From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Mon, 25 Apr 2016 17:21:34 +0200 Subject: [PATCH 4/7] io-64-nonatomic: Add relaxed accessor variants In-Reply-To: <20160425133242.GC30830@arm.com> References: <571A5A9E.7040305@arm.com> <20160425133242.GC30830@arm.com> Message-ID: <5485134.l18Z1dlVmn@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Monday 25 April 2016 14:32:42 Will Deacon wrote: > > >> > > >>+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? > > > > We _could_ - indeed I started doing that, but then decided that the > > obfuscation of horrible macro-templated functions wasn't worth saving a > > couple of hundred bytes in some code that isn't exactly difficult to > > maintain and has needed touching once in 4 years. > > > > If you did want to go down the macro route, I may as well also generate both > > lo-hi and hi-lo headers all from a single template, it'd be really clever... > > > > I certainly wasn't suggesting any more than the obvious macroisation, > but I'll leave it up to Arnd, as I think this falls on his lap. I'd prefer the open-coded variant as well. Arnd