[PATCH] Add IORESOUCE_BUSY flag for System RAM take 2.

Yasunori Goto
2007-11-06T02:23:01Z

Hello.

I merged Baradi-san's patch and mine. This and Kame-san's
following patch is necessary for x86-64 memory unplug.

http://marc.info/?l=linux-mm&m\x119399026017901&w=2

I heard Kame-san's patch is already included in -mm.
So, I'll repost merged patch now.

This patch is tested on 2.6.23-mm1.

Please apply.

---

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 fix 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>

---
arch/ia64/kernel/efi.c | 6 ++----
kernel/resource.c | 2 +-
mm/memory_hotplug.c | 2 +-
3 files changed, 4 insertions(+), 6 deletions(-)

Index: current/arch/ia64/kernel/efi.c
=================================--- current.orig/arch/ia64/kernel/efi.c 2007-11-02 17:17:30.000000000 +0900
+++ current/arch/ia64/kernel/efi.c 2007-11-02 17:19:10.000000000 +0900
@@ -1111,7 +1111,7 @@ efi_initialize_iomem_resources(struct re
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:
@@ -1133,12 +1133,11 @@ efi_initialize_iomem_resources(struct re

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:
@@ -1147,7 +1146,6 @@ efi_initialize_iomem_resources(struct re
case EFI_ACPI_RECLAIM_MEMORY:
default:
name = "reserved";
- flags |= IORESOURCE_BUSY;
break;
}

Index: current/mm/memory_hotplug.c
=================================--- current.orig/mm/memory_hotplug.c 2007-11-02 17:19:09.000000000 +0900
+++ current/mm/memory_hotplug.c 2007-11-02 17:19:10.000000000 +0900
@@ -39,7 +39,7 @@ static struct resource *register_memory_
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);
Index: current/kernel/resource.c
=================================--- current.orig/kernel/resource.c 2007-11-02 17:19:15.000000000 +0900
+++ current/kernel/resource.c 2007-11-02 17:22:39.000000000 +0900
@@ -287,7 +287,7 @@ walk_memory_resource(unsigned long start
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);

--
Yasunori Goto