[PATCH] efi: bump up EFI_MMAP_NR_SLACK_SLOTS to 32

[Hamza Mahfooz]

Recent platforms require more slack slots than the current value of
EFI_MMAP_NR_SLACK_SLOTS, otherwise they fail to boot. The current
workaround is to append `efi=disable_early_pci_dma` to the kernel's
cmdline. So, bump up EFI_MMAP_NR_SLACK_SLOTS to 32 to allow those
platforms to boot with the aforementioned workaround.

Cc: stable@xxxxxxxxxx
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Cc: Allen Pais <apais@xxxxxxxxxxxxxxxxxxx>
Cc: Tyler Hicks <code@xxxxxxxxxxx>
Signed-off-by: Hamza Mahfooz <hamzamahfooz@xxxxxxxxxxxxxxxxxxx>
---
 drivers/firmware/efi/libstub/efistub.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 76e44c185f29..e95ce6ae5c26 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -171,7 +171,7 @@ void efi_set_u64_split(u64 data, u32 *lo, u32 *hi)
  * the EFI memory map. Other related structures, e.g. x86 e820ext, need
  * to factor in this headroom requirement as well.
  */
-#define EFI_MMAP_NR_SLACK_SLOTS	8
+#define EFI_MMAP_NR_SLACK_SLOTS	32
 
 typedef struct efi_generic_dev_path efi_device_path_protocol_t;
 
-- 
2.47.1