x86/mce: Provide a lockless memory pool to save error records

printk() is not safe to use in MCE context. Add a lockless
memory allocator pool to save error records in MCE context.
Those records will be issued later, in a printk-safe context.
The idea is inspired by the APEI/GHES driver.

We're very conservative and allocate only two pages for it but
since we're going to use those pages throughout the system's
lifetime, we allocate them statically to avoid early boot time
allocation woes.

Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
[ Rewrite. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1439396985-12812-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b3a1a5d77d92..06dbb5da90c6 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -955,6 +955,7 @@ config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 
 config X86_MCE
         bool "Machine Check / overheating reporting"
+        select GENERIC_ALLOCATOR
         default y
         ---help---
           Machine Check support allows the processor to notify the