On Fri, Jun 28, 2019 at 10:14:43AM +0530, Anshuman Khandual wrote:
> This enables vmemmap_populate() and vmemmap_free() functions to incorporate
> struct vmem_altmap based device memory allocation and free requests. With
> this device memory with specific atlmap configuration can be hot plugged
> and hot removed as ZONE_DEVICE memory on arm64 platforms.
>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
>
> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> ---
> arch/arm64/mm/mmu.c | 57 ++++++++++++++++++++++++++++++++++-------------------
> 1 file changed, 37 insertions(+), 20 deletions(-)
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index 39e18d1..8867bbd 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -735,15 +735,26 @@ int kern_addr_valid(unsigned long addr)
> }
>
> #ifdef CONFIG_MEMORY_HOTPLUG
> -static void free_hotplug_page_range(struct page *page, size_t size)
> +static void free_hotplug_page_range(struct page *page, size_t size,
> + struct vmem_altmap *altmap)
> {
> - WARN_ON(!page || PageReserved(page));
> - free_pages((unsigned long)page_address(page), get_order(size));
> + if (altmap) {
> + /*
> + * vmemmap_populate() creates vmemmap mapping either at pte
> + * or pmd level. Unmapping request at any other level would
> + * be a problem.
> + */
> + WARN_ON((size != PAGE_SIZE) && (size != PMD_SIZE));
> + vmem_altmap_free(altmap, size >> PAGE_SHIFT);
> + } else {
> + WARN_ON(!page || PageReserved(page));
> + free_pages((unsigned long)page_address(page), get_order(size));
> + }
> }
>
> static void free_hotplug_pgtable_page(struct page *page)
> {
> - free_hotplug_page_range(page, PAGE_SIZE);
> + free_hotplug_page_range(page, PAGE_SIZE, NULL);
> }
>
> static void free_pte_table(pmd_t *pmdp, unsigned long addr)
> @@ -807,7 +818,8 @@ static void free_pud_table(pgd_t *pgdp, unsigned long addr)
> }
>
> static void unmap_hotplug_pte_range(pmd_t *pmdp, unsigned long addr,
> - unsigned long end, bool sparse_vmap)
> + unsigned long end, bool sparse_vmap,
> + struct vmem_altmap *altmap)
Do you still need the sparse_vmap parameter, or can you just pass a NULL
altmap pointer when sparse_vmap is false?
Will
