Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965339AbcLVKYK (ORCPT ); Thu, 22 Dec 2016 05:24:10 -0500 Received: from mail-wj0-f196.google.com ([209.85.210.196]:36168 "EHLO mail-wj0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760771AbcLVKYD (ORCPT ); Thu, 22 Dec 2016 05:24:03 -0500 From: Nicolai Stange To: Matt Fleming Cc: Ard Biesheuvel , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, =?UTF-8?q?Mika=20Penttil=C3=A4?= , Nicolai Stange Subject: [PATCH v2 2/2] efi: efi_mem_reserve(): don't reserve through memblock after mm_init() Date: Thu, 22 Dec 2016 11:23:40 +0100 Message-Id: <20161222102340.2689-2-nicstange@gmail.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20161222102340.2689-1-nicstange@gmail.com> References: <20161222102340.2689-1-nicstange@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1853 Lines: 50 Before invoking the arch specific handler, efi_mem_reserve() reserves the given memory region through memblock. efi_mem_reserve() can get called after mm_init() though -- through efi_bgrt_init(), for example. After mm_init(), memblock is dead and should not be used anymore. Let efi_mem_reserve() check whether memblock is dead and not do the reservation if so. Emit a warning from the generic efi_arch mem_reserve() in this case: if the architecture doesn't provide any other means of registering the region as reserved, the operation would be a nop. Fixes: 4bc9f92e64c8 ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data") Signed-off-by: Nicolai Stange --- Changes to v1: Change the if condition from slab_is_available() to !slab_is_available as pointed out by Mika Penttilä at http://lkml.kernel.org/r/c7bf34ba-56f0-8346-36d1-7069f2115dcf@nextfour.com drivers/firmware/efi/efi.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 92914801e388..158a8df2f4af 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -403,7 +403,10 @@ u64 __init efi_mem_desc_end(efi_memory_desc_t *md) return end; } -void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {} +void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) +{ + WARN(slab_is_available(), "efi_mem_reserve() has no effect"); +} /** * efi_mem_reserve - Reserve an EFI memory region @@ -419,7 +422,7 @@ void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {} */ void __init efi_mem_reserve(phys_addr_t addr, u64 size) { - if (!memblock_is_region_reserved(addr, size)) + if (!slab_is_available() && !memblock_is_region_reserved(addr, size)) memblock_reserve(addr, size); /* -- 2.11.0