From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH] drm/amdgpu: replace readq/writeq with atomic64 operations Date: Wed, 7 Aug 2019 06:07:59 -0700 Message-ID: <20190807130759.GA24028@infradead.org> References: <20190807025640.682-1-tao.zhou1@amd.com> <20190807070834.GA24792@infradead.org> <20190807104104.GA18773@infradead.org> <18cd9fa5-2d87-2f41-b5fa-927b9790287d@amd.com> <20190807125928.GC4048@sirena.co.uk> <461cd4e8-31b8-def3-ca92-5b33db8d5621@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <461cd4e8-31b8-def3-ca92-5b33db8d5621@amd.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: "Koenig, Christian" Cc: "linux-arm-kernel@lists.infradead.org" , "kernel-build-reports@lists.linaro.org" , "Zhou1, Tao" , "amd-gfx@lists.freedesktop.org" , Christoph Hellwig , Mark Brown , "linux-next@vger.kernel.org" , "Deucher, Alexander" , "akpm@linux-foundation.org" , "Li, Dennis" , "Zhang, Hawking" List-Id: amd-gfx.lists.freedesktop.org On Wed, Aug 07, 2019 at 01:00:48PM +0000, Koenig, Christian wrote: > Am 07.08.19 um 14:59 schrieb Mark Brown: > > On Wed, Aug 07, 2019 at 10:55:01AM +0000, Koenig, Christian wrote: > >> Am 07.08.19 um 12:41 schrieb Christoph Hellwig: > >>> writeq/readq are provided whenever the CPU actually supports 64-bit > >>> atomic loads and stores. > >> Is there a config option which we can make the driver depend on? > > 64BIT should do the trick. > > That doesn't work because 32bit x86 does support writeq/readq as far as > I know. I also had a vague memory that x86-32 did support it with SSE, but I can't actually find any traces of that support.