@@ -48,7 +48,16 @@ static int __init smp_spin_table_prepare_cpu(int cpu)
return -ENODEV;
release_addr = __va(cpu_release_addr[cpu]);
- release_addr[0] = (void *)__pa(secondary_holding_pen);
+
+ /*
+ * We write the release address as LE regardless of the native
+ * endianess of the kernel. Therefore, any boot-loaders that
+ * read this address need to convert this address to the
+ * boot-loader's endianess before jumping. This is mandated by
+ * the boot protocol.
+ */
+ release_addr[0] = (void *) cpu_to_le64(__pa(secondary_holding_pen));
+
__flush_dcache_area(release_addr, sizeof(release_addr[0]));
/*
Currently when CPUs are brought online via a spin-table, the address they should jump to is written to the cpu-release-addr in the kernel's native endianness. As the kernel may switch endianness, secondaries might read the value byte-reversed from what was intended, and they would jump to the wrong address. As the only current arm64 spin-table implementations are little-endian, stricten up the arm64 spin-table definition such that the value written to cpu-release-addr is _always_ little-endian regardless of the endianness of any CPU. If a spinning CPU is operating big-endian, it must byte-reverse the value before jumping to handle this. Signed-off-by: Matthew Leach <matthew.leach@arm.com> --- arch/arm64/kernel/smp_spin_table.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)