Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753856AbbHUN16 (ORCPT ); Fri, 21 Aug 2015 09:27:58 -0400 Received: from mail-wi0-f182.google.com ([209.85.212.182]:35300 "EHLO mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753797AbbHUN14 (ORCPT ); Fri, 21 Aug 2015 09:27:56 -0400 Date: Fri, 21 Aug 2015 14:27:53 +0100 From: Matt Fleming To: "Lee, Chun-Yi" Cc: linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, linux-pm@vger.kernel.org, "Rafael J. Wysocki" , Matthew Garrett , Len Brown , Pavel Machek , Josh Boyer , Vojtech Pavlik , Matt Fleming , Jiri Kosina , "H. Peter Anvin" , Ingo Molnar , "Lee, Chun-Yi" Subject: Re: [PATCH v2 09/16] PM / hibernate: Reserve hibernation key and erase footprints Message-ID: <20150821132753.GC3310@codeblueprint.co.uk> References: <1439273796-25359-1-git-send-email-jlee@suse.com> <1439273796-25359-10-git-send-email-jlee@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1439273796-25359-10-git-send-email-jlee@suse.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4640 Lines: 142 On Tue, 11 Aug, at 02:16:29PM, Lee, Chun-Yi wrote: > Add handler to parse the setup data that carrying hibernation key, it > reserves hibernation key by memblock then copies key to a allocated page > in later initcall stage. > > And for erasing footprints, the codes in this patch remove setup > data that carried hibernation key, and clean the memory space that > reserved by memblock. > > Reviewed-by: Jiri Kosina > Tested-by: Jiri Kosina > Signed-off-by: Lee, Chun-Yi > --- > arch/x86/include/asm/suspend.h | 4 +++ > arch/x86/kernel/setup.c | 21 ++++++++++- > arch/x86/power/Makefile | 1 + > arch/x86/power/hibernate_keys.c | 78 +++++++++++++++++++++++++++++++++++++++++ > kernel/power/power.h | 5 +++ > 5 files changed, 108 insertions(+), 1 deletion(-) > create mode 100644 arch/x86/power/hibernate_keys.c [...] > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c > index 80f874b..b345359 100644 > --- a/arch/x86/kernel/setup.c > +++ b/arch/x86/kernel/setup.c > @@ -112,6 +112,8 @@ > #include > #include > > +#include > + > /* > * max_low_pfn_mapped: highest direct mapped pfn under 4GB > * max_pfn_mapped: highest direct mapped pfn over 4GB > @@ -425,10 +427,22 @@ static void __init reserve_initrd(void) > } > #endif /* CONFIG_BLK_DEV_INITRD */ > > +static void __init remove_setup_data(u64 pa_prev, u64 pa_next) > +{ > + struct setup_data *data; > + > + if (pa_prev) { > + data = early_memremap(pa_prev, sizeof(*data)); > + data->next = pa_next; > + early_iounmap(data, sizeof(*data)); This should be early_memunmap for consistency(). > diff --git a/arch/x86/power/hibernate_keys.c b/arch/x86/power/hibernate_keys.c > new file mode 100644 > index 0000000..357dc0e > --- /dev/null > +++ b/arch/x86/power/hibernate_keys.c > @@ -0,0 +1,78 @@ > +/* Hibernation keys handler > + * > + * Copyright (C) 2015 Lee, Chun-Yi > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU General Public Licence > + * as published by the Free Software Foundation; either version > + * 2 of the Licence, or (at your option) any later version. > + */ > + > +#include > +#include > +#include > +#include > + > +/* physical address of hibernation keys from boot params */ > +static u64 keys_phys_addr; > + > +/* A page used to keep hibernation keys */ > +static struct hibernation_keys *hibernation_keys; > + > +void __init parse_hibernation_keys(u64 phys_addr, u32 data_len) > +{ > + struct setup_data *hibernation_setup_data; > + > + /* Reserve keys memory, will copy and erase in init_hibernation_keys() */ > + keys_phys_addr = phys_addr + sizeof(struct setup_data); > + memblock_reserve(keys_phys_addr, sizeof(struct hibernation_keys)); > + > + /* clear hibernation_data */ > + hibernation_setup_data = early_memremap(phys_addr, data_len); > + if (!hibernation_setup_data) > + return; > + > + memset(hibernation_setup_data, 0, sizeof(struct setup_data)); Why is this necessary? You're only clearing the struct setup_data fields and you unlinked this setup_data entry in remove_setup_data() anyway. > + early_memunmap(hibernation_setup_data, data_len); > +} > + > +int get_hibernation_key(u8 **hkey) > +{ > + if (!hibernation_keys) > + return -ENODEV; > + > + if (!hibernation_keys->hkey_status) > + *hkey = hibernation_keys->hibernation_key; > + > + return hibernation_keys->hkey_status; > +} For global functions like this it's usually much preferred to prefix the name with the subsystem, i.e. hibernation_get_key(). > +static int __init init_hibernation_keys(void) > +{ > + struct hibernation_keys *keys; > + int ret = 0; > + > + if (!keys_phys_addr) > + return -ENODEV; > + > + keys = early_memremap(keys_phys_addr, sizeof(struct hibernation_keys)); > + > + /* Copy hibernation keys to a allocated page */ > + hibernation_keys = (struct hibernation_keys *)get_zeroed_page(GFP_KERNEL); > + if (hibernation_keys) { > + *hibernation_keys = *keys; > + } else { > + pr_err("PM: Allocate hibernation keys page failed\n"); > + ret = -ENOMEM; > + } It seems overkill to allocate an entire page for 28 bytes of data. -- Matt Fleming, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/