From 801f33be8e902d8cea75cb7ac056d07c4fdd25f8 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Fri, 23 Sep 2016 14:09:07 +0100 Subject: [PATCH] drivers: cci: add missing CCI port availability firmware check The CCI ports programming interface is available to the kernel only when booted in secure mode (or when firmware enables non-secure access to override CCI ports control). In both cases, firmware reports the CCI ports availability through the device tree CCI ports nodes, which must be parsed and their status checked by the kernel probing path. This check is currently missing and may cause the kernel to erroneously believe it is free to take control of CCI ports where in practice CCI ports control is forbidden. Add the missing CCI port availability check to the CCI driver in order to guarantee sane CCI usage. Cc: Liviu Dudau Cc: Suzuki K Poulose Cc: Marc Zyngier Acked-by: Nicolas Pitre Signed-off-by: Lorenzo Pieralisi Signed-off-by: Sudeep Holla --- drivers/bus/arm-cci.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c index 8900823..2316333 100644 --- a/drivers/bus/arm-cci.c +++ b/drivers/bus/arm-cci.c @@ -2190,6 +2190,9 @@ static int cci_probe_ports(struct device_node *np) if (!of_match_node(arm_cci_ctrl_if_matches, cp)) continue; + if (!of_device_is_available(cp)) + continue; + i = nb_ace + nb_ace_lite; if (i >= nb_cci_ports) @@ -2232,6 +2235,13 @@ static int cci_probe_ports(struct device_node *np) ports[i].dn = cp; } + /* + * If there is no CCI port that is under kernel control + * return early and report probe status. + */ + if (!nb_ace && !nb_ace_lite) + return -ENODEV; + /* initialize a stashed array of ACE ports to speed-up look-up */ cci_ace_init_ports(); -- 2.7.4