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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 475C8C43467 for ; Sat, 17 Oct 2020 23:15:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13CA221582 for ; Sat, 17 Oct 2020 23:15:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602976513; bh=K3HEs8+uulq4zNfuTiInv60TjFABgs0nKl3bYhfpbnk=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=n6UU2rO/tCfZDmk71aKciFZTRI+rXGClOfe8e9ltnsIWn1JyBoekc+IIHG5B2gyNV fEwARxcuTrggT0nUdg8ILf4yq0+hMQoReKHx3rdJLabF3yovhQZc/TG5H4bLFkZiOB 3DPj5dhe1nio1R3f8yNxhkCulW558+MVO+1drfYk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439912AbgJQXPM (ORCPT ); Sat, 17 Oct 2020 19:15:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:49054 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2439878AbgJQXPM (ORCPT ); Sat, 17 Oct 2020 19:15:12 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C976E20EDD; Sat, 17 Oct 2020 23:15:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602976511; bh=K3HEs8+uulq4zNfuTiInv60TjFABgs0nKl3bYhfpbnk=; h=Date:From:To:Subject:In-Reply-To:From; b=fDsFUAhF+RhMEG5bHGWb2ejWWvVUbSPWj3KmK13UvgUlvbqHhzXf7BrFdt/BGM345 NTbkVZq6ib3mJAXsfmud1/Ql86g5DEWUpofUoJraF+2i/UfhfuHJhLWo7UUjfbVpCE ZV19AYvmxX+Ucna3NLZelMPqzrlVqMy7H/qZWkXU= Date: Sat, 17 Oct 2020 16:15:10 -0700 From: Andrew Morton To: akpm@linux-foundation.org, boris.ostrovsky@oracle.com, chris@chris-wilson.co.uk, hch@lst.de, jani.nikula@linux.intel.com, jgross@suse.com, joonas.lahtinen@linux.intel.com, linux-mm@kvack.org, matthew.auld@intel.com, minchan@kernel.org, mm-commits@vger.kernel.org, ngupta@vflare.org, peterz@infradead.org, rodrigo.vivi@intel.com, sstabellini@kernel.org, torvalds@linux-foundation.org, tvrtko.ursulin@intel.com, urezki@gmail.com, willy@infradead.org Subject: [patch 29/40] mm: add a vmap_pfn function Message-ID: <20201017231510.EY4VsFGOW%akpm@linux-foundation.org> In-Reply-To: <20201017161314.88890b87fae7446ccc13c902@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Christoph Hellwig Subject: mm: add a vmap_pfn function Add a proper helper to remap PFNs into kernel virtual space so that drivers don't have to abuse alloc_vm_area and open coded PTE manipulation for it. Link: https://lkml.kernel.org/r/20201002122204.1534411-4-hch@lst.de Signed-off-by: Christoph Hellwig Cc: Boris Ostrovsky Cc: Chris Wilson Cc: Jani Nikula Cc: Joonas Lahtinen Cc: Juergen Gross Cc: Matthew Auld Cc: "Matthew Wilcox (Oracle)" Cc: Minchan Kim Cc: Nitin Gupta Cc: Peter Zijlstra Cc: Rodrigo Vivi Cc: Stefano Stabellini Cc: Tvrtko Ursulin Cc: Uladzislau Rezki (Sony) Signed-off-by: Andrew Morton --- include/linux/vmalloc.h | 1 mm/Kconfig | 3 ++ mm/vmalloc.c | 45 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 49 insertions(+) --- a/include/linux/vmalloc.h~mm-add-a-vmap_pfn-function +++ a/include/linux/vmalloc.h @@ -122,6 +122,7 @@ extern void vfree_atomic(const void *add extern void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot); +void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot); extern void vunmap(const void *addr); extern int remap_vmalloc_range_partial(struct vm_area_struct *vma, --- a/mm/Kconfig~mm-add-a-vmap_pfn-function +++ a/mm/Kconfig @@ -816,6 +816,9 @@ config DEVICE_PRIVATE memory; i.e., memory that is only accessible from the device (or group of devices). You likely also want to select HMM_MIRROR. +config VMAP_PFN + bool + config FRAME_VECTOR bool --- a/mm/vmalloc.c~mm-add-a-vmap_pfn-function +++ a/mm/vmalloc.c @@ -2413,6 +2413,51 @@ void *vmap(struct page **pages, unsigned } EXPORT_SYMBOL(vmap); +#ifdef CONFIG_VMAP_PFN +struct vmap_pfn_data { + unsigned long *pfns; + pgprot_t prot; + unsigned int idx; +}; + +static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private) +{ + struct vmap_pfn_data *data = private; + + if (WARN_ON_ONCE(pfn_valid(data->pfns[data->idx]))) + return -EINVAL; + *pte = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot)); + return 0; +} + +/** + * vmap_pfn - map an array of PFNs into virtually contiguous space + * @pfns: array of PFNs + * @count: number of pages to map + * @prot: page protection for the mapping + * + * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns + * the start address of the mapping. + */ +void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot) +{ + struct vmap_pfn_data data = { .pfns = pfns, .prot = pgprot_nx(prot) }; + struct vm_struct *area; + + area = get_vm_area_caller(count * PAGE_SIZE, VM_IOREMAP, + __builtin_return_address(0)); + if (!area) + return NULL; + if (apply_to_page_range(&init_mm, (unsigned long)area->addr, + count * PAGE_SIZE, vmap_pfn_apply, &data)) { + free_vm_area(area); + return NULL; + } + return area->addr; +} +EXPORT_SYMBOL_GPL(vmap_pfn); +#endif /* CONFIG_VMAP_PFN */ + static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot, int node) { _