Re: [PATCH v1 3/6] bus: mhi: Add MMIO region length to controller structure

[Jeffrey Hugo]

On 4/16/2021 12:47 PM, Bhaumik Bhatt wrote:
> Make controller driver specify the MMIO register region length
> for range checking of BHI or BHIe space. This can help validate
> that offsets are in acceptable memory region or not and avoid any
> boot-up issues due to BHI or BHIe memory accesses.
>
> Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
> ---
>   include/linux/mhi.h | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/include/linux/mhi.h b/include/linux/mhi.h
> index 944aa3a..ad53b24 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -293,6 +293,7 @@ struct mhi_controller_config {
>    * @mhi_dev: MHI device instance for the controller
>    * @debugfs_dentry: MHI controller debugfs directory
>    * @regs: Base address of MHI MMIO register space (required)
> + * @reg_len: Length of the MHI MMIO region (required)
>    * @bhi: Points to base of MHI BHI register space
>    * @bhie: Points to base of MHI BHIe register space
>    * @wake_db: MHI WAKE doorbell register address
> @@ -375,6 +376,7 @@ struct mhi_controller {
>   	struct mhi_device *mhi_dev;
>   	struct dentry *debugfs_dentry;
>   	void __iomem *regs;
> +	size_t reg_len;

Didn't Mani make sure this struct was packed using pahole when things 
were first upstreamed?  Feels like sticking this in the middle of a 
bunch of void * entries will add some padding.  Am I wrong?

>   	void __iomem *bhi;
>   	void __iomem *bhie;
>   	void __iomem *wake_db;