfg->flow_id_num <= 0 ||
+	    cfg->flow_id_use_rxchan_id ||
+	    cfg->def_flow_cfg ||
+	    cfg->flow_id_base < 0)
+		return ERR_PTR(-EINVAL);
+
+	/*
+	 * Remote RX channel is under control of Remote CPU core, so
+	 * Linux can only request and manipulate by dedicated RX flows
+	 */
+
+	rx_chn = devm_kzalloc(dev, sizeof(*rx_chn), GFP_KERNEL);
+	if (!rx_chn)
+		return ERR_PTR(-ENOMEM);
+
+	rx_chn->common.dev = dev;
+	rx_chn->common.swdata_size = cfg->swdata_size;
+	rx_chn->remote = true;
+	rx_chn->udma_rchan_id = -1;
+	rx_chn->flow_num = cfg->flow_id_num;
+	rx_chn->flow_id_base = cfg->flow_id_base;
+	rx_chn->psil_paired = false;
+
+	ret = of_k3_udma_glue_parse_chn_by_id(udmax_np, &rx_chn->common, false, thread_id);
+	if (ret)
+		goto err;
+
+	ret = k3_udma_glue_request_remote_rx_chn_common(rx_chn, cfg, dev);
+	if (ret)
+		goto err;
+
 	return rx_chn;
 
 err:
 	k3_udma_glue_release_rx_chn(rx_chn);
 	return ERR_PTR(ret);
 }
+EXPORT_SYMBOL_GPL(k3_udma_glue_request_remote_rx_chn_for_thread_id);
 
 struct k3_udma_glue_rx_channel *
 k3_udma_glue_request_rx_chn(struct device *dev, const char *name,
diff --git a/include/linux/dma/k3-udma-glue.h b/include/linux/dma/k3-udma-glue.h
index c81386ceb1c1..1e491c5dcac2 100644
--- a/include/linux/dma/k3-udma-glue.h
+++ b/include/linux/dma/k3-udma-glue.h
@@ -114,6 +114,11 @@ struct k3_udma_glue_rx_channel *k3_udma_glue_request_rx_chn(
 		const char *name,
 		struct k3_udma_glue_rx_channel_cfg *cfg);
 
+struct k3_udma_glue_rx_channel *
+k3_udma_glue_request_remote_rx_chn_for_thread_id(struct device *dev,
+						 struct k3_udma_glue_rx_channel_cfg *cfg,
+						 struct device_node *udmax_np, u32 thread_id);
+
 void k3_udma_glue_release_rx_chn(struct k3_udma_glue_rx_channel *rx_chn);
 int k3_udma_glue_enable_rx_chn(struct k3_udma_glue_rx_channel *rx_chn);
 void k3_udma_glue_disable_rx_chn(struct k3_udma_glue_rx_channel *rx_chn);
-- 
2.34.1