Subject: [PATCH] powerpc: Fix up the kdump base cap to 128M

From: Mahesh J Salgaonkar <[email-masked]>
Date: Mon, 09 Dec 2013 15:33:39 +0530

From: Mahesh Salgaonkar <[email-masked]>

The current logic sets the kdump base to min of 2G or ppc64_rma_size/2.
On PowerNV kernel the first memory block 'memory@0' can be very large,
equal to the DIMM size with ppc64_rma_size value capped to 1G. Hence on
PowerNV, kdump base is set to 512M resulting kdump to fail while allocating
paca array. This is because, paca need its memory from RMA region capped
at 256M (see allocate_pacas()).

This patch lowers the kdump base cap to 128M so that kdump kernel can
successfully get memory below 256M for paca allocation.

Signed-off-by: Mahesh Salgaonkar <[email-masked]>
---
 arch/powerpc/kernel/machine_kexec.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c
index 88a7fb4..75d4f73 100644
--- a/arch/powerpc/kernel/machine_kexec.c
+++ b/arch/powerpc/kernel/machine_kexec.c
@@ -148,7 +148,7 @@ void __init reserve_crashkernel(void)
 		 * a small SLB (128MB) since the crash kernel needs to place
 		 * itself and some stacks to be in the first segment.
 		 */
-		crashk_res.start = min(0x80000000ULL, (ppc64_rma_size / 2));
+		crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
 #else
 		crashk_res.start = KDUMP_KERNELBASE;
 #endif