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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 55771C7618F for ; Tue, 16 Jul 2019 16:58:08 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 2AA5D205ED for ; Tue, 16 Jul 2019 16:58:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="cAQz1ZRa"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=soleen.com header.i=@soleen.com header.b="VxsqpYci" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2AA5D205ED Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=soleen.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Cc:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ZeqmXoZanzimYxLPc6BwczdjAjBbl4jb6FJTaJ7s4p8=; b=cAQz1ZRaj4LYLM wDUXPTkS1UucgGFWlNZxEL6BNJBchZCmg02J232QvPWjhHPC0dJ8v8KKFocqf+tg+8hLeWpai620X vQuskJFRphLG2niPY7ZbyRkkWdR8UJNvRbsspXZ0tWWoKj3nNm7crhkGa1+0k2uHITX8MHK+w5rY7 pxmHI45+J9vG2+SQXI2hqeY05d+FJPZjxoW0/RyU8GeOi8OaEdGQvk3vMDUVj6P0FxY5vZz/WYCF5 M1IrrGd8Uvz+Er/QtpKhKyB2uVrQ1QZ9Dui0ocec63UUTPL81t91Fk7toi3QX9sn7+z9EwR7ipSWI j2Bhmv+7Pk8muXMmVT0A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hnQmA-00060I-CS; Tue, 16 Jul 2019 16:58:02 +0000 Received: from mail-qk1-x743.google.com ([2607:f8b0:4864:20::743]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hnQkx-00053s-R2 for linux-arm-kernel@lists.infradead.org; Tue, 16 Jul 2019 16:56:51 +0000 Received: by mail-qk1-x743.google.com with SMTP id a27so15147257qkk.5 for ; Tue, 16 Jul 2019 09:56:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=5D8mlvVawCjEgddelLAduhKCIQh0CPiyGgQp446bGsE=; b=VxsqpYcitDOLAtpg1Jls5stspr2tgCl0PGz2J1Z817sVMFGcuo/roOKCaavlnYeATr jU6YTyCAGZdlqYJ/jAs5NtTWvKRhJMmjirZcQE+Iucd/gw8X+OddfHUsoLTZ8sMYS/3c ve/dJt/iFA5AYuQOfT8c21qt+EjJ268NVoprOSpHjzlTm8z+pnUOXbMTcz0Wg8M1xsbA VBgDOJX8ALLB3Bwq5D6MxZszG6wXjnwReOXDz93IVfYtFF6y2ddjcZH7FZb1wO7Km03h cbJW0XLKEZ9fLZEWNShJLv0RqMAIYlex+//VRDwPg40RaMG+UAF8sT158AGKpfuS8DXz p6jw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=5D8mlvVawCjEgddelLAduhKCIQh0CPiyGgQp446bGsE=; b=LW/8/i0ZxKoMhX6DjTzpSQUmxBqqCroU534kFZChh5AJf/L2WFn4oZus5Mwp85Pi83 tT3l0vpmS6FS+GK7mhxe+xIagFJmEwV5V8U5ImeTd31Uu9CXkaoMKsnacg3HdCUs3AEy l0AZMeR8qxDuVH+N5P4AKXeKfwgMl/0SIA/+LYdgYlQg7zDelFei2/sYKKg6X4dC4KpH u4LEls75f+ShOUx4mzEgmzFrbkZaqmNCMKpfgjWDFfUSZQmKJcykJx5IZEd8iKqyGFqX um/ZpPaOtT1HgYlRpb2LEH1qHHBzkrxzzQCWEpJcNatT3xwf//zc48Gb7/eg9Hdw3Ziw uGbg== X-Gm-Message-State: APjAAAXsXs3iQMeznH34n0ckrxt1tFqO/RC3En6qfAfRACzXPnJHOpOE LL5V9A5nlR+JLGAr1HmsfEg= X-Google-Smtp-Source: APXvYqzvQ0JQLAGkRNhRdaqxRVuO7Hvjn0EZosyRHwPjvqeoogbj3QaW6JZ3XDhFK6dpEIze4WbX/w== X-Received: by 2002:a05:620a:69c:: with SMTP id f28mr22093343qkh.274.1563296206729; Tue, 16 Jul 2019 09:56:46 -0700 (PDT) Received: from localhost.localdomain (c-73-69-118-222.hsd1.nh.comcast.net. [73.69.118.222]) by smtp.gmail.com with ESMTPSA id f20sm8519538qkh.15.2019.07.16.09.56.45 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Tue, 16 Jul 2019 09:56:46 -0700 (PDT) From: Pavel Tatashin To: pasha.tatashin@soleen.com, jmorris@namei.org, sashal@kernel.org, ebiederm@xmission.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, corbet@lwn.net, catalin.marinas@arm.com, will@kernel.org, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [RFC v1 3/4] arm64, kexec: add kexec's own identity page table Date: Tue, 16 Jul 2019 12:56:40 -0400 Message-Id: <20190716165641.6990-4-pasha.tatashin@soleen.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190716165641.6990-1-pasha.tatashin@soleen.com> References: <20190716165641.6990-1-pasha.tatashin@soleen.