linux-kernel - Re: [PATCH 1/3] scsi: ufshcd: switch to a version macro

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20210308080013.GE983@lst.de>
Date:   Mon, 8 Mar 2021 09:00:14 +0100
From:   Christoph Hellwig <hch@....de>
To:     Caleb Connolly <caleb@...nolly.tech>
Cc:     Alim Akhtar <alim.akhtar@...sung.com>,
        Avri Altman <avri.altman@....com>,
        "James E.J. Bottomley" <jejb@...ux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        ejb@...ux.ibm.com, stanley.chu@...iatek.com, cang@...eaurora.org,
        beanhuo@...ron.com, jaegeuk@...nel.org, asutoshd@...eaurora.org,
        linux-scsi@...r.kernel.org, linux-kernel@...r.kernel.org,
        Christoph Hellwig <hch@....de>
Subject: Re: [PATCH 1/3] scsi: ufshcd: switch to a version macro

This looks like a really nice improvement!

A bunch of comments below:

> @@ -696,10 +685,21 @@ static inline u32 ufshcd_get_intr_mask(struct ufs_hba *hba)
>   */
>  static inline u32 ufshcd_get_ufs_version(struct ufs_hba *hba)
>  {
> +	u32 ufshci_ver;

missing eempty line after the declaration.

>  	if (hba->quirks & UFSHCD_QUIRK_BROKEN_UFS_HCI_VERSION)
> +		ufshci_ver = ufshcd_vops_get_ufs_hci_version(hba);
> +	else
> +		ufshci_ver = ufshcd_readl(hba, REG_UFS_VERSION);
>  
> +	/*
> +	 * UFSHCI v1.x uses a different version scheme, in order
> +	 * to allow the use of comparisons with the UFSHCI_VER
> +	 * macro, we convert it to the same scheme as ufs 2.0+.
> +	 */
> +	if (ufshci_ver & 0x00010000)
> +		ufshci_ver = UFSHCI_VER(1, ufshci_ver & 0x00000100);
> +
> +	return ufshci_ver;

I'd use early returns here to clean this up a bit:

 	if (hba->quirks & UFSHCD_QUIRK_BROKEN_UFS_HCI_VERSION)
		ufshci_ver = ufshcd_vops_get_ufs_hci_version(hba);

	...
	ufshci_ver = ufshcd_readl(hba, REG_UFS_VERSION);
	if (ufshci_ver & 0x00010000)
		return UFSHCI_VER(1, ufshci_ver & 0x00000100);
	return ufshci_ver;

> +#define UFSHCI_VER(major, minor) \
> +	((major << 8) + (minor << 4))

This needs braces around major and minor.  Or better just convert it
to an inline function (and use a lower case name).