4.14-stable review patch. If anyone has any objections, please let me know.
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From: Benjamin Herrenschmidt benh@kernel.crashing.org
commit b32e56e5a87a1f9243db92bc7a5df0ffb4627cfb upstream.
When setting up a CPU, we "push" (activate) a pool VP for it.
However it's an error to do so if it already has an active pool VP.
This happens when doing soft CPU hotplug on powernv since we don't tear down the CPU on unplug. The HW flags the error which gets captured by the diagnostics.
Fix this by making sure to "pull" out any already active pool first.
Fixes: 243e25112d06 ("powerpc/xive: Native exploitation of the XIVE interrupt controller") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Benjamin Herrenschmidt benh@kernel.crashing.org Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/sysdev/xive/native.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/arch/powerpc/sysdev/xive/native.c +++ b/arch/powerpc/sysdev/xive/native.c @@ -388,6 +388,10 @@ static void xive_native_setup_cpu(unsign if (xive_pool_vps == XIVE_INVALID_VP) return;
+ /* Check if pool VP already active, if it is, pull it */ + if (in_be32(xive_tima + TM_QW2_HV_POOL + TM_WORD2) & TM_QW2W2_VP) + in_be64(xive_tima + TM_SPC_PULL_POOL_CTX); + /* Enable the pool VP */ vp = xive_pool_vps + cpu; pr_debug("CPU %d setting up pool VP 0x%x\n", cpu, vp);