From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linutronix.de (193.142.43.55:993) by crypto-ml.lab.linutronix.de with IMAP4-SSL for ; 01 Nov 2019 20:39:19 -0000 Received: from youngberry.canonical.com ([91.189.89.112]) by Galois.linutronix.de with esmtps (TLS1.2:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1iQdhV-0004uU-R8 for speck@linutronix.de; Fri, 01 Nov 2019 21:39:18 +0100 Received: from 2.general.tyhicks.us.vpn ([10.172.64.53] helo=sec) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1iQdhP-0006lu-3Y for speck@linutronix.de; Fri, 01 Nov 2019 20:39:11 +0000 Date: Fri, 1 Nov 2019 20:39:09 +0000 From: Tyler Hicks Subject: [MODERATED] [PATCH v2] NX build fixup Message-ID: <20191101203859.GA10998@sec> References: <20191101163150.z7qlfwp6vai3ttp5@treble> MIME-Version: 1.0 In-Reply-To: <20191101163150.z7qlfwp6vai3ttp5@treble> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: speck@linutronix.de List-ID: From: Tyler Hicks Subject: [PATCH] cpu/speculation: Uninline and export CPU mitigations helpers A kernel module may need to check the value of the "mitigations=" kernel command line parameter as part of its setup when the module needs to perform software mitigations for a CPU flaw. Uninline and export the helper functions surrounding the cpu_mitigations enum to allow for their usage from a module. Lastly, privatize the enum and cpu_mitigations variable since the value of cpu_mitigations can be checked with the exported helper functions. Signed-off-by: Tyler Hicks --- include/linux/cpu.h | 25 ++----------------------- kernel/cpu.c | 27 ++++++++++++++++++++++++++- 2 files changed, 28 insertions(+), 24 deletions(-) diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 2a093434e975..bc6c879bd110 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -218,28 +218,7 @@ static inline int cpuhp_smt_enable(void) { return 0; } static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; } #endif -/* - * These are used for a global "mitigations=" cmdline option for toggling - * optional CPU mitigations. - */ -enum cpu_mitigations { - CPU_MITIGATIONS_OFF, - CPU_MITIGATIONS_AUTO, - CPU_MITIGATIONS_AUTO_NOSMT, -}; - -extern enum cpu_mitigations cpu_mitigations; - -/* mitigations=off */ -static inline bool cpu_mitigations_off(void) -{ - return cpu_mitigations == CPU_MITIGATIONS_OFF; -} - -/* mitigations=auto,nosmt */ -static inline bool cpu_mitigations_auto_nosmt(void) -{ - return cpu_mitigations == CPU_MITIGATIONS_AUTO_NOSMT; -} +extern bool cpu_mitigations_off(void); +extern bool cpu_mitigations_auto_nosmt(void); #endif /* _LINUX_CPU_H_ */ diff --git a/kernel/cpu.c b/kernel/cpu.c index fc28e17940e0..e2cad3ee2ead 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -2373,7 +2373,18 @@ void __init boot_cpu_hotplug_init(void) this_cpu_write(cpuhp_state.state, CPUHP_ONLINE); } -enum cpu_mitigations cpu_mitigations __ro_after_init = CPU_MITIGATIONS_AUTO; +/* + * These are used for a global "mitigations=" cmdline option for toggling + * optional CPU mitigations. + */ +enum cpu_mitigations { + CPU_MITIGATIONS_OFF, + CPU_MITIGATIONS_AUTO, + CPU_MITIGATIONS_AUTO_NOSMT, +}; + +static enum cpu_mitigations cpu_mitigations __ro_after_init = + CPU_MITIGATIONS_AUTO; static int __init mitigations_parse_cmdline(char *arg) { @@ -2390,3 +2401,17 @@ static int __init mitigations_parse_cmdline(char *arg) return 0; } early_param("mitigations", mitigations_parse_cmdline); + +/* mitigations=off */ +bool cpu_mitigations_off(void) +{ + return cpu_mitigations == CPU_MITIGATIONS_OFF; +} +EXPORT_SYMBOL_GPL(cpu_mitigations_off); + +/* mitigations=auto,nosmt */ +bool cpu_mitigations_auto_nosmt(void) +{ + return cpu_mitigations == CPU_MITIGATIONS_AUTO_NOSMT; +} +EXPORT_SYMBOL_GPL(cpu_mitigations_auto_nosmt); -- 2.17.1