linux/arch/xtensa/mm
Thomas Gleixner 1eb0616c2d xtensa/mm/highmem: Make generic kmap_atomic() work correctly
The conversion to the generic kmap_atomic() implementation missed the fact
that xtensa's fixmap works bottom up while all other implementations work
top down. There is no real reason why xtensa needs to work that way.

Cure it by:

  - Using the generic fix_to_virt()/virt_to_fix() functions which work top
    down
  - Adjusting the mapping defines
  - Using the generic index calculation for the non cache aliasing case
  - Making the cache colour offset reverse so the effective index is correct

While at it, remove the outdated and misleading comment above the fixmap
enum which originates from the initial copy&pasta of this code from i386.

[ Max: Fixed the off by one in the index calculation ]

Fixes: 629ed3f7da ("xtensa/mm/highmem: Switch to generic kmap atomic")
Reported-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>
Link: https://lore.kernel.org/r/20201116193253.23875-1-jcmvbkbc@gmail.com
2020-11-16 21:19:24 +01:00
..
cache.c mm: remove unneeded includes of <asm/pgalloc.h> 2020-08-07 11:33:26 -07:00
fault.c mm/xtensa: use general page fault accounting 2020-08-12 10:58:04 -07:00
highmem.c xtensa/mm/highmem: Make generic kmap_atomic() work correctly 2020-11-16 21:19:24 +01:00
init.c xtensa/mm/highmem: Make generic kmap_atomic() work correctly 2020-11-16 21:19:24 +01:00
ioremap.c mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
kasan_init.c mm: pgtable: add shortcuts for accessing kernel PMD and PTE 2020-06-09 09:39:13 -07:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
misc.S mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
mmu.c xtensa/mm/highmem: Make generic kmap_atomic() work correctly 2020-11-16 21:19:24 +01:00
tlb.c xtensa: fix TLB sanity checker 2019-11-26 11:33:39 -08:00