MAX_COMPLETIONS
while ((insert - instance->completion_remove) >= MAX_COMPLETIONS) {
completion = &instance->completions[insert & (MAX_COMPLETIONS - 1)];
MAX_COMPLETIONS);
& (MAX_COMPLETIONS - 1)];
completion = &instance->completions[remove & (MAX_COMPLETIONS - 1)];
struct vchiq_completion_data_kernel completions[MAX_COMPLETIONS];