Re: [PATCH] riscv: Don't use hugepage mappings for vmemmap if it's not supported

[Alexandre Ghiti]

Hi Nam,

On 08/05/2024 19:31, Nam Cao wrote:
> Commit ff172d4818ad ("riscv: Use hugepage mappings for vmemmap") broke XIP
> kernel, because huge pages are not supported on XIP kernel.


I don't understand why XIP kernels can't support huge vmalloc mappings, 
so I think the right fix would be to enable such mappings on XIP. WDYT?

Thanks,

Alex


> Only use hugepage mapping if it is supported.
>
> Fixes: ff172d4818ad ("riscv: Use hugepage mappings for vmemmap")
> Signed-off-by: Nam Cao <namcao@xxxxxxxxxxxxx>
> Cc: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>
> ---
>   arch/riscv/mm/init.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 968761843203..c081e7d349b1 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -1414,6 +1414,8 @@ int __meminit vmemmap_check_pmd(pmd_t *pmdp, int node,
>   int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
>   			       struct vmem_altmap *altmap)
>   {
> +	if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
> +		return vmemmap_populate_basepages(start, end, node, NULL);
>   	/*
>   	 * Note that SPARSEMEM_VMEMMAP is only selected for rv64 and that we
>   	 * can't use hugepage mappings for 2-level page table because in case of