Messages in this thread |  | | From | Will Deacon <> | | Subject | [PATCH 0/5] Clean up huge vmap and ioremap code | | Date | Wed, 12 Sep 2018 11:26:09 +0100 |
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Hi all,
The recent introduction of break-before-make on the huge vmap path in b6bdb7517c3d ("mm/vmalloc: add interfaces to free unmapped page table") introduced a pair of arch functions for freeing a child level of page table before putting down a huge mapping at the parent level.
Whilst this works well, the semantics of the pXd_free_pYd_table() function are slightly confusing, and this led to an over-eager VM_WARN_ON in the arm64 code that we fixed in -rc3 [1]. Linus suggested that the interface could be tidied up so that the pXd_present() checks are moved into the caller, so I've implemented that and generally cleaned up the ioremap code so that it's easier to follow. I also extended the break-before-make code to cover the huge p4d case, although this remains unused by any architectures.
Feedback welcome.
Cheers,
Will
[1] https://lkml.org/lkml/2018/9/7/898
--->8
Will Deacon (5): ioremap: Rework pXd_free_pYd_page() API arm64: mmu: Drop pXd_present() checks from pXd_free_pYd_table() x86: pgtable: Drop pXd_none() checks from pXd_free_pYd_table() lib/ioremap: Ensure phys_addr actually corresponds to a physical address lib/ioremap: Ensure break-before-make is used for huge p4d mappings
arch/arm64/mm/mmu.c | 13 +++--- arch/x86/mm/pgtable.c | 14 +++--- include/asm-generic/pgtable.h | 5 ++ lib/ioremap.c | 103 +++++++++++++++++++++++++++++------------- 4 files changed, 91 insertions(+), 44 deletions(-)
-- 2.1.4
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