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From: "Kiwoong Kim" <kwmad.kim@samsung.com>
To: "'Bart Van Assche'" <bvanassche@acm.org>,
	<linux-scsi@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<alim.akhtar@samsung.com>, <avri.altman@wdc.com>,
	<jejb@linux.ibm.com>, <martin.petersen@oracle.com>,
	<beanhuo@micron.com>, <cang@codeaurora.org>,
	<adrian.hunter@intel.com>, <sc.suh@samsung.com>,
	<hy50.seo@samsung.com>, <sh425.lee@samsung.com>,
	<bhoon95.kim@samsung.com>
Subject: RE: [RFC PATCH v1 1/2] scsi: ufs: introduce vendor isr
Date: Mon, 9 Aug 2021 16:33:04 +0900	[thread overview]
Message-ID: <000501d78cf0$ca3157b0$5e940710$@samsung.com> (raw)
In-Reply-To: <9ed9f56c-d7a4-8e68-0968-da0eccb0b38d@acm.org>

> On 8/5/21 11:34 PM, Kiwoong Kim wrote:
> > This patch is to activate some interrupt sources that aren't defined
> > in UFSHCI specifications. Those purpose could be error handling,
> > workaround or whatever.
> >
> > Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
> > ---
> >   drivers/scsi/ufs/ufshcd.c | 10 ++++++++++
> >   drivers/scsi/ufs/ufshcd.h |  8 ++++++++
> >   2 files changed, 18 insertions(+)
> >
> > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> > index 05495c34a2b7..f85a9b335e0b 100644
> > --- a/drivers/scsi/ufs/ufshcd.c
> > +++ b/drivers/scsi/ufs/ufshcd.c
> > @@ -6428,6 +6428,16 @@ static irqreturn_t ufshcd_tmc_handler(struct
> ufs_hba *hba)
> >   static irqreturn_t ufshcd_sl_intr(struct ufs_hba *hba, u32 intr_status)
> >   {
> >   	irqreturn_t retval = IRQ_NONE;
> > +	int res = 0;
> > +	unsigned long flags;
> > +
> > +	retval = ufshcd_vops_intr(hba, &res);
> > +	if (res) {
> > +		spin_lock_irqsave(hba->host->host_lock, flags);
> > +		hba->force_reset = true;
> > +		ufshcd_schedule_eh_work(hba);
> > +		spin_unlock_irqrestore(hba->host->host_lock, flags);
> > +	}
> 
> How can a non-standard extension have error handling code in common code?
> Please move the code under if (res) into the vendor code.
Got it.

> 
> >   	if (intr_status & UFSHCD_UIC_MASK)
> >   		retval |= ufshcd_uic_cmd_compl(hba, intr_status); diff --git
> > a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index
> > 971cfabc4a1e..1ed0a911f864 100644
> > --- a/drivers/scsi/ufs/ufshcd.h
> > +++ b/drivers/scsi/ufs/ufshcd.h
> > @@ -356,6 +356,7 @@ struct ufs_hba_variant_ops {
> >   			       const union ufs_crypto_cfg_entry *cfg, int slot);
> >   	void	(*event_notify)(struct ufs_hba *hba,
> >   				enum ufs_event_type evt, void *data);
> > +	irqreturn_t	(*intr)(struct ufs_hba *hba, int *res);
> >   };
> >
> >   /* clock gating state  */
> > @@ -1296,6 +1297,13 @@ static inline void
> ufshcd_vops_config_scaling_param(struct ufs_hba *hba,
> >   		hba->vops->config_scaling_param(hba, profile, data);
> >   }
> >
> > +static inline irqreturn_t ufshcd_vops_intr(struct ufs_hba *hba, int
> > +*res) {
> > +	if (hba->vops && hba->vops->intr)
> > +		return hba->vops->intr(hba, res);
> > +	return IRQ_NONE;
> > +}
> > +
> >   extern struct ufs_pm_lvl_states ufs_pm_lvl_states[];
> 
> So this code adds an indirect function call in the interrupt handler?
> This will have a negative impact on performance, especially on a kernel
> with security mitigations enabled. See also
> https://protect2.fireeye.com/v1/url?k=fe14d1e9-a18fe89c-fe155aa6-
> 0cc47a31ce4e-8200591154f8c42c&q=1&e=7cf22799-390c-4209-8a19-
> 6ad1fa5fa811&u=https%3A%2F%2Flwn.net%2FArticles%2F774743%2F.
Interesting. I'll refer to this. Thanks.

> 
> Thanks,
> 
> Bart.


  reply	other threads:[~2021-08-09  7:33 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20210806064923epcas2p13dd6b442eed02404d87684afd9c1b229@epcas2p1.samsung.com>
2021-08-06  6:34 ` [RFC PATCH v1 0/2] " Kiwoong Kim
     [not found]   ` <CGME20210806064924epcas2p4572538fd1fa7a73d8262737e38a9b537@epcas2p4.samsung.com>
2021-08-06  6:34     ` [RFC PATCH v1 1/2] " Kiwoong Kim
2021-08-06 16:18       ` Bart Van Assche
2021-08-09  7:33         ` Kiwoong Kim [this message]
     [not found]   ` <CGME20210806064925epcas2p2ba7e711758614384c17648d4924d025c@epcas2p2.samsung.com>
2021-08-06  6:34     ` [RFC PATCH v1 2/2] scsi: ufs: ufs-exynos: implement exynos isr Kiwoong Kim
2021-08-06 16:37       ` Bart Van Assche
2021-08-09  7:31         ` Kiwoong Kim
2021-08-06 16:14   ` [RFC PATCH v1 0/2] scsi: ufs: introduce vendor isr Bart Van Assche
2021-08-08  5:56     ` Avri Altman
2021-08-09  7:46     ` Kiwoong Kim
2021-08-09 16:08       ` Bart Van Assche
2021-08-13  5:31         ` Kiwoong Kim

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