From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756517Ab1KUTrB (ORCPT ); Mon, 21 Nov 2011 14:47:01 -0500 Received: from 184-106-247-128.static.cloud-ips.com ([184.106.247.128]:50856 "EHLO cloud01.chad-versace.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754219Ab1KUTrA (ORCPT ); Mon, 21 Nov 2011 14:47:00 -0500 X-Spam-Flag: NO X-Spam-Score: -1 Date: Mon, 21 Nov 2011 11:46:49 -0800 From: Ben Widawsky To: Daniel Vetter Cc: intel-gfx , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: Re: [Intel-gfx] [PATCH 06/13] drm: add helper to clflush a virtual address range Message-ID: <20111121194649.GC18843@bolo_yeung.jf.intel.com> References: <1320606840-21132-1-git-send-email-daniel.vetter@ffwll.ch> <1320606840-21132-7-git-send-email-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1320606840-21132-7-git-send-email-daniel.vetter@ffwll.ch> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Nov 06, 2011 at 08:13:53PM +0100, Daniel Vetter wrote: > Useful when the page is already mapped to copy date in/out. > > Cc: dri-devel@lists.freedesktop.org > Signed-off-by: Daniel Vetter > --- > drivers/gpu/drm/drm_cache.c | 23 +++++++++++++++++++++++ > include/drm/drmP.h | 1 + > 2 files changed, 24 insertions(+), 0 deletions(-) > > diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c > index 0e3bd5b..502771a 100644 > --- a/drivers/gpu/drm/drm_cache.c > +++ b/drivers/gpu/drm/drm_cache.c > @@ -97,3 +97,26 @@ drm_clflush_pages(struct page *pages[], unsigned long num_pages) > #endif > } > EXPORT_SYMBOL(drm_clflush_pages); > + > +void > +drm_clflush_virt_range(char *addr, unsigned long length) > +{ > +#if defined(CONFIG_X86) > + if (cpu_has_clflush) { > + char *end = addr + length; > + mb(); > + for (; addr < end; addr += boot_cpu_data.x86_clflush_size) > + clflush(addr); > + clflush(end - 1); > + mb(); > + return; > + } > + > + if (on_each_cpu(drm_clflush_ipi_handler, NULL, 1) != 0) > + printk(KERN_ERR "Timed out waiting for cache flush.\n"); > +#else > + printk(KERN_ERR "Architecture has no drm_cache.c support\n"); > + WARN_ON_ONCE(1); > +#endif > +} > +EXPORT_SYMBOL(drm_clflush_virt_range); I'd feel more comfortable with a BUG_ON(irqs_disabled()); before the IPI... though I don't even know how many platforms that actually pertains to (if any).