On Wed, Apr 13, 2016 at 06:13:00PM +0100, Robin Murphy wrote:
> Whilst commit 9439eb3ab9d1 ("asm-generic: io: implement relaxed
> accessor macros as conditional wrappers") makes the *_relaxed forms of
> I/O accessors universally available to drivers, in cases where writeq()
> is implemented via the io-64-nonatomic helpers, writeq_relaxed() will
> end up falling back to writel() regardless of whether writel_relaxed()
> is available (identically for s/write/read/).
>
> Add corresponding relaxed forms of the nonatomic helpers to delegate
> to the equivalent 32-bit accessors as appropriate.
>
> CC: Arnd Bergmann <a...@arndb.de>
> CC: Christoph Hellwig <h...@lst.de>
> CC: Darren Hart <dvh...@linux.intel.com>
> CC: Hitoshi Mitake <mitake.hito...@lab.ntt.co.jp>
> Signed-off-by: Robin Murphy <robin.mur...@arm.com>
> ---
> include/linux/io-64-nonatomic-hi-lo.h | 25 +++++++++++++++++++++++++
> include/linux/io-64-nonatomic-lo-hi.h | 25 +++++++++++++++++++++++++
> 2 files changed, 50 insertions(+)
>
> diff --git a/include/linux/io-64-nonatomic-hi-lo.h
> b/include/linux/io-64-nonatomic-hi-lo.h
> index 11d7e84..1a85566 100644
> --- a/include/linux/io-64-nonatomic-hi-lo.h
> +++ b/include/linux/io-64-nonatomic-hi-lo.h
> @@ -21,6 +21,23 @@ static inline void hi_lo_writeq(__u64 val, volatile void
> __iomem *addr)
> writel(val, addr);
> }
>
> +static inline __u64 hi_lo_readq_relaxed(const volatile void __iomem *addr)
> +{
> + const volatile u32 __iomem *p = addr;
> + u32 low, high;
> +
> + high = readl_relaxed(p + 1);
> + low = readl_relaxed(p);
> +
> + return low + ((u64)high << 32);
> +}
> +
> +static inline void hi_lo_writeq_relaxed(__u64 val, volatile void __iomem
> *addr)
> +{
> + writel_relaxed(val >> 32, addr + 4);
> + writel_relaxed(val, addr);
> +}
Could we not generate the _relaxed variants with some macro magic?
Will
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
