From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7C98C4332F for ; Mon, 13 Dec 2021 15:45:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240205AbhLMPpp (ORCPT ); Mon, 13 Dec 2021 10:45:45 -0500 Received: from mga07.intel.com ([134.134.136.100]:9316 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231132AbhLMPpo (ORCPT ); Mon, 13 Dec 2021 10:45:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1639410344; x=1670946344; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=21nKNVcV8KSqzdESBthYUCCZKtWtFQyHDWyeHHzae70=; b=PlLPB4TJAQfDwbFZuwNDCA7uFA9LMFXmZ2QbUbch5Hex20UFGEHGYaMK z4/hVvnd8evUSftdZOafrw0a25FFEXxEVOZxxno8KXK6+rjf49ilvFtke klll0zGNhxP3SCW7LlVHPEmfEf/zxBCOjsWcA8mPwRyadlsqwZd8pg4d2 B3Sp5G9OkszuBOLEX5K1C7WuvtyQZJh3SCHlv5xgPFm6itY5wM3Ban6yY lH0j8zXnOwxpdn+IQw97tlNbDS2A0GAZMjig079OtoiiotvDyEuCW2RnE gdBZFYYcTZnjbCiydpkyhTD/1mT3bVkZXMHwMOHPWGz7F10/59cTe6Yz/ A==; X-IronPort-AV: E=McAfee;i="6200,9189,10196"; a="302140086" X-IronPort-AV: E=Sophos;i="5.88,202,1635231600"; d="scan'208";a="302140086" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Dec 2021 07:45:44 -0800 X-IronPort-AV: E=Sophos;i="5.88,202,1635231600"; d="scan'208";a="463418510" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Dec 2021 07:45:43 -0800 Date: Mon, 13 Dec 2021 07:45:43 -0800 From: Ira Weiny To: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Cc: David Airlie , Daniel Vetter , Patrik Jakobsson , Rob Clark , Sean Paul , linux-arm-msm@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org Subject: Re: [PATCH 1/7] drm/i915: Replace kmap() with kmap_local_page() Message-ID: <20211213154543.GM3538886@iweiny-DESK2.sc.intel.com> References: <20211210232404.4098157-1-ira.weiny@intel.com> <20211210232404.4098157-2-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.11.1 (2018-12-01) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 13, 2021 at 02:39:59PM +0200, Ville Syrjälä wrote: > On Fri, Dec 10, 2021 at 03:23:58PM -0800, ira.weiny@intel.com wrote: > > From: Ira Weiny > > > > kmap() is being deprecated and these usages are all local to the thread > > so there is no reason kmap_local_page() can't be used. > > > > Replace kmap() calls with kmap_local_page(). > > > > Signed-off-by: Ira Weiny > > --- > > drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 4 ++-- > > drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c | 8 ++++---- > > drivers/gpu/drm/i915/gt/intel_ggtt_fencing.c | 4 ++-- > > drivers/gpu/drm/i915/gt/shmem_utils.c | 4 ++-- > > drivers/gpu/drm/i915/i915_gem.c | 8 ++++---- > > drivers/gpu/drm/i915/i915_gpu_error.c | 4 ++-- > > 6 files changed, 16 insertions(+), 16 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c > > index d77da59fae04..fa8b820e14aa 100644 > > --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c > > @@ -597,9 +597,9 @@ i915_gem_object_create_shmem_from_data(struct drm_i915_private *dev_priv, > > if (err < 0) > > goto fail; > > > > - vaddr = kmap(page); > > + vaddr = kmap_local_page(page); > > memcpy(vaddr, data, len); > > - kunmap(page); > > + kunmap_local(vaddr); > > > > err = pagecache_write_end(file, file->f_mapping, > > offset, len, len, > > diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c > > index 6d30cdfa80f3..e59e1725e29d 100644 > > --- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c > > +++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c > > @@ -144,7 +144,7 @@ static int check_partial_mapping(struct drm_i915_gem_object *obj, > > intel_gt_flush_ggtt_writes(&to_i915(obj->base.dev)->gt); > > > > p = i915_gem_object_get_page(obj, offset >> PAGE_SHIFT); > > - cpu = kmap(p) + offset_in_page(offset); > > + cpu = kmap_local_page(p) + offset_in_page(offset); > > Does kunmap_local() do some magic to make it work even when you > don't pass in the same value you got from kmap_local_page()? Yes. It sounds like a patch like this would be nice to clarify? Ira diff --git a/include/linux/highmem-internal.h b/include/linux/highmem-internal.h index 0a0b2b09b1b8..fb2d3e033c01 100644 --- a/include/linux/highmem-internal.h +++ b/include/linux/highmem-internal.h @@ -246,6 +246,17 @@ do { \ __kunmap_atomic(__addr); \ } while (0) +/** + * kunmap_local - Unmap a page mapped via kmap_local_page(). + * @__addr: An address within the page mapped + * + * __addr is often an address returned from kmap_local_page(). However, + * this address can be any address within the mapped page. It does not need to + * be the exact address returned from kmap_local_page() + * + * Unmapping should be done in the reverse order of the mapping. See + * kmap_local_page() for details. + */ #define kunmap_local(__addr) \ do { \ BUILD_BUG_ON(__same_type((__addr), struct page *)); \