From: Shreyas B. Prabhu Date: Tue, 19 May 2015 19:00:14 +0000 (+0530) Subject: powerpc: Make doorbell check preemption safe X-Git-Tag: omap-for-v4.2/fixes-rc1^2~139^2~11 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3609d819a36c65857816ca1278d80767d6d9b990;p=pandora-kernel.git powerpc: Make doorbell check preemption safe Doorbell can be used to cause ipi on cpus which are sibling threads on the same core. So icp_native_cause_ipi checks if the destination cpu is a sibling thread of the current cpu and uses doorbell in such cases. But while running with CONFIG_PREEMPT=y, since this section is preemtible, we can run into issues if after we check if the destination cpu is a sibling cpu, the task gets migrated from a sibling cpu to a cpu on another core. Fix this by using get_cpu()/ put_cpu() Signed-off-by: Shreyas B. Prabhu Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman --- Reading git-diff-tree failed