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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4AAE1C433EF for ; Wed, 20 Oct 2021 15:46:40 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 0F7C0610E6 for ; Wed, 20 Oct 2021 15:46:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0F7C0610E6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BAB776E4B7; Wed, 20 Oct 2021 15:46:32 +0000 (UTC) Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4C2D26E30C; Wed, 20 Oct 2021 15:46:31 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10143"; a="289658761" X-IronPort-AV: E=Sophos;i="5.87,167,1631602800"; d="scan'208";a="289658761" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2021 08:40:07 -0700 X-IronPort-AV: E=Sophos;i="5.87,167,1631602800"; d="scan'208";a="718997241" Received: from bsieu-mobl1.amr.corp.intel.com (HELO ldmartin-desk2) ([10.254.14.221]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2021 08:40:06 -0700 Date: Wed, 20 Oct 2021 08:40:05 -0700 From: Lucas De Marchi To: Christoph Hellwig Cc: Andrew Morton , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Peter Zijlstra , Daniel Vetter , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Chris Wilson , linux-mm@kvack.org, matthew.auld@intel.com Message-ID: <20211020154005.uk6u4ovcmlhpyubk@ldmartin-desk2> References: <20210326055505.1424432-1-hch@lst.de> <20210326055505.1424432-3-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20210326055505.1424432-3-hch@lst.de> Subject: Re: [Intel-gfx] [PATCH 2/4] mm: add a io_mapping_map_user helper X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Fri, Mar 26, 2021 at 06:55:03AM +0100, Christoph Hellwig wrote: >Add a helper that calls remap_pfn_range for an struct io_mapping, relying >on the pgprot pre-validation done when creating the mapping instead of >doing it at runtime. > >Signed-off-by: Christoph Hellwig >--- > include/linux/io-mapping.h | 3 +++ > mm/Kconfig | 3 +++ > mm/Makefile | 1 + > mm/io-mapping.c | 29 +++++++++++++++++++++++++++++ > 4 files changed, 36 insertions(+) > create mode 100644 mm/io-mapping.c > >diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h >index c093e81310a9b3..e9743cfd858527 100644 >--- a/include/linux/io-mapping.h >+++ b/include/linux/io-mapping.h >@@ -220,3 +220,6 @@ io_mapping_free(struct io_mapping *iomap) > } > > #endif /* _LINUX_IO_MAPPING_H */ >+ >+int io_mapping_map_user(struct io_mapping *iomap, struct vm_area_struct *vma, >+ unsigned long addr, unsigned long pfn, unsigned long size); I'm not sure what exactly brought me to check this, but while debugging I noticed this outside the header guard. But then after some more checks I saw nothing actually selects CONFIG_IO_MAPPING because commit using it was reverted in commit 0e4fe0c9f2f9 ("Revert "i915: use io_mapping_map_user"") Is this something we want to re-attempt moving to mm/ ? thanks Lucas De Marchi >diff --git a/mm/Kconfig b/mm/Kconfig >index 24c045b24b9506..6b0f2cfbfac0f3 100644 >--- a/mm/Kconfig >+++ b/mm/Kconfig >@@ -872,4 +872,7 @@ config MAPPING_DIRTY_HELPERS > config KMAP_LOCAL > bool > >+# struct io_mapping based helper. Selected by drivers that need them >+config IO_MAPPING >+ bool > endmenu >diff --git a/mm/Makefile b/mm/Makefile >index 72227b24a61688..c0135e385984bb 100644 >--- a/mm/Makefile >+++ b/mm/Makefile >@@ -120,3 +120,4 @@ obj-$(CONFIG_MEMFD_CREATE) += memfd.o > obj-$(CONFIG_MAPPING_DIRTY_HELPERS) += mapping_dirty_helpers.o > obj-$(CONFIG_PTDUMP_CORE) += ptdump.o > obj-$(CONFIG_PAGE_REPORTING) += page_reporting.o >+obj-$(CONFIG_IO_MAPPING) += io-mapping.o >diff --git a/mm/io-mapping.c b/mm/io-mapping.c >new file mode 100644 >index 00000000000000..01b3627999304e >--- /dev/null >+++ b/mm/io-mapping.c >@@ -0,0 +1,29 @@ >+// SPDX-License-Identifier: GPL-2.0-only >+ >+#include >+#include >+ >+/** >+ * io_mapping_map_user - remap an I/O mapping to userspace >+ * @iomap: the source io_mapping >+ * @vma: user vma to map to >+ * @addr: target user address to start at >+ * @pfn: physical address of kernel memory >+ * @size: size of map area >+ * >+ * Note: this is only safe if the mm semaphore is held when called. >+ */ >+int io_mapping_map_user(struct io_mapping *iomap, struct vm_area_struct *vma, >+ unsigned long addr, unsigned long pfn, unsigned long size) >+{ >+ vm_flags_t expected_flags = VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; >+ >+ if (WARN_ON_ONCE((vma->vm_flags & expected_flags) != expected_flags)) >+ return -EINVAL; >+ >+ /* We rely on prevalidation of the io-mapping to skip track_pfn(). */ >+ return remap_pfn_range_notrack(vma, addr, pfn, size, >+ __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) | >+ (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK))); >+} >+EXPORT_SYMBOL_GPL(io_mapping_map_user); >-- >2.30.1 > >_______________________________________________ >Intel-gfx mailing list >Intel-gfx@lists.freedesktop.org >https://lists.freedesktop.org/mailman/listinfo/intel-gfx >