From 2842f11419704f8707fffc82e10d2263427fc130 Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Tue, 27 Jun 2006 02:53:36 -0700 Subject: [PATCH] catch valid mem range at onlining memory This patch allows hot-add memory which is not aligned to section. Now, hot-added memory has to be aligned to section size. Considering big section sized archs, this is not useful. When hot-added memory is registerd as iomem resoruce by iomem resource patch, we can make use of that information to detect valid memory range. Note: With this, not-aligned memory can be registerd. To allow hot-add memory with holes, we have to do more work around add_memory(). (It doesn't allows add memory to already existing mem section.) Signed-off-by: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/resource.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'kernel/resource.c') diff --git a/kernel/resource.c b/kernel/resource.c index e3080fcc66a..2404f9b0bc4 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -232,6 +232,44 @@ int release_resource(struct resource *old) EXPORT_SYMBOL(release_resource); +#ifdef CONFIG_MEMORY_HOTPLUG +/* + * Finds the lowest memory reosurce exists within [res->start.res->end) + * the caller must specify res->start, res->end, res->flags. + * If found, returns 0, res is overwritten, if not found, returns -1. + */ +int find_next_system_ram(struct resource *res) +{ + resource_size_t start, end; + struct resource *p; + + BUG_ON(!res); + + start = res->start; + end = res->end; + + read_lock(&resource_lock); + for (p = iomem_resource.child; p ; p = p->sibling) { + /* system ram is just marked as IORESOURCE_MEM */ + if (p->flags != res->flags) + continue; + if (p->start > end) { + p = NULL; + break; + } + if (p->start >= start) + break; + } + read_unlock(&resource_lock); + if (!p) + return -1; + /* copy data */ + res->start = p->start; + res->end = p->end; + return 0; +} +#endif + /* * Find empty slot in the resource tree given range and alignment. */ -- cgit v1.2.3