From: Julien Grall <jgrall@amazon.com>
Date: Fri, 18 Sep 2020 17:11:16 +0000 (+0100)
Subject: xen/arm: bootfdt: Ignore empty memory bank
X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~33^2~14
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=7d2b21fd36c2a47799eed71c67bae7faa1ec4272;p=xen.git

xen/arm: bootfdt: Ignore empty memory bank

At the moment, Xen will stop processing the Device Tree if a memory
bank is empty (size == 0).

Unfortunately, some of the Device Tree (such as on Colibri imx8qxp)
may contain such a bank. This means Xen will not be able to boot
properly.

Relax the check to just ignore the banks. FWIW this also seems to be the
behavior adopted by Linux.

Reported-by: Daniel Wagner <Daniel.Wagner2@itk-engineering.de>
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
(cherry picked from commit 5a37207df52066efefe419c677b089a654d37afc)
---

diff --git a/xen/arch/arm/bootfdt.c b/xen/arch/arm/bootfdt.c
index 08fb59f4e7..dcff512648 100644
--- a/xen/arch/arm/bootfdt.c
+++ b/xen/arch/arm/bootfdt.c
@@ -163,8 +163,9 @@ static int __init process_memory_node(const void *fdt, int node,
     for ( i = 0; i < banks && mem->nr_banks < NR_MEM_BANKS; i++ )
     {
         device_tree_get_reg(&cell, address_cells, size_cells, &start, &size);
+        /* Some DT may describe empty bank, ignore them */
         if ( !size )
-            return -EINVAL;
+            continue;
         mem->bank[mem->nr_banks].start = start;
         mem->bank[mem->nr_banks].size = size;
         mem->nr_banks++;