From: Dave Hansen <haveblue@us.ibm.com>
Date: Sun, 30 Oct 2005 01:16:58 +0000 (-0700)
Subject: [PATCH] memory hotplug: ppc64 specific hot-add functions
X-Git-Tag: v2.6.15-rc1~730^2^2~5
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=bb7e7e032d2cb8e0e9a88a2be209de5e61033b39;p=linux-2.6-omap-h63xx.git

[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>
---

diff --git a/arch/ppc64/mm/init.c b/arch/ppc64/mm/init.c
index 975b26de34d..e2bd7776622 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 */