On Wed, Jan 8, 2025, at 07:57, Qi Zheng wrote:
From: Kevin Brodsky <kevin.brodsky@xxxxxxx> Four architectures currently implement 5-level pgtables: arm64, riscv, x86 and s390. The first three have essentially the same implementation for p4d_alloc_one() and p4d_free(), so we've got an opportunity to reduce duplication like at the lower levels. Provide a generic version of p4d_alloc_one() and p4d_free(), and make use of it on those architectures. Their implementation is the same as at PUD level, except that p4d_free() performs a runtime check by calling mm_p4d_folded(). 5-level pgtables depend on a runtime-detected hardware feature on all supported architectures, so we might as well include this check in the generic implementation. No runtime check is required in p4d_alloc_one() as the top-level p4d_alloc() already does the required check. Signed-off-by: Kevin Brodsky <kevin.brodsky@xxxxxxx> Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx> --- arch/arm64/include/asm/pgalloc.h | 17 ------------ arch/riscv/include/asm/pgalloc.h | 23 ---------------- arch/x86/include/asm/pgalloc.h | 18 ------------- include/asm-generic/pgalloc.h | 45 ++++++++++++++++++++++++++++++++ 4 files changed, 45 insertions(+), 58 deletions(-)
Acked-by: Arnd Bergmann <arnd@xxxxxxxx> # asm-generic
