[PATCH] memory hotplug: ppc64 specific hot-add functions

Here is a set of ppc64 specific patches that at least allow
compilation/booting with the following configurations:

FLATMEM
SPARSEMEN
SPARSEMEM + MEMORY_HOTPLUG

Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 77 insertions, 0 deletions

diff --git a/arch/ppc64/mm/init.c b/arch/ppc64/mm/init.c
index 975b26de34d6..e2bd7776622f 100644
--- a/arch/ppc64/mm/init.c
+++ b/arch/ppc64/mm/init.c
@@ -871,3 +871,80 @@ pgprot_t phys_mem_access_prot(struct file *file, unsigned long addr,
         return vma_prot;
 }
 EXPORT_SYMBOL(phys_mem_access_prot);
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+
+void online_page(struct page *page)
+{
+        ClearPageReserved(page);
+        free_cold_page(page);
+        totalram_pages++;
+        num_physpages++;
+}
+
+/*
+ * This works only for the non-NUMA case.  Later, we'll need a lookup
+ * to convert from real physical addresses to nid, that doesn't use
+ * pfn_to_nid().
+ */
+int __devinit add_memory(u64 start, u64 size)
+{
+        struct pglist_data *pgdata = NODE_DATA(0);
+        struct zone *zone;
+        unsigned long start_pfn = start >> PAGE_SHIFT;
+        unsigned long nr_pages = size >> PAGE_SHIFT;
+
+        /* this should work for most non-highmem platforms */
+        zone = pgdata->node_zones;
+
+        return __add_pages(zone, start_pfn, nr_pages);
+
+        return 0;
+}
+
+/*
+ * First pass at this code will check to determine if the remove
+ * request is within the RMO.  Do not allow removal within the RMO.
+ */
+int __devinit remove_memory(u64 start, u64 size)
+{
+        struct zone *zone;
+        unsigned long start_pfn, end_pfn, nr_pages;
+
+        start_pfn = start >> PAGE_SHIFT;
+        nr_pages = size >> PAGE_SHIFT;
+        end_pfn = start_pfn + nr_pages;
+
+        printk("%s(): Attempting to remove memoy in range "
+                        "%lx to %lx\n", __func__, start, start+size);
+        /*
+         * check for range within RMO
+         */
+        zone = page_zone(pfn_to_page(start_pfn));
+
+        printk("%s(): memory will be removed from "
+                        "the %s zone\n", __func__, zone->name);
+
+        /*
+         * not handling removing memory ranges that
+         * overlap multiple zones yet
+         */
+        if (end_pfn > (zone->zone_start_pfn + zone->spanned_pages))
+                goto overlap;
+
+        /* make sure it is NOT in RMO */
+        if ((start < lmb.rmo_size) || ((start+size) < lmb.rmo_size)) {
+                printk("%s(): range to be removed must NOT be in RMO!\n",
+                        __func__);
+                goto in_rmo;
+        }
+
+        return __remove_pages(zone, start_pfn, nr_pages);
+
+overlap:
+        printk("%s(): memory range to be removed overlaps "
+                "multiple zones!!!\n", __func__);
+in_rmo:
+        return -1;
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */