This is a note to let you know that I've just added the patch titled
efi: Don't add memblocks for soft-reserved memory
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
efi-don-t-add-memblocks-for-soft-reserved-memory.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4063f8a56608c11283d6aaf002f2f2e8f0f7246b
Author: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
Date: Fri Feb 2 10:07:04 2024 -0800
efi: Don't add memblocks for soft-reserved memory
[ Upstream commit 0bcff59ef7a652fcdc6d535554b63278c2406c8f ]
Adding memblocks for soft-reserved regions prevents them from later being
hotplugged in by dax_kmem.
Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/firmware/efi/efi-init.c b/drivers/firmware/efi/efi-init.c
index b2c829e95bd14..4639ac6e4f9af 100644
--- a/drivers/firmware/efi/efi-init.c
+++ b/drivers/firmware/efi/efi-init.c
@@ -141,15 +141,6 @@ static __init int is_usable_memory(efi_memory_desc_t *md)
case EFI_BOOT_SERVICES_DATA:
case EFI_CONVENTIONAL_MEMORY:
case EFI_PERSISTENT_MEMORY:
- /*
- * Special purpose memory is 'soft reserved', which means it
- * is set aside initially, but can be hotplugged back in or
- * be assigned to the dax driver after boot.
- */
- if (efi_soft_reserve_enabled() &&
- (md->attribute & EFI_MEMORY_SP))
- return false;
-
/*
* According to the spec, these regions are no longer reserved
* after calling ExitBootServices(). However, we can only use
@@ -194,6 +185,16 @@ static __init void reserve_regions(void)
size = npages << PAGE_SHIFT;
if (is_memory(md)) {
+ /*
+ * Special purpose memory is 'soft reserved', which
+ * means it is set aside initially. Don't add a memblock
+ * for it now so that it can be hotplugged back in or
+ * be assigned to the dax driver after boot.
+ */
+ if (efi_soft_reserve_enabled() &&
+ (md->attribute & EFI_MEMORY_SP))
+ continue;
+
early_init_dt_add_memory_arch(paddr, size);
if (!is_usable_memory(md))
