Re: [PATCH v11 13/13] powerpc/64s/radix: Enable huge vmalloc mappings

From: Michael Ellerman
Date: Wed Jan 27 2021 - 05:30:50 EST


Nicholas Piggin <npiggin@xxxxxxxxx> writes:
> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
> Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
> ---

Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>

cheers

> .../admin-guide/kernel-parameters.txt | 2 ++
> arch/powerpc/Kconfig | 1 +
> arch/powerpc/kernel/module.c | 21 +++++++++++++++----
> 3 files changed, 20 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index a10b545c2070..d62df53e5200 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -3225,6 +3225,8 @@
>
> nohugeiomap [KNL,X86,PPC,ARM64] Disable kernel huge I/O mappings.
>
> + nohugevmalloc [PPC] Disable kernel huge vmalloc mappings.
> +
> nosmt [KNL,S390] Disable symmetric multithreading (SMT).
> Equivalent to smt=1.
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 107bb4319e0e..781da6829ab7 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -181,6 +181,7 @@ config PPC
> select GENERIC_GETTIMEOFDAY
> select HAVE_ARCH_AUDITSYSCALL
> select HAVE_ARCH_HUGE_VMAP if PPC_BOOK3S_64 && PPC_RADIX_MMU
> + select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP
> select HAVE_ARCH_JUMP_LABEL
> select HAVE_ARCH_KASAN if PPC32 && PPC_PAGE_SHIFT <= 14
> select HAVE_ARCH_KASAN_VMALLOC if PPC32 && PPC_PAGE_SHIFT <= 14
> diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
> index a211b0253cdb..07026335d24d 100644
> --- a/arch/powerpc/kernel/module.c
> +++ b/arch/powerpc/kernel/module.c
> @@ -87,13 +87,26 @@ int module_finalize(const Elf_Ehdr *hdr,
> return 0;
> }
>
> -#ifdef MODULES_VADDR
> void *module_alloc(unsigned long size)
> {
> + unsigned long start = VMALLOC_START;
> + unsigned long end = VMALLOC_END;
> +
> +#ifdef MODULES_VADDR
> BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
> + start = MODULES_VADDR;
> + end = MODULES_END;
> +#endif
> +
> + /*
> + * Don't do huge page allocations for modules yet until more testing
> + * is done. STRICT_MODULE_RWX may require extra work to support this
> + * too.
> + */
>
> - return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, GFP_KERNEL,
> - PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
> + return __vmalloc_node_range(size, 1, start, end, GFP_KERNEL,
> + PAGE_KERNEL_EXEC,
> + VM_NO_HUGE_VMAP | VM_FLUSH_RESET_PERMS,
> + NUMA_NO_NODE,
> __builtin_return_address(0));
> }
> -#endif
> --
> 2.23.0