From f5dd890ef7c905ac61c3d3be1569df06849f74a3 Mon Sep 17 00:00:00 2001
From: Will Deacon <will.deacon@arm.com>
Date: Fri, 11 May 2012 17:42:37 +0100
Subject: [PATCH] ARM: 7417/1: vfp: ensure preemption is disabled when enabling
 VFP access

commit 998de4acb2ba188d20768d1065658377a2e7d29b upstream.

The vfp_enable function enables access to the VFP co-processor register
space (cp10 and cp11) on the current CPU and must be called with
preemption disabled. Unfortunately, the vfp_init late initcall does not
disable preemption and can lead to an oops during boot if thread
migration occurs at the wrong time and we end up attempting to access
the FPSID on a CPU with VFP access disabled.

This patch fixes the initcall to call vfp_enable from a non-preemptible
context on each CPU and adds a BUG_ON(preemptible) to ensure that any
similar problems are easily spotted in the future.

Reported-by: Hyungwoo Yang <hwoo.yang@gmail.com>
Signed-off-by: Hyungwoo Yang <hyungwooy@nvidia.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
Reading git-format-patch failed