From mboxrd@z Thu Jan 1 00:00:00 1970 From: robin.murphy@arm.com (Robin Murphy) Date: Fri, 23 Sep 2016 16:51:48 +0100 Subject: [PATCH] ARM/dt: Respect #address-cells when parsing CPUs Message-ID: <31c4684aa8ef7ef210cc74da5f1b02ff2882a099.1474645829.git.robin.murphy@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Whilst MPIDR values themselves are only 32 bits, it is still perfectly valid for a DT to have #address-cells > 1 in the CPUs node, resulting in the "reg" property having leading zero cell(s). In that situation, the big-endian nature of the data conspires with the current behaviour of just parsing the first cell to cause the kernel to think all CPUs have ID 0, and become resoundingly unhappy as a consequence. Take #address-cells into account when parsing CPUs so as to be correct under any circumstances. CC: Russell King Signed-off-by: Robin Murphy --- arch/arm/kernel/devtree.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c index 40ecd5f514a2..7ab113c5c818 100644 --- a/arch/arm/kernel/devtree.c +++ b/arch/arm/kernel/devtree.c @@ -88,6 +88,7 @@ void __init arm_dt_init_cpu_maps(void) return; for_each_child_of_node(cpus, cpu) { + const u32 *cell; u32 hwid; if (of_node_cmp(cpu->type, "cpu")) @@ -99,12 +100,14 @@ void __init arm_dt_init_cpu_maps(void) * properties is considered invalid to build the * cpu_logical_map. */ - if (of_property_read_u32(cpu, "reg", &hwid)) { + cell = of_get_property(cpu, "reg", NULL); + if (!cell) { pr_debug(" * %s missing reg property\n", cpu->full_name); of_node_put(cpu); return; } + hwid = of_read_number(cell, of_n_addr_cells(cpu)); /* * 8 MSBs must be set to 0 in the DT since the reg property -- 2.8.1.dirty