From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve.Capper@arm.com (Steve Capper) Date: Mon, 26 Nov 2018 12:11:16 +0000 Subject: [PATCH V3 1/5] mm: mmap: Allow for "high" userspace addresses In-Reply-To: <20181123181744.GK3360@arrakis.emea.arm.com> References: <20181114133920.7134-1-steve.capper@arm.com> <20181114133920.7134-2-steve.capper@arm.com> <20181123181744.GK3360@arrakis.emea.arm.com> Message-ID: <20181126121100.GA2012@capper-debian.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Nov 23, 2018 at 06:17:44PM +0000, Catalin Marinas wrote: > On Wed, Nov 14, 2018 at 01:39:16PM +0000, Steve Capper wrote: > > This patch adds support for "high" userspace addresses that are > > optionally supported on the system and have to be requested via a hint > > mechanism ("high" addr parameter to mmap). > > > > Architectures such as powerpc and x86 achieve this by making changes to > > their architectural versions of arch_get_unmapped_* functions. However, > > on arm64 we use the generic versions of these functions. > > > > Rather than duplicate the generic arch_get_unmapped_* implementations > > for arm64, this patch instead introduces two architectural helper macros > > and applies them to arch_get_unmapped_*: > > arch_get_mmap_end(addr) - get mmap upper limit depending on addr hint > > arch_get_mmap_base(addr, base) - get mmap_base depending on addr hint > > > > If these macros are not defined in architectural code then they default > > to (TASK_SIZE) and (base) so should not introduce any behavioural > > changes to architectures that do not define them. > > > > Signed-off-by: Steve Capper > > Reviewed-by: Catalin Marinas Thanks!