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ARM: trusted_foundations: fallback when TF support is missing

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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 <acourbot@nvidia.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
This commit is contained in:
Alexandre Courbot 2014-02-07 13:35:02 +09:00 committed by Stephen Warren
parent a553b7f536
commit c3af6d6855
1 changed files with 8 additions and 3 deletions
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11
arch/arm/include/asm/trusted_foundations.h
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@ -30,6 +30,8 @@
#include <linux/printk.h>
#include <linux/bug.h>
#include <linux/of.h>
#include <linux/cpu.h>
#include <linux/smp.h>
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)