linux-kernel - [PATCH AUTOSEL 5.15 06/11] i2c: tegra: Allocate DMA memory for DMA engine

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 10 Nov 2022 21:35:06 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Thierry Reding <treding@...dia.com>,
        Robin Murphy <robin.murphy@....com>,
        Wolfram Sang <wsa@...nel.org>, Sasha Levin <sashal@...nel.org>,
        ldewangan@...dia.com, thierry.reding@...il.com,
        jonathanh@...dia.com, sumit.semwal@...aro.org,
        christian.koenig@....com, linux-i2c@...r.kernel.org,
        linux-tegra@...r.kernel.org, linux-media@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, linaro-mm-sig@...ts.linaro.org
Subject: [PATCH AUTOSEL 5.15 06/11] i2c: tegra: Allocate DMA memory for DMA engine

From: Thierry Reding <treding@...dia.com>

[ Upstream commit cdbf26251d3b35c4ccaea0c3a6de4318f727d3d2 ]

When the I2C controllers are running in DMA mode, it is the DMA engine
that performs the memory accesses rather than the I2C controller. Pass
the DMA engine's struct device pointer to the DMA API to make sure the
correct DMA operations are used.

This fixes an issue where the DMA engine's SMMU stream ID needs to be
misleadingly set for the I2C controllers in device tree.

Suggested-by: Robin Murphy <robin.murphy@....com>
Signed-off-by: Thierry Reding <treding@...dia.com>
Signed-off-by: Wolfram Sang <wsa@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/i2c/busses/i2c-tegra.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index c883044715f3..444867cef682 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -283,6 +283,7 @@ struct tegra_i2c_dev {
 	struct dma_chan *tx_dma_chan;
 	struct dma_chan *rx_dma_chan;
 	unsigned int dma_buf_size;
+	struct device *dma_dev;
 	dma_addr_t dma_phys;
 	void *dma_buf;
 
@@ -419,7 +420,7 @@ static int tegra_i2c_dma_submit(struct tegra_i2c_dev *i2c_dev, size_t len)
 static void tegra_i2c_release_dma(struct tegra_i2c_dev *i2c_dev)
 {
 	if (i2c_dev->dma_buf) {
-		dma_free_coherent(i2c_dev->dev, i2c_dev->dma_buf_size,
+		dma_free_coherent(i2c_dev->dma_dev, i2c_dev->dma_buf_size,
 				  i2c_dev->dma_buf, i2c_dev->dma_phys);
 		i2c_dev->dma_buf = NULL;
 	}
@@ -466,10 +467,13 @@ static int tegra_i2c_init_dma(struct tegra_i2c_dev *i2c_dev)
 
 	i2c_dev->tx_dma_chan = chan;
 
+	WARN_ON(i2c_dev->tx_dma_chan->device != i2c_dev->rx_dma_chan->device);
+	i2c_dev->dma_dev = chan->device->dev;
+
 	i2c_dev->dma_buf_size = i2c_dev->hw->quirks->max_write_len +
 				I2C_PACKET_HEADER_SIZE;
 
-	dma_buf = dma_alloc_coherent(i2c_dev->dev, i2c_dev->dma_buf_size,
+	dma_buf = dma_alloc_coherent(i2c_dev->dma_dev, i2c_dev->dma_buf_size,
 				     &dma_phys, GFP_KERNEL | __GFP_NOWARN);
 	if (!dma_buf) {
 		dev_err(i2c_dev->dev, "failed to allocate DMA buffer\n");
@@ -1255,7 +1259,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 
 	if (i2c_dev->dma_mode) {
 		if (i2c_dev->msg_read) {
-			dma_sync_single_for_device(i2c_dev->dev,
+			dma_sync_single_for_device(i2c_dev->dma_dev,
 						   i2c_dev->dma_phys,
 						   xfer_size, DMA_FROM_DEVICE);
 
@@ -1263,7 +1267,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 			if (err)
 				return err;
 		} else {
-			dma_sync_single_for_cpu(i2c_dev->dev,
+			dma_sync_single_for_cpu(i2c_dev->dma_dev,
 						i2c_dev->dma_phys,
 						xfer_size, DMA_TO_DEVICE);
 		}
@@ -1276,7 +1280,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 			memcpy(i2c_dev->dma_buf + I2C_PACKET_HEADER_SIZE,
 			       msg->buf, msg->len);
 
-			dma_sync_single_for_device(i2c_dev->dev,
+			dma_sync_single_for_device(i2c_dev->dma_dev,
 						   i2c_dev->dma_phys,
 						   xfer_size, DMA_TO_DEVICE);
 
@@ -1327,7 +1331,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
 		}
 
 		if (i2c_dev->msg_read && i2c_dev->msg_err == I2C_ERR_NONE) {
-			dma_sync_single_for_cpu(i2c_dev->dev,
+			dma_sync_single_for_cpu(i2c_dev->dma_dev,
 						i2c_dev->dma_phys,
 						xfer_size, DMA_FROM_DEVICE);
 
-- 
2.35.1