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190716_095647_875357_5DD325D9 X-CRM114-Status: GOOD ( 14.88 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Allocate and configure identity page table to be used for kexec reboot. Note, for now we still have MMU disabled during kernel relocation phase, so this table is still used the same as idmap_pg_dir was used. Signed-off-by: Pavel Tatashin --- arch/arm64/kernel/machine_kexec.c | 78 ++++++++++++++++++++++++++++++- 1 file changed, 76 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index f4565eb01d09..60433c264178 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include @@ -20,6 +21,7 @@ #include #include #include +#include #include "cpu-reset.h" @@ -55,6 +57,77 @@ static void _kexec_image_info(const char *func, int line, } } +/* Allocates pages for kexec page table */ +static void *kexec_pgtable_alloc(void *arg) +{ + struct kimage *kimage = (struct kimage *)arg; + struct page *page = kimage_alloc_control_pages(kimage, 0); + + if (!page) + return NULL; + + return page_address(page); +} + +/* + * Create identity mapped page table for kexec purposes. The flags that are used + * in this page table are the same as what is set in __create_page_tables. The + * page table is needed for performance reasons. Without it, kernel relocation + * is rather slow, because when MMU is off, d-caching is disabled as well. + */ +static int +kexec_create_pgtable(struct kimage *kimage) +{ + void *pgd_page = kexec_pgtable_alloc(kimage); + phys_addr_t kexec_pgtable; + int rv, i; + struct memblock_region *reg; + struct ident_map_info info = { + .alloc_pgt_page = kexec_pgtable_alloc, + .alloc_arg = kimage, + .page_flags = PMD_SECT_VALID | PMD_SECT_AF | PMD_SECT_S | + PMD_ATTRINDX(MT_NORMAL), + .offset = 0, + .pud_pages = false, + }; + + if (!pgd_page) + return -ENOMEM; + + clear_page(pgd_page); + kexec_pgtable = __pa(pgd_page); + + for_each_memblock(memory, reg) { + phys_addr_t mstart = reg->base; + phys_addr_t mend = reg->base + reg->size; + + rv = ident_map_pgd_populate(&info, kexec_pgtable, mstart, mend); + if (rv) + return rv; + } + + /* + * It is possible new kernel knows of some physical addresses that this + * kernel does not know: for example a different device tree might + * provide information of a memory region, or memory could have been + * reduced via mem= kernel parameter. + * This is why also unconditionally map new kernel segments, even though + * most likely this is redundant. + */ + for (i = 0; i < kimage->nr_segments; i++) { + phys_addr_t mstart = kimage->segment[i].mem; + phys_addr_t mend = mstart + kimage->segment[i].memsz; + + rv = ident_map_pgd_populate(&info, kexec_pgtable, mstart, mend); + if (rv) + return rv; + } + + kimage->arch.kexec_pgtable = pgd_page; + + return 0; +} + void machine_kexec_cleanup(struct kimage *kimage) { /* Empty routine needed to avoid build errors. */ @@ -70,6 +143,7 @@ void machine_kexec_cleanup(struct kimage *kimage) int machine_kexec_prepare(struct kimage *kimage) { void *reloc_buf = page_address(kimage->control_code_page); + int rv; if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) { pr_err("Can't kexec: CPUs are stuck in the kernel.\n"); @@ -84,10 +158,10 @@ int machine_kexec_prepare(struct kimage *kimage) arm64_relocate_new_kernel_size); kimage->arch.relocate_kern = reloc_buf; - kimage->arch.kexec_pgtable = lm_alias(idmap_pg_dir); + rv = kexec_create_pgtable(kimage); kexec_image_info(kimage); - return 0; + return rv; } /** -- 2.22.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel