Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Michael Walle <michael@walle.cc>,
        Codrin Ciubotariu <codrin.ciubotariu@microchip.com>,
        Wolfram Sang <wsa@kernel.org>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.17 572/772] i2c: at91: use dma safe buffers
Date:   Tue,  7 Jun 2022 19:02:44 +0200
Message-Id: <20220607165005.808743827@linuxfoundation.org>
In-Reply-To: <20220607164948.980838585@linuxfoundation.org>
References: <20220607164948.980838585@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Michael Walle <michael@walle.cc>

[ Upstream commit 03fbb903c8bf7e53e101e8d9a7b261264317c411 ]

The supplied buffer might be on the stack and we get the following error
message:
[    3.312058] at91_i2c e0070600.i2c: rejecting DMA map of vmalloc memory

Use i2c_{get,put}_dma_safe_msg_buf() to get a DMA-able memory region if
necessary.

Fixes: 60937b2cdbf9 ("i2c: at91: add dma support")
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/busses/i2c-at91-master.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c
index b0eae94909f4..5eca3b3bb609 100644
--- a/drivers/i2c/busses/i2c-at91-master.c
+++ b/drivers/i2c/busses/i2c-at91-master.c
@@ -656,6 +656,7 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num)
 	unsigned int_addr_flag = 0;
 	struct i2c_msg *m_start = msg;
 	bool is_read;
+	u8 *dma_buf;
 
 	dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num);
 
@@ -703,7 +704,17 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num)
 	dev->msg = m_start;
 	dev->recv_len_abort = false;
 
+	if (dev->use_dma) {
+		dma_buf = i2c_get_dma_safe_msg_buf(m_start, 1);
+		if (!dma_buf) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		dev->buf = dma_buf;
+	}
+
 	ret = at91_do_twi_transfer(dev);
+	i2c_put_dma_safe_msg_buf(dma_buf, m_start, !ret);
 
 	ret = (ret < 0) ? ret : num;
 out:
-- 
2.35.1