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=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 D27CAC433ED for ; Tue, 11 May 2021 17:41:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9729661378 for ; Tue, 11 May 2021 17:41:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231874AbhEKRm4 (ORCPT ); Tue, 11 May 2021 13:42:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:56440 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231502AbhEKRmx (ORCPT ); Tue, 11 May 2021 13:42:53 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CB623613C3; Tue, 11 May 2021 17:41:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620754906; bh=/y24nuaxa3ahuPNyDsX+pUzlA7FV7W7+VmIh+phhWv4=; h=From:To:Cc:Subject:Date:From; b=aLZ+AS1gA5cMZ8RVBKoIqDIZcfszquu/ab7Ff6SE7rkRnIPa1yGD2Wv1/kGeFyZ2s KTKehYlE2EUwCF9G4rnoyYlJ7fZKBBdXEwh0VBqARwd8gn0iA0AUJcR8NWIxsiD36S hnENri5ucimFD/OOKF3SQJ3xLPKR7GMFxJr0mH5IYSAhPVEgIJlYKyxepqOeINvD6B hbzLGO4L4D/Vzw2gjBofuadHnoqU0rF5Vn+NF0QYlcYB2fM0CVcCtM2y9eg5oROn8G X2w6XtAJQagQb7QGiiHjRpxbG3HmR9xROVxxsx5qW0OHbSO3sp4gcYF5EfVvEemxZA cpgazArg1UgDA== From: Stefano Stabellini To: xen-devel@lists.xenproject.org Cc: sstabellini@kernel.org, hch@lst.de, linux-kernel@vger.kernel.org, Stefano Stabellini , boris.ostrovsky@oracle.com, jgross@suse.com Subject: [PATCH 2/2] xen/swiotlb: check if the swiotlb has already been initialized Date: Tue, 11 May 2021 10:41:42 -0700 Message-Id: <20210511174142.12742-2-sstabellini@kernel.org> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stefano Stabellini xen_swiotlb_init calls swiotlb_late_init_with_tbl, which fails with -ENOMEM if the swiotlb has already been initialized. Add an explicit check io_tlb_default_mem != NULL at the beginning of xen_swiotlb_init. If the swiotlb is already initialized print a warning and return -EEXIST. On x86, the error propagates. On ARM, we don't actually need a special swiotlb buffer (yet), any buffer would do. So ignore the error and continue. CC: boris.ostrovsky@oracle.com CC: jgross@suse.com Signed-off-by: Stefano Stabellini --- arch/arm/xen/mm.c | 8 +++++++- drivers/xen/swiotlb-xen.c | 5 +++++ 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index 223b1151fd7d..a7e54a087b80 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -138,9 +138,15 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) static int __init xen_mm_init(void) { struct gnttab_cache_flush cflush; + int rc; + if (!xen_swiotlb_detect()) return 0; - xen_swiotlb_init(); + + rc = xen_swiotlb_init(); + /* we can work with the default swiotlb */ + if (rc < 0 && rc != -EEXIST) + return rc; cflush.op = 0; cflush.a.dev_bus_addr = 0; diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 4c89afc0df62..6412d59ce7f8 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -164,6 +164,11 @@ int __ref xen_swiotlb_init(void) int rc = -ENOMEM; char *start; + if (io_tlb_default_mem != NULL) { + printk(KERN_WARNING "Xen-SWIOTLB: swiotlb buffer already initialized\n"); + return -EEXIST; + } + retry: m_ret = XEN_SWIOTLB_ENOMEM; order = get_order(bytes); -- 2.17.1