From a944a9c40b81a71609692c4909bb57e1d01f4bb7 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Fri, 28 Mar 2014 13:36:29 +1100 Subject: [PATCH] powerpc/ppc64: Gracefully handle early interrupts If we take an interrupt such as a trap caused by a BUG_ON before the MMU has been setup, the interrupt handlers try to enable virutal mode and cause a recursive crash, making the original problem very hard to debug. This fixes it by adjusting the "kernel_msr" value in the PACA so that it only has MSR_IR and MSR_DR (translation for instruction and data) set after the MMU has been initialized for the processor. We may still not have a console yet but at least we don't get into a recursive fault (and early debug console or memory dump via JTAG of the kernel buffer *will* give us the proper error). Signed-off-by: Benjamin Herrenschmidt --- Reading git-format-patch failed