Re: [PATCH v2 14/15] MIPS: memblock: Discard bootmem from SGI IP27 code

[Matt Redfearn]

Hi Serge,

On 02/02/18 03:54, Serge Semin wrote:
> SGI IP27 got its own code to set the early memory allocator up since it's
> NUMA-based system. So in order to be compatible with NO_BOOTMEM config
> we need to discard the bootmem allocator initialization and insert the
> memblock reservation method. Although in my opinion the code isn't
> working anyway since I couldn't find a place where prom_meminit() called
> and kernel memory isn't reserved. It must have been untested since the
> time the arch/mips/mips-boards/generic code was in the kernel.

I don't have access to an IP27, but the change looks sensible to me.

Reviewed-by: Matt Redfearn <matt.redfearn@xxxxxxxx>

> Signed-off-by: Serge Semin <fancer.lancer@xxxxxxxxx>
> ---
>   arch/mips/sgi-ip27/ip27-memory.c | 9 ++-------
>   1 file changed, 2 insertions(+), 7 deletions(-)
>
> diff --git a/arch/mips/sgi-ip27/ip27-memory.c b/arch/mips/sgi-ip27/ip27-memory.c
> index 59133d0abc83..c480ee3eca96 100644
> --- a/arch/mips/sgi-ip27/ip27-memory.c
> +++ b/arch/mips/sgi-ip27/ip27-memory.c
> @@ -389,7 +389,6 @@ static void __init node_mem_init(cnodeid_t node)
>   {
>   	unsigned long slot_firstpfn = slot_getbasepfn(node, 0);
>   	unsigned long slot_freepfn = node_getfirstfree(node);
> -	unsigned long bootmap_size;
>   	unsigned long start_pfn, end_pfn;
>   
>   	get_pfn_range_for_nid(node, &start_pfn, &end_pfn);
> @@ -400,7 +399,6 @@ static void __init node_mem_init(cnodeid_t node)
>   	__node_data[node] = __va(slot_freepfn << PAGE_SHIFT);
>   	memset(__node_data[node], 0, PAGE_SIZE);
>   
> -	NODE_DATA(node)->bdata = &bootmem_node_data[node];
>   	NODE_DATA(node)->node_start_pfn = start_pfn;
>   	NODE_DATA(node)->node_spanned_pages = end_pfn - start_pfn;
>   
> @@ -409,12 +407,9 @@ static void __init node_mem_init(cnodeid_t node)
>   	slot_freepfn += PFN_UP(sizeof(struct pglist_data) +
>   			       sizeof(struct hub_data));
>   
> -	bootmap_size = init_bootmem_node(NODE_DATA(node), slot_freepfn,
> -					start_pfn, end_pfn);
>   	free_bootmem_with_active_regions(node, end_pfn);
> -	reserve_bootmem_node(NODE_DATA(node), slot_firstpfn << PAGE_SHIFT,
> -		((slot_freepfn - slot_firstpfn) << PAGE_SHIFT) + bootmap_size,
> -		BOOTMEM_DEFAULT);
> +	memblock_reserve(slot_firstpfn << PAGE_SHIFT,
> +		((slot_freepfn - slot_firstpfn) << PAGE_SHIFT));

How about PFN_PHYS()? In fact, that could be used throughout the series 
to tidy up some of the shifting by PAGE_SIZE.

Thanks,
Matt

>   	sparse_memory_present_with_active_regions(node);
>   }
>