[PATCH 5.4 129/168] spi: atmel-quadspi: fix possible MMIO window size overrun

Greg Kroah-Hartman
2020-03-10T12:53:39Z

From: Tudor Ambarus <tudor.ambarus@microchip.com>

commit 8e093ea4d3593379be46b845b9e823179558047e upstream.

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@microchip.com>
Link: https://lore.kernel.org/r/20200228155437.1558219-1-tudor.ambarus@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/spi/atmel-quadspi.c | 11 +++++++++++
1 file changed, 11 insertions(+)

--- 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
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 platf
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))