On Tue, Nov 01, 2022 at 08:18:27PM +0000, Matthew Wilcox (Oracle) wrote:
> Introduce vmap_alloc() to simply get the address space. This allows
> for code sharing in the next patch.
>
> Suggested-by: Uladzislau Rezki <urezki@xxxxxxxxx>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> mm/vmalloc.c | 41 +++++++++++++++++++++++------------------
> 1 file changed, 23 insertions(+), 18 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index ccaa461998f3..dcab1d3cf185 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -2230,6 +2230,27 @@ void vm_unmap_ram(const void *mem, unsigned int count)
> }
> EXPORT_SYMBOL(vm_unmap_ram);
>
> +static void *vmap_alloc(size_t size, int node)
> +{
> + void *mem;
> +
> + if (likely(size <= (VMAP_MAX_ALLOC * PAGE_SIZE))) {
> + mem = vb_alloc(size, GFP_KERNEL);
> + if (IS_ERR(mem))
> + mem = NULL;
> + } else {
> + struct vmap_area *va;
> + va = alloc_vmap_area(size, PAGE_SIZE,
> + VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
> + if (IS_ERR(va))
> + mem = NULL;
> + else
> + mem = (void *)va->va_start;
> + }
> +
> + return mem;
> +}
> +
> /**
> * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
> * @pages: an array of pointers to the pages to be mapped
> @@ -2247,24 +2268,8 @@ EXPORT_SYMBOL(vm_unmap_ram);
> void *vm_map_ram(struct page **pages, unsigned int count, int node)
> {
> unsigned long size = (unsigned long)count << PAGE_SHIFT;
> - unsigned long addr;
> - void *mem;
> -
> - if (likely(count <= VMAP_MAX_ALLOC)) {
> - mem = vb_alloc(size, GFP_KERNEL);
> - if (IS_ERR(mem))
> - return NULL;
> - addr = (unsigned long)mem;
> - } else {
> - struct vmap_area *va;
> - va = alloc_vmap_area(size, PAGE_SIZE,
> - VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
> - if (IS_ERR(va))
> - return NULL;
> -
> - addr = va->va_start;
> - mem = (void *)addr;
> - }
> + void *mem = vmap_alloc(size, node);
> + unsigned long addr = (unsigned long)mem;
I think we need to check mem != NULL.
>
> if (vmap_pages_range(addr, addr + size, PAGE_KERNEL,
> pages, PAGE_SHIFT) < 0) {
> --
> 2.35.1
>
>
--
Thanks,
Hyeonggon
