From mboxrd@z Thu Jan 1 00:00:00 1970 From: mans@mansr.com (=?iso-8859-1?Q?M=E5ns_Rullg=E5rd?=) Date: Mon, 30 Jan 2017 16:38:15 +0000 Subject: ARM64: Disabling warnings about deprecated armv8 instructions In-Reply-To: (Ard Biesheuvel's message of "Mon, 30 Jan 2017 14:50:23 +0000") References: <1485072424.14066.2.camel@crowfest.net> <1485075528.14345.1.camel@crowfest.net> <22169925.OhJ0QcnbHM@localhost> <1485087662.1518.1.camel@crowfest.net> <0D1F678D-6F94-4B68-955E-6454F8647FCA@linaro.org> <20170130141308.GV27312@n2100.armlinux.org.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Ard Biesheuvel writes: > On 30 January 2017 at 14:13, Russell King - ARM Linux > wrote: >> On Sun, Jan 22, 2017 at 01:01:53PM +0000, Ard Biesheuvel wrote: >>> Emulating unaligned access in the ARM kernel was a mistake: it even >>> emulates unaligned accesses for instructions like ldm and ldrd, which >>> require word alignment at the hardware level even in the latest v8 >>> version of the architecture. In contrast, the v8 deprecation warnings >>> are about enforcing compliance. >> >> Ard, you're totally wrong on the unaligned access thing. Unaligned >> accesses are a fundamental requirement of the kernel's networking >> stack. If you don't have support for unaligned accesses, then you >> don't have network support - it's as simple as that. >> >> So, in order for ARMv5 and earlier to have network support, there >> was no option to add support for emulating those accesses. >> > > I wasn't aware of that. Not even David Miller is "aware" of that. Then again, we're living in a world of "alternative facts" now. -- M?ns Rullg?rd