#include #include #include /* * This implements the binary GCD algorithm. (Often attributed to Stein, * but as Knuth has noted, appears in a first-century Chinese math text.) * * This is faster than the division-based algorithm even on x86, which * has decent hardware division. */ #if !defined(CONFIG_CPU_NO_EFFICIENT_FFS) && !defined(CPU_NO_EFFICIENT_FFS) /* If __ffs is available, the even/odd algorithm benchmarks slower. */ unsigned long gcd(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; b >>= __ffs(b); if (b == 1) return r & -r; for (;;) { a >>= __ffs(a); if (a == 1) return r & -r; if (a == b) return a << __ffs(r); if (a < b) swap(a, b); a -= b; } } #else /* If normalization is done by loops, the even/odd algorithm is a win. */ unsigned long gcd(unsigned long a, unsigned long b) { unsigned long r = a | b; if (!a || !b) return r; /* Isolate lsbit of r */ r &= -r; while (!(b & r)) b >>= 1; if (b == r) return r; for (;;) { while (!(a & r)) a >>= 1; if (a == r) return r; if (a == b) return a; if (a < b) swap(a, b); a -= b; a >>= 1; if (a & r) a += b; a >>= 1; } } #endif EXPORT_SYMBOL_GPL(gcd); back'>packet-loop-back net-next plumbingsTobias Klauser
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authorMark Rutland <mark.rutland@arm.com>2017-01-25 19:30:09 +0000
committerMark Brown <broonie@kernel.org>2017-01-25 21:05:37 +0000
commit1372cef1c697d8aac0cc923f8aa2c37d790ec9ed (patch)
treeed5f350cd559bc15ae370f0c9fd280204e98597d /include/xen/interface/memory.h
parentd00b74613fb18dfd0a5aa99270ee2e72d5c808d7 (diff)
regulator: fixed: Revert support for ACPI interface
This reverts commit 13bed58ce874 (regulator: fixed: add support for ACPI interface). While there does appear to be a practical need to manage regulators on ACPI systems, using ad-hoc properties to describe regulators to the kernel presents a number of problems (especially should ACPI gain first class support for such things), and there are ongoing discussions as to how to manage this. Until there is a rough consensus, revert commit 13bed58ce8748d43, which hasn't been in a released kernel yet as discussed in [1] and the surrounding thread. [1] http://lkml.kernel.org/r/20170125184949.x2wkoo7kbaaajkjk@sirena.org.uk Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Lu Baolu <baolu.lu@linux.intel.com> Cc: Mark Brown <broonie@kernel.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'include/xen/interface/memory.h')