Re: [PATCH] x86, mm: Reserver some memory for bootmem allocator for NO_BOOTMEM

From: Thomas Gleixner
Date: Sat Sep 15 2018 - 13:28:18 EST


On Sun, 16 Sep 2018, Feng Tang wrote:
> I have tried to change some header files incluing fixmap.h/apicdef.h/
> vsyscall.h, and most of the .c files compile fine now, but I can not
> use the "__end_of_permanent_fixed_addresses" in head_64.S as it is a
> enum type, and could not be recognized by assembly code.

Hrmm. I did not think about the enum. So we have two possibilities:

1) Have some preprocessing which provides the info for the assembler

2) Use a constant for the number of PMDs which is defined in a header and
then compile time checked against the size of the fixmap in a C-file.

#1 would be preferred, but for a quick fix #2 is okay as well.

Thanks,

tglx