x86, efi: Break up large initrd reads
The efi boot stub tries to read the entire initrd in 1 go, however
some efi implementations hang if too much if asked to read too much
data at the same time. After some experimentation I found out that my
asrock p67 board will hang if asked to read chunks of 4MiB, so use a
safe value.
elilo reads in chunks of 16KiB, but since that requires many read
calls I use a value of 1 MiB. hpa suggested adding individual
blacklists for when systems are found where this value causes a crash.
Signed-off-by: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Link: http://lkml.kernel.org/r/4EEB3A02.3090201@gmail.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/boot/compressed/eboot.h b/arch/x86/boot/compressed/eboot.h
index f66d023..3925166 100644
--- a/arch/x86/boot/compressed/eboot.h
+++ b/arch/x86/boot/compressed/eboot.h
@@ -12,6 +12,7 @@
#define DESC_TYPE_CODE_DATA (1 << 0)
#define EFI_PAGE_SIZE (1UL << EFI_PAGE_SHIFT)
+#define EFI_READ_CHUNK_SIZE (1024 * 1024)
#define PIXEL_RGB_RESERVED_8BIT_PER_COLOR 0
#define PIXEL_BGR_RESERVED_8BIT_PER_COLOR 1