[PATCH] spi: atmel-quadspi: fix possible MMIO window size overrun

[PATCH] spi: atmel-quadspi: fix possible MMIO window size overrun

[Tudor.Ambarus-UWL1GkI3JZL3oGB3hsPCZA]

From: Tudor Ambarus <tudor.ambarus-UWL1GkI3JZL3oGB3hsPCZA@public.gmane.org>

The QSPI controller memory space is limited to 128MB:
0x9000_00000-0x9800_00000/0XD000_0000--0XD800_0000.

There are nor flashes that are bigger in size than the memory size
supported by the controller: Micron MT25QL02G (256 MB).

Check if the address exceeds the MMIO window size. An improvement
would be to add support for regular SPI mode and fall back to it
when the flash memories overrun the controller's memory space.

Fixes: 0e6aae08e9ae ("spi: Add QuadSPI driver for Atmel SAMA5D2")
Signed-off-by: Tudor Ambarus <tudor.ambarus-UWL1GkI3JZL3oGB3hsPCZA@public.gmane.org>
---
 drivers/spi/atmel-quadspi.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
index fd8007ebb145..13def7f78b9e 100644
--- a/drivers/spi/atmel-quadspi.c
+++ b/drivers/spi/atmel-quadspi.c
@@ -149,6 +149,7 @@ struct atmel_qspi {
 	struct clk		*qspick;
 	struct platform_device	*pdev;
 	const struct atmel_qspi_caps *caps;
+	resource_size_t		mmap_size;
 	u32			pending;
 	u32			mr;
 	u32			scr;
@@ -329,6 +330,14 @@ static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 	u32 sr, offset;
 	int err;
 
+	/*
+	 * Check if the address exceeds the MMIO window size. An improvement
+	 * would be to add support for regular SPI mode and fall back to it
+	 * when the flash memories overrun the controller's memory space.
+	 */
+	if (op->addr.val + op->data.nbytes > aq->mmap_size)
+		return -ENOTSUPP;
+
 	err = atmel_qspi_set_cfg(aq, op, &offset);
 	if (err)
 		return err;
@@ -480,6 +489,8 @@ static int atmel_qspi_probe(struct platform_device *pdev)
 		goto exit;
 	}
 
+	aq->mmap_size = resource_size(res);
+
 	/* Get the peripheral clock */
 	aq->pclk = devm_clk_get(&pdev->dev, "pclk");
 	if (IS_ERR(aq->pclk))
-- 
2.23.0

Applied "spi: atmel-quadspi: fix possible MMIO window size overrun" to the spi tree

[Mark Brown]

The patch

   spi: atmel-quadspi: fix possible MMIO window size overrun

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 8e093ea4d3593379be46b845b9e823179558047e Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus-UWL1GkI3JZL3oGB3hsPCZA@public.gmane.org>
Date: Fri, 28 Feb 2020 15:55:32 +0000
Subject: [PATCH] spi: atmel-quadspi: fix possible MMIO window size overrun

The QSPI controller memory space is limited to 128MB:
0x9000_00000-0x9800_00000/0XD000_0000--0XD800_0000.

There are nor flashes that are bigger in size than the memory size
supported by the controller: Micron MT25QL02G (256 MB).

Check if the address exceeds the MMIO window size. An improvement
would be to add support for regular SPI mode and fall back to it
when the flash memories overrun the controller's memory space.

Fixes: 0e6aae08e9ae ("spi: Add QuadSPI driver for Atmel SAMA5D2")
Signed-off-by: Tudor Ambarus <tudor.ambarus-UWL1GkI3JZL3oGB3hsPCZA@public.gmane.org>
Link: https://lore.kernel.org/r/20200228155437.1558219-1-tudor.ambarus-UWL1GkI3JZL3oGB3hsPCZA@public.gmane.org
Signed-off-by: Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
 drivers/spi/atmel-quadspi.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
index fd8007ebb145..13def7f78b9e 100644
--- a/drivers/spi/atmel-quadspi.c
+++ b/drivers/spi/atmel-quadspi.c
@@ -149,6 +149,7 @@ struct atmel_qspi {
 	struct clk		*qspick;
 	struct platform_device	*pdev;
 	const struct atmel_qspi_caps *caps;
+	resource_size_t		mmap_size;
 	u32			pending;
 	u32			mr;
 	u32			scr;
@@ -329,6 +330,14 @@ static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 	u32 sr, offset;
 	int err;
 
+	/*
+	 * Check if the address exceeds the MMIO window size. An improvement
+	 * would be to add support for regular SPI mode and fall back to it
+	 * when the flash memories overrun the controller's memory space.
+	 */
+	if (op->addr.val + op->data.nbytes > aq->mmap_size)
+		return -ENOTSUPP;
+
 	err = atmel_qspi_set_cfg(aq, op, &offset);
 	if (err)
 		return err;
@@ -480,6 +489,8 @@ static int atmel_qspi_probe(struct platform_device *pdev)
 		goto exit;
 	}
 
+	aq->mmap_size = resource_size(res);
+
 	/* Get the peripheral clock */
 	aq->pclk = devm_clk_get(&pdev->dev, "pclk");
 	if (IS_ERR(aq->pclk))
-- 
2.20.1