Le 24/01/2021 à 09:22, Nicholas Piggin a écrit :
This changes the awkward approach where architectures provide init
functions to determine which levels they can provide large mappings for,
to one where the arch is queried for each call.
This removes code and indirection, and allows constant-folding of dead
code for unsupported levels.
It looks like this is only the case when CONFIG_HAVE_ARCH_HUGE_VMAP is not defined.
When it is defined, for exemple on powerpc you defined arch_vmap_p4d_supported() as a regular
function in arch/powerpc/mm/book3s64/radix_pgtable.c, so allthough it returns always false, it won't
constant fold dead code.
This also adds a prot argument to the arch query. This is unused
currently but could help with some architectures (e.g., some powerpc
processors can't map uncacheable memory with large pages).
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx> [arm64]
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
---
arch/arm64/include/asm/vmalloc.h | 8 +++
arch/arm64/mm/mmu.c | 10 +--
arch/powerpc/include/asm/vmalloc.h | 8 +++
arch/powerpc/mm/book3s64/radix_pgtable.c | 8 +--
arch/x86/include/asm/vmalloc.h | 7 ++
arch/x86/mm/ioremap.c | 12 ++--
include/linux/io.h | 9 ---
include/linux/vmalloc.h | 6 ++
init/main.c | 1 -
mm/ioremap.c | 88 +++++++++---------------
10 files changed, 79 insertions(+), 78 deletions(-)
Christophe
