From: Andrew Jeffery <andrew@xxxxxxxx> [ Upstream commit 6bf4ddbe2b4805f0628922446a7e85e34013cd10 ] Alignment is a hardware constraint of the LPC2AHB bridge, and misaligned reserved memory will present as corrupted data. Signed-off-by: Andrew Jeffery <andrew@xxxxxxxx> Reviewed-by: Joel Stanley <joel@xxxxxxxxx> Link: https://lore.kernel.org/r/20191016233950.10100-1-andrew@xxxxxxxx Signed-off-by: Joel Stanley <joel@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/soc/aspeed/aspeed-lpc-ctrl.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/soc/aspeed/aspeed-lpc-ctrl.c b/drivers/soc/aspeed/aspeed-lpc-ctrl.c index 01ed21e8bfee5..dd147af494fdf 100644 --- a/drivers/soc/aspeed/aspeed-lpc-ctrl.c +++ b/drivers/soc/aspeed/aspeed-lpc-ctrl.c @@ -4,6 +4,7 @@ */ #include <linux/clk.h> +#include <linux/log2.h> #include <linux/mfd/syscon.h> #include <linux/miscdevice.h> #include <linux/mm.h> @@ -241,6 +242,18 @@ static int aspeed_lpc_ctrl_probe(struct platform_device *pdev) lpc_ctrl->mem_size = resource_size(&resm); lpc_ctrl->mem_base = resm.start; + + if (!is_power_of_2(lpc_ctrl->mem_size)) { + dev_err(dev, "Reserved memory size must be a power of 2, got %u\n", + (unsigned int)lpc_ctrl->mem_size); + return -EINVAL; + } + + if (!IS_ALIGNED(lpc_ctrl->mem_base, lpc_ctrl->mem_size)) { + dev_err(dev, "Reserved memory must be naturally aligned for size %u\n", + (unsigned int)lpc_ctrl->mem_size); + return -EINVAL; + } } lpc_ctrl->regmap = syscon_node_to_regmap( -- 2.27.0
