efi/libstub: Bump up EFI_MMAP_NR_SLACK_SLOTS to 32

commit ec4696925da6b9baec38345184403ce9e29a2e48 upstream.

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.

Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Allen Pais <apais@linux.microsoft.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 685098f9626f2b8cad9f4f4b33258e03ef741160..eebcdf653d0729aea858f586fed4998a95151c39 100644 (file)
--- 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;