diff options
author | Andy Whitcroft <apw@shadowen.org> | 2007-10-16 08:24:17 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-16 16:42:51 (GMT) |
commit | d29eff7bca60c9ee401d691d4562a4abca8de543 (patch) | |
tree | 86715dfec0470a59d3bbad032b3032321f101766 /arch | |
parent | 46644c2477c58906e95281636d04e9cc42b39352 (diff) | |
download | linux-fsl-qoriq-d29eff7bca60c9ee401d691d4562a4abca8de543.tar.xz |
ppc64: SPARSEMEM_VMEMMAP support
Enable virtual memmap support for SPARSEMEM on PPC64 systems. Slice a 16th
off the end of the linear mapping space and use that to hold the vmemmap.
Uses the same size mapping as uses in the linear 1:1 kernel mapping.
[pbadari@gmail.com: fix warning]
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/powerpc/Kconfig | 1 | ||||
-rw-r--r-- | arch/powerpc/mm/init_64.c | 67 |
2 files changed, 68 insertions, 0 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 037664d..5e001ad 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -295,6 +295,7 @@ config ARCH_FLATMEM_ENABLE config ARCH_SPARSEMEM_ENABLE def_bool y depends on PPC64 + select SPARSEMEM_VMEMMAP_ENABLE config ARCH_SPARSEMEM_DEFAULT def_bool y diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c index fa90f65..29ed495 100644 --- a/arch/powerpc/mm/init_64.c +++ b/arch/powerpc/mm/init_64.c @@ -183,3 +183,70 @@ void pgtable_cache_init(void) zero_ctor); } } + +#ifdef CONFIG_SPARSEMEM_VMEMMAP +/* + * Given an address within the vmemmap, determine the pfn of the page that + * represents the start of the section it is within. Note that we have to + * do this by hand as the proffered address may not be correctly aligned. + * Subtraction of non-aligned pointers produces undefined results. + */ +unsigned long __meminit vmemmap_section_start(unsigned long page) +{ + unsigned long offset = page - ((unsigned long)(vmemmap)); + + /* Return the pfn of the start of the section. */ + return (offset / sizeof(struct page)) & PAGE_SECTION_MASK; +} + +/* + * Check if this vmemmap page is already initialised. If any section + * which overlaps this vmemmap page is initialised then this page is + * initialised already. + */ +int __meminit vmemmap_populated(unsigned long start, int page_size) +{ + unsigned long end = start + page_size; + + for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page))) + if (pfn_valid(vmemmap_section_start(start))) + return 1; + + return 0; +} + +int __meminit vmemmap_populate(struct page *start_page, + unsigned long nr_pages, int node) +{ + unsigned long mode_rw; + unsigned long start = (unsigned long)start_page; + unsigned long end = (unsigned long)(start_page + nr_pages); + unsigned long page_size = 1 << mmu_psize_defs[mmu_linear_psize].shift; + + mode_rw = _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX; + + /* Align to the page size of the linear mapping. */ + start = _ALIGN_DOWN(start, page_size); + + for (; start < end; start += page_size) { + int mapped; + void *p; + + if (vmemmap_populated(start, page_size)) + continue; + + p = vmemmap_alloc_block(page_size, node); + if (!p) + return -ENOMEM; + + printk(KERN_WARNING "vmemmap %08lx allocated at %p, " + "physical %p.\n", start, p, __pa(p)); + + mapped = htab_bolt_mapping(start, start + page_size, + __pa(p), mode_rw, mmu_linear_psize); + BUG_ON(mapped < 0); + } + + return 0; +} +#endif |