arm64: smp: honour #address-size when parsing CPU reg property

For systems where the top 32-bits of the MPIDR are all zero, we should
allow the device-tree to specify an #address-size of 0x1 for the CPU reg
property and then zero extend the value there.

Without this patch, kvmtool breaks with the recent mpidr parsing code
introduced in 4c7aa0021356 ("arm64: kernel: initialise cpu_logical_map
from the DT").

Acked-by: Javi Merino <javi.merino@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index d4dcc6515253..a886194e58fd 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -270,6 +270,7 @@ void __init smp_init_cpus(void)
         bool bootcpu_valid = false;
 
         while ((dn = of_find_node_by_type(dn, "cpu"))) {
+                const u32 *cell;
                 u64 hwid;
 
                 /*
@@ -277,10 +278,12 @@ void __init smp_init_cpus(void)
                  * considered invalid to build a cpu_logical_map
                  * entry.
                  */
-                if (of_property_read_u64(dn, "reg", &hwid)) {
+                cell = of_get_property(dn, "reg", NULL);
+                if (!cell) {
                         pr_err("%s: missing reg property\n", dn->full_name);
                         goto next;
                 }
+                hwid = of_read_number(cell, of_n_addr_cells(dn));
 
                 /*
                  * Non affinity bits must be set to 0 in the DT