On 13/02/17 23:39, Shanker Donthineni wrote:
> 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.zyng...@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.
Yeah, that's a bit odd, and I've raised this internally. GICR_CTLR.RWP
doesn't mention anything about GICR_VPENDBASER at all, and this makes me
think that it could be a leftover from an earlier spec...
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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