Add IORESOUCE_BUSY flag for System RAM

i386 and x86-64 registers System RAM as IORESOURCE_MEM | IORESOURCE_BUSY.

But ia64 registers it as IORESOURCE_MEM only.
In addition, memory hotplug code registers new memory as IORESOURCE_MEM too.

This difference causes a failure of memory unplug of x86-64.  This patch
fixes it.

This patch adds IORESOURCE_BUSY to avoid potential overlap mapping by PCI
device.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Luck, Tony" <tony.luck@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 4 insertions, 6 deletions

diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c
index 5181bf551f3..8e8f8b6193e 100644
--- a/arch/ia64/kernel/efi.c
+++ b/arch/ia64/kernel/efi.c
@@ -1113,7 +1113,7 @@ efi_initialize_iomem_resources(struct resource *code_resource,
                 if (md->num_pages == 0) /* should not happen */
                         continue;
 
-                flags = IORESOURCE_MEM;
+                flags = IORESOURCE_MEM | IORESOURCE_BUSY;
                 switch (md->type) {
 
                         case EFI_MEMORY_MAPPED_IO:
@@ -1135,12 +1135,11 @@ efi_initialize_iomem_resources(struct resource *code_resource,
 
                         case EFI_ACPI_MEMORY_NVS:
                                 name = "ACPI Non-volatile Storage";
-                                flags |= IORESOURCE_BUSY;
                                 break;
 
                         case EFI_UNUSABLE_MEMORY:
                                 name = "reserved";
-                                flags |= IORESOURCE_BUSY | IORESOURCE_DISABLED;
+                                flags |= IORESOURCE_DISABLED;
                                 break;
 
                         case EFI_RESERVED_TYPE:
@@ -1149,7 +1148,6 @@ efi_initialize_iomem_resources(struct resource *code_resource,
                         case EFI_ACPI_RECLAIM_MEMORY:
                         default:
                                 name = "reserved";
-                                flags |= IORESOURCE_BUSY;
                                 break;
                 }
 
diff --git a/kernel/resource.c b/kernel/resource.c
index a358142ff48..2eb553d9b51 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -277,7 +277,7 @@ walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
         int ret = -1;
         res.start = (u64) start_pfn << PAGE_SHIFT;
         res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
-        res.flags = IORESOURCE_MEM;
+        res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
         orig_end = res.end;
         while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) {
                 pfn = (unsigned long)(res.start >> PAGE_SHIFT);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 987abe6375e..9512a544d04 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -39,7 +39,7 @@ static struct resource *register_memory_resource(u64 start, u64 size)
         res->name = "System RAM";
         res->start = start;
         res->end = start + size - 1;
-        res->flags = IORESOURCE_MEM;
+        res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
         if (request_resource(&iomem_resource, res) < 0) {
                 printk("System RAM resource %llx - %llx cannot be added\n",
                 (unsigned long long)res->start, (unsigned long long)res->end);