From: Alexandre Courbot Date: Fri, 7 Feb 2014 04:35:02 +0000 (+0900) Subject: ARM: trusted_foundations: fallback when TF support is missing X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=c3af6d68550c50597be25f29bc1cb742c10c63c0;p=linux-beck.git ARM: trusted_foundations: fallback when TF support is missing When Trusted Foundations is detected as present on the system, but Trusted Foundations support is not built into the kernel, the kernel used to issue a panic very early during boot, leaving little clue to the user as to what is going wrong. It turns out that even without TF support built-in, the kernel can boot on a TF-enabled system provided that SMP and cpuidle are disabled. This patch does this and continue booting on one CPU, leaving the user with a usable (however degraded) system. Signed-off-by: Alexandre Courbot Acked-by: Olof Johansson Signed-off-by: Stephen Warren --- diff --git a/arch/arm/include/asm/trusted_foundations.h b/arch/arm/include/asm/trusted_foundations.h index 997862fd5d77..b5f7705abcb0 100644 --- a/arch/arm/include/asm/trusted_foundations.h +++ b/arch/arm/include/asm/trusted_foundations.h @@ -30,6 +30,8 @@ #include #include #include +#include +#include struct trusted_foundations_platform_data { unsigned int version_major; @@ -47,10 +49,13 @@ static inline void register_trusted_foundations( struct trusted_foundations_platform_data *pd) { /* - * If we try to register TF, this means the system needs it to continue. - * Its absence if thus a fatal error. + * If the system requires TF and we cannot provide it, continue booting + * but disable features that cannot be provided. */ - panic("No support for Trusted Foundations, stopping...\n"); + pr_err("No support for Trusted Foundations, continuing in degraded mode.\n"); + pr_err("Secondary processors as well as CPU PM will be disabled.\n"); + setup_max_cpus = 0; + cpu_idle_poll_ctrl(true); } static inline void of_register_trusted_foundations(void)