[PATCH][v2] arm64: Allocate elfcorehdr & crashkernel mem before any reservation

[Poonam Aggrwal]

Address for both crashkernel memory and elfcorehdr can be assigned
statically. For crashkernel memory it is via crashkernel=SIZE at ADDRESS
and elfcorehdr_addr via by kexec-utils in dump kernel device tree.

So memory should be reserved for both the above areas before any
other memory reservations are done. Otherwise overlaps may happen and
memory allocations will fail leading to failure in booting the 
dump capture kernel.

Signed-off-by: Guanhua <guanhua.gao at nxp.com>
Signed-off-by: Poonam Aggrwal <poonam.aggrwal at nxp.com>
Signed-off-by: Abhimanyu Saini <abhimanyu.saini at nxp.com>
---
v2:
 corrected the email address

reworked based on the discussions:(with Will Deacon and Takahiro)
https://patchwork.kernel.org/patch/10104249/
 arch/arm64/mm/init.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 00e7b90..24ce15d 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -453,6 +453,14 @@ void __init arm64_memblock_init(void)
 	 * Register the kernel text, kernel data, initrd, and initial
 	 * pagetables with memblock.
 	 */
+
+	/* make these the first reservations to avoid chances of
+	 * overlap
+	 */
+	reserve_elfcorehdr();
+
+	reserve_crashkernel();
+
 	memblock_reserve(__pa_symbol(_text), _end - _text);
 #ifdef CONFIG_BLK_DEV_INITRD
 	if (initrd_start) {
@@ -472,10 +480,6 @@ void __init arm64_memblock_init(void)
 	else
 		arm64_dma_phys_limit = PHYS_MASK + 1;
 
-	reserve_crashkernel();
-
-	reserve_elfcorehdr();
-
 	high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
 
 	dma_contiguous_reserve(arm64_dma_phys_limit);
-- 
2.7.4