| Subject | Re: [RFC PATCH 23/33] irqchip/gic-v3-its: Add VPENDBASER/VPROPBASER accessors | From | Shanker Donthineni <> | Date | Mon, 13 Feb 2017 17:39:23 -0600 |
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Hi Marc,
On 01/17/2017 04:20 AM, Marc Zyngier wrote: > V{PEND,PROP}BASER being 64bit registers, they need some ad-hoc > accessors on 32bit, specially given that VPENDBASER contains > a Valid bit, making the access a bit convoluted. > > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > --- > arch/arm/include/asm/arch_gicv3.h | 28 ++++++++++++++++++++++++++++ > arch/arm64/include/asm/arch_gicv3.h | 5 +++++ > 2 files changed, 33 insertions(+) > > diff --git a/arch/arm/include/asm/arch_gicv3.h > b/arch/arm/include/asm/arch_gicv3.h > index 2747590..3f18832 100644 > --- a/arch/arm/include/asm/arch_gicv3.h > +++ b/arch/arm/include/asm/arch_gicv3.h > @@ -291,5 +291,33 @@ static inline u64 __gic_readq_nonatomic(const > volatile void __iomem *addr) > */ > #define gits_write_cwriter(v, c) __gic_writeq_nonatomic(v, c) > > +/* > + * GITS_VPROPBASER - hi and lo bits may be accessed independently. > + */ > +#define gits_write_vpropbaser(v, c) __gic_writeq_nonatomic(v, c) > + > +/* > + * GITS_VPENDBASER - the Valid bit must be cleared before changing > + * anything else. > + */ > +static inline void gits_write_vpendbaser(u64 val, void * __iomem addr) > +{ > + u32 tmp; > + > + tmp = readl_relaxed(addr + 4); > + if (tmp & GICR_PENDBASER_Valid) { > + tmp &= ~GICR_PENDBASER_Valid; > + writel_relaxed(tmp, addr + 4); > + } > + > + /* > + * Use the fact that __gic_writeq_nonatomic writes the second > + * half of the 64bit quantity after the first. > + */ > + __gic_writeq_nonatomic(val, addr); I'm not sure whether software has to check a register write pending bit GICR_CTLR.RWP or not. GICv3 spec says, the effect of a write to GICR_VPENDBASER register is not guaranteed to be visible throughout the affinity hierarchy,as indicated by GICR_CTLR.RWP == 0.
-- Shanker Donthineni Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
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