powerpc: Fix memory hotplug with sparse vmemmap

Previous commit 46723bf... introduced a new config option HAVE_BOOTMEM_INFO_NODE that ended up breaking memory hot-remove for ppc when sparse vmemmap is not defined. This patch defines HAVE_BOOTMEM_INFO_NODE for ppc and adds the call to register_page_bootmem_info_node. Without this we get a BUG_ON for memory hot remove in put_page_bootmem(). This also adds a stub for register_page_bootmem_memmap to allow ppc to build with sparse vmemmap defined. Leaving this as a stub is fine since the same vmemmap addresses are also handled in vmemmap_populate and as such are properly mapped. Signed-off-by: Nathan Fontenot <[email protected]> Signed-off-by: Benjamin Herrenschmidt <[email protected]> CC: <[email protected]> [v3.9+]
ambv · Oct 3, 2013 · f7e3334 · f7e3334
1 parent 4b97280
commit f7e3334
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Showing 3 changed files with 14 additions and 1 deletion.
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
@@ -300,5 +300,9 @@ void vmemmap_free(unsigned long start, unsigned long end)
 {
 }
 
+void register_page_bootmem_memmap(unsigned long section_nr,
+				  struct page *start_page, unsigned long size)
+{
+}
 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
 
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
@@ -297,12 +297,21 @@ void __init paging_init(void)
 }
 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */
 
+static void __init register_page_bootmem_info(void)
+{
+	int i;
+
+	for_each_online_node(i)
+		register_page_bootmem_info_node(NODE_DATA(i));
+}
+
 void __init mem_init(void)
 {
 #ifdef CONFIG_SWIOTLB
 	swiotlb_init(0);
 #endif
 
+	register_page_bootmem_info();
 	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 	set_max_mapnr(max_pfn);
 	free_all_bootmem();

diff --git a/mm/Kconfig b/mm/Kconfig
@@ -183,7 +183,7 @@ config MEMORY_HOTPLUG_SPARSE
 config MEMORY_HOTREMOVE
 	bool "Allow for memory hot remove"
 	select MEMORY_ISOLATION
-	select HAVE_BOOTMEM_INFO_NODE if X86_64
+	select HAVE_BOOTMEM_INFO_NODE if (X86_64 || PPC64)
 	depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE
 	depends on MIGRATION