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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id ACC6BE81BD0 for ; Mon, 9 Feb 2026 14:26:04 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 102C210E0D6; Mon, 9 Feb 2026 14:26:04 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=collabora.com header.i=@collabora.com header.b="Kjz94qS9"; dkim-atps=neutral Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6C15810E0D6 for ; Mon, 9 Feb 2026 14:26:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1770647162; bh=Ai1JsGYjgTlQrc8eHRH5768OPEiwDY59ubtKITTwQmM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Kjz94qS9b1XfBmF8cr96hN0kMuxaGtIwA3eZJoiUF+nrcz6ssLOHR4NwypNNeGLYE x5ypN6Sn7uiu3tuB959nEx5vPsxPhMjWzr5bBENEh2S/fgX3Rd4n3EXosnVtrB08UH RMCT88SgNOmIWAUHVLW+H44kFZwgp0FRNrbitmOUbYamcnwe+fVG2b0JJiO6XmXakG K0wLFtZI1bngLjI7IZHWICbog1Id7gG9tUrGGb7Wn6vRuUZVKFeN6mcd+0xz5E/Hbr YnYspRIsly78xk4/LB3yNvrmhTuwrVN2DBR0LEwW2QzTPyr6p8MOKDCdrzIRufgBT6 Gop3C1/1K/W4g== Received: from fedora (unknown [IPv6:2a01:e0a:2c:6930:d919:a6e:5ea1:8a9f]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by bali.collaboradmins.com (Postfix) with ESMTPSA id 824D017E140E; Mon, 9 Feb 2026 15:26:01 +0100 (CET) Date: Mon, 9 Feb 2026 15:25:56 +0100 From: Boris Brezillon To: Thomas Zimmermann Cc: loic.molinari@collabora.com, willy@infradead.org, frank.binns@imgtec.com, matt.coster@imgtec.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, airlied@gmail.com, simona@ffwll.ch, dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: Re: [PATCH v3 4/6] drm/gem-shmem: Refactor drm_gem_shmem_try_map_pmd() Message-ID: <20260209152556.636825c6@fedora> In-Reply-To: <20260209133241.238813-5-tzimmermann@suse.de> References: <20260209133241.238813-1-tzimmermann@suse.de> <20260209133241.238813-5-tzimmermann@suse.de> Organization: Collabora X-Mailer: Claws Mail 4.3.1 (GTK 3.24.51; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Mon, 9 Feb 2026 14:27:13 +0100 Thomas Zimmermann wrote: > The current mmap page-fault handler requires some changes before it > can track folio access. > > Call to folio_test_pmd_mappable() into the mmap page-fault handler > before calling drm_gem_shmem_try_map_pmd(). The folio will become > useful for tracking the access status. > > Also rename drm_gem_shmem_try_map_pmd() to _try_insert_pfn_pmd() > and only pass the page fault and page-frame number. The new name and > parameters make it similar to vmf_insert_pfn_pmd(). > > No functional changes. If PMD mapping fails or is not supported, > insert a regular PFN as before. > > Signed-off-by: Thomas Zimmermann Reviewed-by: Boris Brezillon > --- > drivers/gpu/drm/drm_gem_shmem_helper.c | 25 ++++++++++++------------- > 1 file changed, 12 insertions(+), 13 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c > index ab8e331005f9..c3a054899ba3 100644 > --- a/drivers/gpu/drm/drm_gem_shmem_helper.c > +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c > @@ -550,17 +550,14 @@ int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, > } > EXPORT_SYMBOL_GPL(drm_gem_shmem_dumb_create); > > -static vm_fault_t drm_gem_shmem_try_map_pmd(struct vm_fault *vmf, unsigned long addr, > - struct page *page) > +static vm_fault_t drm_gem_shmem_try_insert_pfn_pmd(struct vm_fault *vmf, unsigned long pfn) > { > #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP > - unsigned long pfn = page_to_pfn(page); > unsigned long paddr = pfn << PAGE_SHIFT; > - bool aligned = (addr & ~PMD_MASK) == (paddr & ~PMD_MASK); > + bool aligned = (vmf->address & ~PMD_MASK) == (paddr & ~PMD_MASK); > > - if (aligned && > - pmd_none(*vmf->pmd) && > - folio_test_pmd_mappable(page_folio(page))) { > + if (aligned && pmd_none(*vmf->pmd)) { > + /* Read-only mapping; split upon write fault */ > pfn &= PMD_MASK >> PAGE_SHIFT; > return vmf_insert_pfn_pmd(vmf, pfn, false); > } > @@ -580,6 +577,7 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) > struct page **pages = shmem->pages; > pgoff_t page_offset = vmf->pgoff - vma->vm_pgoff; /* page offset within VMA */ > struct page *page; > + struct folio *folio; > unsigned long pfn; > > dma_resv_lock(obj->resv, NULL); > @@ -591,15 +589,16 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) > page = pages[page_offset]; > if (drm_WARN_ON_ONCE(dev, !page)) > goto out; > - > - ret = drm_gem_shmem_try_map_pmd(vmf, vmf->address, page); > - if (ret == VM_FAULT_NOPAGE) > - goto out; > + folio = page_folio(page); > > pfn = page_to_pfn(page); > - ret = vmf_insert_pfn(vma, vmf->address, pfn); > > - out: > + if (folio_test_pmd_mappable(folio)) > + ret = drm_gem_shmem_try_insert_pfn_pmd(vmf, pfn); > + if (ret != VM_FAULT_NOPAGE) > + ret = vmf_insert_pfn(vma, vmf->address, pfn); > + > +out: > dma_resv_unlock(obj->resv); > > return ret;