Re: [RFC] virtual memmap for sparsemem [2/2] for ia64.

[Andy Whitcroft <apw@shadowen.org>]

KAMEZAWA Hiroyuki wrote:
> vmemap_sparsemem support for ia64.
> The same logic as CONFIG_VIRTUAL_MEMMAP is used for allocating virtual address range
> for virtual memmap.
> 
> Signed-Off-By: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> 
> 
>  arch/ia64/Kconfig          |    4 ++++
>  arch/ia64/mm/discontig.c   |    5 ++++-
>  arch/ia64/mm/init.c        |    4 +++-
>  include/asm-ia64/pgtable.h |    2 +-
>  4 files changed, 12 insertions(+), 3 deletions(-)
> 
> Index: linux-2.6.19-rc2/arch/ia64/mm/discontig.c
> =================================> --- linux-2.6.19-rc2.orig/arch/ia64/mm/discontig.c	2006-10-19 09:12:06.000000000 +0900
> +++ linux-2.6.19-rc2/arch/ia64/mm/discontig.c	2006-10-19 17:04:31.000000000 +0900
> @@ -685,7 +685,10 @@
>  	unsigned long max_zone_pfns[MAX_NR_ZONES];
>  
>  	max_dma = virt_to_phys((void *) MAX_DMA_ADDRESS) >> PAGE_SHIFT;
> -
> +#ifdef CONFIG_VMEMMAP_SPARSEMEM
> +	vmalloc_end -= NR_MEM_SECTIONS * PAGES_PER_SECTION * sizeof(struct page);
> +	init_vmemmap_sparsemem(vmalloc_end);
> +#endif

I thought I saw that this macro was defined to nothing when
SPARSEMEM_VMEMMAP was undefined, so I'd expect you not to need the
#ifdef round it here.  If its not defined when SPARSEMEM isn't defined
then we should probabally change things so it is.  We do that for the
sparse_init() and sparse_index_init() in linux/mmzone.h, so it would
seem reasonable to do the same for this.

>  	arch_sparse_init();
>  
>  	efi_memmap_walk(filter_rsvd_memory, count_node_pages);
> Index: linux-2.6.19-rc2/arch/ia64/Kconfig
> =================================> --- linux-2.6.19-rc2.orig/arch/ia64/Kconfig	2006-10-19 09:12:06.000000000 +0900
> +++ linux-2.6.19-rc2/arch/ia64/Kconfig	2006-10-19 17:04:31.000000000 +0900
> @@ -333,6 +333,10 @@
>  	def_bool y
>  	depends on ARCH_DISCONTIGMEM_ENABLE
>  
> +config ARCH_VMEMMAP_SPARSEMEM_SUPPORT
> +	def_bool y
> +	depends on PGTABLE_4 && ARCH_SPARSEMEM_ENABLE
> +
>  config ARCH_DISCONTIGMEM_DEFAULT
>  	def_bool y if (IA64_SGI_SN2 || IA64_GENERIC || IA64_HP_ZX1 || IA64_HP_ZX1_SWIOTLB)
>  	depends on ARCH_DISCONTIGMEM_ENABLE
> Index: linux-2.6.19-rc2/arch/ia64/mm/init.c
> =================================> --- linux-2.6.19-rc2.orig/arch/ia64/mm/init.c	2006-10-19 09:12:06.000000000 +0900
> +++ linux-2.6.19-rc2/arch/ia64/mm/init.c	2006-10-19 17:04:31.000000000 +0900
> @@ -45,9 +45,11 @@
>  
>  unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
>  
> -#ifdef CONFIG_VIRTUAL_MEM_MAP
> +#if defined(CONFIG_VIRTUAL_MEM_MAP) || defined(CONFIG_VMEMMAP_SPARSEMEM)
>  unsigned long vmalloc_end = VMALLOC_END_INIT;
>  EXPORT_SYMBOL(vmalloc_end);
> +#endif
> +#ifdef CONFIG_VIRTUAL_MEM_MAP
>  struct page *vmem_map;
>  EXPORT_SYMBOL(vmem_map);
>  #endif
> Index: linux-2.6.19-rc2/include/asm-ia64/pgtable.h
> =================================> --- linux-2.6.19-rc2.orig/include/asm-ia64/pgtable.h	2006-10-19 09:12:06.000000000 +0900
> +++ linux-2.6.19-rc2/include/asm-ia64/pgtable.h	2006-10-19 17:04:31.000000000 +0900
> @@ -231,7 +231,7 @@
>  #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
>  
>  #define VMALLOC_START		(RGN_BASE(RGN_GATE) + 0x200000000UL)
> -#ifdef CONFIG_VIRTUAL_MEM_MAP
> +#if defined(CONFIG_VIRTUAL_MEM_MAP) || defined(CONFIG_VMEMMAP_SPARSEMEM)
>  # define VMALLOC_END_INIT	(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
>  # define VMALLOC_END		vmalloc_end
>    extern unsigned long vmalloc_end;

Well I have to say its nice to find there is basically zero architecture
specific code here.  You call init_vmemmap_sparsmem() (or whatever it
gets renamed to) with the base address, and thats it.

-apw