[PATCH 5.15 066/245] efi: Dont add memblocks for soft-reserved memory

Greg Kroah-Hartman
2024-02-27T14:05:15Z

From: Andrew Bresticker <abrestic@rivosinc.com>

[ 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@rivosinc.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/firmware/efi/efi-init.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

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))
--
2.43.0