This is a little series which serves the purpose to replace kmap() with kmap_local_page() in btrfs/zstd.c. Actually this task is only accomplished in patch 2/2. Instead patch 1/2 is a pre-requisite for the above-mentioned replacement, but, above all else, it has the purpose to conform the prototypes of __kunmap_{local,atomic}() to their own correct semantic. Since those functions don't make changes to the memory pointed by their arguments, change the type of those arguments to become pointers to const void. This little series has version number 4, despite it's the first time the two component patches have been re-united in a series. This may be a questionable choice, however patch 1/2 should be at its v4 and patch 2/2 should be at its v3. I've tried to preserve the logs of version changes. v4 is due to the fact that, when I sent v3, I forgot to Cc several people and mailing lists. Furthermore, Andrew M. made me notice that I've made confusion with the tree structure: this is why now I have to send this series again. I want to apologize for the noise to people who have received these two patches more times than it should have been. Fabio M. De Francesco (2): highmem: Make __kunmap_{local,atomic}() take "const void *" btrfs: Replace kmap() with kmap_local_page() in zstd.c arch/parisc/include/asm/cacheflush.h | 6 ++-- arch/parisc/kernel/cache.c | 2 +- fs/btrfs/zstd.c | 42 +++++++++++++++------------- include/linux/highmem-internal.h | 10 +++---- mm/highmem.c | 2 +- 5 files changed, 33 insertions(+), 29 deletions(-) -- 2.36.1