[PATCH 1/3] memory: extern memory_block_size_bytes and set_memory_block_size_order

[Gregory Price <gourry@gourry.net>]

On CXL systems, block alignment may be as small as 256MB, which may
require a resize of the block size during initialization.  This is done
in the ACPI driver, so the resize function need to be made available.

Presently, only x86 provides the functionality to resize memory
block sizes.  Wire up a weak stub for set_memory_block_size_order,
similar to memory_block_size_bytes, that simply returns -ENODEV.

Since set_memory_block_size_order is now extern, we also need to
drop the __init macro.

Signed-off-by: Gregory Price <gourry@gourry.net>
---
 arch/x86/mm/init_64.c  | 2 +-
 drivers/base/memory.c  | 6 ++++++
 include/linux/memory.h | 4 ++--
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index ff253648706f..6086f99449fa 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1424,7 +1424,7 @@ void mark_rodata_ro(void)
 
 /* Adjustable memory block size */
 static unsigned long set_memory_block_size;
-int __init set_memory_block_size_order(unsigned int order)
+int set_memory_block_size_order(unsigned int order)
 {
 	unsigned long size = 1UL << order;
 
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 67858eeb92ed..f9045642f69e 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -110,6 +110,12 @@ static void memory_block_release(struct device *dev)
 	kfree(mem);
 }
 
+int __weak set_memory_block_size_order(unsigned int order)
+{
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(set_memory_block_size_order);
+
 unsigned long __weak memory_block_size_bytes(void)
 {
 	return MIN_MEMORY_BLOCK_SIZE;
diff --git a/include/linux/memory.h b/include/linux/memory.h
index c0afee5d126e..c57706178354 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -86,8 +86,8 @@ struct memory_block {
 };
 
 int arch_get_memory_phys_device(unsigned long start_pfn);
-unsigned long memory_block_size_bytes(void);
-int set_memory_block_size_order(unsigned int order);
+extern unsigned long memory_block_size_bytes(void);
+extern int set_memory_block_size_order(unsigned int order);
 
 /* These states are exposed to userspace as text strings in sysfs */
 #define	MEM_ONLINE		(1<<0) /* exposed to userspace */
-- 
2.43.0