[PATCH v3 2/2] OMAP: IOMMU: add support to callback during fault handling

[Felipe Balbi]

Hi,

On Mon, Feb 21, 2011 at 10:18:56AM +0200, Hiroshi DOYU wrote:
> From: David Cohen <dacohen at gmail.com>
> Subject: [PATCH v3 2/2] OMAP: IOMMU: add support to callback during fault handling
> Date: Wed, 16 Feb 2011 21:35:51 +0200
> 
> > Add support to register an isr for IOMMU fault situations and adapt it
> > to allow such (*isr)() to be used as fault callback. Drivers using IOMMU
> > module might want to be informed when errors happen in order to debug it
> > or react.
> > 
> > Signed-off-by: David Cohen <dacohen at gmail.com>
> > ---
> >  arch/arm/mach-omap2/iommu2.c            |   17 +++++++++-
> >  arch/arm/plat-omap/include/plat/iommu.h |   14 ++++++++-
> >  arch/arm/plat-omap/iommu.c              |   52 ++++++++++++++++++++++---------
> >  3 files changed, 65 insertions(+), 18 deletions(-)
> > 
> > diff --git a/arch/arm/mach-omap2/iommu2.c b/arch/arm/mach-omap2/iommu2.c
> > index 49a1e5e..adb083e 100644
> > --- a/arch/arm/mach-omap2/iommu2.c
> > +++ b/arch/arm/mach-omap2/iommu2.c
> > @@ -146,18 +146,31 @@ static void omap2_iommu_set_twl(struct iommu *obj, bool on)
> >  static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 *ra)
> >  {
> >  	u32 stat, da;
> > +	u32 errs = 0;
> >  
> >  	stat = iommu_read_reg(obj, MMU_IRQSTATUS);
> >  	stat &= MMU_IRQ_MASK;
> > -	if (!stat)
> > +	if (!stat) {
> > +		*ra = 0;
> >  		return 0;
> > +	}
> >  
> >  	da = iommu_read_reg(obj, MMU_FAULT_AD);
> >  	*ra = da;
> >  
> > +	if (stat & MMU_IRQ_TLBMISS)
> > +		errs |= OMAP_IOMMU_ERR_TLB_MISS;
> > +	if (stat & MMU_IRQ_TRANSLATIONFAULT)
> > +		errs |= OMAP_IOMMU_ERR_TRANS_FAULT;
> > +	if (stat & MMU_IRQ_EMUMISS)
> > +		errs |= OMAP_IOMMU_ERR_EMU_MISS;
> > +	if (stat & MMU_IRQ_TABLEWALKFAULT)
> > +		errs |= OMAP_IOMMU_ERR_TBLWALK_FAULT;
> > +	if (stat & MMU_IRQ_MULTIHITFAULT)
> > +		errs |= OMAP_IOMMU_ERR_MULTIHIT_FAULT;
> >  	iommu_write_reg(obj, stat, MMU_IRQSTATUS);
> >  
> > -	return stat;
> > +	return errs;
> >  }
> >  
> >  static void omap2_tlb_read_cr(struct iommu *obj, struct cr_regs *cr)
> > diff --git a/arch/arm/plat-omap/include/plat/iommu.h b/arch/arm/plat-omap/include/plat/iommu.h
> > index 19cbb5e..174f1b9 100644
> > --- a/arch/arm/plat-omap/include/plat/iommu.h
> > +++ b/arch/arm/plat-omap/include/plat/iommu.h
> > @@ -31,6 +31,7 @@ struct iommu {
> >  	struct clk	*clk;
> >  	void __iomem	*regbase;
> >  	struct device	*dev;
> > +	void		*isr_priv;
> 
> Ideally I'd like to avoid having "isr_priv" in iommu since it's not
> used for iommu but client needs the place to pass its info to its
> custom handler. Any better idea?

I'm not sure if it makes sense as I don't know the mailbox block, but
maybe moving to GENIRQ ? Then IRQ subsystem would take care of the
"dev_id"

-- 
balbi