x86/mm: Avoid overlap the fixmap area on i386
It is a problem when configuring high memory off where the
vmalloc reserve area could end up overlapping the early_ioremap
fixmap area on i386.
The ordering of the VMALLOC_RESERVE space is:
FIXADDR_TOP
fixed_addresses
FIXADDR_START
early_ioremap fixed addresses
FIXADDR_BOOT_START
Persistent kmap area
PKMAP_BASE
VMALLOC_END
Vmalloc area
VMALLOC_START
high_memory
The available address we can use is lower than
FIXADDR_BOOT_START. So we will set the kmap boundary below the
FIXADDR_BOOT_START, if we configure high memory.
If we configure high memory, the vmalloc reserve area should
end up to PKMAP_BASE, otherwise should end up to
FIXADDR_BOOT_START.
Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/6B680A9E-6CE9-4C96-934B-CB01DCB58278@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Minfei Huang